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Dive into the research topics where Stephan Kanzler is active.

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Featured researches published by Stephan Kanzler.


The Lancet | 2000

Identification of target antigen for SLA/LP autoantibodies in autoimmune hepatitis

Ingrid Wies; Silvia Brunner; Juergen Henninger; Johannes Herkel; Stephan Kanzler; Karl-Hermann Meyer zum Büschenfelde; Ansgar W. Lohse

BACKGROUND Autoantibodies are a hallmark of autoimmune hepatitis, but most are not disease specific. Autoantibodies to soluble liver antigen (SLA) and to liver and pancreas antigen (LP) have been described as disease specific, occurring in about 30% of all patients with autoimmune hepatitis, but no standardised assays are available. Methods We tested 2000 serum samples from patients with various liver diseases and controls for SLA autoantibodies by inhibition ELISA. Serum samples positive for SLA antibodies were used for immunoscreening of cDNA expression libraries. Identified clones were tested against a panel of serum samples positive for SLA and LP autoantibodies and control serum samples, and the epitope mapped by deletion mutants and exonuclease digestion. FINDINGS SLA and LP autoantibodies were identical. Of 2000 serum samples screened, 35 were positive for SLA autoantibodies. These positive samples came from patients with autoimmune hepatitis; three from patients with an overlap syndrome (primary biliary cirrhosis and secondary autoimmune hepatitis). Expression cloning and absorption experiments identified a 422 aminoacid protein present in two splice variants as the sole target antigen. Aminoacids 371-409 were critical for immune recognition. INTERPRETATION The identified cDNA encodes the primary target antigen of SLA/LP autoantibodies. The SLA/LP antigen has a previously unknown aminoacid sequence, and presumably codes for an unindentified enzyme, suggested to be UGA-suppressor tRNA-associated protein. SLA/LP autoantibodies are disease specific and recognise a dominant epitope, suggesting a specific antigen-driven immune response. Identification of the SLA/LP target antigen will allow establishment of a reliable, widely available diagnostic assay. Furthermore, its role in the pathogenesis of autoimmune hepatitis can now be studied.


Gastroenterology | 2008

Hepatocyte-Specific Smad7 Expression Attenuates TGF-β–Mediated Fibrogenesis and Protects Against Liver Damage

Steven Dooley; Jafar Hamzavi; L. Ciuclan; Patricio Godoy; Iryna Ilkavets; Sabrina Ehnert; Elke Ueberham; Rolf Gebhardt; Stephan Kanzler; Andreas Geier; Katja Breitkopf; Honglei Weng; Peter R. Mertens

BACKGROUND & AIMS The profibrogenic role of transforming growth factor (TGF)-beta in liver has mostly been attributed to hepatic stellate cell activation and excess matrix synthesis. Hepatocytes are believed to contribute to increased rates of apoptosis. METHODS Primary hepatocyte outgrowths and AML12 cells were used as an in vitro model to detect TGF-beta effects on the cellular phenotype and expression profile. Furthermore, a transgenic mouse model was used to determine the outcome of hepatocyte-specific Smad7 expression on fibrogenesis following CCl(4)-dependent damage. Samples from patients with chronic liver diseases were assessed for (partial) epithelial-to-mesenchymal transition (EMT) in hepatocytes. RESULTS In primary cell cultures and in vivo, the majority of hepatocytes survive despite activated TGF-beta signaling. These cells display phenotypic changes and express proteins characteristic for (partial) EMT and fibrogenesis. Experimental expression of Smad7 in hepatocytes of mice attenuated TGF-beta signaling and EMT, resulted in less accumulation of interstitial collagens, and improved CCl(4)-provoked liver damage and fibrosis scores compared with controls. CONCLUSIONS The data indicate that hepatocytes undergo TGF-beta-dependent EMT-like phenotypic changes and actively participate in fibrogenesis. Furthermore, ablation of TGF-beta signaling specifically in this cell type is sufficient to blunt the fibrogenic response.


Journal of Clinical Gastroenterology | 2009

Safety and efficacy of sorafenib in patients with advanced hepatocellular carcinoma in consideration of concomitant stage of liver cirrhosis.

Marcus A. Wörns; Arndt Weinmann; Kerstin Pfingst; Carla Schulte-Sasse; Claudia-Martina Messow; Henning Schulze-Bergkamen; Andreas Teufel; Marcus Schuchmann; Stephan Kanzler; Christoph Düber; Gerd Otto; Peter R. Galle

Goals and Background The multikinase inhibitor sorafenib provides survival benefit for patients with advanced hepatocellular carcinoma (HCC) and liver cirrhosis (LCI) Child-Pugh A. We report our experiences with sorafenib in advanced HCC, particularly in patients with LCI Child-Pugh B/C, where only limited data are available in regard to safety and efficacy of sorafenib. Methods Thirty-four patients with advanced HCC were treated with sorafenib regardless of liver function and prior anticancer therapy. Adverse events (AEs) were graded using Common Toxicity Criteria version 3.0, tumor response was assessed according to Response Evaluation Criteria in Solid Tumors. Results Fifteen patients presented without LCI or with LCI Child-Pugh A, 15/4 patients had LCI Child-Pugh B/C. Barcelona Clinic Liver Cancer stage was B/C/D in 4/22/8 patients. During treatment period (median 2.2 mo), therapy was discontinued in 61.8% of patients due to tumor progression (32.3%), death (17.6%), AEs (8.8%), or noncompliance (2.9%). Most common grade 3/4 AEs included liver dysfunction (23.5%), diarrhea (14.7%), increased lipase (8.8%), fatigue (8.8%), and hand-foot skin reaction (5.9%). Worsening liver dysfunction/failure was more frequent (P=0.036) in patients with LCI Child-Pugh B/C compared with patients with maintained liver function (no LCI/LCI Child-Pugh A). Median overall survival was 7.2 months for patients with maintained liver function versus 3.3/3.4 months for patients with LCI Child-Pugh B/C. Conclusions These data do not support the use of sorafenib in patients with LCI Child-Pugh C, and patients with LCI Child-Pugh B should be treated with caution until larger trials provide more safety data and a clinically relevant survival benefit under sorafenib therapy.


The American Journal of Gastroenterology | 2008

Mycophenolate mofetil as second line therapy in autoimmune hepatitis

E. M. Hennes; Ye Htun Oo; Christoph Schramm; Ulrike W. Denzer; Peter Buggisch; Christiane Wiegard; Stephan Kanzler; Marcus Schuchmann; W. Boecher; Peter R. Galle; David H. Adams; Ansgar W. Lohse

INTRODUCTION:In patients with autoimmune hepatitis, efficient immunosuppressive therapy is essential to avoid progression to cirrhosis. There is no established second line therapy for patients failing standard therapy with steroids and azathioprine. The aim of this study was to examine the possible role of mycophenolate mofetil (MMF) as second line treatment of autoimmune hepatitis (AIH).PATIENTS AND ETHODS:We were able to identify 37 patients (29 women, 8 men) with AIH proven according to International AIH Group criteria who failed standard therapy. One patient on MMF was excluded due to non-compliance. A total of 28 of 36 patients had experienced side effects necessitating stop of treatment. One patient stopped azathioprine due to pregnancy. A total of nine patients did not respond sufficiently to azathioprine. A total of four patients with a treatment duration of 3 months or less because of severe side effects were considered as intolerant to MMF. Remission was defined as aspartate transaminase (ASP) < twice upper normal limit (UNL).RESULTS:Of 36 patients on MMF included in the analysis, 14 patients (39%) experienced remission. A total of 22 patients (61%) did not respond sufficiently to MMF. The response rate to MMF was dependent on the cause of treatment cessation of azathioprine. Of eight patients with prior nonresponse to azathioprine, six (75%) did not respond to MMF and only two (25%) reached biochemical remission. Of 28 patients with azathioprine intolerance in 16 (57%) patients, the response to MMF was insufficient and in 12 patients (43%) remission was reached. The difference did not reach statistical significance due to the relatively small numbers included.CONCLUSION:In the light of its good tolerability, MMF seems to be an alternative for patients who could not tolerate azathioprine previously. However, our data suggest that a majority of patients fail MMF particularly if they are switched because of an insufficient response to azathioprine.


Journal of Viral Hepatitis | 2001

Prediction of progressive liver fibrosis in hepatitis C infection by serum and tissue levels of transforming growth factor-beta.

Stephan Kanzler; M. Baumann; Peter Schirmacher; Volker Dries; E. Bayer; Guido Gerken; H. P. Dienes; A.W. Lohse

Although many patients with chronic viral hepatitis C infection suffer from progressive liver disease, the rate of fibrosis progression is highly variable and some patients do not show any measurable progression. However, our ability to predict which patients progress is very limited. Since transforming growth factor‐β (TGF‐β) is a key mediator of liver fibrogenesis, we assessed the predictive role of TGF‐β for fibrogenesis in chronic hepatitis C. We studied 39 patients with chronic hepatitis C in whom two liver biopsies were taken at least 12 months apart, and who did not receive therapy during this period. TGF‐β was measured by bioassay and by ELISA in serum samples taken at the time of the first biopsies, and TGF‐β was determined semiquantitatively by immunostaining of liver biopsy sections. Fibrosis was scored blinded in the biopsy samples by two pathologists independently. There was a close correlation between TGF‐β serum levels and the rate of fibrosis progression. Patients with no progression of fibrosis had significantly lower (59 ng/mL ± 22) TGF‐β serum levels than patients with progressive disease (115 ng/mL ± 20), and a TGF‐β level below 75 ng/mL was predictive for stable disease. Immunohistology for TGF‐β in biopsy samples was also predictive for progressive liver disease with fibrosis progression found in those patients displaying staining of hepatocytes and sinusoidal cells. No such correlation was found with other markers such as procollagen III peptide, viral load or transaminase levels. These results further support the role of TGF‐β in liver fibrogenesis, and offer an opportunity to predict clinical disease progression, which may help in selecting patients who are in need of therapeutic interventions.


Journal of Hepatology | 1999

Clinical significance of autoantibodies to soluble liver antigen in autoimmune hepatitis

Stephan Kanzler; Carolyn Weidemann; Guido Gerken; H Löhr; Peter R. Galle; Karl-Hermann Meyer zum Büschenfelde; Ansgar W. Lohse

BACKGROUND/AIMS Classification of autoimmune hepatitis (AIH) into different subgroups according to autoantibody status has been proposed: type I (ANA/SMA), type II (LKM-1) and type III (anti-SLA). However, whether type III AIH forms a clinically distinct disease entity remains controversial. The aim of this study was to evaluate the subclassification of AIH into ANA/SMA and anti-SLA positive patients with regard to clinical, biochemical and histologic differences. METHODS Ninety-seven consecutive patients with a well-documented long-term course of AIH with ANA/SMA and/or anti-SLA autoantibodies were studied. Clinical, biochemical and histological features of patients with ANA/SMA and/or anti-SLA autoantibodies were compared in a secondary analysis of data acquired prospectively. RESULTS Anti-SLA autoantibodies were found in 21.6% of patients. Anti-SLA-positive patients tended to have lower transaminases (mean: 153 vs. 247 IU/l), gamma-globulins (25 vs. 31%) and bilirubin (1.8 vs. 3.3 mg/dl) in comparison to ANA/SMA positive patients, but there was a large overlap. HLA-type A1 B8 was more frequent in anti-SLA positive patients, while there was no difference in HLA DR3 and DR4 allotype. Response to immunosuppressive therapy was excellent, but relapse occurred frequently. Diagnosis of anti-SLA positive AIH was often delayed (mean: 68 months from first elevation of transaminases) since testing for anti-SLA autoantibodies is currently not generally available. CONCLUSIONS ANA/SMA and anti-SLA positive patients share most clinical, biochemical, histologic and prognostic features. Distinction between type I and type III AIH is therefore clinically not helpful. However, testing for anti-SLA autoantibodies helps in the diagnosis of AIH in many patients who may otherwise be misdiagnosed.


Journal of Clinical Gastroenterology | 2010

Concurrent autoimmune diseases in patients with autoimmune hepatitis.

Andreas Teufel; Arndt Weinmann; George J. Kahaly; Catherine Centner; Anja Piendl; Marcus A. Wörns; Ansgar W. Lohse; Peter R. Galle; Stephan Kanzler

Background Although the pathomechanisms of autoimmune diseases in various organs remain unresolved, an accumulation of autoimmune diseases in individual patients has been observed. An overlap of autoimmune hepatitis (AIH) and primary biliary cirrhosis (PBC) or primary sclerosing cirrhosis has been well documented. However, the overlap of autoimmune diseases other than PBC or PSC has not yet been investigated in a large cohort. Goal The goal of our analysis was to investigate the incidence of concurrent autoimmune diseases in patients with AIH. Study We analyzed our cohort of 278 patients with AIH for concurrent autoimmune diseases. Results A total of 111 patients (40%) were diagnosed with additional autoimmune diseases. Besides overlap syndromes for PBC and PSC, autoimmune thyroiditis was the most common concurrent disease (28 patients, 10%). Other concurrent autoimmune diseases comprised vitiligo (5 patients), rheumatoid arthritis (5 patients), Sjogren syndrome (4 patients), ulcerative colitis (4 patients), conjunctivitis (4 patients), celiac disease (3 patients), systemic lupus erythematodes (2 patients), type I diabetes (2 patients), multiple sclerosis (2 patients), polymyalgia rheumatica (2 patients), and urticaria (2 patients). One patient each was diagnosed with Crohns disease, autoimmune gastritis, collagenous colitis, hypophysitis, and sarcoidosis. Investigating 100 patients with polyglandular syndrome and autoimmune thyroid disease for the occurrence of autoantibodies associated with AIH, we identified AIH-associated antibodies only in 1 patient. Conclusions Concurrent autoimmune diseases are common in patients with AIH and mirror the full range of known autoimmune diseases. Therefore, an extended diagnostic screening for accumulating autoimmune diseases, especially autoimmune thyroiditis, seems reasonable in patients with AIH.


Annals of Oncology | 2011

Cetuximab with irinotecan, folinic acid and 5-fluorouracil as first-line treatment in advanced gastroesophageal cancer: a prospective multi-center biomarker-oriented phase II study

Markus Moehler; A. Mueller; T. Trarbach; Florian Lordick; T. Seufferlein; Stefan Kubicka; M. Geißler; S. Schwarz; Peter R. Galle; Stephan Kanzler; German Arbeitsgemeinschaft Internistische Onkologie

BACKGROUND Cetuximab plus irinotecan/folinic acid/5-fluorouracil (5-FU) (IF) was evaluated as first-line treatment of patients with advanced gastric cancer and gastroesophageal junction tumors. Preplanned analyses of the influence of tumor biomarkers on treatment outcome were carried out. PATIENTS AND METHODS Patients received weekly cetuximab (400 mg/m(2) on day 1, subsequently 250 mg/m(2)) plus irinotecan (80 mg/m(2)) and a 24-hour continuous infusion of folinic acid (200 mg/m(2)) and 5-FU (1500 mg/m(2)) on days 1, 8, 15, 22, 29 and 36 of a 50-day cycle, until progressive disease (PD). RESULTS The most common grade 3/4 toxic effects in 49 patients were diarrhea (15%) and skin toxic effects (14%). In 48 assessable patients, the overall response rate was 46% and disease control rate was 79%. Median progression-free survival (PFS) and overall survival (OS) was 9.0 months [95% confidence interval (CI) 7.1-15.6] and 16.5 months (95% CI 11.7-30.1), respectively. Tumor response was more common than nonresponse in epidermal growth factor receptor-expressing tumors (P = 0.041). Tumor PTEN expression was associated with longer PFS (P = 0.035) and OS (P = 0.0127) than no PTEN expression. CONCLUSION Cetuximab plus IF was well tolerated and efficacy data were encouraging. This treatment combination and the role of selected biomarkers are under investigation in the ongoing phase III EXPAND trial.


The American Journal of Gastroenterology | 2001

Autoimmune hepatitis in the elderly

Christoph Schramm; Stephan Kanzler; Karl-Hermann Meyer zum Büschenfelde; Peter R. Galle; Ansgar W. Lohse

OBJECTIVES:Autoimmune hepatitis (AIH) is widely believed to be a disease of young women and menopause. Little is known about the frequency and clinical characteristics in patients aged ≥65 yr.METHODS:We reviewed charts of 120 consecutive outpatients with known AIH to identify patients who were diagnosed at the age of 65 or older. These 20 patients (median age, 69 yr) were compared to the same number of younger patients (median age, 24 yr) with well-documented AIH from the same cohort.RESULTS:Seventeen percent (20/120) of our patients were ≥65 yr at the time of diagnosis. In the older patients median time to diagnosis was significantly longer than in the younger patients (8.5 >vs 3.5 months). Patients most commonly presented with an acute icteric hepatitis. Complete remission was achieved to a similar extent (18/20 and 17/20 patients). Fewer older patients expressed human leukocyte antigen A1-B8 (p = 0.005).CONCLUSIONS:Diagnosis of AIH often seems to be delayed in the elderly, presumably because AIH is erroneously considered to be a disease of young age. Presentation with acute icteric hepatitis is similar to that of younger patients, supporting the assumption that beneficial effects of hormonal changes associated with menopause are not as pronounced in AIH as in other autoimmune diseases. Human leukocyte antigen type seems to have an influence on the age of onset of AIH. Prognosis is excellent, and AIH should be considered in the older patient to avoid delayed initiation of immunosuppressive therapy.


Liver International | 2005

Budesonide in previously untreated autoimmune hepatitis

Johannes Wiegand; Andreas Schüler; Stephan Kanzler; Ansgar W. Lohse; Ulrich Beuers; Wolfgang Kreisel; Ulrich Spengler; Sibylle Koletzko; Peter L. M. Jansen; Günther Hochhaus; Helmut Möllmann; Markus Pröls; Michael P. Manns

Abstract: Background: Autoimmune hepatitis (AIH) is a chronic liver disease that is effectively treated with immunosuppressive therapy. Predniso(lo)ne, often in combination with azathioprine, is the basic therapeutic option to induce remission. However, this regimen can cause numerous side effects. The aim of the present study was to evaluate budesonide as a treatment option in the induction of remission in patients with previously untreated AIH.

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