Cognitive performance and the thymus among HIV-infected subjects receiving HAART

Abstract

Objective:

To evaluate the impact of alcohol use, which is widespread in human immunodeficiency virus (HIV)+ individuals, on highly active antiretroviral therapy (HAART)-associated immune and cognitive improvements and the relationship between those two responses.

Methods:

In a case-control longitudinal study, thymic volume, cognition, and immune responses were evaluated at baseline and after 6 months therapy in HIV+ and HIV- controls. Cognitive performance was evaluated using the HIV Dementia Score (HDS) and the California Verbal Learning Test (CVLT).

Results:

Prior to HAART, thymic volume varied considerably from 2.7 to 29.3 cm³ (11 ± 7.2 cm³). Thymic volume at baseline showed a significantly inverse correlation with the patient’s number of years of drinking (r² = 0.207; p < 0.01), as well as HDS and the CVLT scores in both HIV-infected (r² = 0.37, p = 0.03) and noninfected (r² = 0.8, p < 0.01). HIV-infected individuals with a small thymic volume scored in the demented range, as compared with those with a larger thymus (7 ± 2.7 vs. 12 ± 2.3, p = 0.005). After HAART, light/moderate drinkers exhibited thymus size twice that of heavy drinkers (14.8 ± 10.4 vs. 6.9 ± 3.3 cm³).

Conclusions:

HAART-associated increases of thymus volume appear to be negatively affected by alcohol consumption and significantly related to their cognitive status. This result could have important clinical implications.

Keywords:

• thymus
• CNS
• immune
• alcohol

Acknowledgements

We would like to thank Steven Reiman, MD and Janine Katzen, MD for their assistance with the MR image analysis. The study was funded by the NIAAA of the United States (5R21AA13793-3 MJM). The authors report no conflicts of interest.