Wednesday, April 15, 2009

Delaying HAART Might Prevent Complete Immune System Recuperation

People living with HIV who do not start highly active antiretroviral treatment until their CD4+ T cell counts drop below 200 might not be able to reach a normal CD4 cell count, even after 10 years of otherwise effective treatment, according to a study in the March 15 issue of Clinical Infectious Diseases, Reuters reports. According to Reuters, an HIV-positive person is considered to have a normalized immune status after CD4 counts are maintained above 500.

For the study, researchers examined 366 HIV-positive people who had maintained plasma HIV RNA levels of no more than 1,000 copies per milliliter of blood for at least four years after starting therapy. About 25% of the study's participants were followed for more than 10 years, with a median follow-up of 7.5 years. Reuters reports that 95% of the participants who started therapy with a CD4 cell count of at least 300 were able to reach a normalized CD4 cell count of at least 500. The researchers reported that 44% of participants who began treatment with a CD4 cell count of less than 100 -- as well as 25% who began treatment with a CD4 cell count of between 100 and 200 -- were not able to reach a CD4 cell count higher than 500.

Lead author Steven Deeks of the University of California-San Francisco and colleagues wrote that a "persistently low CD4 cell count during treatment is associated with increased risk of both AIDS and non-AIDS related events," such as liver disease, cardiovascular disease and cancer. They added that "novel immune-based therapeutic approaches may be necessary to restore immunocompetence in these individuals." In a related editorial, Boris Julg and Bruce Walker, both of Massachusetts General Hospital, wrote that major treatment guidelines recommend beginning antiretroviral therapy when CD4 cell counts drop below 350, adding that it can be difficult for developing and low-income countries to follow such advice. Julg and Walker wrote that "adequate early therapy, leading to more-complete immune reconstitution, may save resources because of the resulting lower incidence of opportunistic infections and reduced need for medical care" (Reuters, 4/7).

Online An abstract of the study is available online. An abstract of the accompanying editorial also is available online.

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