Systemic lupus erythematosus and Atopic dermatitis: A two sample Mendelian randomization study

Background Systemic lupus erythematosus (SLE) and atopic dermatitis (AD) are common diseases in human populations. Previous studies have suggested a potential association between SLE and AD. However, the causal relationship and direction between the two conditions remain unclear. Objective The aim of this study is to evaluate the causal relationship between SLE and AD. Methods In this study, we employed Mendelian randomization (MR) analysis to investigate the causal relationship between SLE and AD. MR analysis has the advantage of reducing confounding factors, determining the direction of causality, and providing quantitative effect estimates. We obtained summary data from genome-wide association studies (GWAS) on SLE and AD from publicly available databases. Five MR methods, namely MR Egger, weighted median, inverse variance weighted, simple mode, and weighted mode, were used to assess the causal relationship between SLE and AD. Several techniques, including MR-Egger intercept, MR-PRESSO, and Cochran’s Q test, were utilized to evaluate heterogeneity and pleiotropy. Results Our study demonstrated a causal relationship between the prevalence of SLE and an increased risk of AD (MR Egger OR: 1.567, 95% CI: [1.041, 1.285], P = 0.009; IVW OR: 1.085, 95% CI: [1.005, 1.143], P = 0.035). Furthermore, sensitivity analyses did not detect heterogeneity or pleiotropy. Conclusion Our research finds that SLE is a contributing factor to the development of AD, providing valuable insights into the pathogenesis and prevention of both diseases. Key Points • Currently, there is no research that clearly indicates a causal relationship between SLE and AD. This study, for the first time, identified a positive causal relationship between SLE and AD. • The results of this study contribute to our understanding of the pathogenesis and treatment strategies for SLE and AD, providing some guidance for future clinical practice.