Allergic Diseases and Chronic Adenotonsillar Diseases: A Mendelian Randomization Study.

OBJECTIVE:The existing epidemiological evidence regarding the intricate relationship between allergic diseases and chronic adenotonsillar diseases (CATD) remains inconclusive. Herein, the objective of our study is to explore the causal association using Mendelian randomization (MR). METHODS:Employing data from large genome-wide association studies, a comprehensive two-sample bidirectional MR study was conducted. The studied traits encompassed allergic rhinitis (cases n = 9707, controls n = 331173), allergic asthma (cases n = 8525, controls n = 193857), allergic conjunctivitis (cases n = 18321, controls n = 324178), atopic dermatitis (cases n = 11964, controls n = 306909), and CATD (cases n = 38983, controls n = 258553). All the patients were of European descent and participants in cohort studies. The primary analysis was executed using inverse-variance-weighted MR. Furthermore, six additional MR methods (MR-Egger, weighted median, simple mode, weighted mode, MR pleiotropy residual sum and outlier, MR robust adjusted profile score) were employed to ensure the reliability and detect potential horizontal pleiotropy within the results. The estimates obtained from the MR analysis were factored into the overall effect calculation. RESULTS:Genetically anticipated outcomes demonstrated a significant association between CATD risk and allergic rhinitis (OR = 1.141, p = 6.30E-06), allergic asthma (OR = 1.115, p = 8.31E-05), allergic conjunctivitis (OR = 1.197, p = 8.69E-07), and a suggestive association with atopic dermatitis (OR = 1.053, p = 0.040). However, no substantial correlation was observed in the reverse direction. CONCLUSIONS:Findings of our study provide evidence supporting a causal role of allergic diseases in the development of CATD, whereas the converse relationship does not appear to hold true. LEVEL OF EVIDENCE:3 Laryngoscope, 134:2653-2658, 2024.