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% ( < .001) and 74.4% vs 90.5% ( = .003), respectively). These virological responses became similar between two groups ( > .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/mm ( = .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.