Genome-wide association study of hypersensitivity skin reactions induced by nonionic iodinated contrast media.

Background: In Taiwan, nonionic iodinated contrast media (ICMs) are commonly used but can occasionally cause severe side effects. The infrequency of these adverse events, coupled with the complexities in establishing direct causality, poses significant challenges for genetic research.

Objective: : To investigate the genetic factors associated with skin reactions mediated by nonionic ICMs on a genome-wide scale.

Methods: A hospital-based cohort from the China Medical University Hospital biobank was utilized to conduct a comprehensive genome-wide association study (GWAS) using PLINK v1.9. The study incorporated two distinct cohorts: one based on adverse drug reaction (ADR) reports, capturing immediate reactions, and the other based on self-reports, which primarily reflected delayed reactions. Known loci were determined by the GWAS catalog. Fine mapping was conducted by FINEMAP to predict causal variants. Pathway enrichment analysis was performed by clusterProfiler to reveal the biological function of the identified genetic signatures.

Results: The ADR-based cohort included 120 cases and 3640 controls. GWAS identified 6 candidate risk loci, namely rs150515068, rs6847491, rs192044153, rs191908641, rs376660317, and rs368821335. The self-report-based cohort, consisting of 275 cases and 8338 controls, revealed 36 additional candidate risk loci. Fine mapping further identified 4 causal variants within each cohort. Pathway analysis showed that immediate HSR-related genes are linked to growth hormone response and signaling, while non-immediate HSR genes are involved in neurotransmission.

Conclusion: This study offers new perspectives on the genetic foundation of nonionic ICM-induced skin reactions within the Taiwanese population, suggesting that the genes contributing to immediate and non-immediate HSRs might have different functional roles.