Associations between plasma biomarkers and changes in cognitive function over two years in people with and without HIV.

OBJECTIVE

Chronic inflammation may be associated with cognitive disorders in people with HIV on antiretroviral treatment (ART). We examine associations between cognitive function and plasma biomarkers measured in people with HIV and demographically-similar people without HIV in the POPPY study.

DESIGN

Prospective longitudinal cohort study.

METHODS

At baseline and 2-year follow-up, participants completed a cognitive test battery. Global T-scores were derived by averaging domain T-scores. We used linear regression to explore associations between changes in Global T-scores and log-transformed plasma biomarkers of neuronal injury, systemic inflammation and innate immune activation. We explored whether effects of biomarkers differed by HIV status.

RESULTS

A total of 349 participants were included (73% people with HIV, median [interquartile range, IQR] age 54 [50-60] years, 85% male, 95% white). Among people with HIV, 98% were on ART, 93% had HIV-RNA ≤50 copies/ml and median [IQR] CD4 + cell count was 627 [490 792] cells/mm 3 . Mean [standard deviation (SD)] baseline Global T-score was 47.7 (5.9) which increased to 48.9 (5.5) after a median [IQR] follow-up of 26 [24,29] months. Lower average increases in Global T-scores were seen in those with higher MIP-1α (parameter estimate: -0.27 [95% CI: -0.51,-0.03]/10% increase) and sCD14 (-0.17 [-0.30,-0.03]), though only MIP-1α (-0.46 [-0.58,-0.10]) remained significant after adjustment. There was no evidence that the associations differed by HIV status.

CONCLUSION

Higher MIP-1α and sCD14 showed small associations with lower average increases in Global T-scores, with no differences by HIV status or inflammatory clusters, highlighting the multifactorial influences on cognitive trajectories in people ageing with and without HIV.