Antibody immune responses and causal relationships in four immune skin diseases: Evidence from Mendelian randomization and Bayesian Weighting (Antibody Responses in Skin Diseases: MR & Bayesian)

Abstract Background Recent studies increasingly suggest that microbial infections and the immune responses they elicit play significant roles in the pathogenesis of chronic inflammatory skin diseases. This study uses Mendelian randomization (MR) and Bayesian weighted Mendelian randomization (BWMR) to explore the causal relationships between immune antibody responses and four common skin diseases: psoriasis, atopic dermatitis (AD), rosacea, and vitiligo. Methods We utilized summary statistics from genome‐wide association studies (GWAS) for antibody responses to 13 infectious pathogens and four skin diseases. Single nucleotide polymorphisms (SNPs) were selected as instrumental variables (IVs) to assess causal relationships using multiple MR methods, including inverse variance weighted (IVW), MR Egger, and weighted median. BWMR was also employed to confirm findings and address potential pleiotropy. Results The IVW analysis identified significant associations between specific antibody responses and the skin diseases studied. Key findings include protective associations of anti‐Epstein–Barr virus (EBV) IgG seropositivity and Helicobacter pylori UREA antibody levels with psoriasis and AD. anti‐chlamydia trachomatis IgG seropositivity, anti‐polyomavirus 2 IgG seropositivity, and varicella zoster virus glycoprotein E and I antibody levels were negatively associated with rosacea, while EBV Elevated levels of the early antigen (EA‐D) antibody levels and HHV‐6 IE1B antibody levels were positively associated with rosacea. H. pylori Catalase antibody levels were protectively associated with vitiligo, whereas anti‐herpes simplex virus 2 (HSV‐2) IgG seropositivity was positively associated with vitiligo. The BWMR analysis confirmed these associations. Conclusion This study underscores the significant role of H. pylori and other pathogens in these skin diseases, suggesting both protective and exacerbating effects depending on the specific condition. Understanding these pathogen‐immune interactions can lead to the development of more effective, personalized treatments and preventative strategies, ultimately improving patient outcomes and quality of life.