Significance of early measurement of serum hepatitis C virus RNA in predicting response to interferon therapy in patients with chronic hepatitis C

Qualitative application of COBAS AMPLICOR HCV test version 2.0 assays in patients with chronic hepatitis C virus infection and comparison of clinical performance with version 1.0

The objective of this research was to investigate the clinical performance of COBAS AMPLICOR hepatitis C virus (HCV) test version 2.0 Assays (CA V2.0). Eight serial samples with standard HCV ribonucleic acid (RNA) concentration and 10 times serial dilution of the 500 IU/mL samples were tested in triplicate by CA V2.0 (the limit of detection was 50 IU/mL). HCV RNA was investigated with CA V2.0 in 220 specimens from 100 chronic hepatitis C (CHC) patients, 60 chronic hepatitis B patients, and 60 healthy blood donors. The sensitivity was 99% and the specificity was 98.3%. Sera of 84 naïve CHC patients receiving standard interferon plus ribavirin for 24 weeks were tested by CA V2.0 and CA V1.0 at weeks 2, 4 and 8. The positive detection rates of CA V2.0 were significantly higher than CA V1.0 at week 2 (60.7% vs. 51.2%; p < 0.01) and week 8 (27.4% vs. 21.4%; p < 0.05). At weeks 2, 4 and 8, the positive predictive values were 90.91%, 83.02% and 78.69% with CA V2.0, and 90.24%, 82.14% and 72.73% with CA V1.0. The negative predictive values were 58.82%, 77.42% and 86.96% with CA V2.0, and 67.44%, 82.14% and 83.33% with CA V1.0. However, there was no significant difference between CA V2.0 and CA V1.0 for predicting sustained virologic response.

Effective management of hepatitis C molecular testing improves test use without compromising patient management

CONTEXT

The availability of effective antiviral therapy for hepatitis C has increased the need for molecular detection and quantification of circulating hepatitis C viral particles. The limits of detection differ for the quantitative and qualitative reverse transcriptase polymerase chain reaction (RT-PCR) assays; furthermore, adequate patient assessment requires both detection of hepatitis C virus when it is present and quantitation of the viral load when possible. The combination of these factors promotes the simultaneous ordering of both tests with the possibility of generating redundant test information.

OBJECTIVE

To reduce the number of unnecessary hepatitis C tests performed.

METHODS

We established a reflexive testing protocol for quantitative and qualitative RT-PCR testing for hepatitis C.

RESULTS

During a 3(1/2)-month interval, 170 qualitative RT-PCR hepatitis C tests were eliminated (a 59.4% reduction in the number of these tests). This reduction was achieved without a clinically significant change in turnaround time or a compromise of patient care.

CONCLUSIONS

Establishing the quantitative and qualitative RT-PCR tests in-house and adopting the reflexive testing protocol was cost-effective and did not compromise patient management or care.

Early addition of ribavirin to interferon in chronic hepatitis C not responsive to interferon monotherapy

BACKGROUND/AIM

Persistence of HCV-RNA in serum early in treatment is a strong predictor of failure of alpha-interferon therapy for chronic hepatitis C. Therefore, we compared the efficacy of ribavirin addition to alpha-interferon with a doubling of the dosage of alpha-interferon in case of lack of early virological response to alpha-interferon therapy.

METHODS

Sixty patients were administered interferon alpha2b at the dosage of 3 million units 3 times a week. After the first 4 weeks of therapy, serum HCV-RNA was evaluated. The patients with negative HCV-RNA test received the same treatment for a further 11 months, while those with detectable HCV-RNA were randomized to receive either the same dosage of alpha-interferon plus ribavirin (1000 mg/day) or double dosage of alpha-interferon (6 million units tiw) for 11 months. We considered sustained response to be the maintenance of normal alanine aminotransferase and negativity at HCV-RNA testing until the end of a 6-month post-treatment follow-up.

RESULTS

After the first 4 weeks of treatment, 12 (20%) patients showed virological response and 48 patients (80%) remained positive on HCV-RNA testing. Sustained response was observed in 5/12 (42%) patients with early virological response, in 10/24 (42%) patients without early virological response who were administered ribavirin and alpha-interferon, and in only 1/24 (4%) patients who were administered the double dosage of alpha-interferon (p=0.006).

CONCLUSIONS

This study shows the efficacy of the addition of ribavirin to alpha-interferon and the lack of efficacy of doubling the dosage of alpha-interferon in patients without clearance of hepatitis C virus early on in treatment.

Early clearance of circulating hepatitis C virus enhanced by induction therapy with twice-a-day intravenous injection of IFN-beta

To improve the long-term efficacy of interferon (IFN) for treatment of chronic hepatitis C virus (HCV) infection, we proposed induction therapy with twice-a-day IFN-beta injection. This study was intended to clarify the antiviral mechanism. Thirty patients were randomly assigned to two groups: group A (twice-a-day therapy) received 3 MU IFN-beta intravenously (i.v.) twice a day for 2 weeks; group B (once-a-day therapy) received 6 MU of IFN-beta daily. HCV RNA, IFN-beta, alanine aminotransferase (ALT), 2'5'-oligoadenylate synthetase (2'5'-AS) activity, and beta2-microglobulin in serum were compared between the two groups during the first 2 weeks of IFN therapy. The clearance rate of serum HCV RNA in group A (86.7%) was significantly higher than that in group B (13.3%) at day 3 (p = 0.0006). No accumulation of IFN-beta was shown in serum throughout the therapy. The ratio (day 3/day 1) of 2'5'-AS activity was significantly higher in group A. Multivariate analysis indicated twice-a-day IFN-beta injection therapy led to significantly early clearance of circulating HCV. Twice-a-day IFN-beta injection therapy could induce biologically enhanced antiviral activities and be an efficient induction therapy for eradication of HCV.

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.

Comparison between three quantitative assays in patients with chronic hepatitis C and their relevance in the prediction of response to therapy

To compare three quantitative assays measuring viral load in patients with chronic hepatitis C and to determine their value in predicting response to interferon (IFN) therapy, we analysed serum from 896 patients from eight European Centres using QUANTIPLEXtrade mark bDNA, MONITOR AMPLICORtrade mark and SUPERQUANTtrade mark assays. Analyses were performed on the same sample. Viral genotype was assessed using INNO-LiPA HCV II kits. Intercentre variations were observed that were related to the handling of specimens not processed and stored within 6 h of blood sampling. Among sera with optimal handling, a stronger correlation was observed between bDNA and SUPERQUANT (0.806) than between bDNA and MONITOR (0.677) and between MONITOR and SUPERQUANT (0.632). These discrepancies were greatest with genotype 2 (bDNA/SUPERQUANT= 0.772; bDNA/MONITOR=0. 456; SUPERQUANT/MONITOR= 0.299). This correlation was influenced by viraemia level and was better at lower viral loads. The proportion of sera with undetectable viral load was 15% with bDNA, 9.7% with MONITOR and 7.7% with SUPERQUANT. For the three measurements, the best cut-offs of sustained response to IFN treatment were located at their detection threshold. Among patients with viral load below the detection level, a sustained response was observed in 35% tested with bDNA, 38% with MONITOR and 80% with SUPERQUANT. Hence a stronger correlation was observed between bDNA and SUPERQUANT than between either of these assays and MONITOR. SUPERQUANT was the most sensitive assay and this greater sensitivity was associated with a better predictive value of treatment response.

Early predictors of response to treatment in patients with chronic hepatitis C

The term sustained response should be applied to patients with negative serum HCV-RNA and normal values of serum transaminases 6 months after interferon withdrawal. To investigate which factors identify sustained responders early during treatment we analysed 18 reports which used the definition sustained response. Eight reports, comprising 988 patients, have studied the value of early clearance of viraemia as a predictor of sustained response using multivariate analysis and all of them found that this was the strongest predictor of a sustained response. Determination of HCV-RNA 4 or 12 weeks after initiation of IFN therapy predicts treatment outcome more accurately than baseline viral load (the best pre-treatment predictor). ALT levels during the first 12 weeks of treatment have lower predictive value than early viral clearance. The sensitivity of a negative HCV-RNA test is similar at week 4 and at week 12 of therapy while the specificity and the accuracy is higher at week 4. The value of persistent viraemia for early prediction of no response is higher than 97%, with similar values at weeks 4 and 12. Persistence of HCV-RNA in serum at week 4 strongly indicates that the patient will not respond to treatment and in these cases interruption of treatment or other therapeutic options could be considered.

Should patients with early loss of serum HCV-RNA during alpha interferon therapy for chronic hepatitis C be treated for 6 or 12 months?

BACKGROUND/AIMS

Retrospective studies have suggested that early loss of serum HCV-RNA predicts sustained response to alpha-interferon treatment in chronic hepatitis C, but the optimal duration of therapy after loss of HCV-RNA is not known. The aims of this study were: a) to prospectively evaluate the effectiveness of HCV-RNA testing after 1 month of alpha-interferon treatment in the prediction of sustained response, and b) to compare the efficacy of 6 and 12 months of therapy in patients with a negative serum HCV-RNA test after the first month of treatment.

METHODS

One hundred and thirty patients were administered interferon alpha-2b at doses related to body weight (< or > or = 60 kg) and to HCV genotype: 5 or 8 MU tiw for type 1, and 3 or 5 MU tiw for genotypes non-1. Serum HCV-RNA testing was performed using in-house nested RT-PCR at month 1, at the end of treatment and 6 months afterwards. We considered sustained response to be the maintenance of normal alanine aminotransferase and negativity at serum HCV-RNA testing until the end of follow-up.

RESULTS

Sustained response was observed in 2/72 (2.8%) patients with detectable HCV-RNA after the initial month of therapy, in 8/30 (26.7%) patients with early loss of HCV-RNA treated for 6 months and in 20/28 (71.4%) patients treated for 12 months (p<0.01).

CONCLUSIONS

Serum HCV-RNA detectability after the first month is strongly associated with a very poor chance of sustained response, and these cases should be offered other treatments. Patients with early loss of HCV-RNA should complete a 12-month treatment, which appeared more effective than a 6-month treatment.