Plasma HIV-1 viremia in HIV-1 infected individuals assessed by polymerase chain reaction.

We established a method to estimate the amounts of HIV-1 particles in plasma from patients with HIV-1 infection by using polymerase chain reaction (PCR) following reverse transcription (RT) of viral RNA (RNA-PCR) and assessed the potential usefulness of this approach to monitor the changes of viral load in patients with AIDS or AIDS-related complex (ARC) receiving 2',3'-dideoxyinosine (ddI). Plasma samples were obtained from 77 patients with HIV-1 infection (49 AIDS/ARC and 28 asymptomatic seropositives). Following ultracentrifugation of plasma, RNA was extracted from the pelleted virus and subjected to RT and PCR. The number of HIV-1 virus particles in each sample was determined using known amounts of HIV-1 DNA as reference control for PCR. The current plasma RNA-PCR technique quantitatively detected HIV-1 particles in plasma from 76 of 77 (98.7%) HIV-1-infected individuals examined. The numbers of HIV-1 particles in plasma from patients with AIDS or ARC were markedly higher than those in plasma from asymptomatic seropositive individuals (p less than 0.0001). Higher levels of plasma HIV-1 particle numbers were detected in individuals with lower CD4+ T cell counts. Patients (n = 10) who received oral ddI at doses greater than or equal to 6.4 mg/kg/day for 8 to 14 weeks had a profound decrease in plasma HIV-1 particle numbers (p = 0.0051). Patients (n = 7) receiving ddI for 45 to 71 weeks also had a decrease (p = 0.018). It should be noted, however, that more research is required to evaluate the usefulness of this technique in assessing the disease status and monitoring the activity of antiretroviral therapy.

In vitro inhibition of hepatitis B virus replication by 2',3'-dideoxyguanosine, 2',3'-dideoxyinosine, and 3'-azido-2',3'-dideoxythymidine in 2.2.15 (PR) cells.

Hep G2-derived hepatoblastoma cells (2.2.15), which actively produce hepatitis B virus (HBV), were cultured in the presence of 2',3'-dideoxyguanosine (ddG), 2',3'-dideoxyinosine, or 3'-azido-2',3'-dideoxythymidine (AZT). ddG was the most potent agent. It diminished viral replication by up to 95%, as assessed by the amount of episomal HBV DNA, without impairing cellular growth. AZT was the least effective against HBV. Northern blot analysis revealed no apparent difference in the pregenomic viral RNA profile, suggesting that these dideoxynucleosides suppress reverse transcription in the replicative cycle of HBV. The effect of varying the time of drug exposure showed that these agents can suppress HBV replication even when added late in culture. HBV replication in another 2.2.15 cell population of the same lineage was affected by ddG differently, which may enable the investigation of phenotypic or genetic alterations during culture. The present data suggest that some 2',3'-dideoxynucleosides can exert a potent antiviral activity against HBV in vitro, at least under certain circumstances, although the data do not prove that any of these agents have utility in patients with hepatitis.