Abstract: 【Abstract】 Objective To investigate the correlation of related antibody titers in serum of patients with pemphigus vulgaris （PV） with disease severity and activity. Methods A total of 24 patients with active PV were collected, who firstly visited Hospital for Skin Diseases, Chinese Academy of Medical Sciences from 2012 to 2015. Pemphigus disease area index （PDAI） was evaluated in the patients with PV at active and stable stages, and serum samples were collected. Enzyme-linked immunosorbent assay （ELISA） was conducted to determine titers of pathogenic anti-desmoglein （Dsg） conformational epitope antibodies, total anti-Dsg antibodies and anti-acetylcholine receptor （AChR） antibody in serum samples. Measurement data were compared by using t test, enumeration data were compared by using Fisher′s exact test, and correlations were analyzed by using Pearson correlation analysis. Results Among the patients with active PV, there was no significant difference between the anti-Dsg1 antibody titers （611.4 ± 136.8） and anti-Dsg1 conformational epitope antibody titers （585.5 ± 134.7, t = 0.13, P = 0.89）, but the anti-Dsg3 antibody titers （708.6 ± 130.7） were significantly higher than the anti-Dsg3 conformational epitope antibody titers （297.2 ± 54.4, t = 2.90, P < 0.01）. In addition, both the anti-Dsg1 antibody titers and anti-Dsg1 conformational epitope antibody titers were positively correlated with PDAI scores in the patients with active PV （both r = 0.54, P < 0.01）; PDAI scores were not correlated with the anti-Dsg3 antibody titers （r = 0.11, P = 0.62）, but positively correlated with the anti-Dsg3 conformational epitope antibody titers （r = 0.53, P < 0.01）. Among the 20 patients with stable PV, the serum titers of anti-Dsg1 antibodies and anti-Dsg1 conformational epitope antibodies significantly decreased compared with those at their first visit; anti-Dsg3 antibody titers significantly decreased in only 7 patients, and 13 patients still had high titers of anti-Dsg3 antibodies, including 6 with declined anti-Dsg3 conformational epitope antibody titers, and 5 converted from anti-AChR antibody-positive to anti-AChR antibody-negative. Conclusions Both the anti-Dsg1 antibody and anti-Dsg1 conformational epitope antibody titers can reflect the disease activity of PV. The disease activity was not consistent with anti-Dsg3 antibody titers in some patients, and the anti-Dsg3 conformational epitope antibody or anti-AChR antibody may facilitate evaluating the disease activity of PV.

Key words: Pemphigus, Desmoglein 1, Desmoglein 3, Receptors, cholinergic, Pemphigus disease area index