Molina-Pinelo Sonia, Vivancos Jorge, De Felipe Beatriz, Soriano-Sarabia Natalia, Valladares Angela, De la Rosa Rafael, Vallejo Alejandro, Leal Manuel
Viral Hepatitis and AIDS Unit, Service of Internal Medicine,Virgen del Rocío University Hospital, Seville, Spain.
J Acquir Immune Defic Syndr. 2006 Jun;42(2):203-6. doi: 10.1097/01.qai.0000219778.12551.c0.
To analyze the predictive capacity of thymic volume in CD4 T-cell loss after treatment interruption in HIV-infected patients with high nadir CD4 count.
Thirty-nine HIV-infected patients with CD4 counts greater than or equal to 500 cells/microL, nadir CD4 counts greater than or equal to 250 cells/microL, and plasma viral loads less than 50 copies/mL for at least the past 12 months began a treatment interruption program. The event of interest for this study was the decrease of CD4 count below 350 cells/microL. Kaplan-Meier curves were used for all time-to-event analyses, and log-rank tests were used for comparison between groups in the univariate analysis. All variables with statistical association with CD4 T-cell loss were analyzed using multivariate Cox proportional hazards regression models.
Twenty-three percent of the patients had a decrease in CD4 count to less than 350 cells/microL. In the univariate analysis, only thymic volume was statistically significant with this event (P = 0.02). Nadir CD4 count nearly reached statistical significance. However, age, sex, HCV coinfection, CD4 count, T-cell receptor excision circle-bearing cells, and early viral load rebound did not show statistical differences. Thymic volume and CD4 T-cell loss were independently associated using Cox proportional hazards regression model (P = 0.04; relative risk, 0.76; 95% confidence interval, 0.59-0.99).
In this study, we demonstrate for the first time that thymic volume predicts CD4 T-cell loss in patients with nadir CD4 count greater than or equal to 250 cells/muL under treatment interruption.
