AUTOANTIBODY FORMATION AGAINST A 190-KDA ANTIGEN OF THE DESMOSOMAL PLAQUE IN PEMPHIGUS FOLIACEUS

We report changes in the antigen recognition pattern of sera from two pemphigus foliaceus patients with a long-term follow-up, The patients' sera were analysed by immunoblotting using different antigenic source s: cultured human keratinocytes, bovine tongue epithelium and a recomb inant protein corresponding to the C-terminal end of the 230-kDa bullo us pemphigoid antigen, While initial serum samples reacted exclusively with the 160-kDa desmoglein 1, the later sera reacted both with desmo glein 1 and a 190-kDa antigen immunolocalized to the desmosomal plaque , previously demonstrated to be recognized by sera of some patients wi th paraneoplastic pemphigus. IgG subclass analysis further showed that antidesmoglein 1 antibodies were of IgGl and/or IgG4 subclasses, whil e anti-190-kDa antibodies were IgG3. The patients were free of maligna ncy.