What Are Antimitochondrial Antibodies?

Anti-mitochondrial antibody (AMA) was discovered by Maokey in 1958 for the first time in the serum of patients with primary biliary cirrhosis (PBC). It is an autoantibody with no organ specificity or species specificity. Studies have found that AMA is also found in patients with other autoimmune diseases. The target antigens of AMA are a variety of proteins on the mitochondrial membrane with complex components, and M1-M9 components are now known. M1 is the cardiolipin of the outer membrane of mitochondria; M2 is the main component of the AMA response in the serum of PBC patients, and its essence is the complex of pyruvate dehydrogenase and & alpha; -keto acid dehydrogenase on the inner membrane of mitochondria; It is not clear; M4 is a sulfite oxidase; M5 is a 65kD protein; the properties of M6, M7, and M8 are unknown; M9 is a glycogen phosphorylase.

M6 and M8 are located on the outer membrane of mitochondria and their properties are unknown; M7 is a cardiac muscle-specific sarcosine dehydrogenase. Indirect immunofluorescence IFA is a screening method for detecting AMA. AMA (mainly anti-M2, M4, and M9 antibodies) is related to PBC, especially the anti-M2 antibody is most closely related to PBC.

Name: Anti-mitochondrial antibody

category: Immunology

Anti-mitochondrial antibody normal value

Normal human serum AMA was negative.

Clinical significance of anti-mitochondrial antibodies

Abnormal result: Due to the anti-M1 antibody, that is, the anticardiolipin antibody, it is not currently included in the antimitochondrial antibody. Anti-M2 is found in 90% of PBC patients and is often used as an important laboratory diagnostic indicator of the disease, but AMA has no correlation with the disease stage, disease severity, and treatment effect of PBC. In addition to PBC, anti-M2 is also found in chronic active hepatitis (CAH) and HBsAg negative liver disease. Anti-M2 AMA is seen in patients with pseudo lupus erythematosus (PLE) syndrome induced by the pyrazolone series of drugs, anti-M4 AMA is also seen in PBC; anti-M9 is seen in early PBC; anti-M5 is seen in SLE, autoimmune hemolytic anemia; M6 is found in isproniazid (iproniazid, a monoamine oxidase inhibitor) -induced hepatitis; anti-M7 appears in some patients with unexplained cardiomyopathy, and its target antigen is organ-specific and exists in the mitochondria of cardiac muscle cells. Due to the complex composition of mitochondrial antigens and the nature of many antigens is unknown, almost all patients with primary biliary cirrhosis have high titers of anti-M2 AMA. Therefore, the current AMA (or anti-M2 AMA) assay is mainly used for the diagnosis of PBC . People to be checked: PBC patients, patients with lupus erythematosus (PLE) syndrome, patients with primary biliary cirrhosis

Anti-mitochondrial antibody considerations

Unsuitable people: Generally there is no special group contraindication before examination: because some blood needs to be drawn from the patient, the patient needs to undergo fasting examination. Inspection requirements: AMA is often used for the auxiliary diagnosis of jaundice and liver diseases. It can be used as the basis for the differential diagnosis of primary biliary cirrhosis and extrahepatic biliary obstructive cirrhosis. Doctors should pay attention to their diagnosis during the examination.

Anti-mitochondrial antibody test process

Laboratory introduction: Anti-mitochondrial antibody (AMA) is an autoantibody mainly found in the serum of patients with primary, biliary cirrhosis. Inspection method: indirect fluorescent antibody method