S. Schalm

A replicon-based bioassay for the measurement of interferons in patients with chronic hepatitis C

Overall treatment results of chronic hepatitis C have improved markedly with the introduction of pegylated interferon-alpha (PEG-IFN-alpha) and ribavirin combination therapy. However, cure rates in the most common genotype 1 infection are still unsatisfactory. IFN-alpha dose-response studies on viral kinetics suggest that inadequate dosing might be a key factor but drug levels have hardly been tested, which is in part due to difficulties in measuring this cytokine in patient samples. We have shown recently that hepatitis C virus (HCV) replicons are highly sensitive to IFN-alpha. In this report we tested whether the replicon system could be used as a sensitive bioassay to determine the amount of biologically active IFN-alpha in serum or heparinized plasma of patients under therapy. To facilitate the measurements, a stably replicating subgenomic HCV RNA was developed that carries the gene encoding the firefly luciferase. Dose response studies with IFN-alpha demonstrate that the amount of expressed luciferase directly correlates with the level of HCV replication. By using this cell-based assay, serum samples of HCV patients treated with different types and doses of IFN-alpha were analyzed in parallel to IFN-alpha standards made by serial dilutions of the same type of IFN-alpha the patient was treated with. Based on nonlinear logistic models serum concentrations corresponding to 1.3-19 U/ml were determined in patients under standard or high dose IFN-alpha therapy, and from 3.8 to 4.1 ng/ml in patients treated with PEG IFN-alpha. In conclusion, the HCV-replicon based bioassay allows determining the levels of biologically active IFN-alpha in serum and heparinized plasma of patients under treatment.

Quantitative hepatitis B virus DNA assessment by the limiting‐dilution polymerase chain reaction in chronic hepatitis B patients: evidence of continuing viral suppression with longer duration and higher dose of lamivudine therapy

Lamivudine, a novel cytosine analogue, exhibits potent antiviral activity against hepatitis B virus (HBV) in vitro and in vivo. The standard HBV DNA hybridization assay used in phase II clinical studies has a low sensitivity, the detection limit of HBV DNA levels being ≈ 107 genome equivalents per ml (geq ml–1). In this work we used a semiquantitative polymerase chain reaction (PCR) assay (detection limit ≈ 103 geq ml–1) to determine HBV DNA levels during a 24‐week study of lamivudine in 51 stable chronic hepatitis B patients who were positive for hepatitis B surface antigen (HBsAg) and hepatitis B e antigen (HBeAg). Patients were randomly allocated to receive oral doses of 25, 100 or 300 mg lamivudine once daily. At week 24 the median serum concentration of HBV DNA had fallen from 108 to 104 geq ml–1, a 4‐log median reduction. A trend towards more profound suppression of viral replication with an increased dose of lamivudine was observed. After 12 weeks of therapy, 12% of patients had an HBV DNA level that was undetectable in the PCR assay; this increased to 26% after 24 weeks, while in an additional 20% of patients, HBV DNA decreased to the level of detection of the PCR assay. We conclude that a 24‐week course of lamivudine decreases serum HBV DNA to the level of PCR detection in 46% of patients. Such additional viral suppressive activity with higher doses and more protracted lamivudine may be of clinical utility prior to liver transplantation. Further studies are needed to define the degree of virus suppression required in clinical practice, and methods are required to increase the efficacy of virus suppression.

γ‐Glutamyltransferase and rapid virological response as predictors of successful treatment with experimental or standard peginterferon‐α‐2b in chronic hepatitis C non‐responders

Background: High‐dose peginterferon‐α (PegIFN‐α) induction and prolongation of therapy may be an option to improve sustained virological response (SVR) rates among hepatitis C virus (HCV) non‐responders, although a higher and a longer dosing of PegIFN‐α may intensify side effects.

Long-term effects of treatment and response in patients with chronic hepatitis C on quality of life. An international, multicenter, randomized, controlled study

BackgroundHepatitis C decreases health related quality of life (HRQL) which is further diminished by antiviral therapy. HRQL improves after successful treatment. This trial explores the course of and factors associated with HRQL in patients given individualized or standard treatment based on early treatment response (Ditto-study).MethodsThe Short Form (SF)-36 Health Survey was administered at baseline (n = 192) and 24 weeks after the end of therapy (n = 128).ResultsAt baseline HRQL was influenced by age, participating center, severity of liver disease and income. Exploring the course of HRQL (scores at follow up minus baseline), only the dimension general health increased. In this dimension patients with a relapse or sustained response differed from non-responders. Men and women differed in the dimension bodily pain. Treatment schedule did not influence the course of HRQL.ConclusionsMain determinants of HRQL were severity of liver disease, age, gender, participating center and response to treatment. Our results do not exclude a more profound negative impact of individualized treatment compared to standard, possibly caused by higher doses and extended treatment duration in the individualized group. Antiviral therapy might have a more intense and more prolonged negative impact on females.

Prolonged antiviral therapy for hepatitis B virus-infected health care workers: A feasible option to prevent work restriction without jeopardizing patient safety

Summary.u2002 To prevent transmission of hepatitis B virus (HBV) from health care workers (HCWs) to patients, highly viraemic HCWs are often advised to restrict performing exposure prone procedures (EPPs). To prevent loss of highly qualified medical personnel and simultaneously minimize transmission risk to patients, we offered highly viraemic HCWs antiviral therapy and evaluated the effects of this strategy. Eighteen chronic HBV‐infected HCWs have been monitored every 3–6u2003months for a median period of 5.6u2003years (range 1.1–12.5u2003years). Antiviral therapy was offered if HBV DNA was above 105u2003copies/mL and EPPs were performed or active liver disease was present. Median HBV DNA levels, the percentage of days with HBV DNA above 103, 104 and 105u2003copies/mL, and reduction of HBV DNA during antiviral treatment have been analysed for hepatitis B e antigen (HBeAg)‐positive and HBeAg‐negative HCWs separately. Prolonged viral suppression was achieved in both HBeAg‐positive, as well as HBeAg‐negative HCWs. In HBeAg‐negative HCWs treatment with interferon or lamivudine maintained HBV DNA levels below 105u2003copies/mL. For HBeAg‐positive HCWs continuous treatment with tenofovir or entecavir was essential for reaching low viraemia persistently. In 2004, median HBV DNA levels in both HBeAg‐negative and HBeAg‐positive HCWs were below 103u2003copies/mL and all HCWs executed their professional work full‐range. For both HBeAg‐positive and HBeAg‐negative HCWs, antiviral treatment is effective in persistent suppression of virus levels below 105u2003copies/mL. This observation supports antiviral therapy as a viable management option instead of work restriction, with the provision of regular expert monitoring including quantification of HBV DNA.

Relapse after treatment with peginterferon α-2b alone or in combination with lamivudine in HBeAg positive chronic hepatitis B

Interferon induced HBeAg loss is persistent in up to 90% of patients with chronic hepatitis B (HBV).1–3 Older age and vertical transmission have been shown previously to be independent predictors of relapse after conventional IFN.4 Shorter duration of HBV DNA below 0.7 log10 IU/ml was found to predict relapse after lamivudine.5 Predictors of relapse after PEG-IFN treatment are, however, still unknown. Our aim in this study was to investigate the frequency and predictors of relapse after treatment with PEG-IFN α-2b alone or in combination with lamivudine.nnData for this study were extracted from a multicentre randomised controlled trial comparing 52 weeks of PEG-IFN α-2b monotherapy (100 μg/week) with combined PEG-IFN and lamivudine (100 mg/day) in 266 patients with HBeAg positive chronic hepatitis B. The inclusion and exclusion criteria for the study were reported previously.6 Relapse was defined as HBeAg negativity at the end of treatment (week 52) and recurrence of HBeAg at the end of follow up (week 78).nnTreatment groups were comparable regarding baseline characteristics. At the end of treatment, 57 of 130 patients (44%) in the combination therapy group and 40 of 136 (29%) in the monotherapy group lost HBeAg (pu200a=u200a0.01). HBeAg relapse occurred more often in patients treated with PEG-IFN α-2b and lamivudine combination therapy compared with PEG-IFN α-2b alone (22 of 57 patients (39%) vs five of 40 (13%), pu200a=u200a0.005). Patients with HBeAg relapse were more likely to have relapse of HBV DNA >200 000 copies/ml than …