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Featured researches published by A. Dignass.


Journal of Crohns & Colitis | 2010

The second European evidence-based Consensus on the diagnosis and management of Crohn's disease: Current management

A. Dignass; G. Van Assche; Marc Lemann; Johan D. Söderholm; S. Danese; André D'Hoore; Miquel A. Gassull; Fernando Gomollón; Pierre Michetti; Colm O'Morain; T. Öresland; Alastair Windsor

This paper is the second in a series of three publications relating to the European evidence-based consensus on the diagnosis and management of Crohns disease and concerns the management of active disease, maintenance of medically induced remission and surgery. The aims and methods of the ECCO Consensus, as well as sections on diagnosis and classification are covered in the first paper [van Assche et al. JCC 2009a]. The final paper covers post-operative recurrence, fistulating disease, the management of paediatric and adolescent IBD, pregnancy, psychosomatics, extraintestinal manifestations and complementary or alternative therapy for Crohns disease [Van Assche et al JCC 2009b]. #### Principal changes with respect to the 2006 ECCO guidelines The early use of azathioprine/mercaptopurine or methotrexate in combination with steroids is an appropriate option in moderately active localised ileocaecal CD. Anti-TNF therapy should be considered as an alternative for patients with objective evidence of active disease who have previously been steroid-refractory, steroid-dependent, or steroid-intolerant (based on Statement 5B). For those patients with severely active localised ileocaecal Crohns disease and objective evidence of active disease who have relapsed, anti-TNF therapy with or without an immunomodulator is an appropriate option [EL1a, RG B for infliximab]. For some patients who have infrequently relapsing disease, restarting steroids with an immunomodulator may be appropriate (based on Statement 5C). All currently available anti-TNF therapies appear to have generally similar efficacy and adverse-event profiles for inflammatory (‘luminal’) Crohns disease, so the choice depends on availability, route of delivery, patient preference, cost and national guidelines \[EL5, RG D\] (Statement 5I). Patients receiving azathioprine or mercaptopurine who relapse should be evaluated for adherence to therapy and have their dose optimised. Changing their maintenance therapy to methotrexate [EL1b RG B] or anti-TNF therapy [EL1a RGB] should be considered. Surgery should always be considered as an option in localised disease [EL4, …


Gut | 2006

Genetic basis for increased intestinal permeability in families with Crohn’s disease: role of CARD15 3020insC mutation?

Sabine Buhner; Carsten Büning; Janine Genschel; K Kling; Dana Herrmann; A. Dignass; I Kuechler; S Krueger; H H-J Schmidt; Herbert Lochs

Background and aim: A genetically impaired intestinal barrier function has long been suspected to be a predisposing factor for Crohn’s disease (CD). Recently, mutations of the capsase recruitment domain family, member 15 (CARD15) gene have been identified and associated with CD. We hypothesise that a CARD15 mutation may be associated with an impaired intestinal barrier. Methods: We studied 128 patients with quiescent CD, 129 first degree relatives (CD-R), 66 non-related household members (CD-NR), and 96 healthy controls. The three most common CARD15 polymorphisms (R702W, G908R, and 3020insC) were analysed and intestinal permeability was determined by the lactulose/mannitol ratio. Results: Intestinal permeability was significantly increased in CD and CD-R groups compared with CD-NR and controls. Values above the normal range were seen in 44% of CD and 26% of CD-R but only in 6% of CD-NR, and in none of the controls. A household community with CD patients, representing a common environment, was not associated with increased intestinal permeability in family members. However, 40% of CD first degree relatives carrying a CARD15 3020insC mutation and 75% (3/4) of those CD-R with combined 3020insC and R702W mutations had increased intestinal permeability compared with only 15% of wild-types, indicating a genetic influence on barrier function. R702W and G908R mutations were not associated with high permeability. Conclusions: In healthy first degree relatives, high mucosal permeability is associated with the presence of a CARD15 3020insC mutation. This indicates that genetic factors may be involved in impairment of intestinal barrier function in families with IBD.


Inflammatory Bowel Diseases | 2001

Mechanisms and Modulation of Intestinal Epithelial Repair

A. Dignass

The mucosal epithelium of the alimentary tract represents a crucial barrier to a broad spectrum of noxious and immunogenic substances within the intestinal lumen. An impairment of the integrity of the mucosal epithelial barrier is observed in the course of various intestinal disorders including inflammatory bowel diseases (IBD), celiac disease, intestinal infections, and various other diseases. Furthermore, even under physiologic conditions temporary damage of the epithelial surface mucosa may be caused by proteases, residential flora, dietary compounds, or other factors. Generally, the integrity of the intestinal mucosal surface barrier is rapidly reestablished even after extensive destruction because of an enormous regenerative capability of the mucosal surface epithelium. Rapid resealing of the surface epithelium is accomplished by epithelial cell migration, also termed epithelial restitution, epithelial cell proliferation, and differentiation. Healing of the intestinal surface epithelium is regulated by a complex network of highly divergent factors, among them a broad spectrum of structurally distinct regulatory peptides that have been identified within the mucosa of the intestinal tract. These regulatory peptides, conventionally designated as growth factors and cytokines, play an essential role in regulating differential epithelial cell functions to preserve normal homeostasis and integrity of the intestinal mucosa. In addition, a number of other peptide molecules such as extracellular matrix factors and blood clotting factors, and also nonpeptide molecules including phospholipids, shortchain fatty acids, adenine nucleotides, trace elements, and pharmacological agents, have been demonstrated to modulate intestinal epithelial repair mechanisms. Some of these molecules may be released by platelets, adjacent stromal cells, inflammatory cells, or injured epithelial and nonepithelial cells and may play an important role in the modulation of intestinal injury. Repeated damage and injury of the intestinal surface are key features of various intestinal disorders including IBD and require constant repair of the epithelium. Enhancement of intestinal repair mechanisms by regulatory peptides or other modulatory factors may provide future approaches for the treatment of diseases that are characterized by injuries of the epithelial surface.


Journal of Immunology | 2004

Human Galectin-2: Novel Inducer of T Cell Apoptosis with Distinct Profile of Caspase Activation

Andreas Sturm; Martin Lensch; Sabine André; Herbert Kaltner; Bertram Wiedenmann; Stefan Rosewicz; A. Dignass; Hans-Joachim Gabius

Galectin-2 is structurally closely related to galectin-1, but has a distinct expression profile primarily confined to the gastrointestinal tract. Prominent differences in the proximal promoter regions between galectins-2 and -1 concern Sp1-, hepatocyte NF-3, and T cell-specific factor-1 binding sites. Of note, these sequence elements are positioned equally in the respective regions for human and rat galectins-2. Labeled galectin-2 binds to T cells in a β-galactoside-specific manner. In contrast to galectin-1, the glycoproteins CD3 and CD7 are not ligands, while the shared affinity to β1 integrin (or a closely associated glycoprotein) accounts for a substantial extent of cell surface binding. The carbohydrate-dependent binding of galectin-2 induces apoptosis in activated T cells. Fluorogenic substrate and inhibitor assays reveal involvement of caspases-3 and -9, in accordance with cleavage of the DNA fragmentation factor. Enhanced cytochrome c release, disruption of the mitochondrial membrane potential, and an increase of the Bax/Bcl-2 ratio by opposite regulation of expression of both proteins add to the evidence that the intrinsic apoptotic pathway is triggered. Cell cycle distribution and expression of regulatory proteins remained unaffected. Notably, galectins-1 and -7 reduce cyclin B1 expression, defining functional differences between the structurally closely related galectins. Cytokine secretion of activated T cells was significantly shifted to the Th2 profile. Our study thus classifies galectin-2 as proapoptotic effector for activated T cells, raising a therapeutic perspective. Of importance for understanding the complex galectin network, it teaches the lesson that selection of cell surface ligands, route of signaling, and effects on regulators of cell cycle progression are markedly different between structurally closely related galectins.


Infection and Immunity | 2006

Escherichia coli Strain Nissle 1917 Ameliorates Experimental Colitis via Toll-Like Receptor 2- and Toll-Like Receptor 4-Dependent Pathways

A. Grabig; Daniela Paclik; Claudia Guzy; Anja Dankof; Daniel C. Baumgart; J. Erckenbrecht; Bärbel Raupach; Ulrich Sonnenborn; Jana Eckert; Ralf R. Schumann; B. Wiedenmann; A. Dignass; Andreas Sturm

ABSTRACT Toll-like receptors (TLRs) are key components of the innate immune system that trigger antimicrobial host defense responses. The aim of the present study was to analyze the effects of probiotic Escherichia coli Nissle strain 1917 in experimental colitis induced in TLR-2 and TLR-4 knockout mice. Colitis was induced in wild-type (wt), TLR-2 knockout, and TLR-4 knockout mice via administration of 5% dextran sodium sulfate (DSS). Mice were treated with either 0.9% NaCl or 107E. coli Nissle 1917 twice daily, followed by the determination of disease activity, mucosal damage, and cytokine secretion. wt and TLR-2 knockout mice exposed to DSS developed acute colitis, whereas TLR-4 knockout mice developed significantly less inflammation. In wt mice, but not TLR-2 or TLR-4 knockout mice, E. coli Nissle 1917 ameliorated colitis and decreased proinflammatory cytokine secretion. In TLR-2 knockout mice a selective reduction of gamma interferon secretion was observed after E. coli Nissle 1917 treatment. In TLR-4 knockout mice, cytokine secretion was almost undetectable and not modulated by E. coli Nissle 1917, indicating that TLR-4 knockout mice do not develop colitis similar to the wt mice. Coculture of E. coli Nissle 1917 and human T cells increased TLR-2 and TLR-4 protein expression in T cells and increased NF-κB activity via TLR-2 and TLR-4. In conclusion, our data provide evidence that E. coli Nissle 1917 ameliorates experimental induced colitis in mice via TLR-2- and TLR-4-dependent pathways.


Nature Reviews Gastroenterology & Hepatology | 2010

Diagnosis and management of iron deficiency anemia in patients with IBD

Jürgen Stein; Franz Hartmann; A. Dignass

Anemia is the most prevalent extraintestinal complication of IBD. It can affect quality of life and ability to work, and can also increase the hospitalization rate in patients with IBD. Although the causes of anemia in IBD are multifactorial, iron deficiency anemia (IDA) is the most common. Assessment of the iron status of patients who have a condition associated with inflammation, such as IBD, by using common biochemical values is insufficient. However, new indices of iron metabolism (for instance ferritin:transferrin receptor ratio, reticulocyte hemoglobin content or percentage of hypochromic red blood cells) may help to improve the assessment of iron status in patients with IBD. The treatment of IDA traditionally involves oral iron supplementation. However, because of extensive gastrointestinal adverse effects, and data showing that the use of oral iron in IBD may be associated with disease exacerbation, current guidelines suggest that iron supplementation in IBD should be administered intravenously. This Review provides an overview of iron homeostasis in health before discussing diagnostic and therapeutic strategies for IDA in patients with IBD.


The American Journal of Gastroenterology | 2006

Tacrolimus Is Safe and Effective in Patients with Severe Steroid-Refractory or Steroid-Dependent Inflammatory Bowel Disease—A Long-Term Follow-Up

Daniel C. Baumgart; J. P. Pintoffl; Andreas Sturm; B. Wiedenmann; A. Dignass

OBJECTIVE:We and others have reported the use of tacrolimus in refractory inflammatory bowel disease (IBD). Little is known about its long-term efficacy and safety.METHODS:In this retrospective, observational single center study the charts of 53 adult patients with steroid-dependent (n = 18) or steroid-refractory (n = 35) IBD, Crohns disease (CD) (n = 11), ulcerative colitis (UC) (n = 40), or pouchitis (PC) (n = 2) were reviewed. Tacrolimus (0.1 mg/kg body weight per day) was administered orally in all and initially intravenously in 2 patients (0.01 mg/kg body weight per day), aiming for serum trough levels of 4–8 ng/mL. Forty-one of 53 (77.1%) patients were receiving concomitant azathioprine. The mean treatment duration was 25.2 ± 4.6 SD months (0.43–164 months). Patients were followed for a mean of 39 ± 4.1 SD months (5–164 months). Response was evaluated using a modified clinical activity index (M-CAI).RESULTS:Thirty-one UC (78%), 10 CD (90.1%), and both PC (100%) patients experienced an immediate clinical response or went into remission at 30 days. A statistically significant drop on the M-CAI was documented for UC and CD patients. Nine UC patients (22.5%) underwent colectomy between 1.6 and 41.3 months following initiation. Mean colectomy-free survival was 104.8 ± 15.5 (95% CI 74.4–135.2) months (limited to 164.4 months). Cumulative colectomy-free survival was estimated 56.5% at 43.8 months. Steroids were reduced or discontinued in 40 of 45 UC and CD patients (90%) taking steroids. Side effects included a temporary rise of creatinine (n = 4, 7.6%), tremor or paresthesias (n = 5, 9.4%), hyperkalemia (n = 1, 1.9%), hypertension (n = 1, 1.9%), and opportunistic infections (n = 2, 3.8%).CONCLUSION: Long-term tacrolimus therapy appears safe and effective in refractory IBD.


Zeitschrift Fur Gastroenterologie | 2011

Updated German Guideline on Diagnosis and Treatment of Ulcerative Colitis, 2011

A. Dignass; J. C. Preiss; D. E. Aust; Frank Autschbach; A. Ballauff; G. Barretton; B. Bokemeyer; S. Fichtner-Feigl; S. Hagel; K. R. Herrlinger; G. Jantschek; A. J. Kroesen; Wolfgang Kruis; Torsten Kucharzik; J. Langhorst; Max Reinshagen; Gerhard Rogler; D. Schleiermacher; Carsten Schmidt; Stefan Schreiber; H. Schulze; Eduard F. Stange; Martin Zeitz; Jörg C. Hoffmann; Andreas Stallmach

! Hintergrund Die Colitis ulcerosa (CU) ist neben dem Morbus Crohn die wichtigste chronisch-entzundliche Darmerkrankung (CED). Die Inzidenz fur die Colitis ulcerosa liegt in Deutschland bei bei 3,0–3,9 pro 100000 Einwohner [1, 2]. Die Pravalenz durfte in der westlichen Welt derzeit bei 160– 250 pro 100000 Einwohner liegen [3, 4]. Der hochste Gipfel der alterspezifischen Inzidenz liegt bei den 16bis 25-Jahrigen, wenn auch die Verteilung uber die Altersdekaden weit gleichmasiger ist als fruher beschrieben wurde [2]. Somit beginnt fur die meisten Patienten ihre Erkrankung wahrend der Schulzeit oder der Berufausbildung und dauert wahrend ihres gesamten beruflichen Lebens an. Daraus folgt, dass durch die Erkrankung nicht nur direkte Kosten (Medikamente, Arztbesuche, Operationen, Krankenhausaufenthalte etc.), sondern auch umfangreiche indirekte Kosten (Rente, Arbeitsausfalle etc.) entstehen. Es ist davon auszugehen, dass bei Patienten mit CU ca. die Halfte der Gesamtkosten den indirekten Kosten zuzuordnen sind [5]. An direkten medizinischen Kosten wurden dabei zuletzt zwischen 2500 und 5000€ pro Inhaltsverzeichnis! Hintergrund Die Colitis ulcerosa (CU) ist neben dem Morbus Crohn die wichtigste chronisch-entzündliche Darmerkrankung (CED). Die Inzidenz für die Colitis ulcerosa liegt in Deutschland bei bei 3,0–3,9 pro 100000 Einwohner [1, 2]. Die Prävalenz dürfte in der westlichen Welt derzeit bei 160– 250 pro 100000 Einwohner liegen [3, 4]. Der höchste Gipfel der alterspezifischen Inzidenz liegt bei den 16bis 25-Jährigen, wenn auch die Verteilung über die Altersdekaden weit gleichmäßiger ist als früher beschrieben wurde [2]. Somit beginnt für die meisten Patienten ihre Erkrankung während der Schulzeit oder der Berufausbildung und dauert während ihres gesamten beruflichen Lebens an. Daraus folgt, dass durch die Erkrankung nicht nur direkte Kosten (Medikamente, Arztbesuche, Operationen, Krankenhausaufenthalte etc.), sondern auch umfangreiche indirekte Kosten (Rente, Arbeitsausfälle etc.) entstehen. Es ist davon auszugehen, dass bei Patienten mit CU ca. die Hälfte der Gesamtkosten den indirekten Kosten zuzuordnen sind [5]. An direkten medizinischen Kosten wurden dabei zuletzt zwischen 2500 und 5000€ pro Inhaltsverzeichnis


Journal of Crohns & Colitis | 2010

European evidenced-based consensus on reproduction in inflammatory bowel disease

C. Janneke van der Woude; Sanja Kolaček; Iris Dotan; T. Öresland; Severine Vermeire; Pia Munkholm; Uma Mahadevan; Lucy Mackillop; A. Dignass

Inflammatory bowel diseases (IBD) typically affect patients in their reproductive years. It has been shown that reproductive issues are of key concern to IBD patients,1 especially women.2 In this respect, it is important to note that IBD patients remain voluntary childless more frequently than non-IBD controls.1,3,4 A recent study reported that IBD patients refrain from having children due the concerns about the adverse reproductive outcome.1 Fear of side-effects of the medication on the child and medical advice given by physicians, were the most important reasons for voluntary childlessness in this study. The treatment of IBD patients wishing to conceive is surrounded with uncertainties both for the parents to be and the treating physician. This guideline is developed to address these uncertainties and to promote a European perspective on reproduction in inflammatory bowel disease patients. The strategy to reach consensus involved the following steps: 1. The development of questions that should be covered by these pregnancy guidelines. Participants were asked to review these questions and when necessary to adjust or add questions. 2. The participants met in London in November to agree on the questions 3. The participants performed a systematic literature search of their topic with the appropriate key words using Medline/Pubmed and the Cochrane database, as well as their own files. The evidence level was graded (Table 1) according to the Oxford Centre for Evidence-Based medicine 5. 4. Provisional statements of the participants were written and the participants met in Prague in February 2010 to agree on the statements. This was done by projecting the statements and revising them on screen until a consensus was reached. Consensus was defined as agreement by > 80% of the participants. Each recommendation was graded as stated above. 5. The final document on each topic was written by the …


Alimentary Pharmacology & Therapeutics | 2003

Rescue therapy with tacrolimus is effective in patients with severe and refractory inflammatory bowel disease.

Daniel C. Baumgart; B. Wiedenmann; A. Dignass

Background : Oral tacrolimus, approved for the prophylaxis of organ rejection in liver or kidney transplants, has been reported to be effective in anecdotal cases of refractory inflammatory bowel disease.

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Daniel C. Baumgart

Humboldt University of Berlin

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B. Wiedenmann

Humboldt University of Berlin

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Jürgen Stein

Goethe University Frankfurt

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Juergen Stein

Goethe University Frankfurt

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Daniela Paclik

Free University of Berlin

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Franz Hartmann

Goethe University Frankfurt

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