A 70-year-old man develops tense, fluid-filled blisters over the flexor surfaces of his arms and lower abdomen. The blisters are subepidermal, Nikolsky sign is negative, and direct immunofluorescence shows linear IgG and C3 along the basement membrane zone. The autoantigen targeted in this disease is a component of the:

• A Desmosomal cadherin desmoglein 3
• B Hemidesmosome (BP180/BP230) ✓
• C Keratinocyte cytoplasmic keratin filaments
• D Laminin 332 of the lamina lucida only in mucosal sites

Explanation

Bullous pemphigoid features IgG against BP180 (collagen XVII) and BP230, structural proteins of the hemidesmosome anchoring basal keratinocytes to the basement membrane. Complement activation recruits eosinophils, producing subepidermal tense blisters with a negative Nikolsky sign. Desmoglein 3 is the target in pemphigus vulgaris, which produces flaccid intraepidermal blisters with a positive Nikolsky sign, the key distinction from this patient.

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

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.