Mortality and immunological recovery among older adults on antiretroviral therapy at a large urban HIV clinic in Kampala, Uganda.

Abstract

We describe older (>50 years) HIV-infected adults after antiretroviral therapy (ART) initiation, evaluating immunological recovery by age category, considering individual trajectories based on the pretreatment CD4. We also describe mortality on ART and its risk factors by age category including the contribution of poor immunological recovery at a large urban clinic in Kampala, Uganda. We performed a cohort analysis of adult (>18 years) HIV-infected patients who initiated ART between January 1, 2004 and January 3, 2012. Immunological response was evaluated using mixed-effects linear regression. We described mortality using Kaplan-Meier survival methods analyzing for risk factors of mortality using multivariate Weibull survival regression stratified by age category. Among 9806 individuals who initiated ART, mean age was 37 years (SD: 8.8), average follow-up 5.7 years (SD: 1.7), and median baseline CD4 was 115 cells per cubic millimeter (interquartile range: 42-184). Adults younger than 50 years had on average a higher CD4 increase of 45 cells per cubic millimeter (95% confidence interval: 17 to 72; P = 0.001) compared with counterparts aged 60 years and older. Mortality was highest among older adults compared with younger counterparts. Only CD4 count <100 cells per cubic millimeter after 1 year on ART and a CD4 count less than baseline were associated with a statistically significant higher rate of death among older adults. Older adults had a slower immunological response, which was associated with mortality, but this mortality was not typically associated with opportunistic infections. Future steps would require more evaluation of possible causes of death among these older individuals if survival on ART is to be further improved.