Polymorphisms in the interleukin-7 receptor α gene and mortality in untreated HIV-infected individuals.
Recently, polymorphisms in the gene encoding the interleukin-7 receptor α (IL7Rα) have been shown to influence the CD4 cell count in HIV-infected individuals. The objective of this study was to examine the impact of 10 single nucleotide polymorphisms (SNPs) in or in close proximity to the IL7Rα on mortality among 152 untreated HIV infected in a Zimbabwean cohort. Patients were followed prospectively, median time of follow-up 3.9 year. SNPs were genotyped using competitive allele-specific PCR. Cox regression was used for survival analyses. We found an increased mortality among carriers of the IL7Rα, rs6897932, T-allele (hazard ratio: 2.56 [95% confidence interval (CI) 1.22-5.35], P=0.013). This association remained significant after adjusting for age, sex, baseline HIV-RNA and baseline CD4 cell count (hazard ratio=2.36 (95% CI 1.06-2.58), P=0.036). The results suggest an association between the IL7Rα, rs6897932, T-allele and increased mortality among untreated HIV-infected, Zimbabwean individuals.