Immune activation, which is accompanied by the production of proinflammatory cytokines, is a strong predictor of disease progression in HIV infection. Inflammation is critical in neuronal damage linked to HIV-associated neurocognitive disorders. We examined the relationship between plasma cytokine levels and deficits in neurocognitive function. Multiplex profiling by Luminex® technology was used to quantify 27 cytokines/chemokines from 139 plasma samples of people living with HIV (PLWH). The relationship of plasma cytokine markers, clinical parameters, and cognitive impairment, was assessed using Spearman correlations. Partial least squares regression and variable importance in projection scores were used for further evaluation of the association. Forty-nine (35.3%) participants exhibited neurocognitive impairment based on a global deficit score (GDS) of at least 0.5 and 90 (64.7%) were classified as nonimpaired. Twenty-three (16.5%) initiated on combination antiretroviral therapy for 4 weeks before cognitive assessment and 116 (83.5%) were not on treatment. We identified five proinflammatory cytokines that were significant predictors of GDS namely, IP-10 (β = 0.058; p = .007), RANTES (β = 0.049; p = .005), IL-2 (β = 0.047, p = .006), Eotaxin (β = 0.042, p = .003), and IL-7 (β = 0.039, p = .003). IP-10 and RANTES were the strongest predictors of GDS. Both cytokines correlated with plasma viral load and lymphocyte proviral load and were inversely correlated with CD4+ T cell counts. IP-10 and RANTES formed a separate cluster with highest proximity. Study findings describe novel associations among IP-10, RANTES, cognitive status, plasma viral load, and cell-associated viral load.
Keywords: GDS; Luminex; clustering; immune activation; neuroinflammation.