Cognitive outcomes at ages seven and nine years in South African children from the children with HIV early antiretroviral (CHER) trial: a longitudinal investigation

Abstract

Introduction: Many children living with HIV (CLWH) display impaired cognition. Although early combination antiretroviral therapy (ART) produces improved cognitive outcomes, more long-term outcome data are needed. After concluding the Children with HIV Early antiRetroviral (CHER) trial in 2011, we investigated cognitive performance, at seven and nine years of age. Participants had been randomized to deferred ART (ART-Def; n = 22); immediate time-limited ART for 40 weeks (ART-40W; n = 30) and immediate time-limited ART for 96 weeks (ART-96W; n = 18). We also recruited HIV-exposed uninfected (CHEU; n = 28) and HIV-unexposed (CHU; n = 35) children.

Methods: Data were collected between May 2012 and December 2017. Mixed-model repeated-measures ANOVAs assessed differences over time between CLWH (ART-40W, ART-96W and ART-Def) and CHIV- CHEU and CHU between ART-Early (ART-40W and ART-96W), ART-Def, CHEU and CHU; and between ART-40W, ART-96W, ART-Def, CHEU and CHU.

Results: All comparisons found significant effects of Time for most outcome variables (better scores at nine than at seven years; ps < 0.05). The first ANOVAs found that for (a) motor dexterity, CLWH performed worse than CHIV- at seven years (p < 0.001) but improved to equivalence at nine years, (b) visual-spatial processing and problem solving, only CLWH (p < 0.04) showed significant performance improvement over time and (c) working memory and executive function, CLWH performed worse than CHIV- at both seven and nine years (p = 0.03 and 0.04). The second ANOVAs found that for (a) working memory, CHU performed better than ART-Early and CHEU (p < 0.01 and <0.04), and (b) motor dexterity, ART-Def performed worse than ART-Early, CHEU and CHU at seven years (p = 0.02, <0.001 and <0.001 respectively) but improved to equivalence at nine years (ps > 0.17). Similarly, for motor dexterity, ART-Def performed worse than ART-96W, CHEU and CHU at seven years (p < 0.04, <0.001 and <0.001) but improved to equivalence at nine years (ps > 0.20).

Conclusions: Although neurocognitive developmental trajectories for treatment groups and controls were largely similar (i.e. performance improvements from 7 to 9), all ART-treated children, regardless of treatment arm, remain at risk for cognitive deficits over early school ages. Although the nature of these deficits may change as cognitive development proceeds, there are potential negative consequences for these children's future learning, reasoning and adaptive functioning.

Keywords: HIV-associated neurocognitive impairment; HIV/AIDS; The Children with HIV Early Antiretroviral Therapy (CHER) trial; antiretroviral therapy; paediatric HIV; working memory.