Gamma globulins are a class of
globulin
The globulins are a family of globular proteins that have higher molecular weights than albumins and are insoluble in pure water but dissolve in dilute salt solutions. Some globulins are produced in the liver, while others are made by the immune ...
s, identified by their position after
serum protein electrophoresis
Serum protein electrophoresis (SPEP or SPE) is a laboratory test that examines specific proteins in the blood called globulins. The most common indications for a serum protein electrophoresis test are to diagnose or monitor multiple myeloma, a ...
.
The most significant gamma globulins are immunoglobulins (
antibodies), although some immunoglobulins are not gamma globulins, and some gamma globulins are not immunoglobulins.
Use as medical treatment
Gamma globulin injections are usually given in an attempt to temporarily boost a patient's immunity against disease.
Injections are most commonly used on patients having been exposed to
hepatitis A
Hepatitis A is an infectious disease of the liver caused by ''Hepatovirus A'' (HAV); it is a type of viral hepatitis. Many cases have few or no symptoms, especially in the young. The time between infection and symptoms, in those who develop them ...
or
measles, or to make a kidney donor and a recipient compatible regardless of blood type or tissue match. Injections are also used to boost immunity in patients unable to produce gamma globulins naturally because of an
immune deficiency
Immunodeficiency, also known as immunocompromisation, is a state in which the immune system's ability to fight infectious diseases and cancer is compromised or entirely absent. Most cases are acquired ("secondary") due to extrinsic factors that a ...
, such as
X-linked agammaglobulinemia
X-linked agammaglobulinemia (XLA) is a rare genetic disorder discovered in 1952 that affects the body's ability to fight infection. As the form of agammaglobulinemia that is X-linked, it is much more common in males. In people with XLA, the whit ...
and
hyper IgM syndrome
Hyper IgM syndrome describes a group of primary immune deficiency disorders characterized by defective CD40 signaling; ''via'' B cells affecting class switch recombination (CSR) and somatic hypermutation. Immunoglobulin (Ig) class switch reco ...
. Such injections are less common in modern medical practice than they were previously, and injections of gamma globulin previously recommended for travelers have largely been replaced by the use of hepatitis A
vaccine
A vaccine is a biological preparation that provides active acquired immunity to a particular infectious or malignant disease. The safety and effectiveness of vaccines has been widely studied and verified. .
Gamma globulin infusions are also used to treat some immunological diseases, such as
idiopathic thrombocytopenia purpura
Immune thrombocytopenic purpura (ITP), also known as idiopathic thrombocytopenic purpura or immune thrombocytopenia, is a type of thrombocytopenic purpura defined as an isolated low platelet count with a normal bone marrow in the absence of othe ...
(ITP), a disease in which the platelets are being attacked by antibodies, leading to seriously low platelet counts. It appears that gamma globulin causes the spleen to ignore the antibody-tagged platelets, thus allowing them to survive and function.
Another theory on how gamma globulin administration works in autoimmune disease is by overloading the mechanisms that degrade gamma globulins. Overloading the degradation mechanism causes the harmful gamma globulins to have a much shorter half of the life in sera.
Intravenous immunoglobulin (IVIG) may be used in
Kawasaki disease
Kawasaki disease is a syndrome of unknown cause that results in a fever and mainly affects children under 5 years of age. It is a form of vasculitis, where blood vessels become inflamed throughout the body. The fever typically lasts for more th ...
.
In 1953, gamma globulin was shown to prevent paralytic
polio
Poliomyelitis, commonly shortened to polio, is an infectious disease caused by the poliovirus. Approximately 70% of cases are asymptomatic; mild symptoms which can occur include sore throat and fever; in a proportion of cases more severe s ...
.
Being a product derived from bone marrow and lymph gland cells, gamma globulin injections, along with blood transfusions and intravenous drug use, can pass
hepatitis C to their recipients. Once hepatitis C was identified in 1989, blood banks began screening all blood donors for the presence of the virus in their bloodstream. However, since hepatitis C is known to have been present since at least the 1940s, a gamma globulin shot received prior to the early 1990s put the recipient at risk of being infected.
Intravenous gamma globulin was FDA-approved in 2004 to reduce antibodies in a patient with kidney failure to allow that person to accept a kidney from a donor with a different blood type (ABO-incompatible), or who is an unacceptable tissue match. Stanley Jordan at Cedars-Sinai Medical Center in Los Angeles pioneered this treatment.
Pathology
An excess is known as
hypergammaglobulinemia
Hypergammaglobulinemia is a medical condition with elevated levels of gamma globulin. It is a type of immunoproliferative disorder.
Types
Hypergammaglobulinemia is a condition that is characterized by the increased levels of a certain immunogl ...
. A deficiency is known as
hypogammaglobulinemia
Hypogammaglobulinemia is a problem with the immune system in which not enough gamma globulins are produced in the blood (thus '' hypo-'' + ''gamma'' + ''globulin'' + '' -emia''). This results in a lower antibody count, which impairs the immune sys ...
.
A disease of gamma globulins is called a "gammopathy" (for example, in
monoclonal gammopathy of undetermined significance
Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell dyscrasia in which plasma cells or other types of antibody-producing cells secrete a myeloma protein, i.e. an abnormal antibody, into the blood; this abnormal protein is ...
).
References
External links
*
{{DEFAULTSORT:Gamma Globulin
Blood proteins
de:Gammaglobulin
pt:Imunoglobina