Periplakin and envoplakin are target antigens in canine and human paraneoplastic pemphigus

Background: On the basis of clinical and histopathologic similarities to hu man paraneoplastic pemphigus (PNP), we recently identified the first case o f PNP in a nonhuman species, the dog. Objective: To determine a similar pathogenesis in both species, the present study aimed to define whether common antigens are targeted in dog and man. Methods: Canine and human PNP sera were used in parallel-to immunoprecipita te C-14- labeled human keratinocyte antigens. The immunoreactive proteins w ere then identified by immunoprecipitation of canine keratinocyte extracts with specific antibodies to the antiplakin family members follwed by immuno blot analysis using canine and human PNP sera. Results: Protein bands of 210, 190, 170, and 130 kd were identified in dogs and humans. In both species, envoplakin and periplakin were demonstrated a s antigens. Antidesmoglein 3 antibodies could not be demonstrated in canine PNP, but in human PNP. Conclusion: These results demonstrate that canine PNP closely correlates to the human counterpart and may therefore represent an excellent model for t he human disease.