Childhood bullous pemphigoid: Report of a case with characterization of the targeted antigens

The clinical and immunopathologic features of children with acquired subepi dermal blistering disorders show considerable overlap, and their classifica tion frequently requires characterization of the targeted antigens. A 8-mon th-old boy developed a generalized subepidermal blistering disorder with st riking palmoplantar involvement. The patient's serum contained antibodies r eacting against the epidermal side of 1 M sodium chloride separated normal human skin; Immunoblotting analysis demonstrated circulating IgG autoantibo dies that reacted against a eukaryotic recombinant form of human bullous pe mphigoid antigen 180 (BP180). In addition, the patient had circulating IgG autoantibodies that bound a protein of 120 kDa in skin basement membrane zo ne extracts, that might correspond to the linear IgA bullous disease (LABD) antigen. This study illustrates that a child with clinical and immunopatho logic features considered characteristic of childhood bullous pemphigoid (B P) had circulating IgG antibodies that bound to an eukaryotic recombinant f orm of human BP180, and hence, fulfilled the diagnostic criteria of BP. Rev iew of the literature disclosed only 10 cases of childhood BP, that were ch aracterized on the basis of the targeted antigens. The concomitant-presence of circulating IgG autoantibodies against BP180 and a 120 kDa protein may signify either coexistence of autoantibodies with distinct specificities or reflect antigenic cross-reaclivity between BP180 and the 120/97 LABD antig en.