Relapse of hepatitis C in a pegylated-interferon-alpha-2b plus ribavirin-treated sustained virological responder

Occurrence of late relapse of hepatitis C virus confirmed by molecular analysis after sustained virologic response to interferon-ribavirin-based therapy

AIM

The optimal duration of follow-up for patients who achieve sustained virologic responses (SVR) has become an important issue. Reports on long-term follow-up of SVR have indicated that 99% of patients maintained SVR. However, the limitations of a majority of studies include small patient numbers, short study periods, and lack of molecular analysis of hepatitis C virus (HCV) genome. The present study sought to evaluate the late relapse rate in long-term follow-up of patients who achieved SVR, with molecular analysis of HCV.

METHODS

A total of 224 patients with chronic hepatitis C who were treated by interferon and ribavirin-based therapy and achieved SVR were enrolled. All patients were recommended for follow-up every 6 or 12 months.

RESULTS

The mean follow-up period was 6.0 years (range, 1.0-13.6 years). Cumulative 5- and 10-year follow-up rates of the patients after SVR were 87.8% and 78.8%, respectively. Cumulative 5- and 10-year follow-up rates of serum HCV RNA after SVR were 85.5% and 52.6%, respectively. Two patients had detectable serum HCV RNA at 20 and 30 months, respectively, after SVR. Phylogenetic analyses of core, non-structural protein 3, and 5A regions of HCV strains from late relapse patients confirmed the same strain was present at baseline and late relapse.

CONCLUSIONS

Two of 224 patients developed late relapse of HCV by the original strain, which was confirmed by direct sequencing analysis. Although few patients may develop late relapse, SVR achieved with interferon and ribavirin-based therapy is durable for prolonged periods.

Long-term follow-up of successful hepatitis C virus therapy: waning immune responses and disappearance of liver disease are consistent with cure

BACKGROUND

A sustained viral response (SVR) after interferon-based therapy of chronic hepatitis C virus (HCV) infection is regarded to represent a cure. Previous studies have used different markers to clarify whether an SVR truly represents a cure, but no study has combined a clinical work-up with highly sensitive HCV RNA detection, and the determination of immune responses.

AIM

To determine clinical, histological, virological and immunological markers 5-20 years after SVR.

METHODS

In 54 patients, liver biochemistry, histology and elastography were evaluated. Liver biopsies, plasma and peripheral blood mononuclear cells (PBMCs) were tested for minute amounts of HCV RNA. HCV-specific T-cell responses were monitored by ELISpot and pentamer staining, and humoral responses by measuring HCV nonstructural (NS)3-specific antibodies and virus neutralisation.

RESULTS

Liver disease regressed significantly in all patients, and 51 were HCV RNA-negative in all tissues tested. There was an inverse association between liver disease, HCV-specific T-cell responses and HCV antibody levels with time from SVR, supporting that the virus had been cleared. The three patients, who all lacked signs of liver disease, had HCV RNA in PBMCs 5-9 years after SVR. All three had HCV-specific T cells and NS3 antibodies, but no cross-neutralising antibodies.

CONCLUSIONS

Our combined data confirm that a SVR corresponds to a long-term clinical cure. The waning immune responses support the disappearance of the antigenic stimulus. Transient HCV RNA traces may be detected in some patients up to 9 years after SVR, but no marker associates this with an increased risk for liver disease.

Trace amounts of sporadically reappearing HCV RNA can cause infection

Successful hepatitis C virus (HCV) treatment is defined as the absence of viremia 6 months after therapy cessation. We previously reported that trace amounts of HCV RNA, below the sensitivity of the standard clinical assay, can reappear sporadically in treatment responders. Here, we assessed the infectivity of this RNA and infused 3 chimpanzees sequentially at 9-week intervals with plasma or PBMCs from patients who tested positive for trace amounts of HCV RNA more than 6 months after completing pegylated IFN-α/ribavirin therapy. A fourth chimpanzee received HCV RNA-negative plasma and PBMCs from healthy blood donors. The 3 experimental chimpanzees, but not the control chimpanzee, generated HCV-specific T cell responses against nonstructural and structural HCV sequences 6-10 weeks after the first infusion of patient plasma and during subsequent infusions. In 1 chimpanzee, T cell responses declined, and this animal developed high-level viremia at week 27. Deep sequencing of HCV demonstrated transmission of a minor HCV variant from the first infusion donor that persisted in the chimpanzee for more than 6 months despite undetectable systemic viremia. Collectively, these results demonstrate that trace amounts of HCV RNA, which appear sporadically in successfully treated patients, can be infectious; furthermore, transmission can be masked in the recipient by an extended eclipse phase prior to establishing high-level viremia.

Hepatitis C virus late relapse after sustained virologic response from interferon and ribavirin treatment as confirmed by RNA sequencing

Hepatitis C virus (HCV) viremia is unusual (<5%) after successful treatment, defined as sustained virologic response (SVR) or undetectable HCV PCR 12 to 24 weeks after therapy. We present a case of late virologic relapse (de novo infection was excluded by RNA sequencing) after SVR followed by spontaneous viral clearance.

Investigation of residual hepatitis C virus in presumed recovered subjects

Recent studies have found hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMCs) of the majority of presumed recovered subjects. We investigated this unexpected finding using samples from patients whose HCV RNA and anti-HCV status had been serially confirmed. HCV RNA was detected in PBMCs from 66 of 67 chronic HCV carriers. Subpopulation analysis revealed that the viral load (log copies/10(6) cells) in B cells (4.14 ± 0.71) was higher than in total PBMCs (3.62 ± 0.71; P < 0.05), T cells (1.67 ± 0.88; P < 0.05), and non-B/T cells (2.48 ± 1.15; P < 0.05). HCV negative-strand RNA was not detected in PBMCs from any of 25 chronically infected patients. No residual viral RNA was detected in total PBMCs or plasma of 59 presumed recovered subjects (11 spontaneous and 48 treatment induced) using nested real-time polymerase chain reaction with a detection limit of 2 copies/μg RNA (from ≈ 1 × 10(6) cells). PBMCs from 2 healthy HCV-negative blood donors became HCV RNA positive, with B-cell predominance, when mixed in vitro with HCV RNA-positive plasma, thus passively mimicking cells from chronic HCV carriers. No residual HCV was detected in liver or other tissues from 2 spontaneously recovered chimpanzees.

CONCLUSION

(1) HCV RNA was detected in PBMCs of most chronic HCV carriers and was predominant in the B-cell subpopulation; (2) HCV detected in PBMCs was in a nonreplicative form; (3) HCV passively adsorbed to PBMCs of healthy controls in vitro, becoming indistinguishable from PBMCs of chronic HCV carriers; and (4) residual HCV was not detected in plasma or PBMCs of any spontaneous or treatment-recovered subjects or in chimpanzee liver, suggesting that the classic pattern of recovery from HCV infection is generally equivalent to viral eradication.

Sustained viral response in a hepatitis C virus-infected chimpanzee via a combination of direct-acting antiviral agents

Efforts to develop novel, interferon-sparing therapies for treatment of chronic hepatitis C (HCV) infection are contingent on the ability of combination therapies consisting of direct antiviral inhibitors to achieve a sustained virologic response. This work demonstrates a proof of concept that coadministration of the nucleoside analogue MK-0608 with the protease inhibitor MK-7009, both of which produced robust viral load declines as monotherapy, to an HCV-infected chimpanzee can achieve a cure of infection.