Causal relationships between allergic and autoimmune diseases with chronic rhinosinusitis

Chronic rhinosinusitis (CRS) is a prevalent inflammatory airway disease affecting over 10% of the global population, leading to considerable socio-economic impacts, especially in developing countries. The pathogenesis of CRS is multifactorial, involving potential contributions from both genetic and environmental factors. While the influence of allergic and autoimmune diseases on CRS has been observed, the causal relationships between these diseases and CRS remain unclear. We extracted data from large-scale genome-wide association studies (GWAS) and utilized a bidirectional two-sample Mendelian randomization (MR) analysis to explore the causal relationships between CRS and ten autoimmune and allergic diseases, including asthma, allergic rhinitis (AR), atopic dermatitis (AD), psoriasis, type 1 diabetes (T1D), hypothyroidism, celiac disease (CeD), multiple sclerosis (MS), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE). Additionally, we conducted colocalization analysis to determine whether the allergic/autoimmune diseases showing statistical causal relationships with CRS are driven by the same genetic variants. The MR analysis identified that AR (OR = 1.30; 95% CI = 1.21-1.40; P = 3.26E-13), asthma (OR = 1.35; 95% CI = 1.25-1.45; P = 1.35E-14), and AD (OR = 1.17; 95% CI = 1.06-1.30; P = 0.003) were significantly associated with an increased risk of developing CRS. Interestingly, psoriasis (OR = 0.05; 95% CI = 0.01-0.37; P = 0.004) appeared to have a protective effect against CRS. Associations for T1D and hypothyroidism were also suggestive as potential risk factors for CRS. No significant associations in the reverse MR analysis, suggesting a one-directional relationship. Colocalization analysis indicated that asthma (PP.H4 = 0.99) shared the same genetic variant (IL-33 rs3939286) with CRS. In conclusion, our study confirmed the causal relationships between allergic and autoimmune diseases (AR, asthma, AD, and psoriasis) and CRS. Notably, we identified a shared genetic variant, rs3939286 in the IL-33 gene, between asthma and CRS, suggesting that targeting the IL-33 pathway may provide a therapeutic strategy for both diseases.