Evaluation of circulating natural type 1 interferon-producing cells in HIV/GBV-C and HIV/HCV coinfected patients: a preliminary study.

BACKGROUND: GB virus-C (GBV-C) is a flavivirus that probably influences HIV infection-associated disease among HIV/GBV-C coinfected patients and inhibits the progression of HIV infection to AIDS. To address the possibility of immune-modulating effects of GBV-C coinfection in HIV patients, we evaluated interferon-producing cells in HIV/GBV-C coinfected patients and compared them to HIV-infected patients.

METHODS: We performed a pilot study to enumerate interferon-producing cell count by two-color flow cytometric analysis and also for determining the frequency of ongoing GBV-C and HCV infection among patients infected with HIV. Then, 83 asymptomatic HIV-positive patients were considered for evaluation of interferon-producing cells. Eighty three patients were stratified in four groups according to the HCV and GBV-C infection status: patients infected with HCV and GBV-C (GBV-C+/HCV+), patients infected with GBV-C but not with HCV (GBV-C+/HCV-), patients infected with HCV but not with GBV-C (GBV-C-/HCV+), and patients not infected by GBV-C and HCV (GBV-C-/HCV-).

RESULTS: GBV-C was detected in plasma samples from 15.5% of HIV-infected patients and the frequency of HCV infection was 47.5%. Interferon-producing cells in GBV-C coinfected individuals revealed a wider range of numbers; however, there was no significant difference in the interferon-producing cell count among HIV-infected individuals.

CONCLUSIONS: It does not appear that GBV-C coinfection affects generation or redistribution of interferon-producing cells in HIV-infected patients with relatively intact immune system.