Five-year immunological outcome of highly active antiretroviral treatment in a clinical setting: results from a single HIV treatment centre

Abstract

Our objective was to study the evolution of CD4 cell count five years after starting highly active antiretroviral treatment (HAART) in a clinical setting. The study was performed at the HIV outpatient clinic, Institute of Tropical Medicine, Antwerp. All patients (n=225) who started HAART in 1997, who had a CD4 cell count within six months prior to starting HAART and who were subsequently followed for at least two years were included. Change in CD4 cell count after start of HAART and the influence of patient and clinical factors were investigated using graphical exploration, endpoint analysis and mixed-effects linear regression. The mean CD4 cell count at start of HAART was 280 cells/mm(3). At the five-year endpoint of the study the mean increase in CD4 cell count was 333 cells/mm(3), while 79% of the patients had a viral load less than 400 copies/mL. There was a significant negative correlation between increase in CD4 cell count at five years and time since first positive HIV test at start of HAART (P = 0.021). Patients who ever had a HAART interruption of more than seven days had a significantly lower increase in CD4 cell count than those who did not (225 cells/mm(3) compared with 438 cells/mm3; P<0.001). A mixed-effects linear regression model additionally suggested a significant impact of exposure to antiretrovirals prior to HAART (P=0.03). Overall, the recovery of CD4 cell count after five years of HAART is good, although therapy interruptions have an important negative impact.