Research
Long-term CD4+ lymphocyte response following HAART initiation in a U.S. Military prospective cohort
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* Corresponding author: Alan R Lifson lifso001@umn.edu
1 Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
2 Division of Biostatistics, University of Minnesota, Minneapolis, MN, USA
3 Defense Institute for Military Operations, Wilford Hall USAF Medical Center, San Antonio, TX, USA
4 School of Medicine, Emory University, Atlanta, GA, USA
5 Infectious Disease, Walter Reed Army Medical Center, Washington, DC, USA
6 Infectious Disease, Naval Medical Center-San Diego, San Diego, CA, USA
7 Infectious Disease, National Naval Medical Center, Bethesda, MD, USA
8 Infectious Disease Clinical Research Program, Uniformed Services University of Health Sciences, Bethesda, MD, USA
AIDS Research and Therapy 2011, 8:2 doi:10.1186/1742-6405-8-2
Published: 18 January 2011Abstract
Background
Among HIV-infected persons initiating highly active antiretroviral therapy (HAART), early CD4+ lymphocyte count increases are well described. However, whether CD4+ levels continue to increase or plateau after 4-6 years is controversial.
Methods
To address this question and identify other determinants of CD4+ response, we analyzed data for 1,846 persons from a prospective HIV military cohort study who initiated HAART, who had post-HAART CD4+ measurements, and for whom HIV seroconversion (SC) date was estimated.
Results
CD4+ count at HAART initiation was ≤ 200 cells/mm3 for 23%, 201-349 for 31%, 350-499 for 27%, and ≥500 for 19%. The first 6 months post-HAART, the greatest CD4+ increases (93-151 cells) occurred, with lesser increases (22-36 cells/year) through the first four years. Although CD4+ changes for the entire cohort were relatively flat thereafter, HIV viral load (VL) suppressors showed continued increases of 12-16 cells/year. In multivariate analysis adjusting for baseline CD4+ and post-HAART time interval, CD4+ responses were poorer in those with: longer time from HIV SC to HAART start, lower pre-HAART CD4+ nadir, higher pre-HAART VL, and clinical AIDS before HAART (P < 0.05).
Conclusions
Small but positive long-term increases in CD4+ count in virally suppressed patients were observed. CD4+ response to HAART is influenced by multiple factors including duration of preceding HIV infection, and optimized if treatment is started with virally suppressive therapy as early as possible.