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

Maria J Miguez-Burbano¹, John E Lewis², Jose Moreno³, Joel Fishman⁴

¹Robert Stempel School of Public Health & School of Medicine, Florida International University, Miami, FL, USA; ²Department of Psychiatry and Behavioral Sciences, ³Department of Medicine, ⁴Department of Radiology, University of Miami Miller School of Medicine, Miami, FL, USA

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