Livelli A, et al. - Using longitudinal data from adults living with HIV in the US CHARTER cohort, researchers investigated the correlates of HIV RNA in cerebrospinal fluid (CSF). Among the participants, the majority were antiretroviral therapy-experienced and were receiving a three-drug regimen that did not involve an integrase inhibitor. The lower limit of quantification of the HIV RNA assays was 50 copies per mL. Increased plasma HIV RNA concentration, raised CSF leucocyte count, reduced CD4 cell count, reduced CNS penetration-effectiveness value, increased CD8 cell count, and protease inhibitor use were the components of the best multivariate model of HIV RNA concentration in CSF greater than the lower limit of quantification over time. In addition, the association of increased HIV RNA concentrations in CSF, with black ethnicity, increased total protein in CSF, and the presence of addictive-drug metabolites in urine was also shown.