Immune recovery after antiretroviral therapy initiation: a challenge for people living with HIV in Brazil.

Immune recovery reflects health conditions. Our goal was to estimate the time it takes to achieve immune recovery and its associated factors, in people living with HIV (PLHIV), after antiretroviral therapy (ART) initiation. A historical cohort study was performed among PLHIV (> 18 years-old) in Minas Gerais State, Brazil, using data from healthcare databases. Patients initiating ART between 2009-2018, with T-CD4+ lymphocytes and viral load recorded before and after antiretroviral therapy were included. The outcome is achievement of immune recovery, defined as the first T-CD4+ > 500 cells/µL after ART initiation. Explanatory variables were age, gender, place of residence, year of ART initiation, baseline viral load and T-CD4+, viral load status, and adherence to ART at follow-up. Descriptive analysis, cumulative, and person-time incidences of immune recovery were estimated. Median-time to immune recovery was estimated using Kaplan-Meier method. Factors associated with immune recovery were assessed by Cox regression. Among 26,430 PLHIV, 8,014 (30%) were eligible. Most were male (67%), mean age 38.7 years, resided in non-central region, median-baseline T-CD4+ = 228 cells/µL (< 200 cells/µL = 43%) and viral load median-baseline = 4.7 log10 copies/mL (detectable viral load = 99%). Follow-up time = 15,872 person-years. Cumulative and incidence rate were 58% (95%CI: 57-58) (n = 4,678) and 29.47 cases/100 person-years, respectively. Median-time to immune recovery was of 22.8 months (95%CI: 21.9-24.0). Women living with HIV, younger than 38 years of age, with T-CD4+ baseline > 200 cells/µL, detectable viral load (baseline), antiretroviral therapy-adherence and undetectable viral load (follow-up) were independently associated with immune recovery. Time to immune recovery remains long and depends on early treatment and antiretroviral therapy-adherence.