Correlation of pemphigus disease area index and anti-desmoglein antibody index in pemphigus vulgaris patients

Background Pemphigus is a group of potentially lethal autoimmune blistering diseases. Pemphigus is classified mainly into pemphigus vulgaris (PV) and pemphigus foliaceous (PF). Furthermore, PV is sub classified into mucosal, mucocutaneous and cutaneous. The target antigens are desmogleins (Dsgs) which are cadherins responsible for cell-cell adhesion. PV target Dsg3 + / – Dsg1 while PF target Dsg1. Pemphigus disease area index (PDAI) is a scoring system developed by the international pemphigus committee for standardizing the description of the disease severity aiming to critically evaluate clinical trials among different centers. Objective To determine the usefulness of PDAI and the Dsg ELISA in the follow up of Egyptian PV patients. Patients and methods Twenty PV patients were included in this study. The disease activity was evaluated by PDAI. The Dsg indices were measured by the Dsg3 and Dsg1 ELISA every 1-2 months for 6 months. Results Fifteen patients were females and 5 were males. Three patients were mucosal and 17 were mucocutaneous. As expected all of the tested PV sera possess autoantibodies targeting the Dsg3. Moreover, mucocutaneous PV patients possess autoantibodies targeting the Dsg1. Upon controlling PV, the PDAI decreased sharply followed by the anti-Dsg1 antibodies in the mcPV. The anti-Dsg3 antibodies in mPV and mcPV decreased gradually. Two patients relapsed during the treatment and their anti-Dsg3 antibodies increased before the PDAI. Conclusion In active PV patients, PDAI is valuable in evaluating the disease and in following up the treatment efficacy. However after PDAI reaches 0, the Dsg3 index is valuable for tapering the systemic steroids and detecting early relapse.