Fluorescent "in situ" hybridization of hepatitis C virus RNA in peripheralblood mononuclear cells from patients with chronic hepatitis C

Although the liver is the main target for hepatitis C virus (HCV) infection , HCV RNA of positive and negative polarity has also been detected in perip heral blood mononuclear cells (PBMCs) by polymerase chain reaction. However , no data have been published on the relationship between the number of HCV -infected PBMCs and serum viremia levels. To address this issue, PBMC sampl es from 20 patients with chronic hepatitis C were examined by fluorescent " in situ" hybridization. Serum viremia levels and viral load in infected PBM C were measured using the Amplicor Monitor test. HCV was detected in all PB MC samples corresponding to the HCV-positive patients. Fluorescent signals were found mainly in the cytoplasm of the cell. The percentage of positive cells ranged from 0.08% to 4%, with a statistical correlation with the vira l load in PBMC (r = 0.69; p =.001) but not with the serum viremia levels (r = 0.23). It was demonstrated that HCV infection of PBMCs is a common featu re of HCV chronic carriers. The results suggest that HCV infection of PBMCs does not contribute significantly to HCV viremia. J. Med. Virol. 60:269-27 4, 2000. (C) 2000 Wiley-Liss, Inc.