Serum and CSF biomarkers in asymptomatic patients during primary HIV infection: a randomized study.

Abstract

It is debated whether central nervous system involvement begins during acute HIV infection in persons without meningitis/encephalitis and if specific antiretroviral drugs or combinations would be beneficial. Neurologically asymptomatic participants enrolled in a randomized and controlled study comparing three combination antiretroviral regimens (tenofovir alafenamide/emtricitabine plus dolutegravir, darunavir or both) during primary HIV infection were enrolled. Serum and cerebrospinal fluid (CSF) were collected at baseline, 12 and 48 (serum only) weeks after treatment initiation. Single Molecule Array was used to measure neurofilament light chain (NFL), total tau protein (Tau), Brain-Derived Neurotrophic Factor (BDNF), Glial Fibrillary Acidic Protein (GFAP), Ubiquitin C-terminal Hydrolase (UCH-L1). We assessed the longitudinal change in biomarkers over time as well as the change in the prevalence of serum NFL concentrations above previously published age-adjusted cut-offs (7 pg/mL if 5-18 years, 10 pg/mL if 18-51 years, 15 pg/mL if 51-61 years, 20 pg/mL if 61-70 years and 35 pg/mL if >70 years). Serum was available from 47 participants at all time points while CSF was in 13 and 7 participants (baseline/W12). We observed a significant direct serum-to-CSF correlation for NFL (rho = 0.692, p = 0.009), GFAP (rho = 0.659, p = 0.014) and BDNF (rho = 0.587, p = 0.045). Serum (rho = 0.560, p = 0.046) and CSF NFL (rho = 0.582, p = 0.037) concentrations were directly associated with CSF HIV RNA levels. We observed a significant decrease over time in serum NFL (p = 0.006) and GFAP (p = 0.006) but not in the other biomarkers. No significant difference was observed among the treatment arms. At baseline, serum and CSF age-adjusted NFL levels were above age-adjusted cut-offs in 23 (48.9%) and 4 participants (30.8%); considering serum NFL, this proportion was lower at weeks 12 (31.9%, p = 0.057) and 48 (27.7%, p = 0.13). A relevant proportion of neurologically asymptomatic participants had abnormal CSF and serum NFL levels during primary HIV infection. NFL and GFAP decreased in serum following combination antiretroviral therapy without significant differences among the treatment arms.