Peginterferon alfa-2a and peginterferon alfa-2b combined with ribavirin in patients with genotype 1 chronic hepatitis C: results of a prospective single-centre study

PURPOSE

This prospective, randomized, single-centre study compared peginterferons alfa-2a and alfa-2b, combined with ribavirin, in treating patients infected with hepatitis C virus (HCV) genotype 1.

MATERIAL/METHODS

Hundred-and-one patients received 48 weeks of open-label treatment with peginterferon alfa-2a (180 μg/week) and 111 patients received peginterferon alfa-2b (1.5 μg/kg/week). All patients received the same dose of ribavirin 1000/1200 mg/day, depending on weight. The primary efficacy endpoint was sustained virologic response (SVR), defined as undetectable HCV RNA (<50 IU/mL) 24 weeks after the end of treatment.

RESULTS

Early virologic response (EVR), defined as at least 2 log₁₀ IU/mL reduction of viral load at 12 weeks, was more common in patients treated with peginterferon alfa-2a (88% vs. 74.8%; p=0.04). However, the difference in SVR was not statistically significant (49.5% vs. 44.1%; p=0.43).

CONCLUSIONS

Peginterferon alfa-2a treated patients were also more likely to be HCV RNA negative at the end of treatment (67.3% vs. 57.7%), but this difference did not reach statistical significance. Multivariate logistic regression analysis found that SVR was associated with low fibrosis stage (F1-2 by Scheuer; p=0.001) and low serum HCV RNA level (<400,000 IU/L; p=0.023). While both forms of peginterferon showed similar efficacy as measured by SVR, use of peginterferon alfa-2b could lower the number of patients receiving unnecessary treatment beyond 12 weeks.

Prevalence of hepatitis C virus mutants resistant to protease inhibitors among Polish HCV genotype 1-infected patients

AIM

The aim of this study was to evaluate prevalence of hepatitis C virus (HCV) harbouring mutations associated with decreased susceptibility to protease inhibitors (Boceprevir/Telaprevir) among Polish untreated patients infected with HCV genotype 1.

MATERIAL AND METHOD

Population sequencing was used, sequencing data were interpreted by web based geno2pheno algorithm. A total of 91 serum samples were obtained from patients infected with HCV genotype 1, admitting Outpatient Clinics of Hospital of Infectious Diseases, Warsaw.

RESULTS

Sequencing analysis of the NS3 protease catalytic domain was successful in 85 out of 91 subjects. In seventy three (85.9%) out of 85 samples wild-type HCV was detected; in 12 (14.1%) samples mutations associated with clinically observed Boceprevir/Telaprevir-decreased susceptibility were detected.

SUMMARY AND CONCLUSIONS

Obtained results document the presence of HCV strains harbouring protease inhibitors (PIs) resistance-associated mutations among Polish therapy-naïve patients. The determined prevalence of drug resistant HCV variants is 14.1%. Further and continuous surveillance is necessary to estimate how preexisting and emerging drug resistance mutations influence clinical outcome in triple-therapy experienced patients.

Evolving patterns of HIV-1 transmitted drug resistance in Poland in the years 2000-2008

The aim of the study was to determine the rate of transmission of drug resistant human immunodeficiency virus-1 (HIV-1) variants among therapy-naïve HIV positive patients in Poland in the year 2008, to compare the data with the results from the years 2000 to 2007 and to monitor patterns of HIV-1 subtypes present in Polish population and their evolution. Complete protease and part of reverse transcriptase regions were sequenced from the sera of patients directed to the laboratory for drug resistance testing. The Stanford's HIVdb program was used for the interpretation of results and subtyping. The variants scoring at least "intermediate resistance" for at least one drug were considered as resistant. The results obtained were compared to those obtained in the years 2000-2007. A total of 95 patients were enrolled in the 2008 study. Homosexual transmission of infection was documented in more than 55% of all cases. The overall prevalence of transmitted drug resistance (TDR) was 5.3% (3.9% in 2007, 5.8% in 2006, and 14.1% in the years 2002-2005). The study from the years 2000 to 2001 revealed 28.7% prevalence. Preliminary analysis of the first half of 2009 shows the ratio of 7.8%. In four (4.2%) cases drug resistance was associated with protease inhibitors class, in one case (1.1%) with resistance to non-nucleoside reverse transcriptase inhibitors class. In four cases (4.2%) non-B subtype was identified (C, G, CRF01_AE, CRF02_AG). An increase of percentage of drug resistant mutants-from 3.9% (2007) to 5.3% (2008)-was recognized. In this study, TDR was limited to single classes of antiretroviral drugs. HIV-1 subtype B prevails in Poland.

[Comparison of early virologic response among patients with chronic hepatitis C infected with genotype non 2/3 treated with pegylated interferon alfa-2B and ribavirin in dependence with hepatic fibrosis stages]

Early virologic response (EVR) depending on various hepatic fibrosis was analyzed at 12 week of pegylated interferon alfa-2b (Pegintron, 12 KD) with ribavirin treatment among chronic hepatitis C patients (pts) infected with genotype non 2/3. The A group composed 29 pts. They were of staging 0 and grading 1. The group B composed 47 pts of staging 1, C 33 pts of staging 2, D 35 pts of staging 3 and 4. Liver biopsies were analyzed according to the Scheuer's and Knodell's scores. Early virologic response (ERV) was defined as decrease of VL >2 log or undetectable HCV RNA. Viral load (VL) was determined with HCV RNA Assay and CA HCV Monitor Test (Roche Diagn. Sys.). The EVR rates for the A, B, C, D groups were as follow: 86,2% (25/29), 80,9% (38/47), 75,8% (25/33) and 60% (15/25), respectively.

[Results of 48 weeks lamivudine treatment of patients with chronic hepatitis B and HBeAg (+)]

Chronic hepatitis B is an important public health problem worldwide. In Poland the incidence rate decreased from 40,0 (in the year 1990) to 3,86 (in 2004) per 100,000 inhabitants. The goal of anti-chronic hepatitis B therapy is to prevent the progression of liver disease to cirrhosis which may effect in development of liver failure or HCC. The aims of treatment are: reduction of HBV viral load and normalization of ALT activity. Among HBeAg positive patients important marker is the loss of e antigenemia followed by seroconversion to anti-HBe positivity. Lamivudine is an oral nucleoside analogue with strong antiviral activity against hepatitis B virus. The objective of this study was to analyse the efficacy of lamivudine treatment of chronic hepatitis B patients positive for hepatitis B e antigen (HBeAg). 224 patients were treated in Hospital of Infectious Diseases in Warsaw in the years 2001-2002. Patients were treated for 48 weeks with 100 mg lamivudine once daily (50 mg in case of renal failure). Results obtained at the end of therapy: loss of HBeAg was observed in 33,4% and seroconversion to anti-HBe in 15,1% patients, normalization of ALT activity was noticed in 53,4% patients, inhibition of HBV DNA replication was observed in 37,9% patients. The results are comparable with known randomized clinical trials.

[Study of the efficacy of combined therapy with interferon alfacon-1 and ribavirin for chronic hepatitis C]

The results of combined interferon alfacon-1 and ribavirin therapy of 94 patients with chronic hepatitis C were analyzed. Complete data, including sustained viral response (SVR), were obtained in 88 patients. 46.8% of them achieved SVR. The most important factor influencing SVR, was the presence of HCV RNA in serum at weeks 12 and 24 of therapy. SVR in these cases was achieved in 14.3% and 0%, respectively. Eight patients discontinued therapy due to adverse events. Most frequent were depressive reactions due to interferon (3 cases), and severe anemia due to ribavirin (2 cases). 37% of patients developed thyroiditis, significantly more frequent in women (27 versus 9).

[Results of 48 weeks lamivudine treatment of patients with chronic hepatitis B and HBeAg (-)]

Lamivudine is an oral nucleoside analogue with strong antiviral activity against hepatitis B virus. The HBeAg-negative patients tend to have lower serum HBV viral loads when compared to HBeAg-positive patients, but may develop liver disease. The objective of this study was to analyse the efficacy of lamivudine treatment of chronic hepatitis B patients negative in HBe antigen (HBe-Ag-negative). 102 patients were treated in Hospital of Infectious Diseases in Warsaw in the years 2001-2002. Patients were treated for 48 weeks with 100 mg lamivudine once daily (50 mg in case of renal failure). The end point of therapy of patients with chronic HBV infection negative for e antigen is more difficult to determine than for HBeAg-positive patients because HBeAg seroconversion marker cannot be applied. The only useful markers of therapy efficiency are the supression of HBV DNA replication and normalization ofALT activity level. Results at the end of therapy: normalization of ALT activity was observed in 48,7% patients, inhibition of viral replication was detected in 65,6% patients. The results are comparablewith known randomized clinical trials.

Modern diagnostics of Chlamydia trachomatis infections

Chlamydia trachomatis (C. trachomatis) is the most common agent of sexually transmitted infections. The clinical spectrum of the disease ranges from urethritis to infertility in women and to trachoma. Intracellular localisation of the pathogen creates a challenge for routine diagnostics. In this review possible diagnostic tests have been presented, varying from classic cell culture analysis and serodiagnostics (Enzyme-linked Immunoassays, Indirect Immunofluorescence) to the most sophisticated nucleic acid analyses (hybridisation, Polymerase Chain Reaction, Transcription Mediated Amplification, Ligase Chain Reaction), Advantages and disadvantages of the leading tests are discussed. Possible reasons of false positive as well as false negative results of genetic testing are presented.

[Genetic diagnosis of hepatitis C virus infection]

Hepatitis C virus, a small enveloped RNA member of Flaviviridae, is the major causative agent of non-A, non-B hepatitis. The discovery and genetic characterization of HCV is described. Modern genetic procedures and methods involved in the studies of HCV biology, genetic heterogenity and diagnostics of HCV infections are presented. Interferon-alfa treatment is the only licensed therapy for chronic hepatitis C until now, but an efficacy of such treatment is highly variable. Viral factors predicting the long-term outcome of interferon alfa therapy, such as genotype, baseline viral load, quasispecies or ISDR mutations, and current concepts of their predictive values are discussed. Our own results are presented and compared with those present in the latest publications.