Associations between HLA-A, -B, and -C alleles and iodinated contrast media-induced hypersensitivity in Koreans

A common cause of drug hypersensitivity reactions is iodinated contrast media (ICM). ICM-induced hypersensitivity had been considered to be a non-immunological reaction, but evidence for an immunological mechanism has increased recently. Thus, we evaluated whether HLA-A, -B, and -C alleles were associated with ICM-induced hypersensitivity. In total, 126 patients who underwent contrast-enhanced computed tomography studies through outpatient clinics at a tertiary referral hospital between 2008 and 2012 were assessed. Sixty-one patients experienced ICM-induced hypersensitivity and the remainder, 65, were ICM-tolerant patients (control). ICM-induced hypersensitivity patients showed 51 with immediate, 7 with non-immediate, 3 with both or mixed type. HLA-A, -B, and -C genotyping was performed using a PCR sequence-based typing method. Four kinds of ICM were used: iopromide, iohexol, iobitridol, and iodixanol. The most used ICM among the hypersensitivity patients was iopromide. Significant difference in the frequency of HLA-B* 58: 01 (odds ratios [OR], 3.90; p = 0.0200, 95% confidence interval [CI], 1.16-13.07) was observed between ICM-induced immediate hypersensitivity and control. There were statistically significant differences in the frequencies of the HLA-B*38:02 (OR, 10.24; p = 0.0145; 95% CI, 1.09-96.14) and HLA- B*58:01 (OR, 3.98; p = 0.0348; 95% CI, 1.03-15.39) between iopromide-induced immediate hypersensitivity and control. The mechanism of ICM-induced hypersensitivity remains unknown, but this study showed associations, although weak, with HLA- B*58:01 alleles for ICM-induced immediate hypersensitivity and HLA-B*38:02 and HLA-B*58:01 for iopromide-induced immediate hypersensitivity as risk predictors. Further studies are needed to validate the associations in larger samples and to identify the functional mechanism behind these results.