Biomedical subjects

Manfred Wiese

Publications and source records attributed to Manfred Wiese.

5 recordsLinked to original sources

PubMed2005

Nonstructural protein 5A does not contribute to the resistance of hepatitis C virus replication to interferon alpha in cell culture.

The hepatitis C virus (HCV) subgenomic replicon system was used to study a possible involvement of nonstructural protein 5A (NS5A) in the mechanisms of HCV resistance to interferon alpha (IFN-alpha). A series of chimeric HCV replicons was constructed. In these replicons, the NS5A gene in the backbone of the Con1 replicon was swapped by corresponding fragments obtained from four IFN-alpha responder and four IFN-alpha nonresponder patients that had been infected with the same HCV AD78 strain. Experiments with transfected Huh7 cells did not reveal significant differences in sensitivity of HCV RNA replication to IFN-alpha in cell clones, bearing chimeric Con1/AD78 replicons with NS5A sequences from IFN responders and nonresponders. Thus, these data provide no evidence that the NS5A protein contributes to the resistance of HCV replication to IFN-alpha.

Amino Acid Sequence↗

PubMed2005

Reduced bone mineral density and altered bone turnover markers in patients with non-cirrhotic chronic hepatitis B or C infection.

AIM: Previous studies suggest that loss of bone mineral density (BMD) frequently occurs in patients with chronic viral liver disease, presenting with histologically proven liver cirrhosis. However, little is known about the occurrence of bone disease in non-cirrhotic patients with chronic hepatitis B or C. Therefore, it was the aim of this study to evaluate this particular population for BMD and bone turnover markers. METHODS: Biochemical markers of bone turnover and BMD were measured in 43 consecutive patients with HCV (n = 30) or HBV (n = 13) infection without histological evidence for liver cirrhosis. Mean age was 49 years (range 26-77 years). BMD was measured by dual X-ray absorptiometry in the femoral neck (FN) and the lumbar spine (LS) region. In addition, bone metabolism markers were measured. RESULTS: BMD was lowered in 25 (58%) of the patients with chronic hepatitis B or C (FN: 0.76 (0.53-0.99); LS: 0.96 (0.62-1.23) g/cm(2)). Eight (32%) osteopenic patients were diagnosed with osteoporosis. Bone-specific alkaline phosphatase (P = 0.005) and intact parathyroid hormone (iPTH) (P = 0.001) were significantly elevated in the more advanced stages of fibrosis. Mean T-score value was lower in patients with chronic hepatitis C as compared to patients suffering from chronic hepatitis B; however, the difference was not statistically significant (P = 0.09). CONCLUSION: There was a significantly reduced BMD in non-cirrhotic patients with chronic hepatitis B or C infection. Alterations of bone metabolism already occurred in advanced liver fibrosis without cirrhosis. According to our results, these secondary effects of chronic viral hepatitis should be further investigated.

Adult↗

PubMed2005

Outcome in a hepatitis C (genotype 1b) single source outbreak in Germany--a 25-year multicenter study.

BACKGROUND/AIMS: The natural course of the hepatitis C virus genotype 1b (HCV-1b) infection is still unclear but important for therapeutic decisions. There are few unbiased long-term follow-up studies with known dates of infection. METHODS: Between August 1978 and March 1979, 14 HCV-1b contaminated batches of anti-D immunoglobulin had been administered to 2867 women for prophylaxis of rhesus isoimmunization throughout East Germany. We reexamined 1980 women, representing 70% of the total cohort of 15 centers. RESULTS: After application of the contaminated anti-D, 93% of the recipients developed an acute hepatitis C. After 25 years, 86% of the 1833 affected women still tested positive for hepatitis C virus antibodies and 46% for HCV RNA. Only nine (0.5%) had overt liver cirrhosis, 30 women (1.5%) developed pre-cirrhotic stages and one HCC was diagnosed. Ten (0.5%) died of HCV related complications, half of these related to additional comorbidity. In the last 5 years, a continuous, but low increase of fibrotic scores was observed. CONCLUSIONS: Young women without comorbidity may clear HCV (1b) infection in more than half of the cases, or develop mild chronic hepatitis C. We confirmed the low risk of progression to cirrhosis in this cohort within 25 years.

Adult↗

PubMed2004

Influence of interleukin 12B (IL12B) polymorphisms on spontaneous and treatment-induced recovery from hepatitis C virus infection.

BACKGROUND/AIMS: Interleukin-12 (IL-12) governs the Th1-type immune response, affecting the spontaneous and treatment-induced recovery from HCV-infection. We investigated whether the IL12B polymorphisms within the promoter region (4 bp insertion/deletion) and the 3'-UTR (1188-A/C), which have been reported to influence IL-12 synthesis, are associated with the outcome of HCV infection. METHODS: We analyzed 186 individuals with spontaneous HCV clearance, 501 chronically HCV infected patients, and 217 healthy controls. IL12B 3'-UTR and promoter genotyping was performed by Taqman-based assays with allele-specific oligonucleotide probes and PCR-based allele-specific DNA-amplification, respectively. RESULTS: The proportion of IL12B promoter and 3'-UTR genotypes did not differ significantly between the different cohorts. However, HCV genotype 1-infected patients with high baseline viremia carrying the IL12B 3'-UTR 1188-C-allele showed significantly higher sustained virologic response (SVR) rates (25.3% vs. 46% vs. 54.5% for A/A, A/C and C/C) due to reduced relapse rates (24.2% vs. 12% vs. zero % for A/A, A/C and C/C). CONCLUSIONS: IL12B 3'-UTR 1188-C-allele carriers appear to be capable of responding more efficiently to antiviral combination therapy as a consequence of a reduced relapse rate. No association of IL12B polymorphisms and self-limited HCV infection could be demonstrated.

3' Untranslated Regions↗

PubMed2004

Hepatitis C virus mutation affects proteasomal epitope processing.

The high incidence of hepatitis C virus (HCV) persistence raises the question of how HCV interferes with host immune responses. Studying a single-source HCV outbreak, we identified an HCV mutation that impaired correct carboxyterminal cleavage of an immunodominant HLA-A2-restricted CD8 cell epitope that is frequently recognized by recovered patients. The mutation, a conservative HCV nonstructural protein 3 (NS3) tyrosine to phenylalanine substitution, was absent in 54 clones of the infectious source, but present in 15/21 (71%) HLA-A2-positive and in 11/24 (46%) HLA-A2-negative patients with chronic hepatitis C. In order to analyze whether the mutation affected the processing of the HLA-A2-restricted CD8 cell epitope, mutant and wild-type NS3 polypeptides were digested in vitro with 20S constitutive proteasomes and with immunoproteasomes. The presence of the mutation resulted in impaired carboxyterminal cleavage of the epitope. In order to analyze whether impaired epitope processing affected T cell priming in vivo, HLA-A2-transgenic mice were infected with vaccinia viruses encoding either wild-type or mutant HCV NS3. The mutant induced fewer epitope-specific, IFN-gamma;-producing and fewer tetramer(+) cells than the wild type. These data demonstrate how a conservative mutation in the flanking region of an HCV epitope impairs the induction of epitope-specific CD8(+) T cells and reveal a mechanism that may contribute to viral sequence evolution in infected patients.

Amino Acid Sequence↗