NEUROCOGNITION, PLASMA LEVEL OF TUMOUR NECROSIS FACTORRELATED APOPTOSIS INDUCING LIGAND (TRAIL), AND PHAGOCYTIC ACTIVITY IN HIV PATIENTS ON LONG-TERM ANTIRETROVIRAL THERAPY.

Background: The neuropathological process responsible for neurocognitive disorders in people living with HIV (PLHIV) on long-term antiretroviral therapy (ART) is not well elucidated. Presently, there is a dearth of information on the roles of altered immune response in the pathogenesis of HIV-associated neurocognitive disorders. To investigate the interplay between immune response alteration and neuropathological mechanisms underlying neurocognitive disorders in PLHIV on long-term ART, neurocognition, phagocytic activity and plasma levels of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) and nitric oxide (NO) were determined in PLHIV on long-term ART. Methods: Eighty eight adults comprising 48 PLHIV on long-term ART and 40 controls, were enrolled into this case-control study. Neurocognition was assessed using the Mini-Mental State Examination (MMSE) while the plasma levels of TRAIL and nitric oxide were determined using ELISA and spectrophotometric method respectively. Phagocytic activity was determined using the neutrophil Nitroblue Tetrazolium (NBT) Reduction Test. Results: The plasma TRAIL level and phagocytic activity were significantly lower while the plasma level of NO was significantly higher in PLHIV compared with the controls. However, the mean MMSE score was similar in PLHIV and controls. There were no significant differences in the mean TRAIL levels, phagocytic activity, NO and MMSE score in PLHIV who have been on ART for less than 10 years compared with patients who have been on ART for 10 years or more. Conclusion: Phagocytic activity and plasma levels of TRAIL and NO are altered in PLHIV on long-term ART. However, these alterations appear not to be forerunners to neurocognitive impairment in Nigerians living with HIV on longterm ART.