01 Aug, 2022
Subphenotypes have been identified in several heterogeneous diseases. Having a specific subphenotype often has therapeutic implications or impacts disease progression. In this study, we aimed to assess if children with HIV may show subphenotypes according to clinical, virological and immunological features.
We collected data from 40 HIV+ children included in a cross-sectional multicentric study (CARMA Study, EPIICAL Consortium). All children commenced ART <2 years, suppressed (viral load (VL) <50 copies/ml) within 12 months and remained suppressed for >5 years. Immunological and virological assays were performed at a median of 12 years after ART initiation. We collected clinical and sociodemographic data, baseline VL, CD4 and CD8 data, age at ART, HIV DNA reservoir size, cell-associated RNA (CA-RNA), ultrasensitive VL, CD4 subsets (T effector CD25+, activated memory cells, Treg cells ), humoral-specific HIV response (T-bet B cells), innate response (CD56dim NK cells, NKp46+, perforin), exhaustion markers (PD-1, PD-L1, DNAM), CD8 senesence, and biomarkers for T-lymphocyte thymic output (TREC) and endothelial activation (VCAM). To build the subphenotypes, the most informative variables were selected using an unsupervised penalty selection. Hierarchical clustering was performed using Pearson correlation as distance metric and Ward.D2 as clustering method. Internal validation was applied to select the best number of clusters.
Three subphenotypes were revealed (Cluster 1 n=18, 45%; Cluster 2 n=11, 27.5%; Cluster 3 n=11, 27.5%). Cluster 1 (best controllers) consisted of early ART-treated patients with high baseline %CD4, low reservoir size, low WB score, high TREC values, and low VCAM values. In contrast, Cluster 3 (worst controller) consisted of later ART-treated patients with low baseline %CD4, high reservoir size, low TREC values, high innate response, immunosenescence markers and VCAM. Cluster 2 (low-level viremia, altered immune response) consisted of early-treated patients with low-level (10 to 50 c/mL) VL, high reservoir size but low CA-RNA, higher Treg CD4 than in the other clusters, low TREC, weak innate response and lower levels of T-bet expression.
Three subphenotypes with decreasing levels of viral control and increasing levels of immune well-being were discovered. Response to different therapies may be different across the different clusters.