Effect of interferon therapy on hepatitis C virus RNA in whole blood, plasma, and peripheral blood mononuclear cells

Abstract

Fifty-two patients with chronic hepatitis C virus (HCV)infection were treated with standard doses of interferon alfa-2b. During treatment, HCV RNA detection was studied in samples of whole blood (WB), plasma (Pl), and peripheral blood mononuclear cells (PBMCs). Individuals were classified as sustained responders (SRs), complete responders with relapse (CRs), partial responders (PRs), or nonresponders (NRs) according to normalization of serum alanine transaminase (ALT) during treatment and follow-up. Before treatment, 100% of WB samples and more than 95% of Pl and PBMC samples were positive for HCV RNA. During treatment, there was progressive clearance of HCV RNA from Pl and PBMCs in SRs and CRs, but CRs had significantly more positive WB samples during and following treatment (P Ͻ.0001). At 6 months, only 10% of CR patients were positive by Pl assay, but 50% were positive by WB assay (P Ͻ.01). In the PR group, all WB samples remained positive throughout treatment, although 25% to 40% of PBMC and Pl samples became negative for HCV RNA during the first 2 months of therapy (WB Ͼ Pl or PBMC; P Ͻ .001). However, at later times during treatment most Pl and PBMC samples in the PR group were positive. Samples from the NR group showed no clearance of HCV RNA from WB, Pl, or PBMC fractions. These data document the increased sensitivity of WB assays for detecting HCV RNA in the peripheral blood of patients during interferon therapy. Furthermore, our findings suggest that WB analysis of HCV RNA may be a useful parameter to monitor in determining the end point of interferon therapy.(HEPATOL-OGY 1998;28:1110-1116.)Hepatitis C virus (HCV) is a small, enveloped RNA virus of approximately 9,500 nucleotides that is responsible for more than 90% of parenterally transmitted cases of non-A, non-B hepatitis. 1-3 Infection with HCV usually results in chronic active hepatitis, which may progress to cirrhosis. Currently, end-stage liver disease resulting from chronic HCV infection is a major reason for referral of patients for orthotopic liver transplantation in the United States. 4,5 Interferon therapy is the only approved treatment for chronic hepatitis C. Approximately 50% of patients who are treated respond with normalization of serum aminotransferase levels, although more than half of these responders will relapse after discontinuation of the drug. Thus, approximately 20% of treated patients have a durable, sustained response. 6,7 Although the reasons responsible for relapse are unclear, variables such as length of treatment, HCV genotype, and histological evidence of inflammation and fibrosis at the start of therapy appear to correlate with treatment outcomes. 3,[8][9][10][11] Reverse-transcription (RT) polymerase chain reaction (PCR) techniques to detect HCV RNA during interferon therapy have been widely employed and are considered to be important for optimum management. 12,13 A high level of HCV RNA in serum before treatment is a poor prognostic sign for sustained response; unfortunately, clearance of virus from serum or plasma ...

HCV-RNA positivity in peripheral blood mononuclear cells of patients with chronic HCV infection: does it really mean viral replication

“…Schmidt and colleagues have investigated the distribution of HCV in whole blood and in the different cell fractions. Whole blood contained significantly more HCV-RNA than pasma, which contained more HCV-RNA than PBMC, the lowest level of HCV-RNA was found in granulocytes and in red blood cells/pellets [13,14] . In the case of granulocytes, the virus may simply be ingested by phagocytosis and in the red blood cells or pellets.…”

“…It has been hypothesized that virus replication takes place at extrahepatic sites. Possible sites are the different cell fractions (PBMC, granulocytes or red blood cells/pellets) of the peripheral blood [13,14] or tissues like lymph nodes, pancreas, adrenal gland thyroid, bone marrow or spleen [15] . In particular, PBMCs have been suggested to function as an important extrahepatic reservoir or as a possible site for e x t r a h e p a t i c H C V r e p l i c a t i o n [ 1 6 -1 9 ] .…”

Extrahepatic replication of HCV: Insights into clinical manifestations and biological consequences

“…103 Thus, it is provocative to speculate that low-level replication of HCV in PBMCs may lead to reactivation of HCV after termination of therapy and/or predict response to therapy. 80,99,100,[102][103][104][105] As reviewed elsewhere, HCV is likely involved in several neurologic syndromes. 16 While central nervous system (CNS) involvement is less frequent, the detection of negative-strand HCV RNA in the CNS 29 suggests a potential link between HCV and these extrahepatic pathol- ogies.…”

Whole-Blood Hepatitis C Virus RNA Extraction Methods

“…Our study of 115 patients with HCV infection demonstrated that the improved sensitivity of whole-blood HCV RNA detection correlated with the presence and quantity of cryoglobulins (8). We also noted highly significant differences in the detection of HCV RNA for whole blood and plasma among 52 interferon-treated patients who were monitored throughout treatment (7). As was the case for the one patient studied by Cook et al (3), among our 52 patients the clearance of intracellular virus occurred nearly simultaneously with the clearance of plasma virus during therapy (7).…”

“…We read the article by Cook et al (3) with interest, since they compared their findings with our previous work (4)(5)(6)(7)(8) (3,4). (iv) Finally, the serum volume was not adjusted to the whole-blood volume (3), which we took into account (6).…”