Evaluation of HIV-1 DNA levels among adolescents living with perinatally acquired HIV-1 in Yaounde, Cameroon: A contribution to paediatric HIV cure research in Sub-Saharan Africa

Abstract

With the advent of antiretroviral therapy (ART), most children living with HIV in sub-Saharan Africa (SSA) are growing toward adolescence, with scarcity of evidence on the size of viral reservoirs to enhance paediatric cure research strategies. This study aims to compare HIV-1 proviral DNA levels according to virological response among adolescents living with perinatally acquired HIV-1 (ALPHIV) and identify associated-factors in the Cameroonian context. In this observational cohort-study, HIV-1 RNA viremia and CD4+ T-cell count were assessed through RT-PCR and flow cytometry respectively at three time-points over 18 months of observation. At the third time-point, 80 randomly-selected participants were classified as with viremia (≥50 copies/mL; n = 40) or without viremia (<50 copies/mL; n = 40); immune-competent (≥500 cells/mm3) or immunocompromised (<500 cells/mm3). Among these participants, total HIV-1 DNA load was quantified through droplet digital PCR using Bio-rad QX-200. Of the 80 randomly-selected adolescents, median [IQR] age was 1513–17 years, 56.2% were female, duration on ART was 9.3 [5.4–12.2] years. Among the 40 with viremia participants (median viremia 7312 [283–71482]) copies/ml, 75.0% (30/40) were in virological failure (≥1000 copies/ml), while median of CD4 cells were 494 [360–793] cell/mm3 with 48.8% (39/80) immunocompromised. No significant variation in HIV-1 RNA viremia and CD4-cell count was observed between the three time-points, and 13.7% (11/80) participants remained without viremia and immune-competent throughout (stable adolescents). A positive and moderate correlation (r = 0.59; p < 0.001) was found between HIV-1 DNA levels and RNA viremia. Regarding CD4-cell count, a negative and weak correlation (r = −0.28; p = 0.014) was found with HIV-1 DNA loads only among adolescents with viremia. Adolescents who started ART within the first-year of life, those on ART >9 years and those without viremia appear as predictors of low HIV-1 DNA loads. Among ALPHIV, high HIV-1 RNA indicates an elevated viral reservoir size, representing a drawback to cure research. Interestingly, early ART-initiation and longer ART-duration lead to sustained viral control and limited HIV-1 reservoir size. As limited size of viral reservoir appears consistent with viral control and immune-competence, adolescents with sustained viral control (about 14% of this target population) would be candidates for analytical ART interruptions toward establishing paediatric post-treatment controllers in SSA.