Clinical effects of durability of immunosuppression in virologically suppressed ART-initiating persons with HIV in Latin America. A retrospective cohort study

Background Clinical outcomes are rarely studied in virologically suppressed people living with HIV (PWH) and incomplete CD4 recovery. To explore whether time living with severe immunosuppression predict clinical outcomes better than baseline or time updated CD4, we estimated the association between cumulative percentage of time with CD4 <200 cells/mu L during viral suppression (VS) (%tCD4<200), and mortality and comorbidities during 2000-2019.Methods In a retrospective cohort analysis, we followed PWH initiating ART in Latin America from first VS (HIV-RNA<200 copies/mu L) to death, virological failure or loss to follow-up. We fit Cox models to estimate risk of death and/or AIDS-defining and serious non-AIDS-defining events (ADE and SNADE-cancer, cardiovascular, liver, and renal diseases) by %tCD4<200 (continuous variable). We predicted survival probabilities for each event and calculated risks of hypothetical cases of different %tCD4<200.Findings In 8,369 patients with 34.9 months of follow-up (median, IQR: 16.7, 69.1), 4,274 (51%) started ART with CD4<200 cells/mu L. Median %tCD4<200 was 0% (IQR: 0, 15%). We identified 195 (2.3%) deaths and 584 (7.2%) patients with ADE/SNADE. For an increased %tCD4<200 of 15% (e.g., 15% vs. 0%), the adjusted relative hazard (aHR) of death was 1.27 (95% confidence interval [CI]: 1.19 - 1.35), of ADE/SNADE was 1.13 (95%CI: 1.09 - 1.17), of SNADE was 0.96 (95%CI: 0.89 - 1.02) and of death/ADE/SNADE was 1.11 (95%CI: 1.07 - 1.14). Estimates were similar after adjusting for time updated CD4 count. Interpretation In virologically suppressed PWH, increased time living with severe immunosuppression had an increased risk of death and ADE/SNADE in this Latin American cohort, independently of time updated CD4 count.