Geri

Anti-mitoxondrial antitellər (AMA M2)

30 Azn
Səbətə atƏlavaə olundu

Anti-Mitochondrial Antibodies (AMA M2) Test

Anti-mitochondrial antibodies (AMA) are autoantibodies directed against components of the mitochondrial membrane, specifically targeting the pyruvate dehydrogenase antigen complex.

Types and Clinical Significance

There are nine AMA subtypes (AMA-M1 to AMA-M9), each associated with different conditions.

  • AMA-M2, M4, M8, and M9 specifically target liver cell mitochondria and are associated with the destruction of small bile ducts in Primary Biliary Cholangitis (PBC), an autoimmune liver disease.
  • AMA-M1: Found in syphilis and antiphospholipid syndrome.
  • AMA-M3: Associated with drug-induced lupus (systemic lupus erythematosus, SLE).
  • AMA-M5: Linked to collagen disorders and antiphospholipid syndrome.
  • AMA-M6: May be present in hepatitis related to MAO inhibitor use.
  • AMA-M7: Found in cardiomyopathies.
  • Sample: Serum or plasma.
  • Take the test 2-3 hours after the last meal.
  • Avoid smoking for 1 hour before the test.
  • Avoid physical and emotional stress for 1 hour before the test.

Diagnostic Role of AMA

Anti-mitochondrial antibodies serve as marker antibodies and are one of the three key diagnostic criteria for Primary Biliary Cholangitis (PBC). These antibodies are detected in approximately 95% of PBC patients.

Associated Conditions

Apart from Primary Biliary Cholangitis, AMA may also be present in:

  • Syphilis
  • Collagen vascular diseases
  • Antiphospholipid syndrome
  • Chronic aggressive hepatitis
  • Systemic sclerosis or systemic lupus erythematosus (SLE)
  • Liver cirrhosis
  • Hepatomegaly (enlarged liver)

Positive Result

  • Primary Biliary Cholangitis (PBC) (Antibodies detected in 95% of PBC patients).
  • AMA-M2 subtype has high sensitivity and specificity for PBC.
  • Other subtypes may indicate different conditions:
    • AMA-M1:Syphilis, Antiphospholipid Syndrome
    • AMA-M3:Drug-induced lupus
    • AMA-M5:Collagen vascular diseases, Antiphospholipid Syndrome
    • AMA-M6:Hepatitis due to MAO inhibitors
    • AMA-M7:Cardiomyopathies

Key Considerations

  • In middle-aged women, a positive AMA test along with elevated cholestasis markers (gamma-GT and alkaline phosphatase) is a strong indicator of Primary Biliary Cholangitis.
  • Confirmatory testing may include liver function tests, liver biopsy, and imaging studies to assess bile duct damage.

This test is essential for the early detection and differentiation of autoimmune liver diseases, especially Primary Biliary Cholangitis (PBC).