Association of Atopic Dermatitis With Autoimmune Diseases: A Bidirectional and Multivariable Two-Sample Mendelian Randomization Study

This study used bidirectional and multivariable two-sample Mendelian randomization to explore the causal relationship between atopic dermatitis (AD) and autoimmune diseases, analyzing data from genome-wide association studies involving hundreds of thousands of individuals of European ancestry. The results showed that genetically predicted AD significantly increases the risk of rheumatoid arthritis (RA) and alopecia areata (AA), with odds ratios of 1.28 and 1.98, respectively. Multivariable analyses also suggested a causal link between AD and type 1 diabetes (T1D), but no significant effects were found for systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), and vitiligo. The study underscores the potential shared genetic and immunological pathways between AD and certain autoimmune diseases.