Many patients continue to derive immunologic and clinical benefit from antiretroviral therapy even after drug resistance emerges according to researchers from the University of California, San Francisco.
Viral fitness refers to the inherent ability of a virus to replicate and cause disease.
Although many HIV-infected patients on antiretroviral therapy seem to be failing, UCSF researchers have found that these patients do benefit from continuing the treatments because the therapies slow viral reproduction and the HIV virus that manages to replicate is less fit in that its capacity to reproduce itself is diminished. This study, published in the February .2001 issue of the New England Journal of Medicine , researchers looked at 23 patients who had been treated with antiretroviral medications and had been unable to completely stop the HIV virus from reproducing, the goal of antiretroviral therapy. None had less than 2500 copies of HIV virus per milliliter of blood at the start of the study and they had had significant amounts of virus present in their blood for at least 26 months. Sixteen patients were randomly assigned to continue or discontinue antiretroviral therapy with 11 stopping and five continuing. An additional seven patients were enrolled in a non-randomized arm, all of whom discontinued therapy.