Antimitochondrial Antibody (AMA)
- Sample Type
- Standard
- Fasting
- No
- Unit
- Titer
Antimitochondrial antibodies (AMA) are highly specific biomarkers primarily used in the diagnosis of Primary Biliary Cholangitis (PBC). Within an Autoimmune Hepatitis (AIH) panel, AMA is measured to differentiate AIH from PBC or to identify 'Overlap Syndrome' (where a patient exhibits features of both conditions). AMA targets the E2 subunit of the pyruvate dehydrogenase complex (PDC) on the inner mitochondrial membrane. Elevated titers are found in approximately 95% of patients with PBC, making it a critical component for diagnosing chronic cholestatic liver disease.
Why Context Matters
False positives can occur in patients with other autoimmune conditions like systemic sclerosis or Sjögren's syndrome. Conversely, a small percentage of PBC patients are 'AMA-negative' but have the clinical disease (AMA-negative PBC). Differentiating between AIH and PBC is vital because the treatment for AIH (corticosteroids/immunosuppressants) differs significantly from PBC (Ursodeoxycholic acid).
Lab ranges are statistical averages, not biological laws. "Normal" for a 20-year-old male isn't normal for a 60-year-old female.
Clinical References
Source-of-truth databases and clinical guidelines for Antimitochondrial Antibody (AMA):
Official Sources
Research & Guidelines
Related Indicators
Medically Reviewed by Dr. Binoy Babu, MBBS
Board Certified Doctor • 10+ Years Clinical Experience
Dr. Babu is a practicing physician dedicated to empowering patients with clear, actionable medical information. He founded 2opi to bridge the gap between complex lab reports and patient understanding, ensuring everyone has access to a reliable second opinion.
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