Gamma globulins are a class of
globulins, identified by their position after
serum protein electrophoresis.
The most significant gamma globulins are immunoglobulins (
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 ...
), 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 the ...
or
measles
Measles is a highly contagious infectious disease caused by measles virus. Symptoms usually develop 10–12 days after exposure to an infected person and last 7–10 days. Initial symptoms typically include fever, often greater than , cough, ...
, 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, such as
X-linked agammaglobulinemia and
hyper IgM syndrome. 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practice than they were previously, and injections of gamma globulin previously recommended for travelers have largely been replaced by the use of hepatitis A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 (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.
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 sy ...
.
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
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, ...
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. A deficiency is known as
hypogammaglobulinemia.
A disease of gamma globulins is called a "gammopathy" (for example, in
monoclonal gammopathy of undetermined significance).
References
External links
*
{{DEFAULTSORT:Gamma Globulin
Blood proteins
de:Gammaglobulin
pt:Imunoglobina