Detection of hepatitis C virus RNA in serum and peripheral blood mononuclear cells in patients with chronic hepatitis C treated with interferon alpha

Genetic variations in host IL28B links to the detection of peripheral blood mononuclear cells-associated hepatitis C virus RNA in chronically infected patients

Hepatitis C virus (HCV) is mainly hepatotropic; however, several reports document the presence of genomic viral RNA in extrahepatic sites including peripheral blood mononuclear cells (PBMCs). In this study, the presence of HCV RNA was initially evaluated in the plasma and peripheral blood mononuclear cells (PBMCs) of 53 HCV-infected patients who were treated per protocol. PBMC-associated HCV RNA was detectable in 79% of patients. Early virological response to combined pegylated interferon-α (PegIFN) and ribavirin (RBV) therapy in patients with undetectable levels of PBMCs-associated HCV RNA was 100%, while it was 60% (P = 0.003) in those who had detectable levels of PBMC-associated HCV RNA. A sustained virological response was observed in 35% of patients with detectable PBMC-associated HCV RNA, but was 70% in patients with undetectable levels of PBMC-associated HCV RNA (P = 0.07). In a multivariate analysis incorporating parameters such as HCV genotype, viral load, presence of cirrhosis and absence of PBMC-associated HCV RNA, a significant relationship was observed between the detection of PBMC-associated HCV RNA and the sustained virological response (OR 19.4, 95% CI: 2.1-486.2, P = 0.0061). The association between single nucleotide polymorphism (SNP) in IL28B, known predictor of antiviral therapy outcome, and the occurrence of HCV RNA in PBMC in 84 chronically infected patients was then evaluated. Results suggest that the presence of a G allele in rs8099917, known to associate to a poor response to PegIFN/RBV therapy, also predicts an increased association of HCV RNA with PBMC (OR: 3.564; 95% CI: 1.114-11.40, P = 0.0437).

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.

Adult post-transplant lymphoproliferative disease in the liver graft in patients with recurrent hepatitis C

AIM

The aim of this study is to clarify the association between hepatitis C virus (HCV) infection and post-transplant lymphoproliferative disease (PTLD) in the liver allograft.

METHODS

Of the 933 adults who underwent liver transplantation (LT) between 1990 and 2005, 10 patients developed PTLD. Seven of the 10 patients that were HCV(+) (group 1) were compared with three HCV-negative recipients (group 2).

RESULTS

The mean time between LT and PTLD was 24.5 months. There were no differences between in Epstein-Barr virus antibody status or tumor lymphocyte subsets. In five of the seven HCV-positive recipients who developed PTLD, PTLD recurred preferentially in the liver allograft, whereas none of the three HCV-negative patients who developed PTLD did so in the liver (71.4 vs. 0%, respectively, P=0.038). In all five patients with graft PTLD, HCV recurred within 12 months followed by PTLD. There were significant differences between groups 1 and 2 in mean lymphocyte infiltrate scores (6.0±2.1 vs. 2.0±0.7, P=0.037), fibrosis stage (2.4±0.5 vs. 0.7±0.5, P=0.029), and frequency of lymphoid follicles in portal areas (33.6±14.8% vs. 1.1±2.3%, P=0.0002).

CONCLUSION

When PTLD occurs in patients with HCV recurrence after LT, it does so preferentially in the liver allograft.

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.

Late disappearance of hepatitis C virus RNA from peripheral blood mononuclear cells in patients with chronic hepatitis C in sustained response after alpha-interferon therapy

OBJECTIVE

We aimed to investigate the modifications of HCV RNA (genomic and antigenomic strands) in peripheral blood mononuclear cells (PBMCs) of long-term responder patients to alpha-interferon therapy, and their usefulness as criteria of definitive HCV eradication.

METHODS

We studied 10 patients with chronic hepatitis C with > 1 yr of sustained response after alpha-interferon therapy (normal alanine aminotransferase [ALT] and negative serum HCV RNA). Serum HCV RNA and genotyping were determined. Approximately 2 and 4 yr after completion of treatment we investigated the presence of HCV RNA (genomic and antigenomic strands) in PBMCs. Eight of 10 patients were rebiopsed 2 yr after discontinuation of treatment.

RESULTS

The mean follow-up was 46.6 +/- 4.6 months (range, 39-51 months). In this period, all patients remained in sustained response. In the first determination, all patients had HCV RNA genomic strands and two patients had antigenomic strands detectable in PBMCs. Two years later only two patients had genomic and none had antigenomic strands detectable. After 4 yr of sustained response, eight of 10 patients lost HCV RNA from PBMCs.

CONCLUSIONS

In the long-term follow-up, the majority of patients with chronic hepatitis C with sustained response after alpha-interferon therapy progressively lost HCV RNA from PBMCs. This determination in PBMCs is not a predictor of response.

Detection of HGV in serum and peripheral blood mononuclear cells of maintenance haemodialysis patients

The aim of the present study was to investigate the prevalence of hepatitis G virus (HGV) and also hepatitis C virus (HCV) infections in maintenance haemodialysis patients, and to identify extrahepatic sites as HGV reservoirs. HGV RNA was detected in the serum of 6/61 (10%) patients and in the peripheral blood mononuclear cells of 2/61 (3%) patients (one of whom was serum negative). These findings suggest that lymphoid cells constitute an extrahepatic HGV reservoir. HCV RNA was detected in 7/61 (11%) patients. Five of these patients (71%) were identified as carrying HCV genotype 1b. Co-infection with HCV and HGV was detected only in one patient. Haemodialysis patients are at risk for HGV infection, by nosocomial routes or via transfusions. HGV itself does not seem to be an important cause of hepatitis since all six HGV RNA positive patients not co-infected by HCV or HBV showed normal ALT values.

Distribution of HCV genotypes in patients infected by different sources

To determine the distribution of hepatitis C virus (HCV) genotypes in our population within the Basque country, 58 HCV-infected patients were analysed. The predominant HCV genotype among subjects infected by blood transfusions (n = 9) and surgical procedures (n = 14) was 1b (88 and 50%, respectively). On the other hand, genotype 3a was the most common among intravenous drug users (n = 16), with data statistically significant (p < 0.0001). There were 18 patients (31%) with unknown risk factors, twelve of whom (66.7%) were infected with genotype 1b. Patients infected with genotype 1b were older than patients infected with genotype 3a (p < 0.0001). There existed a relationship between the HCV genotype and the source of infection.