Question

Anti-mitochondrial antibody (AMA) is most commonly seen in which condition?

• A. Autoimmune hepatitis
• B. Primary biliary cholangitis
• C. Primary sclerosing cholangitis
• D. Systemic lupus erythematosus

Hint:

AMA = Primary biliary cholangitis. p-ANCA = Primary sclerosing cholangitis.

Answer 1

The Correct Option is B

Step 1: Understanding the Question:
The question tests the knowledge of specific serological markers used to diagnose chronic autoimmune liver diseases.
Step 2: Detailed Explanation:

Primary Biliary Cholangitis (PBC): This is a chronic disease characterized by the autoimmune destruction of small intrahepatic bile ducts.

The AMA Marker: Anti-mitochondrial antibodies (specifically against the M2 subunit) are highly sensitive and specific for PBC, being present in about 95% of patients.

Differential - Autoimmune Hepatitis: This condition is associated with Anti-Nuclear Antibody (ANA) and Anti-Smooth Muscle Antibody (ASMA), but NOT typically AMA.

Differential - PSC: Primary Sclerosing Cholangitis is associated with p-ANCA (anti-neutrophil cytoplasmic antibody) and is strongly linked to Ulcerative Colitis. Imaging (MRCP) showing a "beaded" appearance is diagnostic.

Differential - SLE: Lupus is associated with ANA, anti-dsDNA, and anti-Smith antibodies.

Clinical Presentation of PBC: Often seen in middle-aged women presenting with fatigue and pruritus (itching).

Step 3: Final Answer:
AMA is the hallmark diagnostic antibody for Primary Biliary Cholangitis (PBC).