A 55-year-old woman develops recurrent blistering of oral mucosa and skin. Biopsy shows intraepidermal acantholysis with tombstoning of basal cells. Direct immunofluorescence demonstrates IgG in an intercellular 'fish-net' or 'chicken-wire' pattern. The autoantigen targeted is:

• A Desmoglein-1 (DSG1) of desmosomes
• B Type XVII collagen (BP180) of hemidesmosomes
• C Desmoglein-3 (DSG3) and/or DSG1 of desmosomes ✓
• D Laminin-332 of the lamina densa

Explanation

Pemphigus vulgaris is a type II hypersensitivity-mediated autoimmune blistering disorder in which IgG antibodies target desmoglein-3 (expressed in oral mucosa and basal/suprabasal epidermis) and, in the mucocutaneous form, also DSG1 (expressed in superficial epidermis). Loss of desmosomal adhesion causes suprabasal acantholysis and the characteristic tombstone basal cell layer on biopsy. BP180/type XVII collagen is targeted in bullous pemphigoid (subepidermal). Laminin-332 is the antigen in mucous membrane pemphigoid.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.