Short-term effect of HAART on CD4 cell response in adults of the reproductive age(15-49 years)living with HIV/AIDS in Lusaka, Zambia-A retrospective cohort study

Abstract

Introduction: The Highly active antiretroviral therapy (HAART) results in an improvement in immunologic function. Studies on kinetics of CD4+ cell count response post-HAART indicate that CD4+ cell count increases rapidly during the first 3-6 months, in part due to release of memory T-cells from lymphoid tissue, and then increase slowly during the next 3-4 years reflecting the reconstitution of the immune system. The first 6 months of ART is a critical period for future and should be given special attention. However, there is limited data on studies of effect of HAART on CD4 cell response 6 months after HAART initiation hence the effect is not well understood. This study aims to report on the outcome of clients on HAART after 6 months of treatment. Objectives: The aim of this study was to determine the short-term effect of HAART on CD4 count response in adults of the reproductive age (15-49 years) living with HIV/AIDS in Lusaka, Zambia and also help identify the early predictive factors limiting CD4 cell count recovery among the adults of the reproductive age (15-49 years) living with HIV/AIDS. Method: The retrospective cohort study was conducted by reviewing 455 medical records of adult HIV-positive patients aged 15-49 years at baseline and at 6 months follow-up who were enrolled and accessing ART services from Adult Centre of Excellence- UTH ART clinic from January to December 2010 and were residing in Lusaka. Of the 455 participants, 350 were initiated on HAART whereas 105 were not. The CD4 count was measured at baseline in the treated group and the untreated group, and also after 6 months in the untreated group and in the HAART treated group and the difference between the two groups was tested statistically for significance using Wilcoxon matched pairs rank-sum tests. Other factors associated with CD4 count response to HAART were assessed using quantile regression which was used for modeling the median since the CD4 count data was skewed and to make the distribution normal. HAART was the priori variable. Those on HAART were coded 1 and those not on HAART were coded 0. Bivariate and multivariate analyses were performed for each independent variable and the CD4 count difference between baseline and 6 months follow-up. Missing values of some variables (income and residence) were excluded in the analysis using the STATA default command. Results: The median CD4 count at baseline was 177 (IQR: 81.0, 291.0) and 272 (IQR: 191.0, 420.0) 6 months after HAART initiation. The difference in the median CD4 count was statistically significant, P < 0.0001. There was a significant association between HAART and xiii CD4 count response in that those who were on HAART were most likely to increase their CD4 count by a median value of 187 (IQR: 95% CI: 159.1, 214.9) and the association was significant, P < 0.001. BMI was found to be the only predictive factor for CD4 count response to HAART. HIV patients with normal weight and overweight were less likely to increase their CD4 count by median values of -80 (95% CI: -141.70, -18.30) and -90 (95% CI: -178.20, -19.80) respectively and this was significant, P < 0.005. Conclusion: The study demonstrated an increase in CD4 cells of patients on HAART after 6 months of receiving treatment. BMI was the only predictive factor for CD4 count response to HAART.