Usefulness of specific anti-desmoglein 1 and 3 enzyme-linked immunoassay and indirect immunofluorescence in the evaluation of pemphigus activity

Objective The objective was to assess the relationship between enzyme-linked immunoassay (ELISA) values of desmoglein (Dsg) 1 and Dsg3 antibodies and indirect immunofluorescence (IIF) values of anti-epithelial antibodies with disease activity in patients with pemphigus. Patients and methods In a retrospective study, we analyzed 353 serum samples taken from 35 patients with pemphigus vulgaris (PV) and nine with pemphigus foliaceus (PF) during the course of the disease. In each sample, we measured anti-Dsg1 and anti-Dsg3 antibodies by ELISA. A receiver operating characteristics (ROC) curve was calculated to determine a cutoff value for anti-Dsg1 and anti-Dsg3 antibodies with optimal sensitivity and specificity. In 263 samples, we compared the ROC curves of anti-Dsg1 and anti-Dsg3 antibodies with the ROC curves of the IIF results. Results Activity of pemphigus was associated with a wide range of anti-Dsg1 and anti-Dsg3 antibody values. Levels of anti-Dsg1 antibodies showed a better relationship with cutaneous activity of pemphigus than levels of IIF anti-epithelial antibodies. The levels of IIF anti-epithelial antibodies showed a relationship with activity of mucosas similar to the levels of anti-Dsg3 antibodies. Discussion Abnormal values of anti-Dsg antibodies are not always associated with disease activity. ELISA detects both pathogenic and nonpathogenic anti-Dsg antibodies. Conclusions Therapeutic strategies should not be based exclusively on anti-Dsg antibody values. Anti-Dsg1 antibodies showed a closer relationship with skin activity than IIF, while anti-Dsg3 antibodies showed a relationship with mucosal activity similar to the IIF test.