GB virus C and HIV-1 RNA load in single virus and co-infected West African individuals

Background: Investigations on the impact of GB virus C (GBV-C) co-infection on HIV disease progression relied essentially on clinical follow-up but not on virologic parameters. Objectives: To detect and quantify GBV-C RNA in West African populations co-infected or not with HIV-1 and to correlate the RNA load of HIV-1 and GBV-C in co-replicating patients with different clinical conditions. Methods: Three Ghanaian populations (blood donors, pregnant women and HIV-infected patients) were subdivided into six groups according to HIV-1 and clinical status and GBV-C and HIV-1 RNA load was tested by quantitative real time reverse transcriptase-polymerase chain reaction. In one population with HIV-1 disease, CD4+ cell count was also measured. Results: Prevalence of GBV-C markers in HIV-1-infected groups and HIV-1 non-infected pregnant women were significantly higher than in healthy blood donors. Similar levels and distribution of GBV-C RNA load were found in each population irrespective of HIV-1 status except for a lower GBV-C RNA load in AIDS patients. There was a significant shift of HIV-1 load towards lower value when GBV-C RNA was present and a trend towards an inverse correlation between HIV-1 and GBV-C RNA load. A positive correlation between CD4+ cell count and GBV-C RNA load in symptomatic HIV-1-infected patients was observed. Conclusions: The moderate impact of GBV-C on HIV-1 viremia is unlikely to entirely account for a favourable clinical outcome of replicating co-infections.