Longitudinal Examination of the Neuroimmunological Mechanisms of HIV-Associated Neurocognitive Disorders in a Nigerian Adult Cohort

HIV-associated neurocognitive disorders affect a significant proportion of people living with HIV globally, and their immunopathological mechanisms in the context of clade A and G HIV strains predominant in Nigeria differ from the clade B-focused mechanistic literature. This study longitudinally examines the neuroimmunological mechanisms underlying HIV-associated neurocognitive disorders in a cohort of 800 Nigerian adults living with HIV recruited from ART centres in Lagos, Enugu, and Maiduguri. A prospective 48-month cohort design is applied, with participants undergoing standardised neuropsychological battery assessment (PHAB-ND), cerebrospinal fluid biomarker sampling (neopterin, neurofilament light chain, CXCL10), and brain MRI volumetry at enrolment, 24 months, and 48 months. HIV clade typing and viral load quantification are performed on plasma and CSF specimens. Linear mixed-effects models in R examine the longitudinal trajectory of neurocognitive performance and neuroimaging measures, testing proposed mediating pathways including monocyte activation, interferon signalling, and disrupted blood-brain barrier integrity. The Neuroinflammation Theory and the Integrated HIV Neuroscience Framework provide the mechanistic theoretical basis. The study's original contribution is the characterisation of clade-specific neuroimmunological trajectories in a Nigerian cohort, filling a critical gap in global HIV neuroscience literature. Findings will inform neurologically targeted treatment adjunct strategies in sub-Saharan Africa. Keywords: HIV-associated neurocognitive disorders, neuroimmunology, Nigerian cohort, cerebrospinal fluid biomarkers, HIV clade.