Study population
A total of 300 plasma/CSF paired VL from 282 participants met the eligibility criteria. Demographic and HIV-related characteristics of the study population are described in Tab.1. Participants were mostly male (67.0%), with a median age of 49 years. Plasma and CSF VL were<50 cp/mL in 202 (67.3%) and 195 (65.0%) participants. Current CD4+ T-cell count was 310 cells/µL with a high prevalence of subjects with nadir CD4+ T-cell count below 200 (75.7%; Tab.1). The median duration of any ART was 5 years (30.7% started ART within 2 years) and of current ART was 19 months. ART consisted of standard NRTI-backbone-based triple regimens in 74.7% and less conventional regimens in 25.3% of the cases (three different ARVs classes, dual therapy, monotherapy and ≥4 drugs; see Suppl.Tab.1); 36.7% of participants were on their first ART regimen. Participants underwent LP in 16.7% of cases due to enrollment in prospective studies involving HIV infection of CNS with no CNS confounding or neurological signs or symptoms, in 46.7% due to clinical indications without eventual CNS involvement (to rule out CNS infections/disorders, due to complaints of neurological signs or symptoms, or due to perypheral lymphomas without meningeal/CNS involvement) and in 36.6% due to self-reported or objectified neurocognitive impairment; no differences in LP indications was observed between participants with and without CVE (Tab.1).