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Sjögren syndrome or Sjögren's syndrome (SjS, SS) is a long-term
autoimmune disease An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...
that affects the body's moisture-producing (lacrimal and salivary)
glands In animals, a gland is a group of cells in an animal's body that synthesizes substances (such as hormones) for release into the bloodstream (endocrine gland) or into cavities inside the body or its outer surface (exocrine gland). Structure De ...
, and often seriously affects other organ systems, such as the lungs, kidneys, and nervous system. Primary symptoms are dryness (
dry mouth Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause. This symptom is very common and is often seen as a side eff ...
and
dry eyes Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...
), pain and
fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
. Other symptoms can include
dry skin Xeroderma, xerosis or xerosis cutis, or simply dry skin, is a skin condition characterized by excessively dry skin. The medical term ''xeroderma'', meaning "dry skin", derives from modern Latin, ''xero-'' 'dry' + Greek ''derma'' 'skin'. In most ...
, vaginal dryness, a chronic cough, numbness in the arms and legs, feeling tired, muscle and joint pains, and
thyroid problems Thyroid disease is a medical condition that affects the function of the thyroid gland. The thyroid gland is located at the front of the neck and produces thyroid hormones that travel through the blood to help regulate many other organs, meaning ...
. Those affected are also at an increased risk (15%) of
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
. While the exact cause is unclear, it is believed to involve a combination of
genetics Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...
and an
environmental trigger An environmental factor, ecological factor or eco factor is any factor, abiotic or biotic, that influences living organisms. Abiotic factors include ambient temperature, amount of sunlight, and pH of the water soil in which an organism lives. Bi ...
such as exposure to a
virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...
or
bacterium Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
. It can occur independently of other health problems (primary Sjögren's syndrome) or as a result of another
connective tissue disorder A connective tissue disease (collagenosis) is any disease that has the connective tissues of the body as a target of pathology. Connective tissue is any type of biological tissue with an extensive extracellular matrix that supports, binds togeth ...
(secondary Sjögren's syndrome). Sjögren's syndrome may be associated with other autoimmune diseases, including rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) or systemic sclerosis. The
inflammation Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
that results progressively damages the glands. Diagnosis is by biopsy of moisture-producing glands and
blood tests A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a cholester ...
for specific
antibodies An antibody (Ab), also known as an immunoglobulin (Ig), is a large, Y-shaped protein used by the immune system to identify and neutralize foreign objects such as pathogenic bacteria and viruses. The antibody recognizes a unique molecule of the ...
. On
biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...
there are typically
lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...
s within the glands. While Sjögren's syndrome is one of the most common auto-immune diseases, it has no specific and non-invasive diagnostic tests and treatment is directed at managing the person's
symptoms Signs and symptoms are the observed or detectable signs, and experienced symptoms of an disease, illness, injury, or condition. A sign for example may be a higher or lower temperature than normal, raised or lowered blood pressure or an abnormali ...
. For dry eyes,
artificial tears Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface. Dry eye syndrome (keratoconjunctivitis sicca) is a common ocular surface disorder and is characterized by disruption of the tear film and inc ...
, medications to reduce inflammation, punctal plugs, or surgery to shut the
tear ducts The nasolacrimal duct (also called the tear duct) carries tears from the lacrimal sac of the Human eye, eye into the nasal cavity. The duct begins in the eye socket between the maxillary and lacrimal bones, from where it passes downwards and backw ...
may be tried. For a dry mouth,
chewing gum Chewing gum is a soft, cohesive substance designed to be chewed without being swallowed. Modern chewing gum is composed of gum base, sweeteners, softeners/plasticizers, flavors, colors, and, typically, a hard or powdered polyol coating. Its te ...
(preferably sugar-free), sipping water, or a
saliva substitute Saliva (commonly referred to as spit) is an extracellular fluid produced and secreted by salivary glands in the mouth. In humans, saliva is around 99% water, plus electrolytes, mucus, white blood cells, epithelial cells (from which DNA can be ...
may be used. In those with joint or muscle pain,
ibuprofen Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) that is used for treating pain, fever, and inflammation. This includes painful menstrual periods, migraines, and rheumatoid arthritis. It may also be used to close a patent ductus arte ...
may be used. Medications that can cause dryness, such as
antihistamines Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides re ...
, may also be stopped. The most specific extant diagnostic test requires lip biopsy. The disease was described in 1933 by
Henrik Sjögren Henrik Samuel Conrad Sjögren (, , ; 23 July 1899, Köping, Sweden, Köping – 17 September 1986, Lund) was a Sweden, Swedish ophthalmologist best known for describing the eponymous condition Sjögren syndrome. Sjögren received his medical degr ...
, after whom it is named; however, a number of earlier descriptions of people with the symptoms exist. Between 0.2 and 1.2% of the population is affected, with half having the primary form and half the secondary form. Females are affected about 10 times as often as are males. Though the disease commonly begins in
middle age In the history of Europe, the Middle Ages or medieval period lasted approximately from the late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...
, anyone can be affected. Among those without other autoimmune disorders,
life expectancy Life expectancy is a statistical measure of the average time an organism is expected to live, based on the year of its birth, current age, and other demographic factors like sex. The most commonly used measure is life expectancy at birth ...
is unchanged.


Signs and symptoms

The hallmark symptom of Sjögren syndrome is
dry mouth Xerostomia, also known as dry mouth, is dryness in the mouth, which may be associated with a change in the composition of saliva, or reduced salivary flow, or have no identifiable cause. This symptom is very common and is often seen as a side eff ...
and
keratoconjunctivitis sicca Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...
(dry eyes).
Vaginal dryness Vaginal lubrication is a naturally produced fluid that lubricates a vagina. Vaginal lubrication is always present, but production increases significantly near ovulation and during sexual arousal in anticipation of sexual intercourse. Vaginal ...
,
dry skin Xeroderma, xerosis or xerosis cutis, or simply dry skin, is a skin condition characterized by excessively dry skin. The medical term ''xeroderma'', meaning "dry skin", derives from modern Latin, ''xero-'' 'dry' + Greek ''derma'' 'skin'. In most ...
, and dry
nose A nose is a protuberance in vertebrates that houses the nostrils, or nares, which receive and expel air for respiration alongside the mouth. Behind the nose are the olfactory mucosa and the sinuses. Behind the nasal cavity, air next passes th ...
may also occur. Other organs of the body may also be affected, including the kidneys, blood vessels, lungs, liver, pancreas, and brain. Skin dryness in some people with SS may be the result of
lymphocytic A lymphocyte is a type of white blood cell (leukocyte) in the immune system of gnathostomata, most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated immunity, cell-mediated, cytotoxicity, cytotoxic innate imm ...
infiltration Infiltration may refer to: Science, medicine, and engineering *Infiltration (hydrology), downward movement of water into soil *Infiltration (HVAC), a heating, ventilation, and air conditioning term for air leakage into buildings *Infiltration (me ...
into
skin glands Skin appendages (or adnexa of skin) are anatomical skin-associated structures that serve a particular function including sensation, contractility, lubrication and heat loss in animals. In humans, some of the more common skin appendages are hairs ( ...
. The symptoms may develop insidiously, with the diagnosis often not considered for several years because sicca may be attributed to medications, a dry environment, or aging, or may be regarded as not of a severity warranting the level of investigation necessary to establish the presence of the underlying autoimmune disorder. Sjögren's syndrome can damage
vital organs In biology, an organ is a collection of tissues joined in a structural unit to serve a common function. In the hierarchy of life, an organ lies between tissue and an organ system. Tissues are formed from same type cells to act together in a fu ...
, with symptoms that may plateau or worsen, or go into remission, as with other autoimmune diseases. Some people may experience only the mild symptoms of dry eyes and mouth, while others have symptoms of severe disease. Many patients can treat problems
symptomatically Symptomatic treatment, supportive care, supportive therapy, or palliative treatment is any medical therapy of a disease that only affects its symptoms, not the underlying cause. It is usually aimed at reducing the signs and symptoms for the comfor ...
. Others experience
blurred vision Blurred vision is an ocular symptom where vision becomes less precise and there is added difficulty to resolve fine details. Temporary blurred vision may involve dry eyes, eye infections, alcohol poisoning, hypoglycemia, or low blood pressure. ...
, constant eye discomfort, recurrent
mouth infections Mouth infections, also known as oral infections, are a group of infections that occur around the oral cavity. They include dental infection, dental abscess, and Ludwig's angina. Mouth infections typically originate from Tooth decay, dental caries at ...
, swollen
parotid glands The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...
,
dysphonia A hoarse voice, also known as dysphonia or hoarseness, is when the voice involuntarily sounds breathy, raspy, or strained, or is softer in volume or lower in pitch. A hoarse voice, can be associated with a feeling of unease or scratchiness in the ...
( vocal disorders including hoarseness), and difficulty in swallowing and eating. Debilitating fatigue and joint pain can seriously impair quality of life. Some patients can develop kidney involvement (autoimmune
tubulointerstitial nephritis Interstitial nephritis, also known as tubulointerstitial nephritis, is inflammation of the area of the kidney known as the renal interstitium, which consists of a collection of cells, extracellular matrix, and fluid surrounding the renal tubules. ...
) leading to
proteinuria Proteinuria is the presence of excess proteins in the urine. In healthy persons, urine contains very little protein; an excess is suggestive of illness. Excess protein in the urine often causes the urine to become foamy (although this symptom ma ...
(excess protein in urine), urinary concentrating defect, and
distal renal tubular acidosis Distal renal tubular acidosis (dRTA) is the classical form of RTA, being the first described. Distal RTA is characterized by a failure of acid secretion by the alpha intercalated cells of the distal tubule and cortical collecting duct of the di ...
. Hypokalemic paralysis due to primary Sjögren syndrome was rarely reported in the literature.


Complications

Among the complications discussed above, women with anti-Ro/SS-A and anti-La/SS-B antibodies who become pregnant have an increased rate of
neonatal lupus erythematosus Neonatal lupus erythematosus is an autoimmune disease in an infant born to a mother with anti-Ro/SSA and with or without anti-La/SSB antibodies. The disease most commonly presents with a rash resembling subacute cutaneous lupus erythematosus and c ...
with
congenital A birth defect, also known as a congenital disorder, is an abnormal condition that is present at birth regardless of its cause. Birth defects may result in disabilities that may be physical, intellectual, or developmental. The disabilities can ...
heart block Heart block (HB) is a disorder in the heart's rhythm due to a fault in the natural pacemaker. This is caused by an obstruction – a block – in the electrical conduction system of the heart. Sometimes a disorder can be inherited. Despite the se ...
requiring a
pacemaker An artificial cardiac pacemaker (or artificial pacemaker, so as not to be confused with the natural cardiac pacemaker) or pacemaker is a medical device that generates electrical impulses delivered by electrodes to the chambers of the heart eith ...
. Type I
cryoglobulinemia Cryoglobulinemia is a medical condition in which the blood contains large amounts of pathological cold sensitive antibodies called cryoglobulins – proteins (mostly immunoglobulins themselves) that become insoluble at reduced temperatures. T ...
is a known complication of Sjögren's syndrome. Sjögren's syndrome can affect such organs as the liver, pancreas, kidneys, lungs, and central nervous system.


Associated conditions

Sjögren's syndrome is associated with a number of other medical conditions, many of which are
autoimmune In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". P ...
or
rheumatic Rheumatology (Greek ''ῥεῦμα'', ''rheûma'', flowing current) is a branch of medicine devoted to the diagnosis and management of disorders whose common feature is inflammation in the bones, muscles, joints, and internal organs. Rheumatolog ...
disorders, such as
celiac disease Coeliac disease (British English) or celiac disease (American English) is a long-term autoimmune disorder, primarily affecting the small intestine, where individuals develop intolerance to gluten, present in foods such as wheat, rye and barl ...
,
fibromyalgia Fibromyalgia (FM) is a medical condition defined by the presence of chronic widespread pain, fatigue, waking unrefreshed, cognitive symptoms, lower abdominal pain or cramps, and depression. Other symptoms include insomnia and a general hyp ...
, SLE (lupus),
autoimmune thyroiditis Autoimmune thyroiditis, is a chronic disease in which the body interprets the thyroid glands and its hormone products T3, T4 and TSH as threats, therefore producing special antibodies that target the thyroid's cells, thereby destroying it. It may ...
,
multiple sclerosis Multiple (cerebral) sclerosis (MS), also known as encephalomyelitis disseminata or disseminated sclerosis, is the most common demyelinating disease, in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This d ...
and
spondyloarthropathy Spondyloarthropathy or spondyloarthrosis refers to any joint disease of the vertebral column. As such, it is a class or category of diseases rather than a single, specific entity. It differs from spondylopathy, which is a disease of the vertebra ...
, and several
malignancies Malignancy () is the tendency of a medical condition to become progressively worse. Malignancy is most familiar as a characterization of cancer. A ''malignant'' tumor contrasts with a non-cancerous ''benign'' tumor in that a malignancy is not s ...
, principally
non-Hodgkin lymphoma Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. ...
.


Causes

The cause of Sjögren's syndrome is unknown, but it may be the influence of a combination of genetic, environmental, and other factors, as is the case with many other autoimmune disorders. Around 20 autoantibodies could be involved.


Genetics

The observation of high rates of autoimmune disorders in families with a history of Sjögren's syndrome is linked with a
genetic predisposition A genetic predisposition is a genetic characteristic which influences the possible phenotypic development of an individual organism within a species or population under the influence of environmental conditions. In medicine, genetic susceptibilit ...
to the syndrome. Studies on the polymorphisms of
human leukocyte antigen The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for the regulation of the immune system. The HLA system is also known as the human version of th ...
(HLA)-DR and
HLA-DQ HLA-DQ (DQ) is a cell surface receptor protein found on antigen-presenting cells. It is an αβ heterodimer of type MHC class II. The α and β chains are encoded by two loci, HLA-DQA1 and HLA-DQB1, that are adjacent to each other on chromos ...
gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...
regions in Sjögren's patients show differential susceptibility to the syndrome as the result of different types of the resulting
autoantibody An autoantibody is an antibody (a type of protein) produced by the immune system that is directed against one or more of the individual's own proteins. Many autoimmune diseases (notably lupus erythematosus) are associated with such antibodies. Pr ...
production.


Hormones

Since Sjögren's syndrome is associated with a high prevalence in women,
sex hormone Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effects ar ...
s, especially
estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
, are believed to affect
humoral Humoral immunity is the aspect of immunity that is mediated by macromolecules - including secreted antibodies, complement proteins, and certain antimicrobial peptides - located in extracellular fluids. Humoral immunity is named so because it invo ...
and cell-mediated immune responses affecting susceptibility to the syndrome.
Androgen An androgen (from Greek ''andr-'', the stem of the word meaning "man") is any natural or synthetic steroid hormone that regulates the development and maintenance of male characteristics in vertebrates by binding to androgen receptors. This inc ...
s are generally considered to prevent autoimmunity. Studies on mice models suggest
estrogen deficiency Hypoestrogenism, or estrogen deficiency, refers to a lower than normal level of estrogen. It is an umbrella term used to describe estrogen deficiency in various conditions. Estrogen deficiency is also associated with an increased risk of cardiov ...
stimulates presentation of
autoantigens In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". P ...
, inducing Sjögren's-like symptoms.


Microchimerism

Microchimerism Microchimerism is the presence of a small number of cells in an individual that have originated from another individual and are therefore genetically distinct. This phenomenon may be related to certain types of autoimmune diseases although the res ...
of fetal cells (offspring
lymphoid cells A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic adapt ...
in
maternal circulation In humans, the circulatory system is different before and after birth.  The fetal circulation is composed of the placenta, umbilical blood vessels encapsulated by the umbilical cord, heart and systemic blood vessels. A major difference between the ...
) may generate autoimmunity in women who have previously been
pregnant Pregnancy is the time during which one or more offspring develops (gestation, gestates) inside a woman, woman's uterus (womb). A multiple birth, multiple pregnancy involves more than one offspring, such as with twins. Pregnancy usually occur ...
. Generation of an autoimmune potential via microchimerism may lead to a switch from a silent form of autoimmunity with age-dependent decrease in
self-tolerance Immune tolerance, or immunological tolerance, or immunotolerance, is a state of unresponsiveness of the immune system to substances or tissue that would otherwise have the capacity to elicit an immune response in a given organism. It is induced by ...
.


Environment

Viral proteins A viral protein is both a component and a product of a virus. Viral proteins are grouped according to their functions, and groups of viral proteins include structural proteins, nonstructural proteins, regulatory proteins, and accessory proteins. V ...
, engulfed
molecules A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
, or degraded self-structures may initiate autoimmunity by
molecular mimicry Molecular mimicry is defined as the theoretical possibility that sequence similarities between foreign and self-peptides are sufficient to result in the cross-activation of autoreactive T or B cells by pathogen-derived peptides. Despite the preva ...
and increase the chances of Sjögren's syndrome development.
Epstein–Barr virus The Epstein–Barr virus (EBV), formally called ''Human gammaherpesvirus 4'', is one of the nine known human herpesvirus types in the herpes family, and is one of the most common viruses in humans. EBV is a double-stranded DNA virus. It is b ...
,
hepatitis C Hepatitis C is an infectious disease caused by the hepatitis C virus (HCV) that primarily affects the liver; it is a type of viral hepatitis. During the initial infection people often have mild or no symptoms. Occasionally a fever, dark urine, a ...
, and human T-cell leukemia virus-1 are among the most studied
infectious agents In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a Germ ...
in Sjögren's syndrome. To date, no direct causes and effect relationship has been identified between these pathogens and the development of Sjögren's syndrome. Damaged self-structures targeted for
apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
may be mistakenly exposed to the immune system, triggering autoimmunity in
exocrine gland Exocrine glands are glands that secrete substances on to an epithelial surface by way of a duct. Examples of exocrine glands include sweat, salivary, mammary, ceruminous, lacrimal, sebaceous, prostate and mucous. Exocrine glands are one of two ...
s, which are often prone to autoimmune responses.


Pathogenesis

The
pathogenetic Pathogenesis is the process by which a disease or disorder develops. It can include factors which contribute not only to the onset of the disease or disorder, but also to its progression and maintenance. The word comes from Greek πάθος ''pat ...
mechanisms of Sjögren's syndrome have not been fully elucidated, resulting in the lack of
pathophysiology Pathophysiology ( physiopathology) – a convergence of pathology with physiology – is the study of the disordered physiological processes that cause, result from, or are otherwise associated with a disease or injury. Pathology is the ...
knowledge of the management of this autoimmune exocrinopathy. Although the numerous factors contributing to the progression of this disease have made discovering the exact origin and cause difficult, major advances over the past decade have contributed to a proposed set of pathogenic events that occur prior to the diagnosis of Sjögren's syndrome. Sjögren's syndrome was originally proposed as a specific,
self-perpetuating Self-perpetuation, the capability of something to cause itself to continue to existence, exist, is one of the main characteristics of life. Organisms' capability of reproduction leads to self-perpetuation of the species, if not to the individual. P ...
, immune system-mediated loss of exocrine glands, specifically acinar and
ductal cells Ductal cells refer to the Epithelium, epithelial cell lining of the pancreatic duct that deliver enzymes from the Acinus, acinar cells to the duodenum. They have the essential function of producing bicarbonate-rich (HCO3-) secretion to neutralize st ...
. Although this explains the more obvious symptoms (such as the lack of saliva and
lacrimal fluid Tears are a clear liquid secreted by the lacrimal glands (tear gland) found in the eyes of all land mammals. Tears are made up of water, electrolytes, proteins, lipids, and mucins that form layers on the surface of eyes. The different types of ...
), it does not explain the more widespread systemic effects seen in the progression of the disease. In the presence of a susceptible genetic background, both
environmental A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...
and
hormonal A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required fo ...
factors are thought capable of triggering the infiltration of lymphocytes, specifically
CD4+ T cells In molecular biology, CD4 (cluster of differentiation 4) is a glycoprotein that serves as a co-receptor for the T-cell receptor (TCR). CD4 is found on the surface of immune cells such as T helper cells, monocytes, macrophages, and dendritic ce ...
,
B cells B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted or ...
, and
plasma cells Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B lymphocytes and secrete large quantities of proteins called antibodies in response to being presented specific substan ...
, causing glandular dysfunction in the salivary and lacrimal glands. Sjögren's syndrome is associated with increased levels in
cerebrospinal fluid Cerebrospinal fluid (CSF) is a clear, colorless body fluid found within the tissue that surrounds the brain and spinal cord of all vertebrates. CSF is produced by specialised ependymal cells in the choroid plexus of the ventricles of the bra ...
(CSF) of
IL-1RA The interleukin-1 receptor antagonist protein (IL-1RN) is a protein that in humans is encoded by the ''IL1RN'' gene. IL-1RN was initially called the IL-1 inhibitor and was discovered separately in 1984 by two independent laboratories. IL-1RN is a ...
, an
interleukin 1 The Interleukin-1 family (IL-1 family) is a group of 11 cytokines that plays a central role in the regulation of immune and inflammatory responses to infections or sterile insults. Discovery Discovery of these cytokines began with studies on t ...
antagonist An antagonist is a character in a story who is presented as the chief foe of the protagonist. Etymology The English word antagonist comes from the Greek ἀνταγωνιστής – ''antagonistēs'', "opponent, competitor, villain, enemy, riv ...
. This suggests that the disease begins with increased activity in the interleukin 1 system, followed by an autoregulatory
upregulation In the biological context of organisms' production of gene products, downregulation is the process by which a cell decreases the quantity of a cellular component, such as RNA or protein, in response to an external stimulus. The complementary proce ...
of IL-1RA to reduce the successful binding of interleukin 1 to its receptors. Interleukin 1 likely is the marker for fatigue, but increased IL-1RA is observed in the CSF and is associated with increased
fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
through
cytokine Cytokines are a broad and loose category of small proteins (~5–25 kDa) important in cell signaling. Cytokines are peptides and cannot cross the lipid bilayer of cells to enter the cytoplasm. Cytokines have been shown to be involved in autocrin ...
-induced
sickness behavior 350px, Ancher, Michael, "The Sick Girl", 1882, Statens Museum for Kunst Sickness behavior is a coordinated set of adaptive behavioral changes that develop in ill individuals during the course of an infection. They usually, but not always, accom ...
. However, Sjögren's syndrome is characterized by decreased levels of IL-1ra in saliva, which could be responsible for mouth inflammation and dryness. Patients with secondary Sjögren's syndrome also often exhibit signs and symptoms of their primary rheumatic disorders, such as
systemic lupus erythematosus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
,
rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...
, or
systemic sclerosis Systemic scleroderma, or systemic sclerosis, is an autoimmune rheumatic disease characterised by excessive production and accumulation of collagen, called fibrosis, in the skin and internal organs and by injuries to small arteries. There are two m ...
.


Genetic predisposition

The
genetic locus In genetics, a locus (plural loci) is a specific, fixed position on a chromosome where a particular gene or genetic marker is located. Each chromosome carries many genes, with each gene occupying a different position or locus; in humans, the total ...
most significantly associated with primary SS is the
major histocompatibility complex The major histocompatibility complex (MHC) is a large locus on vertebrate DNA containing a set of closely linked polymorphic genes that code for cell surface proteins essential for the adaptive immune system. These cell surface proteins are calle ...
/
human leukocyte antigen The human leukocyte antigen (HLA) system or complex is a complex of genes on chromosome 6 in humans which encode cell-surface proteins responsible for the regulation of the immune system. The HLA system is also known as the human version of th ...
(MHC/HLA) region, as demonstrated by the preliminary results of the first
genome-wide association study In genomics, a genome-wide association study (GWA study, or GWAS), also known as whole genome association study (WGA study, or WGAS), is an observational study of a genome-wide set of Single-nucleotide polymorphism, genetic variants in different i ...
. This study included data from a discovery cohort of 395 patients of European ancestry with primary Sjögren's syndrome, and 1,975 healthy control individuals, and from a replication study that comprised 1,234 cases and 4,779 healthy controls. Associations with polymorphisms located at six independent loci were also detected; ''
IRF5 Interferon regulatory factor 5 is a protein that in humans is encoded by the ''IRF5'' gene. The IRF family is a group of transcription factors that are involved in signaling for virus responses in mammals along with regulation of certain cellular ...
,
STAT4 Signal transducer and activator of transcription 4 (STAT4) is a transcription factor belonging to the STAT protein family, composed of STAT1, STAT2, STAT3, STAT5A, STAT5B, STAT6. STAT proteins are key activators of gene transcription which bind ...
, BLK,
IL12A Interleukin-12 subunit alpha (IL-12 p35) is a protein that in humans is encoded by the ''IL12A'' gene. Function This gene encodes a subunit of the cytokine Interleukin 12 (IL-12) that acts on T and natural killer cells, and has a broad array o ...
,
TNIP1 TNFAIP3-interacting protein 1, also known as ABIN-1, is a protein that in humans is encoded by the ''TNIP1'' gene. Association with autoimmune diseases Genetic variations within the region of the ''TNIP1'' gene have been shown to have associ ...
,'' and ''
CXCR5 C-X-C chemokine receptor type 5 (CXC-R5) also known as CD185 (cluster of differentiation 185) or Burkitt lymphoma receptor 1 (BLR1) is a G protein-coupled seven transmembrane receptor for chemokine CXCL13 (also known as BLC) and belongs to the C ...
''. This also suggested the activation of the
innate immune system The innate, or nonspecific, immune system is one of the two main immunity strategies (the other being the adaptive immune system) in vertebrates. The innate immune system is an older evolutionary defense strategy, relatively speaking, and is the ...
, notably through the IFN system, B-cell activation through ''CXCR5''-directed recruitment to
lymphoid follicles A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that include ...
and B-cell receptor (BCR) activation involving'' BLK'', and
T-cell activation A T cell is a type of lymphocyte. T cells are one of the important white blood cells of the immune system and play a central role in the adaptive immune response. T cells can be distinguished from other lymphocytes by the presence of a T-cell rec ...
owing to HLA susceptibility and the IL-12-IFN-γ-axis. Patients of different ethnic origin carry different HLA-susceptibility
allele An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution. ::"The chro ...
s, of which HLA-DR and HLA-DQ are involved in the pathogenesis of Sjögren's syndrome. For example, patients from Northern and Western Europe and from North America show a high prevalence of ''B8, DRw52,'' and ''DR3'' genes. HLA class II alleles are associated with the presence of specific subsets of
autoantibodies An autoantibody is an antibody (a type of protein) produced by the immune system that is directed against one or more of the individual's own proteins. Many autoimmune diseases (notably lupus erythematosus) are associated with such antibodies. Pr ...
, rather than with the disease itself. Autoantibodies refer to the loss of B-cell tolerance leading to production of antibodies directed against diverse organ-specific and organ nonspecific antigens. Association between HLA and SS is restricted to patients with anti-SSA/Ro or anti-SSB/La antibodies. Seropositivity for anti-Ro and anti-La is associated with greater severity and longer duration of disease, and findings of their high abundance from the
salivary glands The salivary glands in mammals are exocrine glands that produce saliva through a system of ducts. Humans have three paired major salivary glands (parotid, submandibular, and sublingual), as well as hundreds of minor salivary glands. Salivary gla ...
of Sjögren's patients suggests their imperative role in the pathogenesis of SS. Beyond genetics,
epigenetic In biology, epigenetics is the study of stable phenotypic changes (known as ''marks'') that do not involve alterations in the DNA sequence. The Greek prefix '' epi-'' ( "over, outside of, around") in ''epigenetics'' implies features that are "o ...
abnormality related to
DNA methylation DNA methylation is a biological process by which methyl groups are added to the DNA molecule. Methylation can change the activity of a DNA segment without changing the sequence. When located in a gene promoter, DNA methylation typically acts t ...
,
histone acetylation Histone acetyltransferases (HATs) are enzymes that acetylate conserved lysine amino acids on histone proteins by transferring an acetyl group from acetyl-CoA to form ε-''N''-acetyllysine. DNA is wrapped around histones, and, by transferring an ...
, or
microRNA MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRN ...
expression probably has a key role in the pathogenesis of autoimmune diseases, including Sjögren's syndrome, though research in this area is very limited.


Environmental triggers

Environmental factors, such as glandular
viral infection A viral disease (or viral infection) occurs when an organism's body is invaded by pathogenic viruses, and infectious virus particles (virions) attach to and enter susceptible cells. Structural Characteristics Basic structural characteristics, s ...
, could prompt
epithelial cells Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
to activate the HLA-independent innate immune system through
toll-like receptors Toll-like receptors (TLRs) are a class of proteins that play a key role in the innate immune system. They are single-pass membrane-spanning receptors usually expressed on sentinel cells such as macrophages and dendritic cells, that recognize st ...
. Although a number of infectious,
exogenous In a variety of contexts, exogeny or exogeneity () is the fact of an action or object originating externally. It contrasts with endogeneity or endogeny, the fact of being influenced within a system. Economics In an economic model, an exogeno ...
agents have been implicated in the pathogenesis of Sjögren's syndrome, such as Epstein-Barr virus (EBV),
human T-lymphotropic virus 1 Human T-cell lymphotropic virus type 1 or human T-lymphotropic virus (HTLV-I), also called the adult T-cell lymphoma virus type 1, is a retrovirus of the human T-lymphotropic virus (HTLV) family that has been implicated in several kinds of disea ...
, and
hepatitis C virus The hepatitis C virus (HCV) is a small (55–65 nm in size), enveloped, positive-sense single-stranded RNA virus of the family ''Flaviviridae''. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer ( hepato ...
, their association with Sjögren's syndrome appears weak. While EBV is present in the salivary glands of normal individuals, a high incidence of EBV reactivation in Sjögren's patients has been reported with increased levels of EBV DNA. This indicates viral reactivation and inability of lymphoid infiltrates to control EBV replication in Sjögren's syndrome, leading to the
initiation Initiation is a rite of passage marking entrance or acceptance into a group or society. It could also be a formal admission to adulthood in a community or one of its formal components. In an extended sense, it can also signify a transformation ...
or perpetuation of an immune response in target organs. Nonetheless, exactly how reactivation of EBV is induced in
lesions A lesion is any damage or abnormal change in the tissue of an organism, usually caused by disease or trauma. ''Lesion'' is derived from the Latin "injury". Lesions may occur in plants as well as animals. Types There is no designated classifi ...
of patients with Sjögren's syndrome, and which specific molecular mechanisms are involved in the process of viral reactivation, remain to be clarified.


Inflammation

Epithelial cells in Sjögren's syndrome lesions are active participants in the induction and perpetuation of the inflammatory process. Environmental and hormonal factors, in concert with an appropriate genetic background, are believed to trigger Sjögren's syndrome, which dysregulates epithelial cells and allows aberrant homing and activation of
dendritic cells Dendritic cells (DCs) are antigen-presenting cells (also known as ''accessory cells'') of the mammalian immune system. Their main function is to process antigen material and present it on the cell surface to the T cells of the immune system. The ...
(DCs), T cells, and B cells. Dendritic cells are
antigen-presenting cells An antigen-presenting cell (APC) or accessory cell is a cell that displays antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation. T cells may recognize these complexes using ...
that process
antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...
material and present it to other T cells. Following the
migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...
of lymphocytes into the glands in response to
chemokines Chemokines (), or chemotactic cytokines, are a family of small cytokines or signaling proteins secreted by cells that induce directional movement of leukocytes, as well as other cell types, including endothelial and epithelial cells. In addition ...
and specific
adhesion molecule Cell adhesion molecules (CAMs) are a subset of cell surface proteins that are involved in the binding of cells with other cells or with the extracellular matrix (ECM), in a process called cell adhesion. In essence, CAMs help cells stick to each ...
s, T cells interact with epithelial cells. Epithelial cells are further activated by
proinflammatory cytokines An inflammatory cytokine or proinflammatory cytokine is a type of signaling molecule (a cytokine) that is secreted from immune cells like helper T cells (Th) and macrophages, and certain other cell types that promote inflammation. They include int ...
(IL-1β, IFN-γ, and TNF), which are produced by adjacent T cells. The early accumulation of
plasmacytoid Plasma cells, also called plasma B cells or effector B cells, are white blood cells that originate in the lymphoid organs as B lymphocytes and secrete large quantities of proteins called antibodies in response to being presented specific substa ...
dendritic cells in the target tissues, which produce high levels of type 1 IFNs, seems important, as these cells can further dysregulate the immune response through abnormal retention of lymphocytes in the tissues and their subsequent activation. IFN-α stimulates the production of
B-cell activating factor B-cell activating factor (BAFF) also known as tumor necrosis factor ligand superfamily member 13B and CD257 among other names, is a protein that in humans is encoded by the ''TNFSF13B'' gene. BAFF is also known as B Lymphocyte Stimulator (BLyS) an ...
(BAFF) by epithelial cells, DCs, and T cells. BAFF stimulates aberrant B-cell maturation, leading to the emergence of self-reactive B cells, which locally produce autoantibodies, in a
germinal centre Germinal centers or germinal centres (GCs) are transiently formed structures within B cell zone (follicles) in secondary lymphoid organs – lymph nodes, ileal Peyer's patches, and the spleen – where mature B cells are activated, prolifera ...
-like structure (GC-like), which is also the location of lymphomagenesis (origin of
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
).


Programmed cell death

Dysregulation of
apoptosis Apoptosis (from grc, ἀπόπτωσις, apóptōsis, 'falling off') is a form of programmed cell death that occurs in multicellular organisms. Biochemical events lead to characteristic cell changes (morphology) and death. These changes incl ...
(programmed cell death) is believed to play a role in the pathogenesis of a variety of autoimmune diseases, though its role in Sjögren's syndrome is controversial. Both the Fas and Fas ligand proteins are overexpressed in primary Sjögren's patients, while expression of BCL-1, which is known to downregulate apoptosis, was found significantly reduced in acinar and ductal
epithelial cells Epithelium or epithelial tissue is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. It is a thin, continuous, protective layer of compactly packed cells with a little intercellula ...
of Sjögren's patients compared to healthy people. ''
In situ ''In situ'' (; often not italicized in English) is a Latin phrase that translates literally to "on site" or "in position." It can mean "locally", "on site", "on the premises", or "in place" to describe where an event takes place and is used in ...
'' studies did not show increased apoptosis among glandular epithelial cells, but did show reduced apoptosis among infiltrating mononuclear cells. Reduced apoptosis was also implicated in the accumulation of autoreactive B-cells found in the glands. The relationship of autoantibodies expressed in Sjögren's syndrome with apoptosis is still being researched.


Hormonal factors

Sex hormones Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effects are ...
seem to influence humoral and cell-mediated immune response, with
estrogen Estrogen or oestrogen is a category of sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics. There are three major endogenous estrogens that have estrogenic hormonal acti ...
being considered one of the biggest factors responsible for sex-
immunologic Immunology is a branch of medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there ...
dimorphism.
Estrogen deficiency Hypoestrogenism, or estrogen deficiency, refers to a lower than normal level of estrogen. It is an umbrella term used to describe estrogen deficiency in various conditions. Estrogen deficiency is also associated with an increased risk of cardiov ...
appears to play a role in development of Sjögren's syndrome. It has been
hypothesized A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous obser ...
that androgen administration to the ocular surface may serve as an effective therapy for dry eyes.


Diagnosis

Diagnosing Sjögren's syndrome (SS) is complicated by the range of symptoms that a patient may manifest, and the similarity between symptoms of Sjögren's syndrome and those of other conditions. Also, patients with SS symptoms approach different specialities for treatment, which can make diagnosis difficult. Since dry eyes and dry mouth are very common symptoms, and frequently occur in people over 40, affected people may believe that the symptoms are age-related, so ignore them. Some medications can cause symptoms similar to those of Sjögren's syndrome. The combination of several tests, which can be done in a series, can eventually diagnose Sjögren's syndrome. Blood tests can be done to determine if a patient has high levels of antibodies that are indicative of the condition, such as
antinuclear antibody Antinuclear antibodies (ANAs, also known as antinuclear factor or ANF) are autoantibodies that bind to contents of the cell nucleus. In normal individuals, the immune system produces antibodies to foreign proteins (antigens) but not to human prote ...
(ANA) and
rheumatoid factor Rheumatoid factor (RF) is the autoantibody that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG and different RFs can recognize different parts of the IgG-Fc. RF and IgG join to form immune com ...
(because Sjögren's syndrome frequently occurs secondary to rheumatoid arthritis), which are associated with autoimmune diseases. Typical SS ANA patterns are SSA/Ro and SSB/La, of which anti-SSB/La is far more specific; anti-SSA/Ro is associated with numerous other autoimmune conditions, but is often present in SS, but aAnti-SSA and anti-SSB tests are frequently not positive in SS. The
rose bengal Rose bengal (4,5,6,7-tetrachloro-2',4',5',7'-tetraiodofluorescein) is a stain. Rose bengal belongs to the class of organic compounds called xanthenes. Its sodium salt is commonly used in eye drops to stain damaged conjunctival and corneal cells ...
test uses a stain that measures state and function of the
lacrimal gland The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each or ...
s. This test involves placing the
nontoxic Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a subs ...
dye rose bengal on the eyes. The dye's distinctive colour helps in determining the state and functioning of tear film and the rate of tear evaporation. Any distinctive colour change can indicate SS, but confirming the condition requires many related diagnostic tools.
Schirmer's test Schirmer's test determines whether the eye produces enough tears to keep it moist. This test is used when a person experiences very dry eyes or excessive watering of the eyes. It poses no risk to the subject. A negative (more than 10 mm of mo ...
measures the production of tears: a strip of
filter paper Filter paper is a semi-permeable paper barrier placed perpendicular to a liquid or air flow. It is used to separate fine solid particles from liquids or gases. The raw materials are different paper pulps. The pulp may be made from softwood, hardwo ...
is held inside the lower eyelid for five minutes, and its wetness is then measured with a ruler. Producing less than of liquid is usually indicative of SS. This measurement analysis varies among people depending on other eye-related conditions and medications in use when the test is taken. A
slit-lamp examination A slit lamp is an instrument consisting of a high-intensity light source that can be focused to shine a thin sheet of light into the eye. It is used in conjunction with a biomicroscope. The lamp facilitates an examination of the anterior segm ...
can reveal dryness on the surface of the eye. Symptoms of dry mouth and dryness in the oral cavity are caused by the reduced production of saliva from the salivary glands (
parotid gland The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the man ...
,
submandibular gland The paired submandibular glands (historically known as submaxillary glands) are major salivary glands located beneath the floor of the mouth. They each weigh about 15 grams and contribute some 60–67% of unstimulated saliva secretion; on stimula ...
, and
sublingual gland The paired sublingual glands are major salivary glands in the mouth. They are the smallest, most diffuse, and the only unencapsulated major salivary glands. They provide only 3-5% of the total salivary volume. There are also two other types of sal ...
). To check the status of salivary glands and the production of saliva, a salivary flow-rate test is performed, in which the person is asked to spit as much as they can into a cup, and the resulting saliva sample is collected and weighed. This test's results can determine whether the salivary glands are functioning adequately. Not enough saliva produced could mean the person has SS. An alternative test is nonstimulated whole saliva flow collection, in which the person spits into a
test tube A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom. Test tubes are usually placed in s ...
every minute for 15 minutes. A resultant collection of less than is considered a positive result.Dr. J. Parks, Ancaster ON Canada A lip/salivary gland
biopsy A biopsy is a medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist. The process involves extraction of sample cells or tissues for examination to determine the presence or extent of a diseas ...
takes a tissue sample that can reveal
lymphocyte A lymphocyte is a type of white blood cell (leukocyte) in the immune system of most vertebrates. Lymphocytes include natural killer cells (which function in cell-mediated, cytotoxic innate immunity), T cells (for cell-mediated, cytotoxic ad ...
s clustered around salivary glands, and damage to these glands from inflammation. This test involves removing a sample of tissue from a person's inner lip/salivary gland and examining it under a
microscope A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
. On such biopsies, the single most important test result in the diagnosis of the oral component of Sjögren syndrome is likely the ''focus score'', which is the number of mononuclear cell infiltrates containing at least 50 inflammatory cells in a 4 mm2 glandular section. The Chisholm-Mason grades are also widely used for salivary gland biopsies (see table). A radiological procedure is available as a reliable and accurate test for Sjögren's syndrome, in the form of a
sialogram Sialography (also termed radiosialography) is the radiographic examination of the salivary glands. It usually involves the injection of a small amount of contrast medium into the salivary duct of a single gland, followed by routine X-ray projection ...
. A
contrast agent A contrast agent (or contrast medium) is a substance used to increase the contrast of structures or fluids within the body in medical imaging. Contrast agents absorb or alter external electromagnetism or ultrasound, which is different from radiop ...
is injected into the parotid duct, which opens from the cheek into the vestibule of the mouth opposite the neck of the upper second
molar tooth The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone to ...
. The test is intended to detect any blockage in the salivary gland ducts (i.e.
parotid duct The parotid duct, or Stensen duct, is a salivary duct. It is the route that saliva takes from the major salivary gland, the parotid gland, into the mouth. Structure The parotid duct is formed when several interlobular ducts, the largest ducts insi ...
) and the amount of saliva that flows into the mouth. For Sjögren's syndrome,
sudomotor Sudomotor function refers to the autonomic nervous system control of sweat gland activity in response to various environmental and individual factors. Sweat production is a vital thermoregulatory mechanism used by the body to prevent heat-related ...
function through
electrochemical skin conductance Electrochemical skin conductance (ESC) is an objective, non-invasive and quantitative electrophysiological measure. It is based on reverse iontophoresis and (multiple) steady chronoamperometry (more specifically chronovoltametry). ESC is intend ...
may help in the diagnosis process. Sjögren's syndrome can be excluded from people with past head and neck
radiation therapy Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...
,
acquired immunodeficiency syndrome Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ma ...
, pre-existing
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
,
sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...
,
graft-versus-host disease Graft-versus-host disease (GvHD) is a syndrome, characterized by inflammation in different organs. GvHD is commonly associated with bone marrow transplants and stem cell transplants. White blood cells of the donor's immune system which remain wit ...
, and use of anticholinergic drugs.


Prevention

No prevention mechanism exists for Sjögren's syndrome (SS) because of its complexity as an autoimmune disorder, but
lifestyle Lifestyle often refers to: * Lifestyle (sociology), the way a person lives * ''Otium'', ancient Roman concept of a lifestyle * Style of life (german: Lebensstil, link=no), dealing with the dynamics of personality Lifestyle may also refer to: Bus ...
changes can reduce the
risk factors In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection. Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often use ...
related to developing SS or reduce the severity of the condition for patients who have already been diagnosed.
Diet Diet may refer to: Food * Diet (nutrition), the sum of the food consumed by an organism or group * Dieting, the deliberate selection of food to control body weight or nutrient intake ** Diet food, foods that aid in creating a diet for weight loss ...
is strongly associated with the inflammation seen in many autoimmune related diseases, including SS. An
experimental study An experiment is a procedure carried out to support or refute a hypothesis, or determine the efficacy or likelihood of something previously untried. Experiments provide insight into cause-and-effect by demonstrating what outcome occurs when ...
concluded that SS patients often show high sensitivity to gluten that directly relates to inflammation. Moderate exercise is also helpful in SS patients, mainly reducing the effect of lung inflammation.


Treatment

Neither a cure nor a specific treatment for Sjögren's syndrome is known to permanently restore gland
secretion 440px Secretion is the movement of material from one point to another, such as a secreted chemical substance from a cell or gland. In contrast, excretion is the removal of certain substances or waste products from a cell or organism. The classical ...
. Instead, treatment is generally symptomatic and supportive.


Eye care

Moisture replacement therapies such as
artificial tears Artificial tears are lubricating eye drops used to relieve dryness and irritation of the ocular surface. Dry eye syndrome (keratoconjunctivitis sicca) is a common ocular surface disorder and is characterized by disruption of the tear film and inc ...
may ease the symptoms of dry eyes. Some patients with more severe problems use
goggles Goggles, or safety glasses, are forms of protective eyewear that usually enclose or protect the area surrounding the eye in order to prevent particulates, water or chemicals from striking the eyes. They are used in chemistry laboratories and ...
to increase local
humidity Humidity is the concentration of water vapor present in the air. Water vapor, the gaseous state of water, is generally invisible to the human eye. Humidity indicates the likelihood for precipitation, dew, or fog to be present. Humidity depe ...
or have punctal plugs inserted to help retain tears on the
ocular Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...
surface for a longer time. Additionally,
cyclosporine Ciclosporin, also spelled cyclosporine and cyclosporin, is a calcineurin inhibitor, used as an immunosuppressant medication. It is a natural product. It is taken orally or intravenously for rheumatoid arthritis, psoriasis, Crohn's disease ...
(Restasis) is available by prescription to treat chronic dry eye by suppressing the inflammation that disrupts tear secretion.
Prescription drug A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription. The rea ...
s are also available that help to stimulate salivary flow, such as
cevimeline Cevimeline (trade name Evoxac) is a synthetic analog of the natural alkaloid muscarine with a particular agonistic effect on M1 and M3 receptors. It is used in the treatment of dry mouth and Sjögren's syndrome. Medical uses Cevimeline is us ...
(Evoxac) and pilocarpine.
Salagen Pilocarpine is a medication used to reduce pressure inside the eye and treat dry mouth. As eye drops it is used to manage angle closure glaucoma until surgery can be performed, ocular hypertension, open angle glaucoma, primary open angle glaucom ...
, a manufactured form of
pilocarpine Pilocarpine is a medication used to reduce pressure inside the eye and treat dry mouth. As eye drops it is used to manage angle closure glaucoma until surgery can be performed, ocular hypertension, primary open angle glaucoma, and to bring abou ...
, can be used to help produce tears, as well as saliva in the mouth and intestines. It is derived from the jaborandi plant.


Vaginal dryness

In women with Sjögren's syndrome,
vaginal dryness Vaginal lubrication is a naturally produced fluid that lubricates a vagina. Vaginal lubrication is always present, but production increases significantly near ovulation and during sexual arousal in anticipation of sexual intercourse. Vaginal ...
,
vulvodynia Vulvodynia is a chronic pain syndrome that affects the vulvar area and occurs without an identifiable cause. Symptoms typically include a feeling of burning or irritation. It has been established by the ISSVD that for the diagnosis to be made s ...
and
dyspareunia Dyspareunia ( ) is painful sexual intercourse due to medical or psychological causes. The term ''dyspareunia'' covers both female dyspareunia and male dyspareunia, but many discussions that use the term without further specification concern the f ...
(painful
sexual intercourse Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetrat ...
) are often reported;
personal lubricants Personal lubricants (colloquially termed lube) are specialized lubricants used during sexual acts, such as intercourse and masturbation, to reduce friction to or between the penis and vagina, anus or other body parts or applied to sex toys to ...
are recommended to help lessen irritation or pain that may result from dryness in the vaginal and
vulva The vulva (plural: vulvas or vulvae; derived from Latin for wrapper or covering) consists of the external sex organ, female sex organs. The vulva includes the mons pubis (or mons veneris), labia majora, labia minora, clitoris, bulb of vestibu ...
l areas.


Musculoskeletal

Nonsteroidal anti-inflammatory drugs Non-steroidal anti-inflammatory drugs (NSAID) are members of a therapeutic drug class which reduces pain, decreases inflammation, decreases fever, and prevents blood clots. Side effects depend on the specific drug, its dose and duration of ...
(NSAIDs) may be used to treat musculoskeletal symptoms. For individuals with severe complications,
corticosteroids Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involve ...
or
immunosuppressive drugs Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are medication, drugs that inhibit or prevent activity of the immune system. Classification Immunosuppressive drugs can be cla ...
may be prescribed, and sometimes
intravenous immunoglobulins Immunoglobulin therapy is the use of a mixture of antibodies (normal human immunoglobulin or NHIG) to treat several health conditions. These conditions include primary immunodeficiency, immune thrombocytopenic purpura, chronic inflammatory dem ...
. Also,
disease-modifying antirheumatic drugs Disease-modifying antirheumatic drugs (DMARDs) comprise a category of otherwise unrelated disease-modifying drugs defined by their use in rheumatoid arthritis to slow down disease progression. The term is often used in contrast to nonsteroidal ...
such as
methotrexate Methotrexate (MTX), formerly known as amethopterin, is a chemotherapy agent and immune-system suppressant. It is used to treat cancer, autoimmune diseases, and ectopic pregnancies. Types of cancers it is used for include breast cancer, leuke ...
may be helpful.
Hydroxychloroquine Hydroxychloroquine, sold under the brand name Plaquenil among others, is a medication used to prevent and treat malaria in areas where malaria remains sensitive to chloroquine. Other uses include treatment of rheumatoid arthritis, lupus, an ...
(Plaquenil) is another option and is generally considered safer than methotrexate. However, these prescribed drugs have a range of
side effects In medicine, a side effect is an effect, whether therapeutic or adverse, that is secondary to the one intended; although the term is predominantly employed to describe adverse effects, it can also apply to beneficial, but unintended, consequence ...
such as
nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the ...
,
loss of appetite Anorexia is a medical term for a loss of appetite. While the term in non-scientific publications is often used interchangeably with anorexia nervosa, many possible causes exist for a loss of appetite, some of which may be harmless, while others i ...
,
dizziness Dizziness is an imprecise term that can refer to a sense of disorientation in space, vertigo, or lightheadedness. It can also refer to disequilibrium or a non-specific feeling, such as giddiness or foolishness. Dizziness is a common medical c ...
,
hair loss Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. Typically at least the head is involved. The severity of hair loss can vary from a small area to the entire body. Inflammation or scarri ...
, stomach aches/cramps,
headache Headache is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches. Headaches can occur as a result ...
,
liver toxicity Hepatotoxicity (from ''hepatic toxicity'') implies chemical-driven liver damage. Drug-induced liver injury is a cause of acute and chronic liver disease caused specifically by medications and the most common reason for a drug to be withdrawn fro ...
and increased risk of
infections An infection is the invasion of tissue (biology), tissues by pathogens, their multiplication, and the reaction of host (biology), host tissues to the infectious agent and the toxins they produce. An infectious disease, also known as a transmiss ...
.


Systemic

For systemic symptoms, including fatigue, joint pain, myositis and
neuropathy Peripheral neuropathy, often shortened to neuropathy, is a general term describing disease affecting the peripheral nerves, meaning nerves beyond the brain and spinal cord. Damage to peripheral nerves may impair sensation, movement, gland, or o ...
, biologic
immunosuppressant Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent activity of the immune system. Classification Immunosuppressive drugs can be classified in ...
drugs such as
rituximab Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric p ...
and
belimumab Belimumab, sold under the brand name Benlysta, is a human monoclonal antibody that inhibits B-cell activating factor (BAFF), also known as B-lymphocyte stimulator (BLyS). It is approved in the United States, Canada, and the European Union to treat ...
that work via
B-cell B cells, also known as B lymphocytes, are a type of white blood cell of the lymphocyte subtype. They function in the humoral immunity component of the adaptive immune system. B cells produce antibody molecules which may be either secreted o ...
pathology are often used and have less toxic profiles than traditional immunosuppressive regimens.


Dental care

Preventive dental treatment is also necessary (and often overlooked by the patient), as the lack of saliva associated with xerostomia creates an ideal environment for the proliferation of bacteria that cause
cavities Cavity may refer to: Biology and healthcare *Body cavity, a fluid-filled space in many animals where organs typically develop **Gastrovascular cavity, the primary organ of digestion and circulation in cnidarians and flatworms *Dental cavity or too ...
. Treatments include at-home
topical A topical medication is a medication that is applied to a particular place on or in the body. Most often topical medication means application to body surfaces such as the skin or mucous membranes to treat ailments via a large range of classes ...
fluoride application to strengthen tooth enamel and frequent teeth cleanings by a dental hygienist. Existing cavities must also be treated, as cavities that extend into the tooth cannot be effectively treated by teeth cleaning alone, and are at a high risk of spreading into the pulp of the tooth, leading to the loss of vitality and need for extraction or
root canal A root canal is the naturally occurring anatomic space within the root of a tooth. It consists of the pulp chamber (within the coronal part of the tooth), the main canal(s), and more intricate anatomical branches that may connect the root c ...
therapy. This treatment regimen is the same as for all xerostomia patients, such as for those undergoing head and neck radiation therapy, which often damages the salivary glands; these glands are more susceptible to radiation than are other body tissues.


Prognosis

Published studies on the survival of Sjögren's syndrome patients are limited in varied respects, perhaps owing to the relatively small sample sizes, and the fact that secondary Sjögren's syndrome is associated with other autoimmune diseases. Results from a number of studies indicate that, compared to other autoimmune diseases, Sjögren's syndrome is associated with a notably high incidence of malignant
non-Hodgkin lymphoma Non-Hodgkin lymphoma (NHL), also known as non-Hodgkin's lymphoma, is a group of blood cancers that includes all types of lymphomas except Hodgkin lymphomas. Symptoms include enlarged lymph nodes, fever, night sweats, weight loss, and tiredness. ...
, a cancer of white blood cells. About 5% of patients with SS develop some form of
lymphoid malignancy Tumors of the hematopoietic and lymphoid tissues (American English) or tumours of the haematopoietic and lymphoid tissues (British English) are tumors that affect the blood, bone marrow, lymph, and lymphatic system. Because these tissues are al ...
. Patients with severe cases are much more likely to develop lymphomas than patients with mild or moderate cases. The most common lymphomas are salivary extranodal marginal zone B cell lymphomas (
MALT lymphoma MALT lymphoma (MALToma) is a form of lymphoma involving the mucosa-associated lymphoid tissue (MALT), frequently of the stomach, but virtually any mucosal site can be affected. It is a cancer originating from B cells in the marginal zone of the MAL ...
s in the salivary glands) and
diffuse large B-cell lymphoma Diffuse large B-cell lymphoma (DLBCL) is a cancer of B cells, a type of lymphocyte that is responsible for producing antibody, antibodies. It is the most common form of non-Hodgkin lymphoma among adults, with an annual Incidence (epidemiology), in ...
. Lymphomagenesis in primary Sjögren's syndrome patients is considered as a multistep process, with the first step being chronic stimulation of autoimmune B cells, especially B cells that produce
rheumatoid factor Rheumatoid factor (RF) is the autoantibody that was first found in rheumatoid arthritis. It is defined as an antibody against the Fc portion of IgG and different RFs can recognize different parts of the IgG-Fc. RF and IgG join to form immune com ...
at sites targeted by the disease. This increases the frequency of
oncogenic Carcinogenesis, also called oncogenesis or tumorigenesis, is the formation of a cancer, whereby normal cells are transformed into cancer cells. The process is characterized by changes at the cellular, genetic, and epigenetic levels and abno ...
mutation In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, mi ...
, leading to any dysfunction at checkpoints of autoimmune B-cell activation to transform into malignancy. A study's finding has concluded the continuous stimulation of autoimmune B cells, leading to subtle germinal abnormalities in genes having specific consequences in B cells, which underlies the susceptibility to lymphoma. Apart from this notably higher incidence of malignant NHL, Sjögren's patients show only modest or clinically insignificant deterioration in specific organ-related function, which explains the only slight increases in
mortality rate Mortality rate, or death rate, is a measure of the number of deaths (in general, or due to a specific cause) in a particular population, scaled to the size of that population, per unit of time. Mortality rate is typically expressed in units of de ...
s of Sjögren's patients in comparison with the remainder of the population. Sjögren's syndrome is associated with a high burden of illness, and has been shown to markedly reduce
quality of life Quality of life (QOL) is defined by the World Health Organization as "an individual's perception of their position in life in the context of the culture and value systems in which they live and in relation to their goals, expectations, standards ...
(QoL), with a significant impact on ability to work resulting from increased rates of disability. The reduction in QoL is similar to that seen in other chronic conditions such as
rheumatoid arthritis Rheumatoid arthritis (RA) is a long-term autoimmune disorder that primarily affects joints. It typically results in warm, swollen, and painful joints. Pain and stiffness often worsen following rest. Most commonly, the wrist and hands are involv ...
,
lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
and
fibromyalgia Fibromyalgia (FM) is a medical condition defined by the presence of chronic widespread pain, fatigue, waking unrefreshed, cognitive symptoms, lower abdominal pain or cramps, and depression. Other symptoms include insomnia and a general hyp ...
.


Epidemiology

Sjögren's syndrome (SS) is the second-most common rheumatic autoimmune disorder, behind rheumatoid arthritis and
systemic lupus erythematosus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
. There are no geographical differences in the rates of SS. Sjögren's syndrome has been reported in all areas of the world, although regional rates have not been well studied. Depending on the criteria for determining prevalence, studies estimate the prevalence of SS at between 500,000 and two million people in the United States. Broader studies of SS prevalence range widely, with some reports of up to a prevalence of 3% of the population. A few studies have reported that the incidence of the syndrome varies between three and six per 100,000 per year. Nine out of 10 SS patients are women. In addition to prevalence in women, having a
first-degree relative A first-degree relative (FDR) is a person's parent (father or mother), full sibling (brother or sister) or child. It constitutes a category of family members that largely overlaps with the term nuclear family, but without spouses. If the persons ...
with an autoimmune disease and previous pregnancies have been identified as epidemiological risk factors. Despite the lower risk for men, primary SS in men tends to represent a more severe form of the disease. The role of race and ethnicity in the prevalence of the disease is unknown. Although Sjögren's syndrome occurs in all age groups, the average age of onset is between ages 40 and 60, although as many as half of all cases may be left undiagnosed or unreported. The prevalence of SS generally increases with age. Sjögren's syndrome is reported in 30-50% of people with rheumatoid arthritis and in 10-25% with systemic lupus erythematosus.


History

Jan Mikulicz-Radecki Jan Mikulicz-Radecki (german: Johann Freiherr von Mikulicz-Radecki) was a German-Polish-Austrian surgeon who worked mainly in the German Empire. He was born on 16 May 1850 in Czerniowce in the Austrian Empire (present-day Chernivtsi in Ukraine) ...
(1850–1905) is generally credited with the first description of SS. In 1892, he described a 42-year-old man with enlargement of the
parotid The parotid gland is a major salivary gland in many animals. In humans, the two parotid glands are present on either side of the mouth and in front of both ears. They are the largest of the salivary glands. Each parotid is wrapped around the ma ...
and
lacrimal gland The lacrimal glands are paired exocrine glands, one for each eye, found in most terrestrial vertebrates and some marine mammals, that secrete the aqueous layer of the tear film. In humans, they are situated in the upper lateral region of each or ...
s associated with a round-cell infiltrate and acinar
atrophy Atrophy is the partial or complete wasting away of a part of the body. Causes of atrophy include mutations (which can destroy the gene to build up the organ), poor nourishment, poor circulation, loss of hormonal support, loss of nerve supply t ...
. However, the criteria that Mikulicz established for diagnosis often led to
misdiagnosis A medical error is a preventable adverse effect of care ("iatrogenesis"), whether or not it is evident or harmful to the patient. This might include an inaccurate or incomplete diagnosis or treatment of a disease, injury, syndrome, behavior, i ...
of Mikulicz's syndrome. Many conditions, such as
tuberculosis Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
, infections,
sarcoidosis Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...
and
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
present with similar conditions to those ascribed to Mikulicz's syndrome. Nevertheless, the term "Mikulicz’s syndrome" is still used occasionally to describe the appearance of lymphocytic infiltrates on salivary-gland biopsies. In 1930,
Henrik Sjögren Henrik Samuel Conrad Sjögren (, , ; 23 July 1899, Köping, Sweden, Köping – 17 September 1986, Lund) was a Sweden, Swedish ophthalmologist best known for describing the eponymous condition Sjögren syndrome. Sjögren received his medical degr ...
(1899–1986), an ophthalmologist in
Jönköping Jönköping (, ) is a city in southern Sweden with 112,766 inhabitants (2022). Jönköping is situated on the southern shore of Sweden's second largest lake, Vättern, in the province of Småland. The city is the seat of Jönköping Municipali ...
,
Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
, observed a patient with low secretions from the lacrimal and salivary glands.Murube, J. Henrik Sjögren, 1899–1986. The ocular surface 8, 2-2 (2010) Sjögren introduced the term keratoconjunctivitis sicca for the symptom of dry eyes (
keratoconjunctivitis Keratoconjunctivitis is inflammation ("-itis") of the cornea and conjunctiva. When only the cornea is inflamed, it is called ''keratitis''; when only the conjunctiva is inflamed, it is called ''conjunctivitis''. Causes There are several potentia ...
). In 1933, he published his
doctoral thesis A thesis ( : theses), or dissertation (abbreviated diss.), is a document submitted in support of candidature for an academic degree or professional qualification presenting the author's research and findings.International Standard ISO 7144: ...
describing 19 females, most of whom were postmenopausal and had arthritis, showing clinical and pathological manifestations of the syndrome. Sjögren clarified that keratoconjunctivitis sicca, resulting from water deficiency, had no relation to
xerophthalmia Xerophthalmia (from Ancient Greek "xērós" (ξηρός) meaning "dry" and "ophthalmos" (οφθαλμός) meaning "eye") is a medical condition in which the eye fails to produce tears. It may be caused by vitamin A deficiency, which is someti ...
, resulting from vitamin A deficiency. Sjögren's thesis was not well received as the Board of Examiners criticized some clinical aspects. After extensive research and data collection, Sjögren published an essential paper in 1951, describing 80 patients with
keratoconjunctivitis sicca Dry eye syndrome (DES), also known as keratoconjunctivitis sicca (KCS), is the condition of having dry eyes. Other associated symptoms include irritation, redness, discharge, and easily fatigued eyes. Blurred vision may also occur. Symptoms range ...
, 50 of whom also had arthritis. His subsequent follow-up conference trips pertaining to his paper led to an international interest in Sjögren's syndrome. The term "keratoconjunctivitis sicca" was coined by Sjögren himself and began to be identified as Sjögren's syndrome in literature, although it can now have more general usage.


Research

Research into multifactorial autoimmune diseases such as SS focuses on expanding the knowledge surrounding the disorder, improving diagnostic tools and finding ways to prevent, manage and cure the disorder. The
United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...
Primary Sjögren's Syndrome Registry, a tissue
biobank A biobank is a type of biorepository that stores biological samples (usually human) for use in research. Biobanks have become an important resource in medical research, supporting many types of contemporary research like genomics and personalize ...
of samples taken for research, supported by the Medical Research Council, UK, was established in 2010. It supports
clinical trials Clinical trials are prospective biomedical or behavioral research studies on human participants designed to answer specific questions about biomedical or behavioral interventions, including new treatments (such as novel vaccines, drugs, dietar ...
and genetic studies of Sjögren's syndrome and is open to those wishing to participate in research studies and to researchers studying the disease. As with other autoimmune diseases, susceptibility to Sjögren's syndrome is greatly influenced by the human leukocyte antigen. DQA1*05:01, DQB1*02:01, and DRB1*03:01 alleles were identified as
risk factors In epidemiology, a risk factor or determinant is a variable associated with an increased risk of disease or infection. Due to a lack of harmonization across disciplines, determinant, in its more widely accepted scientific meaning, is often use ...
, while DQA1*02:01, DQA1*03:01 and DQB1*05:01 alleles were found to be protective factors for the disease. The relationship between alleles and specific race was also established.
HLA-DQ2 HLA-DQ3 (DQ3) is a serotype group within HLA-DQ (DQ) serotyping system. The serotype is determined by the antibody recognition of β2 subset of DQ β-chains. The β-chain of DQ is encoded by HLA-DQB1 locus and DQ2 are encoded by the HLA-DQB1 a ...
and
HLA-B8 HLA-B8 (B8) is an HLA- B serotype. The serotype identifies the HLA-B*08 gene products. (For terminology help see: HLA-serotype tutorial) HLA-B8, previously known as HL-A8 was one of the first identified of the HLA antigens. It coined the "Supe ...
are generally found in
Caucasian Caucasian may refer to: Anthropology *Anything from the Caucasus region ** ** ** ''Caucasian Exarchate'' (1917–1920), an ecclesiastical exarchate of the Russian Orthodox Church in the Caucasus region * * * Languages * Northwest Caucasian l ...
patients, while
HLA-DR5 HLA-DR5 (DR5) is a broad-antigen serotype that is further split into HLA-DR11 and HLA-DR12 antigen serotypes. HLA-DR5 (Human Leukocyte Antigen DR5) is a protein that is encoded by a gene in the human leukocyte antigen (HLA) complex. The HLA comp ...
is related to
Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...
and
Israeli Israeli may refer to: * Something of, from, or related to the State of Israel * Israelis, citizens or permanent residents of the State of Israel * Modern Hebrew, a language * ''Israeli'' (newspaper), published from 2006 to 2008 * Guni Israeli ...
patients. Multiple genome-wide association scans may be conducted in the future to identify key risk variants.
Virus A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1 ...
es that have been associated with Sjögren's syndrome include human T-lymphotropic virus type 1 (
HTLV-1 Human T-cell lymphotropic virus type 1 or human T-lymphotropic virus (HTLV-I), also called the adult T-cell lymphoma virus type 1, is a retrovirus of the human T-lymphotropic virus (HTLV) family that has been implicated in several kinds of diseas ...
), Epstein-Barr virus (EBV),
human immunodeficiency virus The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause AIDS, acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the ...
(HIV),
hepatitis delta virus Hepatitis D is a type of viral hepatitis caused by the hepatitis delta virus (HDV). HDV is one of five known hepatitis viruses: A, B, C, D, and E. HDV is considered to be a satellite (a type of subviral agent) because it can propagate only in ...
(HDV) and
hepatitis C virus The hepatitis C virus (HCV) is a small (55–65 nm in size), enveloped, positive-sense single-stranded RNA virus of the family ''Flaviviridae''. The hepatitis C virus is the cause of hepatitis C and some cancers such as liver cancer ( hepato ...
(HCV). Some research has showed that the lack of
vitamin A Vitamin A is a fat-soluble vitamin and an essential nutrient for humans. It is a group of organic compounds that includes retinol, retinal (also known as retinaldehyde), retinoic acid, and several provitamin A carotenoids (most notably bet ...
and
vitamin D Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group are vitamin D3 (c ...
are associated with the disease.
Vitamin D deficiency Vitamin D deficiency or hypovitaminosis D is a vitamin D level that is below normal. It most commonly occurs in people when they have inadequate exposure to sunlight, particularly sunlight with adequate ultraviolet B rays (UVB). Vitamin D defic ...
was found to be related to neurological manifestations and the presence of
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
among patients, but vitamin A levels were inversely associated with extraglandular manifestations of the disease. Saliva is a potential diagnostic tool for Sjögren's syndrome because the salivary component is changed after onset of the disease. With the new
miniaturization Miniaturization ( Br.Eng.: ''Miniaturisation'') is the trend to manufacture ever smaller mechanical, optical and electronic products and devices. Examples include miniaturization of mobile phones, computers and vehicle engine downsizing. In ele ...
technology, called
lab on a chip A lab-on-a-chip (LOC) is a device that integrates one or several laboratory functions on a single integrated circuit (commonly called a "chip") of only millimeters to a few square centimeters to achieve automation and high-throughput screening. ...
, the diagnosis can be more convenient. With regard to therapeutics, multiple
monoclonal antibodies A monoclonal antibody (mAb, more rarely called moAb) is an antibody produced from a cell Lineage made by cloning a unique white blood cell. All subsequent antibodies derived this way trace back to a unique parent cell. Monoclonal antibodies ca ...
were under investigation in 2007. The most promising seemed to be the anti-
CD20 B-lymphocyte antigen CD20 or CD20 is expressed on the surface of all B-cells beginning at the pro-B phase (CD45R+, CD117+) and progressively increasing in concentration until maturity. In humans CD20 is encoded by the ''MS4A1'' gene. This gene e ...
rituximab Rituximab, sold under the brand name Rituxan among others, is a monoclonal antibody medication used to treat certain autoimmune diseases and types of cancer. It is used for non-Hodgkin lymphoma, chronic lymphocytic leukemia (in non-geriatric p ...
and the anti-
CD22 CD22, or cluster of differentiation-22, is a molecule belonging to the SIGLEC family of lectins. It is found on the surface of mature B cells and to a lesser extent on some immature B cells. Generally speaking, CD22 is a regulatory molecule that ...
epratuzumab Epratuzumab (planned trade name LymphoCide) is a humanized monoclonal antibody. Potential uses may be found in oncology and in treatment of inflammatory autoimmune disorders, such as systemic lupus erythematosus (SLE). Clinical trials A clinic ...
, while the anti-
TNF-α Tumor necrosis factor (TNF, cachexin, or cachectin; formerly known as tumor necrosis factor alpha or TNF-α) is an adipokine and a cytokine. TNF is a member of the TNF superfamily, which consists of various transmembrane proteins with a homolog ...
and
IFN-α The type-I interferons (IFN) are cytokines which play essential roles in inflammation, immunoregulation, tumor cells recognition, and T cell, T-cell responses. In the human genome, a cluster of thirteen functional IFN genes is located at the 9p2 ...
seemed less effective. In 2014, the Sjögren's Syndrome Foundation announced a five-year goal to halve the disease's average time to diagnosis.


Notable cases

*
Shannon Boxx Shannon Leigh Boxx Spearman (; born June 29, 1977) is an American retired soccer player and former member of the United States women's national soccer team, playing the defensive midfielder position. She last played club soccer for the Chicago Re ...
( U.S. Olympic soccer player) has both Sjögren's syndrome and
lupus Lupus, technically known as systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Comm ...
. *
Carrie Ann Inaba Carrie Ann Inaba (born January 5, 1968) is an American television personality, dancer, choreographer, actress, and singer. She is best known for her work on ABC TV's ''Dancing with the Stars'' for which she has served as a judge since 2005. She c ...
(singer-actress) is the national awareness ambassador and spokesperson for the Sjögren's Syndrome Foundation. *
Venus Williams Venus Ebony Starr Williams (born June 17, 1980) is an American professional tennis player. A former world No. 1 in both singles and doubles, Williams has won seven Grand Slam singles titles, five at Wimbledon and two at the US Open. She is ...
(world-champion
tennis Tennis is a racket sport that is played either individually against a single opponent ( singles) or between two teams of two players each ( doubles). Each player uses a tennis racket that is strung with cord to strike a hollow rubber ball ...
player) has been diagnosed with Sjögren's syndrome and said she had struggled with
fatigue Fatigue describes a state of tiredness that does not resolve with rest or sleep. In general usage, fatigue is synonymous with extreme tiredness or exhaustion that normally follows prolonged physical or mental activity. When it does not resolve ...
for years. *
Stephen McPhail Stephen John Paul McPhail (born 9 December 1979) is an Irish former professional footballer and the sporting director of Shamrock Rovers in the League of Ireland Premier Division. A play-making central midfielder, McPhail started his career at ...
(professional soccer player for Ireland, Leeds and Cardiff City) was diagnosed with
lymphoma Lymphoma is a group of blood and lymph tumors that develop from lymphocytes (a type of white blood cell). In current usage the name usually refers to just the cancerous versions rather than all such tumours. Signs and symptoms may include enlar ...
and Sjögren's syndrome at age 29. * Halsey (singer) diagnosed with Sjorgen's, Ehlers-Danlos syndrome,
Mast Cell Activation Syndrome Mast cell activation syndrome (MCAS) is a type of mast cell activation disorder (MCAD), and is an immunological condition in which mast cells inappropriately and excessively release chemical mediators, resulting in a range of chronic symptoms, ...
, and
Postural Orthostatic Tachycardia Syndrome Postural orthostatic tachycardia syndrome (POTS) is a condition characterized by an abnormally large increase in heart rate upon standing. Symptoms may include lightheadedness, brain fog, blurred vision, weakness, fatigue, headaches, heart ...


References

* Some of the original text for this article was obtained from a
public domain The public domain (PD) consists of all the creative work A creative work is a manifestation of creative effort including fine artwork (sculpture, paintings, drawing, sketching, performance art), dance, writing (literature), filmmaking, ...
resource a
NIH


External links


Sjögren syndrome at NHS Choices

Sjögren syndrome
– US National Institute of Arthritis and Musculoskeletal and Skin Diseases
US Sjögren‘s Foundation
* {{DEFAULTSORT:Sjogrens Syndrome Ailments of unknown cause Autoimmune diseases Connective tissue diseases Hepatitis C virus-associated diseases Wikipedia medicine articles ready to translate Salivary gland pathology Syndromes Systemic connective tissue disorders Wikipedia neurology articles ready to translate