Abstract:
Objective To explore the causal association between immune cells and allergic rhinitis using Mendelian randomization (MR) approach.
Methods GWAS data for 731 types of immune cells and allergic rhinitis were obtained from genome-wide association study (GWAS) databases. A two-sample bidirectional MR analysis was conducted, with the inverse-variance weighted (IVW) method as the primary analytical approach, and the weighted median method, MR-Egger regression, simple mode method, and weighted mode method as supplementary approaches. Sensitivity analyses, including heterogeneity tests, pleiotropy tests, and the leave-one-out method, were performed. Bonferroni correction was applied to the preliminary results to enhance their reliability and rigor.
Results The two-sample forward MR analysis revealed correlations between 67 immune cell phenotypes and allergic rhinitis. After Bonferroni correction, four immune cell phenotypes were finally identified. Among them, the expression of CD3 on CD39-positive activated CD4 regulatory T cells (OR=0.953, 95%CI, 0.931 to 0.978, P < 0.001, Padj=0.007), the expression of herpesvirus entry mediator (HVEM) on CD45RA-negative CD4+ T cells (OR=0.965, 95%CI, 0.948 to 0.983, P < 0.001, Padj=0.008), and the percentage of human leukocyte antigen class DR (HLA-DR)-high-expressing monocytes among leukocytes (OR=0.929, 95%CI, 0.885 to 0.974, P=0.002, Padj=0.157) were protective factors for allergic rhinitis. In contrast, the percentage of transitional B cells among B cells (OR=1.094, 95%CI, 1.032 to 1.161, P=0.003, Padj=0.183) was a risk factor for allergic rhinitis. The reverse MR analysis showed no causal relationship between allergic rhinitis and the four immune cell phenotypes.
Conclusion The two-sample forward MR analysis confirms a causal link between immune cells and allergic rhinitis. MR analysis has the advantages of reducing confounding factor interference and avoiding reverse causation, providing a theoretical basis for in-depth research on immune mechanisms, sensitive biomarkers, and drug treatment targets of allergic rhinitis.