An 18-year-old girl presents with jaundice and fatigue. ALT is 520 U/L, IgG is elevated, and immunoglobulin A level is normal. Antinuclear antibody and anti-smooth muscle antibody are negative. Anti-liver kidney microsomal type 1 antibody is positive at high titre. Which subtype of autoimmune hepatitis does she have?

• A Drug-induced autoimmune-like hepatitis
• B Type 1 autoimmune hepatitis
• C Overlap syndrome with primary biliary cholangitis
• D Type 2 autoimmune hepatitis ✓

Explanation

Type 2 autoimmune hepatitis is defined by anti-LKM1 antibodies directed against CYP2A6, occurs predominantly in girls and young women, and characteristically lacks the antinuclear and smooth muscle antibodies that define type 1 disease. Patients may have associated vitiligo or other organ-specific autoimmunity. An overlap with primary biliary cholangitis would require cholestatic biochemistry and antimitochondrial antibody, neither of which is present here.

Reference: Sherlock's Diseases of the Liver and Biliary System, 13th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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