Long-term virological and immunological outcomes between HIV-positive individuals with and without pretreatment HIV drug resistance

Background: Pretreatment HIV drug resistance (PHDR) has emerged after scaling-up access to antiretroviral therapy (ART). This study aimed to compare long-term virological and immunological outcomes between HIV-positive individuals with and without PHDR. Methods: An observational cohort study was conducted in HIV-positive individuals who had a genotypic resistance test performed prior to ART initiation. Results: Of 335 participants, 39 were in the PHDR group and 296 were in the control group. ART regimen in PHDR group was adjusted at 6–10 weeks after ART initiation when results of baseline genotypic resistance test were available. Proportions of participants with undetectable viral load were significantly lower in PHDR group at 6 and 12 months (46.2% vs 79.4% (p <.001) and 74.4% vs 90.5% (p =.003), respectively). These virological responses became similar between two groups (p >.05) from 18 through 60 months. Mean change of CD4 counts of PHDR group was significantly lower only at 6 months (+59 vs + 81 cells/mm³ (p =.012); these immunological responses were similar between two groups from 12 through 60 months. Conclusion: Early virological response was lower in HIV-positive participants with PHDR compared to participants without PHDR. Subsequent adjustment of ART according to pretreatment genotypic resistance has contributed to the long-term virological and immunological success that is similar to participants without PHDR.