Atypical pemphigus associated with monoclonal IgA gammopathy.

Abstract

We describe a 60-year-old woman with atypical pemphigus and IgA-lambda monoclonal gammopathy. Histopathologic study of vesiculopustular lesions showed intraepidermal acantholytic and neutrophilic blisters. Direct immunofluorescence revealed intercellular IgG deposition with concurrent deposits of IgA and C3. Indirect immunofluorescence and immunoblotting studies revealed that the patient had circulating IgG anti-intercellular antibodies that recognized the 150 kd desmoglein (pemphigus foliaceus antigen) in bovine desmosome preparation. Immunoblot studies with human epidermal extract showed that the IgG of this patient exclusively reacted with the 140 kd protein (between the 150 kd human desmoglein and the 130 kd human pemphigus vulgaris antigen), the nature of which is currently unknown. The patient also had IgA anti-intercellular autoantibodies, which reacted with the desmoglein in the bovine desmosome sample but did not show any reactivity in human epidermal extract.