Our analyses employed log-binomial regression models to calculate both unadjusted and race/ethnicity-adjusted prevalence ratios. However, when assessing alleles without a high prior probability of association (i.e., alleles not included in Table 1) we corrected the P-values for multiple comparisons via permutation resampling using PROC MULTTEST; a method that empirically incorporates correlations within and between loci.26 Because some prior studies have described variation in HLA associations by race,27, 28 we assessed potential heterogeneity

in click here effect estimates (i.e., interaction) by race/ethnicity. In contrast, we did not expect to observe heterogeneity by HIV-serostatus or CD4+ T-cell count among HIV-seropositive women. A variety of sources suggest that HCV infection generally occurs prior to HIV infection in new IDU,29–31 and therefore that the majority HCV RNA clearance/persistence occurs without relation to HIV. It is possible, however, that HIV preceded HCV RAD001 price infection in some women. For completeness, therefore, we assessed heterogeneity by HIV serostatus/CD4+ T-cell count (HIV-seronegative, HIV-seropositive with CD4+ T-cell count ≥500 cells/mm3, and HIV-seropositive with CD4+ T-cell count <500 cells/mm3). Lastly, we examined whether groups of HLA alleles

that act as ligand for killer immunoglobulin-like receptors (KIR) were associated with HCV infection and HCV viremia. KIR play a major role in the activation of natural killer (NK) cells and the innate immune response and specific combinations of KIR and HLA ligands have been associated with clearance of HCV RNA.32, 33 These ligand groups were Bw4 reflecting 141 HLA-B alleles, Cw group 1 reflecting 48 HLA-Cw alleles, and Cw group 2 reflecting 43 HLA-Cw alleles.32 All statistical analyses were performed using SAS 9.1 (SAS Institute,

Cary, NC). Selected characteristics of the 758 HCV-seropositive women with and without detectable HCV RNA are shown in Table 2A. Most HCV-seropositive women reported IDU, and this did not vary according to C-X-C chemokine receptor type 7 (CXCR-7) HCV RNA positivity. The HCV RNA-positive women, though, were more likely than those who were HCV RNA-negative to be Black, non-Hispanic. HIV-seroprevalence did not differ between HCV RNA-positive/-negative women, but the CD4+ T-cell counts were significantly lower among those HIV-seropositives who had detectable HCV RNA. HCV genotype was determined for 226 of the women with detectable HCV viremia. The genotype distribution among these women was: 1a in 125 (55%) of the 226 women; 1b in 65 (29%); type 1 but with undetermined subtype in 8 (4%); 2a in 3 (1%); 2b in 6 (3%); 3a in 14 (6%); 3d in 1 (<1%); and 4a in 4 (2%) women.