Long-Term Immunological and Virological Outcomes of Perinatally Acquired HIV in Nigerian Adolescents Transitioning from Paediatric to Adult Care

Perinatally HIV-infected (PHIV) adolescents constitute a growing cohort of long-term ART survivors in Nigeria, yet their virological and immunological trajectories through the transition from paediatric to adult HIV care are incompletely characterised. Poor transition management is associated with loss to follow-up and virological failure. This study characterises the long-term immunological and virological outcomes of a national cohort of PHIV Nigerian adolescents and examines the impact of structured versus unstructured transition pathways on outcomes. A multisite longitudinal cohort study will recruit 300 PHIV adolescents aged 15 to 24 years at the point of transition from paediatric to adult HIV care at five ART centres in Lagos, Kano, Abuja, Enugu, and Ibadan. Viral load, CD4 count, and ART adherence data will be collected at 6, 12, 24, and 36 months post-transition. Deep sequencing of HIV pol gene will be used to characterise acquired drug resistance mutations in participants experiencing virological failure. Immunological profiles including T cell activation markers, immune senescence signatures, and thymic output markers will be assessed by flow cytometry. Structural equation modelling will examine the relationships between transition pathway quality, adherence, immune activation, and virological outcomes. This study advances a theoretical model of PHIV transition vulnerability specific to Nigerian healthcare contexts and generates evidence for a national PHIV adolescent transition framework under the federal HIV programme. Keywords: perinatally acquired HIV, adolescent transition, long-term outcomes, virological failure, Nigeria