Bullous pemphigoid of childhood - Autoantibodies target the same epitopes within the NC16A domain of BP180 as autoantibodies in bullous pemphigoid ofadulthood

Background: Bullous pemphigoid (BP) is an autoimmune subepidermal blisterin g disease of the elderly that rarely occurs in children. Most adult BP seru m samples react with epitopes within the NC16A domain of BP180, a glycoprot ein or the cutaneous basement. Objectives: To characterize the autoimmune response in childhood BP using r ecombinant forms of BP180 and to determine the subclass distribution of aut oantibodies and their correlation with disease activity. Observations: Serum samples from 2 infants with BP, aged 4 and 5 months, re acted by immunoblot analysis with 4 epitopes clustered within the N-termina l 45 amino acids of the NC16A domain. The same 4 epitopes have previously b een shown to be the target in adult BP. Childhood BP antibodies to BP180 NC 16A belonged to IgG1, IgG2, IgG3, and IgG4 immunoglobulin subclasses. IgE r eactivity was not detected. Serum levels of antibodies targeting BP180 NC16 A paralleled disease activity as detected by enzyme-linked immunosorbent as say. Conclusions: The fine specificity of autoantibodies to BP180 is the same in BP of childhood and adulthood. Childhood BP is a true variant of BP.