HIV Viral Load Is Not Reliable Indicator for CD4+ T Cell Counts, Study Says

Measuring HIV viral loads in the blood of people living with the virus is not a reliable indicator to predict CD4+ T cell counts of HIV-positive people, according to a study published in the Sept. 27 issue of the Journal of the American Medical Association, Long Island Newsday reports (Talan, Long Island Newsday, 9/28). Benigno Rodríguez of Case Western Reserve University and colleagues from August 2004 through March 2006 assessed the medical records from 1984 through 2004 for viral loads and CD4+ T cell counts of 2,801 HIV-positive men and women who had been observed without initiating antiretroviral treatment for more than six months (Rodríguez et al., JAMA, 9/27). Each person had at least two CD4+ T cell counts (Long Island Newsday, 9/28). The study finds that about 5% of the variations in viral loads corresponded to variations in CD4+ T cell counts (Reuters, 9/27). Patients included in the study were from Boston, Cleveland, San Diego, San Francisco and Seattle (McEnery, Cleveland Plain Dealer, 9/27).

Study Implications, Reaction
According to Reuters, the study challenges the current theory that the amount of HIV replication directly indicates the amount of CD4+ T cell loss (Reuters, 9/27). The study also suggests that predicting disease progression -- which is "crucial" in deciding when to start highly active antiretroviral therapy -- might be "more complex" and could include indirect ways HIV can harm the immune system, according to BBC News. Physicians often avoid initiating HAART until absolutely necessary because of its tendency to cause serious side effects, BBC News reports (BBC News, 9/26). "There is a lot of variability from person to person that has nothing to do with viral load," Rodriguez said, adding, "There must be other factors we just don't know about." He recommended that physicians council HIV/AIDS patients about treatments based on CD4+ T cell counts, not viral loads (Long Island Newsday, 9/28). In a related JAMA editorial, physician W. Keith Henry and colleagues write that the study results are stimulating and suggest that researchers should seek to identify nonviral factors that might trigger the decline of CD4+ T cells (Reuters, 9/27). "I think we need to do a better job predicting who would benefit from earlier therapy," Clifford Lane of the National Institute of Allergy and Infectious Diseases, who co-authored the editorial, said. "The field has been trending away from using plasma levels of HIV in predicting what will happen to someone down the road," Michael Lederman, director of CWRU's Center for AIDS Research and co-author of the study, said, adding, "I think this piece indicates that those directions are the correct directions" (Cleveland Plain Dealer, 9/27).

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