Mutations in nonstructural 5A gene of hepatitis C virus and its response to interferon alfa

Alterations of HCV in peripheral blood mononuclear cells from IFN-treated patients with chronic HCV RNA infection

AIM: To study HCV RNA and HCV protein expression in peripheral blood mononuclear cells (PBMC) and to evaluate the therapeutic efficacy of alpha 2b interferon on the treatment of HCV RNA in PBMC of patients with chronic hepatitis C.

METHODS: Fluorescence quantitative RT-PCR was used to detect the quantitation of HCV RNA in PBMC and plasma, and immunohistochemistry assay was applied to identify HCV NS3 protein expression in PBMC from 20 patients with chronic hepatitis C; Eight patients with chronic hepatitis C received IFN therapy (5 MU/d, three times/week for 16 wks). HCV RNA load in plasma and PBMC was tested with a quantitative assay before and after treatment for 16 wks and compared with that of the control. The data were analyzed by Wilcoxon 2-sample test and Fisher's exact test.

RESULTS: HCV RNA in plasma was found in 15 of 20 (75%) chronic hepatitis C patients and in PBMC was found in 9 of 20 (45%) by fluorescence quantitative RT-PCR. HCV NS3 protein expression was found in 7 of 20 (35%) chronic hepatitis C patients by immunohistochemical assay. HCV RNA loads in PBMC was uncorrelated with those in plasma.In 8 patients, there were significant differences of the decreasing of HCV-RNA loads in plasma and PBMC between before and after interferon treatment for 16 wks (^aP = 0.0 017, ^bP = 0.0 059).The loads of HCV in plasma and PBMC in patients were significantly lower than that of controls after interferon treatment for 16 wks (^cP = 0.0 042, ^dP = 0.0 155).

CONCLUSION: HCV can infect, replicate and express in PBMC. HCV RNA loads in PBMC is uncorrelated with those in plasma. HCV RNA in PBMC can be cleaned out by alpha 2b interferon treatment.