Two patients with unusual skin lesions and circulating antikeratinocyte cell surface antibodies: detection of antibodies to the intracellular domain of the pemphigus foliaceus antigen (desmoglein) by studies using fusion proteins.

Abstract

We report two patients with unusual skin lesions, who had antikeratinocyte cell surface IgG autoantibodies in their sera. Immunoblot analysis of both a human epidermal extract and a bovine desmosome preparation revealed that the sera of both patients reacted exclusively with the 160-kDa pemphigus foliaceus antigen (desmoglein). We further investigated the antigen molecule using bacterial fusion proteins produced by using bovine desmoglein cDNA, and found that both the sera reacted strongly and exclusively with the intracellular domain of the desmoglein. These results suggest that production of antidesmoglein autoantibodies in the present cases may be an epiphenomenon associated with damage to the keratinocyte cell membrane.