Outcome of chronic HIV-1 patients who interrupt their highly active antiretroviral treatments

Abstract

Introduction: Highly active antiretroviral treatments (HAART) have become a sin qua non in the live of HIV/AIDS patients most especially for those that have access to it in the developed world. It has become an unfulfilled dream for those in developing world due to their cost that may not be afforded by the concern patients. Some chronic HIV-1 patients at Institute of Tropical Medicine, Antwerp, Belgium are having their treatments interrupted for reasons other than treatment failure. Objective of the study: The objectives of the study were to examine the outcome of the patients with chronic HIV-1 infection who interrupt their highly active antiretroviral treatments for reasons other than treatment failure, in terms of rebound of plasma viral loads and decrease in CD4 cell counts and come up with risk factors that are predictive of „good control‟ of the infection. Methodology: Apart from using exploratoy data analysis with inclusion of nonparametric Kapla-Meier survivorship estimates to compare the risk groups, two major ways of dealing with survival data are used in achieving the desired objectives which are Cox proportional hazards regression model for right censored-data and Weibull parametric regression model for interval censored-data based on the fact that the viral load and CD4 counts are not constantly monitored but are only measured every 3 to 6 months, the exact time of treatment failure is unknown. Results: Of the 1296 patients in the follow-up study, 148 had such treatments interruption since 2000. We found that the median failure time for the patients is 2 and 3 months respective for viral and immunological failures. The following variables are identified as risk factors predicting viral and immunological failures; viral load at start HAART on log scale, duration of the disease on log scale, duration of treatment interruption, CD4 at start HAART, percentage change in CD4 cell counts and continent of origin. For some of these variables, they reduce the hazard of having viral and CD4 failure with about 8% while some increase the hazards of failure by more than 100%. Conclusion: The findings from this study show that treatments interruption of at least three months worsen disease outcome. The results suggest that interruptions might be risky, particularly when there is viral rebound of more than 1000 copies/μl and CD4 cell counts less than 20%.