Novel feline autoimmune blistering disease resembling bullous pemphigoid in humans: IgG autoantibodies target the NC16A ectodomain of type XVII collagen (BP180/BPAG2)

In humans and dogs, bullous pemphigoid (BP) is an autoimmune blistering dis ease associated with the production of basement membrane autoantibodies tha t target the 180-kd type XVII collagen (BP180, BPAG2) and/or the 230-kd pla kin epidermal isoform BPAGle (BP230). In two adult cats, an acquired dermat osis and stomatitis was diagnosed as BP subsequent to the fulfillment of th e following criteria: 1) presence of cutaneous vesicles, erosions, and ulce rs; 2) histologic demonstration of subepidermal vesiculation with in-flamma tory cells, including eosinophils; 3) in vivo deposition of IgG autoantibod ies at the epidermal basement membrane zone; and 4) serum IgG autoantibodie s targeting a 180-kd epidermal protein identified as type XVII collagen. In both cats, the antigenic epitopes targeted by Ige autoantibodies were show n to be situated in the NC16A ectodomain of type XVII collagen, a situation similar to that of humans and dogs with BP. Feline BP therefore can be con sidered a clinical, histopathologic, and immunologic homologue of BP in hum ans and dogs.