A 55-year-old woman presents with flaccid blisters over the trunk and oral erosions. Direct immunofluorescence shows intercellular IgG deposits in a 'fishnet' pattern throughout the epidermis. The target antigen responsible for this condition has a molecular weight of:

• A Desmoglein-1 (160 kDa)
• B Desmoglein-3 (130 kDa)
• C Desmoglein-3 predominantly and Desmoglein-1 (both) ✓
• D Collagen XVII (BP180) (180 kDa)

Explanation

Pemphigus vulgaris with mucocutaneous involvement targets both Desmoglein-3 (130 kDa, expressed in mucosa and deep epidermis) and Desmoglein-1 (160 kDa, expressed throughout epidermis). Mucosal-dominant pemphigus vulgaris has anti-Dsg3 alone, but mucocutaneous disease requires both anti-Dsg3 and anti-Dsg1 antibodies. BP180 (collagen XVII) is the target in bullous pemphigoid, not pemphigus.

Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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