Desmoglein 1 and 3 enzyme-linked immunosorbent assay in Iranian patients with pemphigus vulgaris: correlation with phenotype, severity, and disease activity.

BACKGROUND: Pemphigus vulgaris (PV) is a chronic autoimmune blistering disorder of the skin and mucosa characterized by the presence of autoantibodies against desmoglein3 (Dsg3). Some patients also have antibodies against desmoglein1 (Dsg1). The aims of this study were to evaluate the diagnostic value of Dsg enzyme-linked immunosorbent assay (ELISA) in Iranian PV patients, to assess its correlation with the clinical phenotype and severity of disease and to investigate the changes of these antibodies after treatment.

METHODS: Seventy-three patients with PV (29 men, 44 women) presenting to the Pemphigus Research Unit at Razi Hospital, Tehran, Iran were enrolled. ELISAs were used to detect IgG autoantibodies reactive with the ectodomains of Dsg1 and Dsg3, and the correlation of antibodies with the clinical phenotype as well as oral and skin disease severity was assessed. In addition, the tests were repeated in 18 patients after treatment and the resulting remission.

RESULTS: Anti-Dsg1 and anti-Dsg3 were detected in 56 (76.7%) and 69 (94.5%) patients, respectively. Anti-Dsg1 and anti-Dsg3 antibodies were present in 48 (94.1%) and 50 (98%) patients with mucocutaneous type, in 2 (12.5%) and 15 (93.7%) patients with mucosal type, and in 6 (100%) and 4 (66.7%) patients with cutaneous PV, respectively. The mean anti-Dsg1 index values were significantly higher in cutaneous and mucocutaneous phenotypes than mucosal PV (P < 0.001). The mean anti-Dsg3 index values were significantly lower in cutaneous and mucosal phenotypes than mucocutaneous PV (P < 0.01). The severity of skin lesions (but not oral lesions) was correlated with anti-Dsg1 antibody level (P < 0.001); on the other hand, the severity of oral lesions (P < 0.01) as well as skin lesions (P < 0.001) was significantly correlated with anti-Dsg3 antibody levels. Both anti-Dsg1 and anti-Dsg3 levels were significantly reduced after treatment and clinical remission (P < 0.001).

CONCLUSION: Dsg ELISA is not only a sensitive tool for the diagnosis of PV, it can also serve as a predictive means for assessing the severity as well as for monitoring the disease activity. Although, in general, the clinical phenotype is related to the antibody profile, there are occasional cases with discordant phenotype and antibody profile. These discrepancies might be explained by genetic variations or the presence of possible minor antigens involved in the pathogenesis of pemphigus.