Abstract:

Objective To explore the mechanisms underlying the mediating effect of regulatory B （Breg） cells in the pathogenesis of pemphigus. Methods Peripheral blood specimens were collected from 48 patients with pemphigus at different degrees of severity and 20 healthy controls. Flow cytometry was conducted to analyze the frequency of Breg （CD19+CD24hiCD38hi） cells in peripheral CD19+ B cells, enzyme linked immunosorbent assay （ELISA） to determine the titer and subtypes of anti-desmoglein （Dsg） 1 and 3 antibodies in sera from these subjects. The relationship of anti-Dsg 1 and 3 antibodies with the frequency of Breg cells was assessed by Spearman′s rank correlation test. Results Significant differences were observed in the proportion of Breg cells in CD19+ B cells between patients with pemphigus and healthy controls （11.54% ± 0.97% vs. 8.19% ± 0.85%, P = 0.04）, as well as between patients with acute mild pemphigus and those with moderate and severe pemphigus （5.17% ± 2.14% vs. 11.38% ± 5.30% and 11.17% ± 5.31%, P = 0.042, 0.046, respectively）. The frequency of Breg cells was positively correlated with the absorbance value for anti-Dsg1 antibodies of IgG4 subclass and IgG4/IgG1 ratio（r = 0.527, 0.565, respectively, both P < 0.01）. Conclusions Breg cells are mainly associated with the production of antibodies in and disease severity of pemphigus, while the actual mechanism of action remains unknown.

Key words: pemphigus, regulatory B cells, pathogenic antibodies and subclasses