A. Bergk

Comparison of adefovir and tenofovir in the treatment of lamivudine-resistant hepatitis B virus infection.

Adefovir dipivoxil was recently approved for the treatment of wild‐type and lamivudine‐resistant hepatitis B virus (HBV) infection. Tenofovir disoproxil fumarate, a congender of adefovir that is used in the treatment of HIV infected patients, has recently been shown to also be effective in patients with lamivudine‐resistant HBV infection. We therefore compared the two substances in a study of 53 patients defined by high HBV DNA (>6 log10 copies/mL) levels and genotypic evidence of lamivudine resistance. Thirty‐five patients received tenofovir for 72 to 130 weeks, and 18 received adefovir for 60 to 80 weeks. Changes in HBV DNA levels were followed for the complete period of 48 weeks. Early viral kinetics were compared on matched subgroups of 5 patients each. Individually, all tenofovir‐treated patients showed a strong and early suppression of HBV DNA within a few weeks whether they were coinfected with HIV or were without comorbidity. In contrast, considerable individual variations in HBV DNA decline were observed in the adefovir group. Thus at week 48, only 44% of these patients had HBV DNA levels below 105 copies/mL in contrast to 100% of the tenofovir‐treated patients (P = .001). No severe side effects were noticed in either group. No evidence of phenotypic viral resistance could be demonstrated in the tenofovir‐treated patients in the long term (up to 130 weeks). In conclusion, tenofovir may become an effective alternative for the treatment of patients with lamivudine‐resistant HBV infection. (HEPATOLOGY 2004;40:1421–1425.)

The HEP-NET B/C co-infection trial: A prospective multicenter study to investigate the efficacy of pegylated interferon-α2b and ribavirin in patients with HBV/HCV co-infection☆

BACKGROUND/AIMS The efficacy of pegylated interferon alpha and ribavirin in HBV/HCV co-infected patients is unknown. METHODS Nineteen patients with chronic HBV/HCV co-infection (HBsAg and HCV-RNA positive; 10 HCV-genotype 1; 9 HCV-genotype 2 or 3) were included in this prospective multicenter pilot study. Baseline HBV-DNA was negative in 13 individuals. All patients received weight-adjusted PEG-IFN-alpha2b and ribavirin for 48 weeks. RESULTS In the intent-to-treat analysis, a biochemical and an HCV-RNA response were observed in 12 and 14 patients, respectively (63% and 74%). At the end of the treatment as well as at the end of the follow-up the HCV-RNA response was 93% (14/15) in patients adherent to therapy (86% in genotype 1 and 100% in genotypes 2 and 3 infection). Two of the five initially HBV-DNA positive patients with follow-up available were HBV-DNA negative at follow-up week 24. In contrast, HBV-DNA became detectable after the clearance of HCV in four initially HBV-DNA negative patients. CONCLUSIONS Combination therapy with PEG-IFN-a2b and ribavirin is highly effective in inducing a virological response concerning HCV in patients with HBV/HCV co-infection. However, HBV replication may increase after the clearance of HCV and thus close monitoring for both the viruses is recommended even in patients with initially undetectable HBV-DNA.

Association of TLR7 single nucleotide polymorphisms with chronic HCV‐infection and response to interferon‐a‐based therapy

Summary.  An efficient immune response against hepatitis C virus (HCV) is necessary to clear infection. As HCV is a single‐stranded RNA virus, a role for TLR7 in the immune response against HCV is possible, and early clinical studies have demonstrated an antiviral effect of TLR7 stimulation. We tested the hypothesis that genetic variations of TLR7 are associated with chronic HCV‐infection and outcome of therapy. The prevalence of three TLR7 variations was analysed in 978 patients with chronic HCV‐infection, 898 patients with chronic liver disease of other aetiologies, and in 203 healthy controls. The prevalence of TLR7 variations was correlated with the response to interferon‐α‐based treatment in 544 patients with chronic HCV‐infection. We analysed TLR7 polymorphisms by melting curve analysis and reconstructed haplotypes. The c.32A>T variation was over‐represented in female patients with chronic HCV‐infection compared to patients with other chronic liver diseases and to healthy controls (P < 0.05). In contrast, c.2403 G>A was less prevalent in male patients with chronic HCV‐infection (P < 0.05). No association was observed for the third variant, c.1‐120T>G. Haplotype analysis confirmed the differential distribution of TLR7 variants between the groups. Within the group of female patients with chronic HCV‐infection, c.32T was predictive of an unfavourable outcome of interferon‐α therapy (P < 0.05). This study reports the association of TLR7 variants with chronic HCV‐infection and with the response to interferon‐α therapy in patients with chronic HCV‐infection. Our results suggest that variations of TLR7 impair the immune response to HCV and imply a gender‐specific effect of this X‐chromosomal variation.

Association of CTLA4 single nucleotide polymorphisms with viral but not autoimmune liver disease.

Background CTLA4 is an inhibitory receptor expressed on a subset of T lymphocytes. Single nucleotide polymorphisms of the CTLA4 gene have been implicated in autoimmune diseases, including autoimmune hepatitis and primary biliary cirrhosis. In reverse form, CTLA4 variations are associated with chronic infections such as chronic hepatitis B. Methods CTLA4 variations −318C>T and +49A>G were analyzed in 2366 patients with chronic liver disease of various etiologies, including 323 patients with chronic hepatitis B virus (HBV) infection, 1181 patients with chronic hepatitis C virus infection, 180 patients with primary biliary cirrhosis, and 127 patients with autoimmune hepatitis, as well as 202 healthy control individuals. Genotyping was performed by melting curve analysis. Results The −318C>T variation was underrepresented in patients with chronic HBV infection compared with healthy controls (14.6 vs. 25.7%, P=0.002) and with patients with chronic liver disease of other origin (14.6 vs. 20.7%, P=0.011). Patients with cryptogenic cirrhosis also showed a lower frequency of the −318T allele than healthy controls (12.0 vs. 25.7%, P=0.014). No association of the +49G>A variation was found with any diagnosis, including autoimmune hepatitis and primary biliary cirrhosis. Conclusion We describe the association of the CTLA4 −318C>T variation with chronic HBV infection and cryptogenic cirrhosis but find no association of the +49G>A variation with autoimmune liver disease.

Induction of ischemic tolerance in rat cortical neurons by 3-nitropropionic acid: chemical preconditioning

Sublethal ischemia leads to increased tolerance against subsequent ischemia. We investigated whether tolerance could also be elicited by mild respiratory-chain inhibition (chemical hypoxia) in a rat neuronal-cell enriched culture system. 3-Nitropropionic acid (3-NPA) caused a concentration-dependent inhibition of succinate-dehydrogenase. Two hours preconditioning with 3-NPA 24-48 h before oxygen-glucose deprivation (OGD) reduced neuronal damage morphologically and reduced lactate deydrogenase (LDH) release up to 72% compared to sham-treated sister cultures without 3-NPA. In an attempt to elucidate transcriptional mechanisms, we found no rapid translocation of the hypoxia-sensitive transcription factors N F-KB or hypoxia-inducible factor-I (HIF-I) at 3-NPA concentrations sufficient to trigger tolerance against OGD. In accordance to previous in vivo and brain slice data, we conclude that 3-NPA chemically induces tolerance against oxygen-glucose deprivation in vitro. However, the underlying mechanisms remain elusive.

Hepatitis-C Patients Have Reduced Growth Hormone (GH) Secretion Which Improves During Long-Term Therapy With Pegylated Interferon-α

OBJECTIVES:In vitro and in vivo data indicate multiple, but contradictory effects of interferon on pituitary hormone secretion. We therefore investigated prospectively basal and stimulated pituitary hormone secretion in 21 patients with chronic hepatitis C virus (HCV) infection before and during antiviral therapy.METHODS:Twenty-one patients received pegylated interferon-α plus either ribavirin or levovirin. Baseline and stimulated growth hormone (GH), cortisol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin (PRL), and thyroid-stimulating hormone (TSH) responses were measured using standard pituitary function tests, before therapy in all and during therapy in 17 out of the 21 patients.RESULTS:Before therapy 17 patients (81%) had severe GH insufficiency and 9 of these had low insulin-like growth factor-1 (IGF-1) concentrations. Basal and stimulated GH concentrations increased significantly during therapy, reducing the number of patients with severe GH insufficiency to four, but IGF-1 remained low. Basal PRL and TSH concentrations were normal before and during therapy, while thyroid-releasing hormone (TRH)-stimulated concentrations increased significantly during therapy. The adrenocorticotropic hormone (ACTH)/cortisol axis, basal and stimulated gonadotropin, and testosterone concentrations were normal throughout. Neither the HCV RNA level nor transaminases correlated with hormone concentrations before or during therapy.CONCLUSIONS:GH insufficiency is common in patients with chronic HCV infection. While GH secretion improves during antiviral therapy, IGF-1 remains low, indicating persistent GH resistance of hepatocytes. Whether improvement in GH secretion during treatment is due to a direct drug effect or related to the suppression of viral load could not be differentiated, as most patients demonstrated a positive virologic response.

Evaluation of complement factor 5 variants as genetic risk factors for the development of advanced fibrosis in chronic hepatitis C infection

BACKGROUND/AIMS Intercross studies in inbred mice susceptible or resistant to liver fibrosis revealed complement factor 5 as a quantitative trait gene associated with the development of fibrosis. In 277 patients with hepatitis C, two C5 SNPs, rs17611 and rs2300929, have been associated with advanced fibrosis. METHODS We investigated the association of these C5 SNPs with advanced fibrosis in 1435 HCV infected patients and in 1003 patients with other liver diseases. We performed genotyping with melting curve analysis using fluorescence resonance energy transfer probes in the LightCycler. RESULTS The defined high-risk genotypes (AA and TT) and alleles (A and T) were not associated with advanced fibrosis in HCV patients when Chi square testing and logistic regression analysis were applied (rs17611A 0.45 in F0-1 vs. 0.43 in F2-4, P=0.31; rs2300929T 0.91 F0-1 and 0.91 in F2-4, P=0.82). In the group of patients with liver diseases other than HCV we neither found an association of the C5 SNPs with advanced fibrosis nor an overrepresentation of the SNPs in patients with cirrhosis. CONCLUSIONS We found no evidence that these C5 SNPs are genetic risk factors for the development of advanced fibrosis in chronic HCV infection or other chronic liver diseases.

Bezafibrate maintenance therapy in patients with advanced chronic hepatitis C.

Background Bezafibrate exerts multiple effects on lipid metabolism by activating the peroxisome proliferator-activated receptor-&agr;, which modulates the expression of key genes of lipid transport, lipoprotein metabolism as well as inflammation. The aim of the present study was to assess the efficacy and safety of bezafibrate in patients with advanced chronic hepatitis C. Materials and methods A total of 34 patients received oral bezafibrate treatment (400 mg/day) on the basis of a prospective observational open-label study design. Clinical, biochemical and virological data were evaluated during a mean treatment duration of 19 months. In a subpopulation (n=8), cytokine expression analysis was carried out and compared with an hepatitis C virus treatment-naive control group (n=7). Results A significant improvement in aspartate aminotransferase (P=0.007), alanine aminotransferase (P<0.0001), alkaline phosphatase (P=0.001), &ggr;-glutamyltranspeptidase levels (P=0.001) and aspartate aminotransferase-to-platelets ratio index Score (P=0.026) could be found at the end of observation. No significant effect on viral load was observed. Bezafibrate treatment for at least 4 months markedly increased interferon-&ggr; expression compared with the treatment-naive patients (4.81 vs. 1.63 arbitrary units; P=0.005), whereas tumour necrosis factor-&agr; and interleukin-6 levels were not significantly influenced. Conclusion This observational study provides evidence that bezafibrate is effective for patients with advanced chronic hepatitis C by reducing liver enzymes significantly and should be further evaluated as a potentially beneficial maintenance therapy.

Strategien zur Prävention des hepatozellulären karzinoms bei der hepatitis-Virus-Infektion

Liver cirrhosis induced by HBV and HCV infections is the main risk factor for the development of hepatocellular carcinoma (HCC). Therefore, prevention of chronic infection with hepatitis viruses and prevention of the development of cirrhosis are essential for the primary prevention of HCC. A consequent vaccination program for HBV is suitable to reduce the rate of infections and the HCC-associated mortality. Since no vaccine is available for HCV, the reduction of risky behaviour and the improvement of hygiene standards are the mainstays for prevention of HCV. An efficient antiviral therapy aimed at the durable suppression of the viral load reduces the risk of progression to cirrhosis and development of HCC in precirrhotic stages of chronic HBV or HCV infections. In cirrhotic patients, the risk of developing HCC remains elevated even if a sustained virological response is achieved, thus requiring further screening with the intention of the early detection of HCC. It is too early to judge whether virological nonresponders profit from continued antiviral therapy. Therefore, the early diagnosis of chronic HBV or HCV infection is the single most important factor for the prevention of HCC. Secondary prevention after surgical resection or local ablative therapy may reduce the frequency of late recurrence. Liver transplantation is today the most effective measure of secondary prevention for selected patients with HCC. Due to its antiproliferative effects, the immunosuppressive drug sirolimus may play a role for secondary prevention of HCC following transplantation.