Prediction of relapses after interferon-alpha therapy by hepatitis C virus RNA in peripheral blood mononuclear cells

Quantitation of hepatitis C virus RNA in peripheral blood mononuclear cells in HCV-monoinfection and HIV/HCV-coinfection

Peripheral blood mononuclear cells (PBMCs) represent an extrahepatic hepatitis C virus (HCV) reservoir, the significance of which is unclear due to limited studies and varying test methodologies. In this study, a commercial viral load assay for measuring cell-associated PBMC HCV RNA was evaluated. HCV RNA was extracted from PBMCs, sorted CD14+, and CD19+ cells and corresponding plasma samples using the Abbott m2000 and Real-Time HCV assay. Test performance and influence of HIV seropositivity on plasma and PBMC HCV RNA were studied. Among 51 patients, 67 and 62 unique patient samples had detectable plasma and PBMC HCV viral load, respectively. The median PBMC viral load was 535 IU/1 M cells (range 29-5,190). CD19+ cells had significantly higher viral load than CD14+ cells (median log(10) HCV viral load 2.63 vs. 1.50 IU/ml; P< 0.001). Stability of PBMC viral load over time was demonstrated in untreated patients; all patients with an undetectable plasma HCV viral load after HCV treatment also demonstrated undetectable PBMC viral load. Repeated testing in nine samples yielded consistent PBMC viral load, differing by only 1.3-fold (range 1.0-1.7-fold). Among samples with detectable plasma HCV RNA, the correlation between PBMC and plasma viral load was moderate (r = 0.66) and was greater among HCV mono-infected compared to HIV/HCV co-infected subjects (r = 0.80 vs. 0.52). Measurement of cell-associated PBMC HCV RNA using a commercial assay demonstrated promising test characteristics. Differences in PBMC HCV viral load based on HIV-coinfection status and the significance of greater copy number in B-cells requires further study.

Presence of plus-strand HCV RNA in serum and PBMCs as an indicator for relapse and resistance to IFN therapy in patients infected by HCV

Aim: The aim of our study was to investigate the correlation between the presence of plus-/minus-strand HCV RNA in peripheral blood mononuclear cells (PBMCs) and serum following pegylated IFN/ribavirin therapy with response to therapy in HCV-infected patients. Methods: Forty-three HCV-infected patients who completed 48 weeks of IFN/ribavirin therapy, including 25 sustained virologic responders, 12 resistants and six relapsers, comprised the study population. Plus-/minus-strand HCV RNA was detected by reverse transcription PCR in serum and PBMCs. Results: The frequency of plus-strand HCV RNA was significantly higher in PBMC and serum samples of relapsers and resistants, and this might have important implications in clinical practice and patient management. There was no correlation between presence of plus- and minus-strand HCV RNA and genotypes, except the fact that most of the patients who had plus-strand HCV RNA in PBMCs (60%) and in serum (61.53%) belonged to genotype 1a. Conclusion: Presence of plus-strand HCV RNA in PBMCs and serum after termination of therapy is associated with viral relapse and resistance to IFN/ribavirin treatment in HCV-infected patients.

Distribution of different hepatitis C virus genotypes in patients with hepatitis C virus infection

AIM: To investigate the presence of mixed infection and discrepancy between hepatitis C virus (HCV) genotypes in plasma, peripheral blood mononuclear cells (PBMCs), and liver biopsy specimens.

METHODS: From September 2008 up to April 2009, 133 patients with chronic hepatitis C referred to Firouzgar Hospital for initiation of an antiviral therapy were recruited in the study. Five milliliters of peripheral blood was collected from each patient and liver biopsy was performed in those who gave consent or had indications. HCV genotyping was done using INNO-LiPA™ HCV II in serum, PBMCs, and liver biopsy specimens and then confirmed by sequencing of 5’-UTR fragments.

RESULTS: The mean age of patients was 30.3 ± 17.1 years. Multiple transfusion was seen in 124 (93.2%) of patients. Multiple HCV genotypes were found in 3 (2.3%) of 133 plasma samples, 9 (6.8%) of 133 PBMC samples, and 8 (18.2%) of 44 liver biopsy specimens. It is notable that the different genotypes found in PBMCs were not the same as those found in plasma and liver biopsy specimens.

CONCLUSION: Our study shows that a significant proportion of patients with chronic hepatitis C are affected by multiple HCV genotypes which may not be detectable only in serum of patients.

Hepatitis C virus lymphotropism and peculiar immunological phenotype: Effects on natural history and antiviral therapy

Hepatitis C virus (HCV) has been recognized to be both a hepato- and lymphotropic virus. HCV lymphotropism represents an essential lap in the pathogenesis of virus-related autoimmune and lymphoproliferative disorders, ranging from clonal expansion of B-cells with organ- and non-organ-specific autoantibody production up to overt non-Hodgkin’s lymphoma along a continuous step-by-step model of B-cell lymphomagenesis, where the intermediated mixed cryoglobulinemia could be considered as a stage of suppressible antigen-driven lymphoproliferation. HCV infection of lymphoid cells could set up privileged reservoirs able to interfere with the host viral clearance efficiency and may be implicated in viral recurrence after apparently successful antiviral therapy. The HCV long-lasting extrahepatic replicative state generates an abnormal systemic immunological response, easily detectable by searching simple laboratory and clinical parameters, mainly represented by vasculitis-like skin features and hypocomplementemia. The presence or absence of this hypersensitivity pattern seems to correlate with the antiviral response and could be identified as a novel immunological cofactor. Further research is required to fully verify the real impact on therapeutic choice/regimen.

Hepatitis C virus lymphotropism: lessons from a decade of studies

The possibility that HCV infects lymphoid cells has been widely discussed. Evidence in favor of HCV tropism for lymphoid cells derives from a series of data including: (1) the higher sensitivity of testing HCVRNA in PBMC than in serum or plasma samples, with possible detection of HCV RNA-positive PBMC in the absence of HCV viremia; (2) short-term cultures of PBMC which yield a significant increase in the amount of viral RNA on stimulation by mitogens; (3) results of "in situ" methods (i.e. in situ hybridization, immunofluorescence); (4) efficient infection of lymphoid cell lines or PBMC from normal individuals; (5) the persistence of HCV RNA in PBMC obtained from HCV-positive subjects and injected into SCID mice; (6) the long-term persistence of HCV RNA in PBMC in spite of HCV RNA negativity of serum and liver in sustained responder patients after therapy. The principal criticisms concerning effective HCV infection of lymphoid cells arise from technical difficulty in identifying HCV RNA replicative intermediate in these elements. Conflicting data may also result from differences in PBMC infection by different genotypes, samples taken at different stages in the disease process and differences in the sensitivity of detection methods, as well as low replication levels and/or proportion of infected PBMC. Interesting available data about HCV lymphotropism, which is possibly important in influencing the natural history of infection, include: (1) possible preferential viral tropism for specific PBMC subsets; (2) different lymphotropism of different viral strains; (3) selection of distinctive viral strains; (4) identification of putative HCV cell receptors; (5) association between determination of HCV lymphatic infection and t(14; 18) translocation. The clinical correlates of HCV lymphotropism are potentially very numerous, including, first, its role in determining HCV-related lymphoproliferative disorders.

Effect of anti-viral therapy for occult hepatitis C virus infection

BACKGROUND

Occult hepatitis C virus infection is defined by the presence of hepatitis C virus-RNA in liver but with undetectable anti-hepatitis C virus and serum viral RNA.

AIM

To study the response to anti-viral therapy in occult hepatitis C virus infection to assess the pathogenic effect of occult hepatitis C virus.

METHODS

Ten patients with occult hepatitis C virus infection were treated with pegylated-interferon plus ribavirin for 24 weeks and were followed-up 24 weeks after therapy. All patients had abnormal alanine aminotransferase, hepatitis C virus-RNA positive in peripheral blood mononuclear cells and liver necroinflammation.

RESULTS

At the end of treatment and follow-up, the percentage of patients with normal alanine aminotransferase was 80% (95% CI: 48-96%) and 60% (95% CI: 31-84%) respectively, and hepatitis C virus-RNA in peripheral blood mononuclear cells was negative in 80% (95% CI: 48-96%) and 70% (95% CI: 40-90%) cases. At the end of follow-up sustained response was observed in 30% (95% CI: 11-61%) of cases. Five patients underwent a second liver biopsy. In all cases, liver hepatitis C virus-RNA persisted, although hepatitis C virus-RNA load was significantly lower (3.2 x 10(4) +/- 5.1 x 10(4) copies/microg RNA) than in the basal biopsy (2.4 x 10(5) +/- 3.8 x 10(5) copies/microg RNA); (P = 0.043). Necroinflammation and fibrosis decreased in three cases.

CONCLUSION

The biochemical, virological and histological response to therapy achieved in patients with occult hepatitis C virus infection demonstrates the pathologic effects of occult hepatitis C virus.

[Dual infection with hepatitis B and C. Spontaneous course and response to virostatic therapy in children following neoplastic diseases]

Combined chronic hepatitis B and C is a long-term complication in children surviving malignancy. We report on seven children who acquired hepatitis B as well as C virus infection during treatment for different malignancies. Four patients showed a spontaneous HBe Ag/anti-HBe seroconversion, two patients spontaneous clearance of hepatitis C virus, and one patient showed both HBe Ag/anti-HBe seroconversion and clearance of hepatitis C virus. One patient developed HBe Ag/anti-HBe seroconversion after antiviral interferon monotherapy and another patient after combination therapy with interferon/famcyclovir. Three patients developed complete sustained response of hepatitis C to a combined virostatic therapy with interferon and ribavirin. A total of 4 of 7 patients had a clearance of both infections and 3 of 7 patients had a clearance of at least one infection.

CONCLUSION

Our data in long-term survivors of childhood cancer with combined hepatitis B and C showed a remarkably high rate of spontaneous cure and a favourable response to antiviral therapy.

Fully automated detection of hepatitis C virus RNA in serum and whole-blood samples

In this study, we established a fully automated molecular assay for qualitative detection of hepatitis C virus (HCV) in serum and whole-blood samples and compared it with conventional molecular assays, including manual HCV RNA extraction protocols. Whole-blood samples were collected from patients with and without chronic HCV infection in EDTA tubes and nucleic acid stabilization tubes (NASTs). Prior to HCV RNA extraction, the HCV Internal Control (IC), derived from the COBAS AMPLICOR HCV test, version 2.0 (Roche Molecular Diagnostics), was added. The new assay was based on an automated extraction protocol on the MagNA Pure LC instrument (Roche Applied Science), followed by automated reverse transcription, amplification, hybridization, and detection on the Cobas Amplicor analyzer (Roche Molecular Diagnostics). The detection limit of the new assay was found to be similar to those of conventional molecular assays. In clinical samples, 100% agreement between the new assay and conventional methods was observed. The introduced amount of IC was detected in 45 of 45 serum samples, 41 of 45 EDTA tube whole-blood samples, and 43 of 45 NAST whole-blood samples. Retesting led to more frequent IC detection. The fully automated molecular assay was found to be suitable for detection of HCV RNA in different kinds of sample materials. It may be recommended for use in the high-throughput routine molecular diagnostic laboratory.

Effects of storage and type of blood collection tubes on hepatitis C virus level in whole blood samples

In this study, we compared serum hepatitis C virus (HCV) RNA concentrations with HCV RNA concentrations in whole blood collection tubes, including two different types of EDTA tubes and nucleic acid stabilization tubes (NASTs). We also investigated the impact of a processing delay on HCV RNA concentration in these tubes. In NASTs, the mean HCV RNA concentration was comparable to the mean serum HCV RNA concentration at "date zero." In EDTA tubes, mean baseline HCV RNA concentrations were higher. Storage at room temperature up to 96 h did not result in a decline of HCV RNA concentration in any of the whole blood collection tubes. In NASTs, HCV RNA concentrations remained stable during the whole study period, whereas a significant increase of HCV RNA was observed in both types of EDTA tubes at 96 h compared to date zero. We concluded that HCV RNA remains stable in NASTs at room temperature for at least 96 h, allowing greater flexibility in sample collection and transport.

Viral, host and interferon-related factors modulating the effect of interferon therapy for hepatitis C virus infection

The estimated prevalence of hepatitis C virus infection in the US is approximately 1.8%. Although interferon monotherapy and combination therapy of interferon with ribavirin represent mainstay for treating HCV infection, the rate of sustained virologic response remains suboptimal. The growing evidence suggested that the clinical sequence and treatment response of chronic hepatitis C are determined by a dynamic, complex tripartite relationship among HCV infection, the host immune response, and the effect of different interferon regimens. The treatment response is associated with various viral factors including the pretreatment viral level, dynamic change of viral level during treatment, viral genotype quasispecies and nucleotide mutation in nonstructural protein 5A of hepatitis C virus. Host factors that may affect treatment response include age, gender, race, HLA alleles and the host immune responses. Interferon regimens, including type, dose, frequency and duration of treatment and combination of interferon with other anti-HCV agents also alter the therapeutic response. Understanding these complicated interaction may provide better insights into the mechanism(s) of interferon response, leading to more effective clinical application of interferon therapy.

Methodological issues in papers on IFN therapy: time for reappraisal

We conducted an analytical review of 194 full papers on interferon (IFN) therapy for chronic hepatitis C to evaluate current methodology (i.e. study design, criteria for evaluating the efficacy of therapy and predictors of response). Of the papers evaluated, 64 were randomized controlled trials (RCT), 40 were non-randomized controlled trials (NRCT) and 90 were observational studies (OS). The methodological analysis was focused mainly on clinical trials. The number of patients enrolled in RCT was higher compared with the number enrolled in NRCT. Uniform enrolment criteria were used in less than 50% of the trials. Only 20% of RCT and 2.5% of NRCT used criteria for defining sample size. The response rate was calculated on an intention-to-treat basis in 36 of the RCT and in 14 of the NRCT. The outcome of treatment and the criteria employed to define the response to treatment were found to be far from standardized. In 51.5% of the RCT and 42.5% of the NRCT, normalization of alanine aminotransferase (ALT) level at the end of follow-up was the only marker of response studied. Only 57.6% of the trials considered histological evidence as an important outcome. Among the clinical trials, 71.1% evaluated predictors of good response to IFN therapy. In 51% of the OS, ALT normalization by the end of follow-up was the only criterion for defining response. In conclusion, to ensure a high level of reliability in comparing or combining the results of different studies, some basic general requirements must be followed when planning trials on antiviral therapy.

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

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 <.0001). At 6 months, only 10% of CR patients were positive by Pl assay, but 50% were positive by WB assay (P <.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 > Pl or PBMC; P < .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.

Hepatitis C viral RNA status at two weeks of therapy predicts the eventual response

We investigated the timing of the disappearance and reappearance of serum hepatitis C viral (HCV) RNA in patients with chronic hepatitis C during interferon treatment and follow-up. Serum samples were tested for HCV RNA by polymerase chain reaction in 62 patients with chronic hepatitis C treated with interferon-alpha for 24 weeks. We found that 17 patients obtained complete response, with absence of serum HCV RNA for 6 months after the treatment. Twenty-nine patients had a partial response, with reappearance of serum HCV RNA within 6 months of follow-up, and 16 patients were nonresponders who were positive for serum HCV RNA throughout the observation period. HCV RNA disappeared within 2 weeks of treatment in 31 patients, including all 17 (100%) complete responders and 14 (48.3%) of the 29 partial responders. The patients remaining positive for HCV RNA at the second week were 15 (51.7%) of the 29 partial responders and the 16 nonresponders. In all of the 29 partial responders, viremia recurred within 1 month after the treatment. These results indicate that the status of HCV RNA at the second week of treatment is a useful predictor of effective treatment, whereas status at the first month after cessation of treatment is useful for assessing the effectiveness of interferon itself.

Quantitative assessment of hepatitis C virus RNA in peripheral blood mononuclear cells during therapy with interferon-alpha2a

A significant number of patients with hepatitis C (HCV) treated with interferon (IFN) will initially clear their serum of HCV RNA, but will then have recurrence of viraemia either during or after therapy. One proposed mechanism for relapse is that HCV may persist in peripheral blood mononuclear cells (PBMCs) and that the PBMCs serve as a 'viral reservoir' that is resistant to IFN. To address this hypothesis, we performed serial, quantitative polymerase chain reaction (PCR) of HCV RNA in serum and PBMCs from 26 consecutive patients treated with IFN-alpha2a. Of the 26 patients, 11 (42%) did not clear virus from their serum during therapy and were termed non-responders. Five patients (19%) had sustained clearance of virus from serum and were termed complete responders. The remaining 10 patients (39%) initially eliminated HCV RNA from their serum, but had relapse of viraemia. They were termed partial responders. In all 10 partial responders HCV RNA was undetectable in PBMCs at the same time that it was undetectable in serum. When virus recurred in serum, it was preceded by or occurred at the same time as the return of virus in PBMCs. The results of our study indicate that PBMCs did not serve as an IFN-resistant 'viral reservoir' during therapy. Partial responders who transiently cleared virus from serum also cleared virus from PBMCs and the presence or titre of HCV RNA in PBMCs at the initiation of therapy did not predict response to therapy.

Chronic hepatitis C: T-helper1/T-helper2 imbalance could cause virus persistence in peripheral blood

Interferon gamma (IFN gamma) and interleukin 4, 10 and 12 (IL-4, -10, -12) production was measured in whole peripheral blood (WPB) and peripheral blood mononuclear cells (PBMC) of 10 chronic hepatitis C (CHC) patients. The level of IFN gamma in supernatants in mitogen-activated WPB was lower than in healthy donors. IL-10 served as a possible downregulative factor for IFN gamma, since its spontaneous IL-10 production was enhanced in CHC. Neutralization of IL-10 partly restored IFN gamma response in CHC patients. Recombinant IL-12 (rIL-12) also enhanced IFN gamma of CHC patients, but IL-12 production was decreased in CHC. Thus, IFN gamma production deficiency in CHC patients is secondary to blockage by high levels of IL-10-impaired IL-12 production.

Quantification of hepatitis C virus RNA in peripheral blood mononuclear cells: a comparison between patients chronically infected by HCV and patients coinfected by HIV

In patients chronically infected by hepatitis C virus (HCV), peripheral blood mononuclear cells (PBMCs) were shown to be targets for virus replication and in those coinfected with HIV, HCV viraemia was considerably increased. The purpose of this study was to quantify HCV RNA in PBMCs from 25 patients infected by HCV and from 25 patients coinfected by HCV and HIV. We used the branched DNA assay after extraction of total RNA on 5 x 10(6) cells to quantify HCV RNA, and the Inno LiPA assay to determine the HCV genotype. HCV RNA in PBMCs could be quantified in 8/25 patients in each group, but the HCV RNA concentration was very low in comparison with viraemia, since the highest result was 8.1 x 10(4) Eq genome/10(6) cells. In 10 ml of total blood, there was approximately 100 to 5,000 times less HCV RNA in PBMCs than in the plasma. It is therefore likely that PBMCs play only a minor part in the viral load present in the plasma. There was no preferential genotype associated with quantifiable HCV RNA in the PBMCs. In the case of HIV coinfection, there was no increase in the HCV-RNA concentration in PBMCs that could explain the increased viraemia observed in these patients. On the contrary, HCV RNA could not even be detected by RT-PCR in some of our coinfected patients.