Interpretation of positive transcription-mediated amplification test results from polymerase chain reaction-negative samples obtained after treatment of chronic hepatitis C

Long-term follow-up after cure from chronic hepatitis C virus infection shows occult hepatitis and a risk of hepatocellular carcinoma in noncirrhotic patients

OBJECTIVES

Curing of hepatitis C virus (HCV) infection primarily aims to prevent severe liver complications. Our objectives were to investigate the long-term presence and impact of occult HCV infection (OCI) and to study the outcomes in terms of liver disease after virological cure.

PATIENTS AND METHODS

A total of 97 patients with achieved sustained virological response (SVR) during 1990-2005 were followed either by a clinical follow-up (FU) visit with blood sampling and liver elastography (n=54) or through national registries for outcomes (n=43). To diagnose OCI among patients with SVR, a highly sensitive method was used to detect HCV-RNA traces in whole blood. The FU duration was a median of 10.5 years, with samples up to 21.5 years after the end of treatment (EOT).

RESULTS

The majority of patients [52 (96%)] were HCV-RNA negative at FU, and regression of fibrosis was statistically significant. OCI was found in two (4%) of them at 8 and 9 years after EOT. These patients had F1 and F2 fibrosis before treatment and F2 at FU, but no other abnormal findings. Three previously noncirrhotic men were diagnosed with hepatocellular carcinoma 8-11 years after EOT.

CONCLUSION

Occult infection could be detected many years after the achievement of SVR but was not associated with serious liver disease. The majority had persistent viral eradication and regression of fibrosis after SVR. However, an increased risk of hepatocellular carcinoma may persist in the long term after SVR even in noncirrhotic patients. Further studies with FU after direct-acting antiviral therapy and on the long-term impact after cure are needed.

APASL consensus statements and recommendations for hepatitis C prevention, epidemiology, and laboratory testing

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on "APASL consensus statements and recommendations for management of hepatitis C" in March 2015 to revise the "APASL consensus statements and management algorithms for hepatitis C virus infection" (Hepatol Int 6:409-435, 2012). The working party consisted of expert hepatologists from the Asian-Pacific region gathered at the Istanbul Congress Center, Istanbul, Turkey on 13 March 2015. New data were presented, discussed, and debated during the course of drafting a revision. Participants of the consensus meeting assessed the quality of the cited studies. The finalized recommendations for hepatitis C prevention, epidemiology, and laboratory testing are presented in this review.

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.

Processes to manage analyses and publications in a phase III multicenter randomized clinical trial

Background

The timely publication of findings in peer-reviewed journals is a primary goal of clinical research. In clinical trials, the processes leading to publication can be complex from choice and prioritization of analytic topics through to journal submission and revisions. As little literature exists on the publication process for multicenter trials, we describe the development, implementation, and effectiveness of such a process in a multicenter trial.

Methods

The Hepatitis C Antiviral Long-Term Treatment against Cirrhosis (HALT-C) trial included a data coordinating center (DCC) and clinical centers that recruited and followed more than 1,000 patients. Publication guidelines were approved by the steering committee, and the publications committee monitored the publication process from selection of topics to publication.

Results

A total of 73 manuscripts were published in 23 peer-reviewed journals. When manuscripts were closely tracked, the median time for analyses and drafting of manuscripts was 8 months. The median time for data analyses was 5 months and the median time for manuscript drafting was 3 months. The median time for publications committee review, submission, and journal acceptance was 7 months, and the median time from analytic start to journal acceptance was 18 months.

Conclusions

Effective publication guidelines must be comprehensive, implemented early in a trial, and require active management by study investigators. Successful collaboration, such as in the HALT-C trial, can serve as a model for others involved in multidisciplinary and multicenter research programs.

Trial registration

The HALT-C Trial was registered with clinicaltrials.gov (NCT00006164).

Prevalence of occult hepatitis C infection in chronic hemodialysis and kidney transplant patients

BACKGROUND & AIMS

Detection of hepatitis C virus (HCV) RNA in peripheral blood mononuclear cells (PBMC) and/or hepatocytes in absence of HCV RNA in serum, designated as 'occult HCV infection', has been a matter of controversy in recent years. We investigated for the first time the prevalence of occult HCV infection in large cohorts of chronic hemodialysis (CHD) and kidney transplant (KTx) patients.

METHODS

We enrolled 417 CHD patients, 417 KTx recipients and 2 control groups - 25 anti-HCV (antibody against HCV)-positive and HCV RNA-positive patients with chronic hepatitis C, and 40 anti-HCV-, HCV RNA-, and HBsAg-negative healthy subjects. HCV RNA was tested in serum and PBMC using a sensitive commercial assay.

RESULTS

In CHD patients, the prevalence of anti-HCV was 3.6% (15/417) and of positive serum HCV RNA 2.4% (10/417). HCV RNA was detected in PBMC in 1/407 (0.25%) HCV serum RNA-negative patients ("occult HCV infection"). In KTx recipients, prevalence of anti-HCV was 4.8% (20/417) and of positive serum HCV RNA 4.6% (19/417). Occult HCV infection was found in 2/398 (0.5%) serum HCV RNA-negative patients. On a mean longitudinal follow-up of 30months of the 3 patients with occult HCV infection, there was no clinical or virological evidence of HCV infection.

CONCLUSIONS

The prevalence of occult HCV infection was very low in our CHD and KTx patients, and it did not appear to be clinically relevant. Further studies in geographic populations with high HCV endemicity are required to clarify the significance of occult HCV infection in these patient groups.

[To consider negative viral loads below the limit of quantification can lead to errors in the diagnosis and treatment of hepatitis C virus infection]

INTRODUCTION

For years many clinical laboratories have routinely classified undetectable and unquantifiable levels of hepatitis C virus RNA (HCV-RNA) determined by RT-PCR as below limit of quantification (BLOQ). This practice might result in erroneous clinical decisions.

AIM

To assess the frequency and clinical relevance of assuming that samples that are BLOQ are negative.

MATERIAL AND METHOD

We performed a retrospective analysis of RNA determinations performed between 2009 and 2011 (Cobas/Taqman, lower LOQ: 15 IU/ml). We distinguished between samples classified as «undetectable» and those classified as «<1.50E+01IU/mL» (BLOQ).

RESULTS

We analyzed 2.432 HCV-RNA measurements in 1.371 patients. RNA was BLOQ in 26 samples (1.07%) from 23 patients (1.68%). BLOQ results were highly prevalent among patients receiving Peg-Riba: 23 of 216 samples (10.6%) from 20 of 88 patients receiving treatment (22.7%). The clinical impact of BLOQ RNA samples was as follows: a) 2 patients initially considered to have negative results subsequently showed quantifiable RNA; b) 8 of 9 patients (88.9%) with BLOQ RNA at week 4 of treatment later showed sustained viral response; c) 3 patients with BLOQ RNA at weeks 12 and 48 of treatment relapsed; d) 4 patients with BLOQ RNA at week 24 and/or later had partial or breakthrough treatment responses, and e) in 5 patients the impact were null or could not be ascertained.

CONCLUSIONS

This study suggests that BLOQ HCV-RNA indicates viremia and that equating a BLOQ result with a negative result can lead to treatment errors. BLOQ results are highly prevalent in on-treatment patients. The results of HCV-RNA quantification should be classified clearly, distinguishing between undetectable levels and levels that are BLOQ.

Hepatitis C virus viral assays in the direct-acting antiviral era

In the direct-acting antiviral (DAA) era of hepatitis C virus (HCV) therapy, health care providers must be knowledgeable about genotype and subtype of HCV infection and interpretation of quantitative HCV viral assays to monitor treatment responses. They may also choose to assess interleukin 28B genotypes or resistance-associated variants after ineffective DAA therapy. DAA therapies require understanding of performance characteristics of quantitative HCV RNA assays and the definitions of terms used to report results. Only quantitative HCV RNA assays with a limit of detection of 10 to 15 IU/mL are appropriate for managing patients on DAA therapy.

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.

APASL consensus statements and management algorithms for hepatitis C virus infection

The Asian Pacific Association for the Study of the Liver (APASL) convened an international working party on the "APASL Consensus Statements and Management Algorithms for Hepatitis C Virus Infection" in December, 2010, in order to revise "Asian Pacific Association for the Study of the Liver consensus statements on the diagnosis, management and treatment of hepatitis C virus infection (J Gastroenterol Hepatol 22:615-633, 2007)". The working party consisted of expert hepatologists from the Asian-Pacific region gathered at Makuhari, Chiba, Japan on 19 December 2010. New data were presented, discussed and debated to draft a revision. Participants of the consensus meeting assessed the quality of cited studies. Finalized recommendations are presented in this review.

Clinical significance of discordant positive hepatitis C virus transcription-mediated amplification following end of treatment response

BACKGROUND

Polymerase chain reaction (PCR) assays are the standard for detecting hepatitis C virus viremia. The transcription-mediated amplification (TMA)-based assay is more sensitive.

METHODS

We retrospectively reviewed the charts of patients with a post-end of treatment (EOT) PCR-/TMA+ result to assess the clinical significance of a positive TMA result after a PCR negative EOT response or sustained viral response (SVR). Patients were divided into Group 1: PCR-/TMA+ after EOT response but during 24 week follow-up (n = 4); and Group 2: PCR-/TMA+ after SVR (n = 11).

RESULTS

All Group 1 patients achieved SVR. No Group 2 patients became PCR positive or had a rise in ALT. The TMA subsequently became negative in 6/7 patients with follow-up evaluation.

CONCLUSIONS

A discordant positive TMA post-EOT response or SVR did not seem to be clinically significant. This finding supports the possibility that patients with SVR have an acquired immune surveillance that prevents low-level viremia from progressing to clinical relapse.

Discordance between HCV RNA assays for week 24 HCV RNA determination during pegylated interferon-α/ribavirin treatment for chronic hepatitis C

BACKGROUND

The development of more sensitive HCV RNA assays might necessitate re-evaluation of the rules for stopping treatment (for example, HCV RNA negativity at week 24 during treatment with pegylated interferon-α and ribavirin for chronic hepatitis C). The aim of this study was to assess discordance between the week 24 HCV RNA test results of two PCR-based assays (Amplicor and TaqMan) and the transcription-mediated amplification (TMA) HCV RNA qualitative assay.

METHODS

A total of 89 week 24 samples that were negative using PCR-based assays during treatment were retested with the TMA qualitative assay to investigate discordance between tests results. All week 24 samples were HCV RNA negative by Amplicor or by TaqMan.

RESULTS

Of the 89 patients, 46 (52%) achieved sustained virological response (SVR). Viral breakthrough or relapse occurred in 43 patients (48%). All 89 HCV RNA negative week 24 samples were retested with the qualitative TMA assay. Eleven out of 89 samples had detectable HCV RNA (12%). All patients with detectable HCV RNA experienced breakthrough or relapse (negative predictive value 100%). Of the 78 patients with undetectable HCV RNA at week 24 using the TMA assay, 46 achieved SVR. This resulted in a positive predictive value (PPV) of 59% for the TMA assay compared with a PPV of 52% for the PCR-based assays.

CONCLUSIONS

All patients with detectable HCV RNA at week 24 using the TMA assay eventually relapsed. On the basis of these results, the use of this more sensitive HCV RNA assay could lead to the prevention of unnecessary treatment.

Hepatitis C virus RNA assays: current and emerging technologies and their clinical applications

Molecular diagnostic assays represent a cornerstone in the management of hepatitis C virus (HCV) patients. Qualitative and quantitative HCV molecular assays are used for the diagnosis of acute and chronic HCV infections, viral genotyping, viral-load determination, treatment monitoring and prognosis. Reverse-transcription PCR, transcription-mediated amplification and branched DNA amplification are commonly employed for detection of HCV RNA. Recently, new HCV molecular assays that employ nanostructures have emerged and have been proposed as suitable for both low- and high-resource settings, without sacrificing sensitivity and specificity. This article will present current and future HCV molecular diagnostic assays with a focus on their clinical applications.

Sporadic reappearance of minute amounts of hepatitis C virus RNA after successful therapy stimulates cellular immune responses

BACKGROUND & AIMS

Several studies have reported hepatitis C virus (HCV) RNA sequences in the circulation after treatment-induced or spontaneous recovery. We investigated whether the HCV RNA represents persistence of HCV infection or reinfection.

METHODS

We studied 117 patients who recovered from HCV infection (98 following therapy and 19 spontaneously). A reverse-transcription polymerase chain reaction assay was used to detect the 5'-untranslated region of HCV. T-cell responses were studied by enzyme-linked immunospot for interferon-γ.

RESULTS

Plasma samples from 15% of treatment-recovered patients and no spontaneously recovered patient tested positive for HCV RNA. Lymphocytes from 3 patients who responded to therapy and 1 who recovered spontaneously tested positive. The frequency of HCV RNA detection in plasma correlated inversely with the time after the end of treatment. Post-treatment HCV 5'-untranslated region sequences matched pretreatment sequences in 85% of cases. T-cell responses were significantly greater at time points with detectable trace amounts of HCV RNA than at time points without detectable HCV RNA (P = .035) and were primarily against nonstructural HCV antigens. The immune hierarchy was preserved over 5 years in patients whose post-treatment HCV RNA sequences matched pretreatment sequences, indicating HCV RNA persistence. An altered immune hierarchy with dominant immune responses, shifting from nonstructural to structural antigens, was observed in a single patient whose post-treatment HCV genotype differed from that of the pretreatment genotype, indicating HCV reinfection.

CONCLUSIONS

Trace amounts of HCV RNA of pretreatment sequence persisted and reappeared sporadically in the circulation within 8 years after recovery from hepatitis C but not thereafter, indicating that patients are cured of HCV infection. Reappearance of HCV RNA induced HCV-specific T-cell responses.

Twelve weeks posttreatment follow-up is as relevant as 24 weeks to determine the sustained virologic response in patients with hepatitis C virus receiving pegylated interferon and ribavirin

A sustained virologic response (SVR) in patients with chronic hepatitis C receiving pegylated interferon (PEG-IFN) plus ribavirin is defined as undetectable serum HCV-RNA at 24 weeks (W+24) posttreatment follow-up. Viral load outcome in patients with virological relapse (VR) has not been explored. This study evaluated whether the assessment of serum HCV-RNA 12 weeks (W+12) after the end of treatment was as relevant as W+24 to evaluate SVR in 573 patients who received combination PEG-IFN and ribavirin and had a virological response at the end of treatment. Serum HCV-RNA was measured, using a new assay based on transcription-mediated amplification (TMA) with a lowest detection limit of 5-10 IU/mL, at W+12 and W+24 after the end of treatment. VR was defined as reappearance of detectable HCV-RNA at W+24 posttreatment follow-up. The positive predictive value (PPV) of undetectable serum HCV-RNA at W+12 was evaluated to identify patients with SVR, and the viral load outcome was measured in relapse patients. At the W+24 posttreatment follow-up, 408 (71%) patients had an SVR, 181 (71.2%) were treated with PEG-IFNalpha-2a and ribavirin, and 227 (71.1%) were treated with PEG-IFNalpha-2b and ribavirin. At W+12, serum HCV-RNA was undetectable in 409 patients, and 408 patients were SVR (PPV 99.7%, 95% confidence interval 99.1-100). In relapse patients, serum HCV-RNA levels were 5.623 +/- 0.748, 4.979 +/- 0.870, and 5.216 +/- 0.758 log(10) IU/mL at baseline, W+12, and W+24, respectively.

CONCLUSION

Our results show that the assessment of serum HCV-RNA 12 weeks after the end of treatment, using the highly sensitive TMA assay (PPV 99.7%), is as relevant as after 24 weeks to predict SVR and make decisions on the management of treated patients, suggesting a new definition for SVR.

Presence of HCV-RNA after ultracentrifugation of serum samples during the follow-up of chronic hepatitis C patients with a sustained virological response may predict reactivation of hepatitis C virus infection

BACKGROUND

Concentration of viral particles by ultracentrifugation of serum prior to PCR allows detection of hepatitis C virus (HCV) RNA in patients with undetectable viral RNA by conventional PCR assays.

AIM

To analyse if HCV-RNA is detected after serum ultracentrifugation in chronic hepatitis C patients with a sustained virological response to antiviral therapy (defined as serum HCV-RNA negativity by conventional assays 6 months after the end of therapy).

METHODS

HCV-RNA was tested using real-time PCR in ultracentrifuged sera collected during the post-treatment follow-up (mean: 42 +/- 27 months) in 57 sustained virological responders (SVR).

RESULTS

After serum ultracentrifugation, HCV-RNA was detected on at least one occasion during the follow-up in 29/57 (51%) SVR. Thirteen (23%) of these 57 SVR suffered a reactivation 18 +/- 8 months after the end of therapy (reappearance of serum HCV-RNA detectable by conventional assays). Among reactivated patients, 11/13 (85%) had HCV-RNA in ultracentrifuged serum samples (detectable 10 +/- 5 months before reactivation), while HCV-RNA was positive after ultracentrifugation in 18/44 (41%) long-term SVR (P = 0.01). Persistence of detectable HCV-RNA after serum ultracentrifugation was associated with reactivation (P = 0.001).

CONCLUSIONS

Serum ultracentrifugation prior to PCR allows detection of HCV-RNA in SVR and its persistence may predict late reactivation.