Determination of HIV RNA concentration for evaluation of the efficacy of combined therapy of HIV infection

: Plasma HIV RNA (viral load) and count of CD4+ T cells were evaluated in 23 patients with HIV infection treated with invirase (1800 mg/day), zidovudine (600 mg/day), and zalcitabine (2.25 mg/day) for 6 months in order to evaluate the efficiency of antiretroviral therapy. Viral load was measured by AMPLICOR HIV-1 Monitor test. The reproducibility of HIV RNA measurements was in line with reported data (CV 15-41%), allowing highly accurate (15%) evaluation of RNA in a standard control sample provided by National Institute for Biological Standards and Control, Great Britain. Plasma HIV RNA concentration decreased to an undetectable level (below 400 RNA copies/ml plasma) after 6 months of treatment in 52.2% patients. In 17.4% the therapy failed, and in 30.4% it resulted in a reduction of viral load to > 1 lg, although HIV RNA was still detected in the plasma after 6-month therapy. The count of CD4+ T cells increased by 9.5%. Changes in the viral load outstripped changes in CD4+ cells. Viral load was in high correlation with the count of CD4+ lymphocytes: -0.53, p = 0.01 before treatment and -0.61, p = 0.002 after 6-month treatment.