Histopathology of anti-laminin 5 mucous membrane pemphigoid

Background: Anti-laminin 5 MUCOUS membrane pemphigoid (MMP) is an autoimmune blistering disease characterizecl by autoantibodies against the major basement membrane component laminin 5 (laminin 332, epiligrin). Objective and Methods:We reviewed 17 biopsy specimens from 9 Patients with anti-laminin 5 MMP in an attempt to define typical histopathologic features of the disease. Results: Fifteen specimens showed subepidermal blister formation, while two biopsy specimens revealed an epithelial ulcer. In 11 biopsies a sparse to moderate inflammatory infiltrate composed of lymphocytes and neutrophils with some eosinophils was observed. Four biopsies showed a dense infiltrate dominated by neutrophils in two cases and by eosinophils in one case. The remaining biopsy revealed a dense lymphoplasmacellular infiltrate without granulocytes. Scarring of the upper dermis was present only in 5 specimens. Immunohistochemical analysis localized type IV collagen to the dermal side of the blister, suggesting that split formation occurred within the lamina lucida of the cutaneous basement membrane. Limitations: The number of patients studied was relatively small. Conclusion: Histopathology of anti-laminin 5 MMP is characterized by subepidermal blistering and a sparse to moderate superficial lymphohistiocytic infiltrate with neutrophils and/or eosinophils. Both infiltrate density and composition may vary, making, anti-laminin 5 MMP indistinguishable from other autoimmune subepidermal blistering diseases by histopathology alone. Scarring is present only in a minority of cases and is not a sensitive due to the diagnosis of anti-laminin 5 MMP. (J Am Acad Dermatol 2009;61:433-40.)