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Dive into the research topics where Thomas Berg is active.

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Featured researches published by Thomas Berg.


Gut | 2004

Sustained virological response in hepatitis C virus type 1b infected patients is predicted by the number of mutations within the NS5A-ISDR : a meta-analysis focused on geographical differences

M Pascu; Peter Martus; Marina Höhne; B. Wiedenmann; U. Hopf; Eckart Schreier; Thomas Berg

Background and aims: There is growing evidence that the response of hepatitis C virus (HCV) genotype 1b infected patients towards interferon (IFN) therapy is influenced by the number of mutations within the carboxy terminal region of the NS5A gene, the interferon sensitivity determining region (ISDR). Patients and methods: In order to attain better insight into this correlation, a file comprising published data on ISDR strains from 1230 HCV genotype 1b infected patients, mainly from Japan and Europe, was constructed and analysed by logistic regression. Sustained virological response (SVR) was defined as negative HCV RNA six months after treatment. Results: The distribution of wild-, intermediate-, and mutant-type ISDR sequences differed significantly between Japanese (nu200a=u200a655) (44.1%, 37.6%, and 18.3%) and European patients (nu200a=u200a525) (24.8%, 63.4%, and 11.8%; p<0.001). There was a significant positive correlation between the number of ISDR mutations and SVR rate, irrespective of geographical region. The likelihood of SVR with each additional mutation within the ISDR was considerably more pronounced in Japanese compared with European patients (odds ratios 1.82 v 1.39; p<0.001). Pretreatment viraemia of <6.6 log copies/ml and ISDR mutant-type infection was associated with an SVR rate of 97.1% in Japanese patients but only 52.5% in European patients. Pretreatment viraemia was a stronger predictor of SVR than ISDR mutation number in Japanese patients whereas in European patients both parameters had similar predictive power. Conclusion: These data support the concept that mutant-type ISDR strains may represent a subtype within genotype 1b with a more favourable response towards IFN therapy.


Journal of Clinical Investigation | 2010

Antagonism of the chemokine Ccl5 ameliorates experimental liver fibrosis in mice

Marie-Luise Berres; Rory R. Koenen; Anna Rueland; Mirko Moreno Zaldivar; Daniel Heinrichs; Hacer Sahin; P. Schmitz; Konrad L. Streetz; Thomas Berg; Nikolaus Gassler; Ralf Weiskirchen; Amanda E. I. Proudfoot; Christian Weber; Christian Trautwein; Hermann E. Wasmuth

Activation of hepatic stellate cells in response to chronic inflammation represents a crucial step in the development of liver fibrosis. However, the molecules involved in the interaction between immune cells and stellate cells remain obscure. Herein, we identify the chemokine CCL5 (also known as RANTES), which is induced in murine and human liver after injury, as a central mediator of this interaction. First, we showed in patients with liver fibrosis that CCL5 haplotypes and intrahepatic CCL5 mRNA expression were associated with severe liver fibrosis. Consistent with this, we detected Ccl5 mRNA and CCL5 protein in 2 mouse models of liver fibrosis, induced by either injection of carbon tetrachloride (CCl4) or feeding on a methionine and choline-deficient (MCD) diet. In these models, Ccl5-/- mice exhibited decreased hepatic fibrosis, with reduced stellate cell activation and immune cell infiltration. Transplantation of Ccl5-deficient bone marrow into WT recipients attenuated liver fibrosis, identifying infiltrating hematopoietic cells as the main source of Ccl5. We then showed that treatment with the CCL5 receptor antagonist Met-CCL5 inhibited cultured stellate cell migration, proliferation, and chemokine and collagen secretion. Importantly, in vivo administration of Met-CCL5 greatly ameliorated liver fibrosis in mice and was able to accelerate fibrosis regression. Our results define a successful therapeutic approach to reduce experimental liver fibrosis by antagonizing Ccl5 receptors.


Transplantation | 2001

Preoperative antiviral treatment and postoperative prophylaxis in HBV-DNA positive patients undergoing liver transplantation.

Daniel Seehofer; Nada Rayes; Uta Naumann; Ruth Neuhaus; A.R Müller; Stefan G. Tullius; Thomas Berg; Thomas Steinmüller; Wolf Otto Bechstein; Peter Neuhaus

BACKGROUNDnDespite passive immunoprophylaxis a significant number of patients, especially if hepatitis B virus (HBV) DNA is positive prior to transplantation, develop HBV recurrence. This number might be reduced by lowering viral replication pretransplant with antiviral agents and by postoperative combination of antiviral agents and passive immunoprophylaxis.nnnPATIENTS AND METHODSnA total of 74 HBV-DNA positive patients who underwent liver transplantation between 9/88 and 4/00 were analyzed retrospectively. Before lamivudine or famciclovir were available, in total 40 patients did not receive any preoperative antiviral therapy. Since 11/93, 17 patients were treated with famciclovir 1500 mg daily, after 4/96 17 patients with lamivudine 150 mg daily prior liver transplantation. Posttransplant all patients received passive immunoprophylaxis aiming at a titer of more than 100 U/liter. In the 34 patients with preoperative antiviral therapy an additional prophylaxis with the respective antiviral agent was applied.nnnRESULTSnUnder preoperative famciclovir and lamivudine 30 and 71% of patients became HBV-DNA negative, respectively. Actuarial reinfection rate 2 years after liver transplantation was 48% without antiviral prophylaxis, which was not statistically different from 55% under perioperative famciclovir therapy. In contrast only 18% developed HBV recurrence under perioperative lamivudine treatment. During both antiviral regimens neither pre nor posttransplant severe side effects were observed.nnnCONCLUSIONnPerioperative application of famciclovir is not recommendable, whereas lamivudine seems to lower recurrence rates significantly. Whether the observed effect is due to pre- or postoperative application remains to be addressed in further studies. In addition the long-term course has to be awaited.


The Journal of Infectious Diseases | 2000

Mutations in the protein kinase-binding domain of the NS5A protein in patients infected with hepatitis C virus type 1a are associated with treatment response.

Sarrazin Christoph; Thomas Berg; Jung-Hun Lee; Brigitte Rüster; B. Kronenberger; W. Kurt Roth; Stefan Zeuzem

An interaction of the hepatitis C virus (HCV) NS5A protein with the interferon (IFN)-alpha-inducible double-stranded RNA-activated protein kinase (PKR) was demonstrated in vitro. The clinical correlation between amino acid mutations within the HCV NS5A region and response to antiviral treatment is controversial. Thirty-two patients chronically infected with HCV-1a, who were treated with IFN-alpha with or without ribavirin, were studied. The carboxy-terminal half of HCV NS5A was sequenced and was investigated by phylogenetic and conformational analyses. Eight patients achieved a sustained virologic response. An end-of-treatment response but relapse thereafter was observed among 8 patients, whereas 16 patients were nonresponders. The median number of mutations within the PKR-binding domain but not within the previously described IFN sensitivity-determining region was significantly higher for patients with sustained (3 mutations [range, 1-5]) or end-of-treatment (4 mutations [range, 1-5]) virologic response than for nonresponders (2 mutations [range, 0-3]) (P=.0087). Phylogenetic and conformational analyses of NS5A sequences allowed no differentiation between sensitive and resistant strains.


Journal of Hepatology | 1999

Improved correlation between multiple mutations within the NS5A region and virological response in European patients chronically infected with hepatitis C virus type 1b undergoing combination therapy

Christoph Sarrazin; Thomas Berg; Jung-Hun Lee; G. Teuber; Christoph F. Dietrich; W. Kurt Roth; Stefan Zeuzem

BACKGROUND/AIMSnStudies from Japan showed that HCV-1b isolates with at least four amino acid changes within NS5A2209-2248 compared with the prototype sequence HCV-J are more sensitive to interferon than isolates with a prototype sequence. However, the data were not unequivocally confirmed in studies from other geographical areas. These discrepancies may be explained by differences in the prevalence of multiple mutations within the NS5A2209-2248 and/or the treatment efficacy.nnnMETHODSnIn the present study, we therefore investigated the correlation between NS5A2209-2248 sequences of HCV-1b isolates and sustained virological response in 72 European patients treated with 3x6 MU interferon-a per week with (n = 26) and without (n = 46) ribavirin (1000-1200 mg/day). Serum HCV RNA was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and the NS5A2209-2248 region was analyzed by sequencing of PCR products or individual clones.nnnRESULTSnCompared with HCV-1b prototype sequences, 19 patients (26%) had no amino acid changes (prototype), 47 patients (65%) had 1-3 mutations (intermediate type) and six patients (8%) had at least 4 mutations in the NS5A2209-2248 region (mutant type). Nine of the 12 patients with sustained virological response were infected with an intermediate type HCV-1b, the remaining three patients revealed a mutant type HCV-1b. A sustained virological response was achieved in three of four patients with a mutant type HCV-1b treated with interferon-alpha and ribavirin, but in none of the mutant type HCV-1b infected patients treated with interferon-a alone. Quasispecies analysis of HCV in the NS5A2209-2248 region showed only minor heterogeneity of the amino acid sequence.nnnCONCLUSIONSnThe prevalence of mutant type HCV-1b isolates in European patients is low. In patients treated with combination therapy interferon-a and ribavirin, a correlation between mutant type HCV-1b isolates and sustained virological response was observed. The discrepancies between previous studies appear to be related to the efficacy of antiviral treatment and to the low prevalence of mutant type HCV-1b isolates in Western countries.


American Journal of Transplantation | 2005

MMF and Calcineurin Taper in Recurrent Hepatitis C After Liver Transplantation: Impact on Histological Course

M. Bahra; Uif P. Neumann; Dietmar Jacob; Gero Puhl; J Klupp; Jan M. Langrehr; Thomas Berg; Peter Neuhaus

Hepatitis C virus (HCV) recurrence after orthotopic liver transplantation (OLT) is almost universal. The optimal immunosuppression for these patients is still under discussion. We designed a retrospective case‐control study to evaluate the effect of mycophenolate mofetil (MMF) treatment in patients with recurrent hepatitis C.


Antiviral Therapy | 2011

Rapid viral response of once-daily TMC435 plus pegylated interferon/ribavirin in hepatitis C genotype-1 patients: a randomized trial

Michael P. Manns; H. W. Reesink; Thomas Berg; Geoffrey Dusheiko; Robert Flisiak; Patrick Marcellin; Christophe Moreno; Oliver Lenz; Paul Meyvisch; M Peeters; Vanitha Sekar; Kenneth Alan Simmen; Rene Verloes

BACKGROUNDnAntiviral activity of TMC435, an oral, once-daily, HCV NS3/4A protease inhibitor, was evaluated with pegylated interferon-α2a/ribavirin (P/R) in HCV genotype-1 patients.nnnMETHODSnOptimal Protease inhibitor Enhancement of Response to TherApy (OPERA-1; TMC435-C201; NCT00561353) is a Phase IIa, randomized, placebo-controlled study. Treatment-naive patients (n=74) received 25, 75 or 200 mg TMC435 once daily, or placebo for 7 days followed by 21 days of triple therapy with P/R, or triple therapy for 28 days. Treatment-experienced patients (n=37; 56.8% with cirrhosis) received 75, 150 or 200 mg TMC435 once daily, or placebo with P/R for 28 days. Patients continued P/R up to week 48.nnnRESULTSnTreatment-naive patients who received initial monotherapy had a rapid decline in HCV RNA by day 3. At day 7, HCV RNA reductions were greatest for the 75 and 200 mg doses (0.02, -2.63, -3.43 and -4.13 log(10) IU/ml for placebo, and TMC435 25, 75 and 200 mg, respectively). At day 28, all patients who received triple therapy with TMC435 75 or 200 mg had HCV RNA<25 IU/ml versus 4/9 for placebo. In total, 18/28 treatment-experienced patients (9/9 prior relapsers, 9/19 non-responders) who received TMC435 had HCV RNA<25 IU/ml at day 28 versus 0/9 for placebo; similar results were observed for the 150 and 200 mg doses. Most adverse events were grade 1/2. No relevant changes in laboratory parameters occurred, except mild and reversible bilirubin elevations, mostly at the 200 mg dose.nnnCONCLUSIONSnOnce-daily TMC435 with P/R showed potent, dose-dependent antiviral activity over 28 days, and had a favourable tolerability profile.


Journal of Hepatology | 1996

Responsiveness to interferon alpha treatment in patients with chronic hepatitis C coinfected with hepatitis G virus

Thomas Berg; Ullrike Dirla; Uta Naumann; Hans-Gerd Heuft; Stefan Küther; Hartmut Lobeck; Eckart Schreier; U. Hopf

BACKGROUND/AIMSnPatients with chronic hepatitis C are often coinfected with the new identified Flaviviridae-like agent, termed hepatitis G virus (HGV). The aim of the study was to investigate the responsiveness of hepatitis G virus to interferon alpha and to evaluate whether a hepatitis G virus coinfection negatively influences the outcome of treatment in chronic hepatitis C.nnnMETHODSnOne hundred and fifteen patients with histologically proven chronic hepatitis C were treated with interferon alpha and investigated for the presence of hepatitis G virus coinfection by nested polymerase chain reaction with primers from the helicase region of hepatitis G virus. All patients received at least 3 MU (range 3-6) interferon alpha thrice weekly for at least 6 months (mean 8, range 6-12). Polymerase chain reaction products of seven pre- and post-treatment hepatitis G virus positive patients were directly sequenced for identification of sequence variability during the follow-up.nnnRESULTSnEighteen (16%) patients were coinfected with hepatitis G virus. Although nine (50%) of these patients became HGV RNA negative during interferon alpha therapy, only three patients (17%) remained HGV RNA negative at the end of follow-up (mean 24 months). The rate of sustained response of chronic hepatitis C was not significantly different between patients with hepatitis C virus infection and HCV/HGV coinfection (19% vs 28%). Severity of liver disease as determined by alanine aminotransferase levels, histology and hepatitis C virus viremia was not significantly different in patients with hepatitis C virus or HCV/HGV coinfection. Sequence analysis of the helicase region revealed that our isolates all belonged to the hepatitis G virus and not to the GBV-C like genotype. No amino acid exchanges during the observation period of up to 48 months were observed, indicating that this region is highly conserved.nnnCONCLUSIONSnThe responsiveness of hepatitis G virus to interferon alpha in chronic HCV/HGV coinfected patients is similar to that observed in chronic hepatitis C. Hepatitis G virus coinfection seems not to interfere with the efficacy of interferon alpha treatment in patients with chronic hepatitis C.


Journal of Hepatology | 1998

A clinical and virological study of hepatitis C virus-related cryoglobulinemia in Germany

Stefan M. Weiner; Thomas Berg; Hans Berthold; Sabine Weber; Thomas Peters; Hubert E. Blum; U. Hopf; H. H. Peter

BACKGROUND/AIMSnSeveral reports, especially from Southern Europe, have demonstrated a close association between hepatitis C virus (HCV) infection and mixed cryoglobulinemia. In this study we have analyzed the significance of HCV-related cryoglobulinemia in Germany.nnnMETHODSnSera from 79 patients with cryoglobulinemia of type I (n=21), II (n=28) or III (n=30) were investigated for HCV markers. Furthermore, 132 consecutive patients with chronic hepatitis C were studied for the presence of cryoglobulins. Genotypes of HCV were determined according to Simmonds, and HCV-RNA concentrations were measured in patients with and without cryoglobulinemia.nnnRESULTSnIn 79 patients with cryoglobulinemia we found anti-HCV antibodies in 17 (22%) and HCV-RNA in 11 patients (14%). HCV antibodies were more frequent in essential (44%) compared to secondary mixed cryoglobulinemia (15%). In 132 patients with chronic HCV infection cryoglobulins were detected in 37 patients (28%), in 21 of them at low levels. Clinical symptoms due to cryoglobulinemia were observed in eight of the 37 patients, severe vasculitis in three patients with high cryocrit-levels and cryoprecipitation at room temperature. HCV genotype 1 and subtype 1b were most prevalent, both in patients with and without cryoglobulinemia, and mean HCV-RNA levels were not different between the two groups. Comparison of HCV-RNA levels in cryoprecipitates, supernatant and native serum suggests binding of HCV-RNA to the cryoprecipitate with different affinity in individual patients.nnnCONCLUSIONSnThe lower prevalence of HCV-related cryoglobulinemia in our study compared with data from Italy and France suggests a south-north gradient in the prevalence of HCV-associated cryoglobulinemia in Europe.


Hepatology | 2011

Retreatment with telaprevir combination therapy in hepatitis C patients with well-characterized prior treatment response†‡

Andrew J. Muir; Fred Poordad; John G. McHutchison; Mitchell L. Shiffman; Thomas Berg; Peter Ferenci; E. Jenny Heathcote; Jean-Michel Pawlotsky; Stefan Zeuzem; H. W. Reesink; Geoffrey Dusheiko; Emily C. Martin; Shelley George; Robert S. Kauffman; Nathalie Adda

Retreatment with peginterferon alpha and ribavirin (PR) offers a limited chance of sustained virologic response (SVR) in patients who did not achieve SVR with prior PR treatment. This study evaluated the safety and efficacy of telaprevir‐based treatment in combination with PR in well‐characterized patients who did not achieve SVR in the control arms of three Phase II clinical trials. Patients eligible to enroll in this open‐label nonrandomized study either met on‐treatment criteria for nonresponse or relapsed after 48 weeks of treatment in the control arm of the three Phase II PROVE studies. The initial protocol was a 24‐week regimen: 12 weeks of telaprevir and PR followed by an additional 12 weeks of PR. During the study the protocol was amended to extend PR to 48 weeks for patients with previous null response. All other patients with undetectable hepatitis C virus (HCV) RNA at weeks 4 and 12 received 24 weeks of therapy. Those with detectable HCV RNA at weeks 4 or 12 received a total of 48 weeks of therapy. The overall SVR rate was 59% (69/117). SVR rates with T12PR were 37% (19/51) in prior null responders, 55% (16/29) in prior partial responders, 75% (6/8) in prior breakthroughs, and 97% (28/29) in prior relapsers. The overall relapse rate was 16% (13/83). Adverse events were similar to those in previous trials with telaprevir, with 9% of patients discontinuing due to an adverse event (most commonly rash and anemia). Conclusion: This study demonstrated the benefit of retreatment with a telaprevir‐based regimen for patients with well‐characterized nonresponse (null and partial) or relapse to a prior course of PR treatment. (HEPATOLOGY 2011;)

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U. Hopf

Humboldt University of Berlin

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Hartmut Lobeck

Humboldt University of Berlin

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Thomas Steinmüller

Humboldt University of Berlin

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W.O Bechstein

Humboldt University of Berlin

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A.R Müller

Humboldt University of Berlin

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K.-P. Platz

Humboldt University of Berlin

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Stefan Zeuzem

Goethe University Frankfurt

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Ulf P. Neumann

Humboldt University of Berlin

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