Impact of polymorphisms in the HCP5 and HLA-C, and ZRND1 genes on viral load

AIMS: Single nucleotide polymorphisms (SNPs) in the HLA complex P5 gene (HCP5), HLA-C, and near the zinc ribbon domain containing 1 gene (ZNRD1) have been shown to influence viral load (VL) set point in HIV infected individuals with a known seroconversion onset. We aimed to determine the influence of HCP5 rs2395029, HLA-C rs9264942, and ZNRD1 rs3869068 on VL in antiretroviral-naïve individuals and on time to the first VL<51 copies/ml and on CD4+ T-cell recovery after initiation of combination antiretroviral therapy (cART).

MATERIAL AND METHODS: We genotyped the rs2395029 (A>C), rs9264942 (T>C), and rs3869068 (C>T) SNPs in 1897 Caucasians from The Danish HIV Cohort Study - a prospective, nationwide, population-based study of HIV-infected individuals in Denmark. General linear models evaluated the effect of SNPs on VL in antiretroviral-naïve individuals 0-18months after diagnosis and on CD4(+) T-cell recovery during cART. Cox proportional hazard regression analysis assessed the association with time to first VL<51 copies/ml. All models were assuming additive genetic effects.

RESULTS: The rs2395029, rs9264942, and rs3869068 minor alleles were associated with lower VL in antiretroviral-naïve individuals (rs2395029: [mean VL (copies/ml)], A/A: 70,795 [61,660-79,433], A/C: 33,884 [19,498-58,884], P=0.002; rs9264942: TT: 81,283 [67,608-97,724], T/C: 63,096 [54,954-75,858], CC: 38,905 [25,119-58,884], P<0.0001; rs3869068, CC: 72,444 [63,096-83,176], C/T: 45,709 [33,113-64,565], TT: 58,884 [20,417-169,824], P=0.01). Moreover, the C-alleles of rs2395029 and rs9264942 were associated with shorter time to VL<51 copies/ml: (HR [95% confidence interval], 1.67 [1.09-1.72], P=0.008; 1.16 [1.06-1.28], P=0.002; 1.30 [1.08-1.53], P=0.005, respectively, adjusted for last VL before cART). None of the SNPs predicted CD4(+) T-cell recovery during cART.

CONCLUSIONS: The minor alleles of rs2395029, rs9264942, and rs3689068 associate with lower VL among antiretroviral-naïve individuals and with shorter time to first VL<51copies/ml during cART even after adjustment for VL before cART.