The relationship between pemphigus and systemic lupus erythematosus: a cross-sectional study, systematic review, and meta-analysis.

The coexistence of pemphigus and systemic lupus erythematosus (SLE) had been reported anecdotally. Anti-desmoglein (Dsg)1 and anti-Dsg3 antibodies were detected concomitantly with antinuclear autoantibodies among blood donors. The aim of the current study was to study the association between pemphigus and SLE in Israeli patients and to synthesize existing data on this association in the current literature. The current study included two sections. Initially, a cross-sectional study was performed to compare pemphigus patients with age-, sex-, and ethnicity-matched control subjects regarding the prevalence of SLE using a real-life large-scale computerized database. Next, a systematic review and meta-analysis of similar observational studies in Medline, Embase, and Web of Science (1823-2017) was conducted. As for the cross-sectional study, a total of 1985 patients with pemphigus and 9874 controls were included in the study. The prevalence of SLE was slightly higher among patients with pemphigus as compared to controls (OR, 1.85; 95% CI, 0.89-3.82). In a sensitivity analysis that included patients who received pemphigus-related treatments, the association between pemphigus and SLE had been substantiated and was statistically significant (OR, 2.10; 95% CI, 1.00-4.48). In the meta-analysis section, three eligible studies, comprising 10,389 pemphigus patients met the eligibility criteria. The overall pooled multivariate OR was 2.50 (95% CI 1.54-4.07, I2  = 44.19%, P = 0.167) across all studies. In conclusion, the meta-analysis provides epidemiologic evidence that these B cell-driven diseases are significantly associated. Further research is required to elucidate the molecular mechanism underlying this association.