Prevalence and associated factors of neurocognitive impairment in HIV-positive patients on effective efavirenz/emtricitabine/tenofovir disoproxil fumarate treatment.

Neurocognitive impairment (NCI) is still a common complication in HIV-infected patients. Aim of this study was to investigate the frequency of NCI in HIV-positive patients successfully treated with fixed-dose EFV/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF). Baseline therapeutic drug monitoring of EFV plasma levels, neuropsychologic examination with the NPZ8 calculation and adherence assessment were performed. 127 HIV-positive patients were analyzed and 25 (19.7%) had neurocognitive impairment: 2 mild NCI, 15 asymptomatic NCI, 8 non-HIV-related impairment. At multivariable logistic regression, NCI was significantly associated with older age (p=0.02) and lower educational level (p<0.001). Considering the 17 patients with HAND, NCI was significantly associated with education only (p=0.03). At multivariable linear regression on the whole population, a better NPZ8 score was significantly associated to higher educational level (p=0.008), while higher EFV plasma levels were significantly associated to a worse performance (p=0.024). Even in the 17 HAND cases, higher EFV plasma levels were significantly associated to a worse performance (p=0.05). In conclusion, we found that, among HIV-infected patients on successful cART with EFV/FTC/TDF, almost 20% had minor forms of NCI, that in two thirds were related to HIV. This finding is noteworthy result because our study population was on stable cART, had a durable control of HIV in plasma and reported high adherence to antivirals. Education was the only factor independently associated with HIV- and non-HIV-related NCI. Higher EFV plasma concentrations correlated to worse neurocognitive performance. Concerns about EFV neurotoxicity are emerging.