Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by granulomatous destruction of interlobular bile ducts. The diagnostic autoantibody is:

• A Anti-smooth muscle antibody (ASMA)
• B Anti-liver kidney microsomal (anti-LKM1) antibody
• C Anti-nuclear antibody (ANA) with 'rim' pattern
• D Anti-mitochondrial antibody (AMA) against the E2 subunit of pyruvate dehydrogenase ✓

Explanation

Primary biliary cholangitis (formerly primary biliary cirrhosis) is diagnosed by antimitochondrial antibodies (AMA) present in 95% of patients, specifically targeting the E2 subunit of the pyruvate dehydrogenase complex (PDC-E2) on the inner mitochondrial membrane. AMA titer >1:40 with compatible clinical features is virtually diagnostic. ASMA and ANA are markers of autoimmune hepatitis. Anti-LKM1 antibodies are found in type 2 autoimmune hepatitis.

Reference: Robbins & Cotran Pathologic Basis of Disease, 10th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.