Etude de l’immunosénescence chez les patients nés VIH positif r ayant une charge virale indétectable sous antirétroviraux et suivis au Centre Hospitalier et Universitaire de Yaoundé

Abstract

Antiretroviral therapy (ART) has significantly increased survival rates for people living with HIV (PLWH), but has also led to the emergence of non-HIV-related comorbidities, accelerating immune system aging or immunosenescence. Young individuals, especially those born with HIV, often exhibit immunosenescence-related abnormalities at a younger age. Immune activation and inflammation are thought to play a significant role in this phenomenon. This study aimed to identify biomarkers that could be incorporated into the monitoring of HIV positive individuals born with HIV, with undetectable viral loads under ART, to predict the occurrence of immunosenescence. The survey was conducted between 2020 and 2021 at the Yaounde University Teaching Hospital (YUTH) in Cameroon. Blood samples were collected for full blood counts (CBC), T cell phenotyping, and plasma extraction for determining transaminases, creatinine, urea, serology (CMV, EBV, Herpes simplex virus 1/2, Rubella virus, Toxoplasmosis, HBV, HCV), and cytokine levels (IL-2, IL-6, IFN-γ, and TNF-α). The same biomarkers were measured in the same participants 12 months later. Data was analyzed using XLSTAT software version 2019 for Windows. A Z-score was used to identify relevant biomarker combinations for studying immunosenescence, allowing participants to be categorized as having either a restored or senescent immune system. A total of 74 HIV-positive individuals, aged 3-19 years, with undetectable viral loads under ART completed the study. Results showed a mean age of 9.05 ± 5.09 years, with a female predominance. From the first to the second sample, the average of the CD4:CD8 ratio remained inverted (<1), leukopenia and thrombocytopenia were observed, and the most prevalent infectious agent was herpes simplex virus (93.24%) at the first measure and cytomegalovirus (95.95%) at the second measure. Cytokine concentrations (IL-2, IL-6, IFN-γ, and TNF-α) were abnormally elevated, and at the second measure, 81.08% of participants were anemic, with creatinine levels at 10 μmol/l (normal range: 71-115 μmol/l). At the first measure, a positive association was observed between Urea and TNF-α (p=0.03) and at the second measure, a positive association was observed between ASAT and TNF-α (p=0.02). Using the Z-score, five biomarkers (CD4+ T cells, Total Leukocytes, Platelets, IL-2, and IFN γ) were found to be associated with immunosenescence. However, no single biomarker, when considered individually, could accurately predict the immune status of the participants.