Autoimmune polyendocrine syndromes (APSs), also called polyglandular autoimmune syndromes (PGASs) or polyendocrine autoimmune syndromes (PASs), are a heterogeneous group of

rare disease A rare disease is any disease that affects a small percentage of the population. In some parts of the world, an orphan disease is a rare disease whose rarity means there is a lack of a market large enough to gain support and resources for discov ...

s characterized by

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". ...

activity against more than one

endocrine organ The endocrine system is a messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system, regulating distant target organs. In vertebrates, the hypothalamus is the neur ...

, although non-endocrine organs can be affected. There are three types of APS, and there are a number of other diseases which involve endocrine autoimmunity.

Types

Autoimmune polyendocrine syndrome type 1 Autoimmune polyendocrine syndrome type 1 (APS-1), is a subtype of autoimmune polyendocrine syndrome (autoimmune polyglandular syndrome). It causes the dysfunction of multiple endocrine glands due to autoimmunity. It is a genetic disorder, inherite ...

, an autosomal recessive syndrome due to mutation of the ''AIRE'' gene resulting in

hypoparathyroidism Hypoparathyroidism is decreased function of the parathyroid glands with underproduction of parathyroid hormone (PTH). This can lead to low levels of calcium in the blood, often causing cramping and twitching of muscles or tetany (involuntary m ...

, adrenal insufficiency,

hypogonadism Hypogonadism means diminished functional activity of the gonads—the testes or the ovaries—that may result in diminished production of sex hormones. Low androgen (e.g., testosterone) levels are referred to as hypoandrogenism and low estroge ...

vitiligo Vitiligo is a disorder that causes the skin to lose its color. Specific causes are unknown but studies suggest a link to immune system changes. Signs and symptoms The only sign of vitiligo is the presence of pale patchy areas of depigmen ...

candidiasis Candidiasis is a fungal infection due to any type of '' Candida'' (a type of yeast). When it affects the mouth, in some countries it is commonly called thrush. Signs and symptoms include white patches on the tongue or other areas of the mouth ...

and others. * Autoimmune polyendocrine syndrome type 2, an autosomal dominant syndrome due to multifactorial gene involvement resulting in adrenal insufficiency plus hypothyroidism and/or

type 1 diabetes Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that originates when cells that make insulin (beta cells) are destroyed by the immune system. Insulin is a hormone required for the cells to use blood sugar ...

. * Immunodysregulation polyendocrinopathy enteropathy X-linked syndrome (IPEX syndrome) is

X-linked recessive X-linked recessive inheritance is a mode of inheritance in which a mutation in a gene on the X chromosome causes the phenotype to be always expressed in males (who are necessarily homozygous for the gene mutation because they have one X and one Y ...

due to mutation of the ''

FOXP3 FOXP3 ( forkhead box P3), also known as scurfin, is a protein involved in immune system responses. A member of the FOX protein family, FOXP3 appears to function as a master regulator of the regulatory pathway in the development and function of ...

'' gene on the X chromosome. Most patients develop diabetes and diarrhea and many die due to autoimmune activity against many organs. Boys are affected, while girls are carriers and might experience mild disease.

Cause

Each "type" of this condition has a different genetic cause. IPEX syndrome is inherited in males by an

process. The ''FOXP3'' gene, whose

cytogenetic Cytogenetics is essentially a branch of genetics, but is also a part of cell biology/cytology (a subdivision of human anatomy), that is concerned with how the chromosomes relate to cell behaviour, particularly to their behaviour during mitosis an ...

location is Xp11.23, is involved in the mechanism of the IPEX condition.

Diagnosis

Diagnosis for ''type 1'' of this condition for example, sees that the following methods/tests are available: *

Endoscopic An endoscopy is a procedure used in medicine to look inside the body. The endoscopy procedure uses an endoscope to examine the interior of a hollow organ or cavity of the body. Unlike many other medical imaging techniques, endoscopes are insert ...

* CT scan * Histologic test

Differential diagnosis

For this condition, differential diagnosis sees that the following should be considered: *

CD25 Interleukin-2 receptor alpha chain (also called CD25) is the human protein encoded by the ''IL2RA'' gene. The interleukin 2 (IL2) receptor alpha (IL2RA) and beta ( IL2RB) chains, together with the common gamma chain (IL2RG), constitute the high-a ...

deficiency * STAT5B deficiency *

Severe combined immunodeficiency Severe combined immunodeficiency (SCID), also known as Swiss-type agammaglobulinemia, is a rare genetic disorder characterized by the disturbed development of functional T cells and B cells caused by numerous genetic mutations that result in diffe ...

* X linked thrombocytopenia

Management

Immunosuppressive therapy may be used in type I of this condition. Ketoconazole can also be used for type I under certain conditions. The component diseases are managed as usual; the challenge is to detect the possibility of any of the syndromes and to anticipate other manifestations. For example, in a person with known type 2 autoimmune polyendocrine syndrome but no features of Addison's disease, regular screening for antibodies against

21-hydroxylase Steroid 21-hydroxylase (also known as steroid 21-monooxygenase, cytochrome P450C21, 21α-hydroxylase and less commonly 21β-hydroxylase) is an enzyme that hydroxylates steroids at the C21 position and is involved in biosynthesis of aldosterone a ...

may prompt early intervention and

hydrocortisone Hydrocortisone is the name for the hormone cortisol when supplied as a medication. Uses include conditions such as adrenocortical insufficiency, adrenogenital syndrome, high blood calcium, thyroiditis, rheumatoid arthritis, dermatitis, asthm ...

replacement to prevent characteristic crises

References

External links

*
PubMed
{{Hypersensitivity and autoimmune diseases Endocrine diseases Autoimmune diseases Rare syndromes Diseases of immune dysregulation