Impact of First-line Antiretroviral Therapy Regimen on CD4+ T-cell Count Recovery at 12 months in HIV-infected Adults in Libreville, Gabon: A Retrospective Cohort Study

Manomba Boulingui C, Ntsame Owono MM, Essomeyo Ngui Mebale M, Moutombi Ditombi BC, Sibi Matotou R, Mihindou JC, Bouyou Akotet MK.

Abstract

Background: Before the introduction of dolutegravir, first-line antiretroviral therapy (ART) in sub-Saharan Africa mainly relied on non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimens. Evidence on whether regimen choice independently affects CD4+ T-cell recovery at 12 months remains limited in Central Africa. This study aimed to describe CD4+ trajectories and assess the relationship between ART regimen composition and immune reconstitution at Month 12 among HIV-infected adults in Libreville, Gabon.

Methods: We conducted a retrospective cohort study including ART-naive HIV-infected adults initiating first-line ART in a referral clinic in Libreville. Patients with a documented CD4+ count at 12 months (±3 months) were eligible. The primary outcome was CD4+ count at Month 12, analyzed as a continuous variable and dichotomized (≥500 cells/mm³). Regimens were categorized by NRTI backbone (TDF-AZT-ABC-based) and third agent (efavirenz [EFV] or nevirapine [NVP]). Multivariate logistic regression identified factors associated with complete immune reconstitution, adjusting for baseline CD4, WHO stage, age, sex, and opportunistic infections.

Results: A total of 132 patients were included (70.5% female; median age 42 years). The most common regimen was TDF+FTC+EFV (39.4%). Median CD4+ count rose from 218 to 325 cells/mm³ at Month 12 (p < 0.001). Complete immune reconstitution was achieved in 23.5% of patients. No significant differences in CD4 recovery were observed across NRTI backbones or between EFV- and NVP-based regimens. In multivariate analysis, regimen type was not associated with immune reconstitution. Only baseline CD4 <200 cells/mm³ predicted failure to reach ≥500 cells/mm³ (aOR = 0.13; p = 0.017).

Conclusions: In this pre-dolutegravir cohort, ART regimen choice did not independently influence immune recovery. Advanced immunosuppression at initiation was the main limiting factor, while possible undetected virological failure may explain CD4 decline in some patients. These findings highlight the importance of early HIV diagnosis and systematic viral load monitoring.