Associations between allergic diseases and autoimmune thyroid diseases: A meta-analysis of Mendelian randomization...

Both allergic and autoimmune thyroid disorders (AITD) exhibit a high prevalence and a low cure rate, but their relationship remained debated. Therefore, bidirectional Mendelian randomization (MR) method and cross-phenotype association analysis (CPASSOC) were used to investigate the correlation between 2 diseases. Genome-wide association studies (GWAS) data was used as genetic instruments, followed by performing linkage disequilibrium score regression (LDSC) analysis. We have utilized the bidirectional MR method to examine the mutual association between allergic asthma (AA), allergic rhinitis (AR), urticaria, and Graves' disease (GD), autoimmune thyroiditis (AIT). In addition, the false discovery rate (FDR) was carried out to control the false positive results. After synthesizing all the results, correlation was found between allergic diseases and GD, with colocalization analysis performed to clarify the genetic relationship. In the LDSC test, none of the results were confounded by the shared genetic component (rg_P > .05). Primary MR analysis indicated the link between GD and allergic diseases, AA and AIT, AR and AIT. After FDR correction, meta-analysis further confirmed significant risk association between GD and AA (OR = 1.007, 95% CI = [1.003, 1.011], PFDR < .001), GD and AR (OR = 1.010, 95% CI = [1.004, 1.015], PFDR = .001), GD and urticaria (OR = 1.044, 95% CI = [1.015, 1.073], PFDR = .002). Finally, there were no shared genetic variant loci among 3 sets of diseases by the colocalization analysis (all of the pp.H4.abf < .75). GD is a risk factor for allergic diseases. AA and AR can increase the morbidity of AIT without sharing genetic loci.