Autoantibodies to human alpha6 integrin in patients with bullous pemphigoid

Bullous pemphigoid (BP) is characterized immunologically by tissue-bound and circulating autoantibodies targeting the hemidesmosomal proteins BP230 and BP180. Recent evidence suggests a pathophysiological role for autoantibodies against alpha6 integrin in the subepidermal blister formation of oral pemphigoid. The objective of our study was to investigate the presence of anti-alpha6 integrin antibodies in patients with classical BP. The autoantibody profiles of 30 patients with BP, 10 patients with pemphigus vulgaris, and 20 healthy persons were identified. With the use of PeptideStructure and PlotStructure software, four different antigenic epitopes for alpha6 integrin were predicted, and their fusion recombinant constructs were prepared in an E. coli expression system. Sera were tested for alpha6 integrin autoantibodies by an ELISA technique. Altogether, 52% of the patients with BP displayed circulating antibodies against at least one recombinant protein. Our findings provide the first evidence for the presence of anti-alpha6 integrin antibodies in patients with classical BP.