Impact of the HLA-B^⋆58:01 Allele and Renal Impairment on Allopurinol-Induced Cutaneous Adverse Reactions

Allopurinol, a common drug for treating hyperuricemia, is associated with cutaneous adverse drug reactions ranging from mild maculopapular exanthema to life-threatening severe cutaneous adverse reactions, including drug reaction with eosinophilia and systemic symptoms, Stevens-Johnson syndrome, and toxic epidermal necrolysis. We have previously reported that HLA-B⋆58:01 is strongly associated with allopurinol-induced severe cutaneous adverse reactions in Han Chinese, but the associations of the HLA-B⋆58:01 genotype in an allopurinol-induced hypersensitivity phenotype remain unclear. To investigate the comprehensive associations of HLA-B⋆58:01, we enrolled 146 patients with allopurinol-induced cutaneous adverse drug reactions (severe cutaneous adverse reactions, n = 106; maculopapular exanthema, n = 40) and 285 allopurinol-tolerant control subjects. Among these allopurinol-induced cutaneous adverse drug reactions, HLA-B⋆58:01 was strongly associated with severe cutaneous adverse reactions (odds ratio [OR] = 44.0; 95% confidence interval = 21.5–90.3; P = 2.6 × 10^-41), and the association was correlated with disease severity (OR = 44.0 for severe cutaneous adverse reactions, OR = 8.5 for maculopapular exanthema). The gene dosage effect of HLA-B⋆58:01 also influenced the development of allopurinol-induced cutaneous adverse drug reactions (OR = 15.25 for HLA-B⋆58:01 heterozygotes and OR = 72.45 for homozygotes). Furthermore, coexistence of HLA-B⋆58:01 and renal impairment increased the risk and predictive accuracy of allopurinol-induced cutaneous adverse drug reactions (heterozygous HLA-B⋆58:01 and normal renal function: OR = 15.25, specificity = 82%; homozygous HLA-B⋆58:01 and severe renal impairment: OR = 1269.45, specificity = 100%). This HLA-B⋆58:01 correlation study suggests that patients with coexisting HLA-B⋆58:01 and renal impairment (especially estimated glomerular filtration rate < 30ml/minute/1.73 m²) should be cautious and avoid using allopurinol.