[Show abstract][Hide abstract]ABSTRACT: BACKGROUND: Crohn's disease (CD) is an inflammatory bowel disease caused by genetic and environmental factors. More than 160 susceptibility loci have been identified for IBD, yet a large part of the genetic variance remains unexplained. Recent studies have demonstrated genetic differences between monozygotic twins, who were long thought to be genetically completely identical.
RESULTS: We aimed to test if somatic mutations play a role in CD etiology by sequencing the genomes and exomes of directly affected tissue from the bowel and blood samples of one and the blood-derived exomes of two further monozygotic discordant twin pairs. Our goal was the identification of mutations present only in the affected twins, pointing to novel candidates for CD susceptibility loci. We present a thorough genetic characterization of the sequenced individuals but detected no consistent differences within the twin pairs. An estimate of the CD susceptibility based on known CD loci however hinted at a higher mutational load in all three twin pairs compared to 1,920 healthy individuals.
CONCLUSION: Somatic mosaicism does not seem to play a role in the discordance of monozygotic CD twins. Our study constitutes the first to perform whole genome sequencing for CD twins and therefore provides a valuable reference dataset for future studies. We present an example framework for mosaicism detection and point to the challenges in these types of analyses.
Full-text available · Article · Jul 2014 · BMC Genomics
[Show abstract][Hide abstract]ABSTRACT: Environmental factors may play an important role in the pathogenesis of IBD. The history of patients of the German IBD twin study was analyzed by questionnaires and interviews.
Randomly selected German monozygotic (MZ) and dizygotic (DZ) twins with at least one sibling suffering from IBD (n=512) were characterized in detail including demography, medical history and concomitant medications. Controls comprised of non-twin IBD patients (n=392) and healthy subjects (n=207).
The most significant variables that were associated with Crohn's disease (CD) or ulcerative colitis (UC) included living abroad before time of diagnosis (OR, 4.32; 95% CI, 1.57-13.69), high frequency of antibiotic use (MZ CD OR, 5.03; 95% CI 1.61-17.74, DZ CD OR, 7.66; 95% CI, 3.63-16.82, MZ UC OR, 3.82; 95% CI, 1.45-10.56, DZ UC OR, 3.08; CI, 1.63-5.92), high consumption of processed meat including sausage (MZ CD OR, 7.9; 95% CI, 2.15-38.12, DZ CD OR, 10.75; 95% CI, 4.82-25.55, MZ UC OR, 5.69; 95% CI, 1.89-19.48, DZ UC OR, 18.11; 95% CI, 7.34-50.85), and recall of bacterial gastrointestinal infections (MZ CD OR, 15.9; 95% CI, 4.33-77.14, DZ CD OR, 17.21; 95% CI, 4.47-112.5, MZ UC OR, 5.87; 95% CI, 1.61-28.0, DZ UC OR, 11.34; 95% CI, 4.81-29.67).
This study reinforced the association of life style events, in particular a specific dietary and infections history, with IBD. Alteration of gut flora or alterations of the mucosal immune system in reactivity to the flora could be an important factor to explain the relationship between life-style and disease.
Article · Feb 2012 · Journal of Crohn s and Colitis
[Show abstract][Hide abstract]ABSTRACT: Interactions between genetic and environmental factors are believed to be involved in onset and initiation of inflammatory bowel disease. We analyzed the interaction between gastrointestinal mucosal microbiota and host genes in twin pairs discordant for ulcerative colitis (UC) to study the functional interaction between microbiota and mucosal epithelium.
Biopsy were collected from sigmoid colon of UC patients and their healthy twins (discordant twin pairs) and from twins without UC. Microbiota profiles were determined from analysis of 16S ribosomal DNA libraries; messenger RNA profiles were determined by microarray analysis.
Patients with UC had dysbiotic microbiota, characterized by less bacterial diversity and more Actinobacteria and Proteobacteria than that of their healthy siblings; healthy siblings from discordant twins had more bacteria from the Lachnospiraceae and Ruminococcaceae families than twins who were both healthy. In twins who were both healthy, 34 mucosal transcripts correlated with bacterial genera, whereas only 25 and 11 correlated with bacteria genera in healthy individuals and their twins with UC, respectively. Transcripts related to oxidative and immune responses were differentially expressed between patients with UC and their healthy twins.
The transcriptional profile of the mucosa appears to interact with the colonic microbiota; this interaction appears to be lost in colon of patients with UC. Bacterial functions, such as butyrate production, might affect mucosal gene expression. Patients with UC had different gene expression profiles and lower levels of biodiversity than their healthy twins, as well as unusual aerobic bacteria. Patients with UC had lower percentages of potentially protective bacterial species than their healthy twins.
Full-text available · Article · Apr 2011 · Gastroenterology
[Show abstract][Hide abstract]ABSTRACT: Complementary therapies are frequently used by patients with inflammatory bowel disease (IBD). The aim of this study was to evaluate the efficacy and safety of long-term therapy with a new Boswellia serrata extract (Boswelan, PS0201Bo) in maintaining remission in patients with Crohn's disease (CD).
In 22 German centers a double-blind, placebo-controlled, randomized, parallel study was performed. In all, 108 outpatients with CD in clinical remission were included. Patients were randomized to Boswelan (3×2 capsules/day; 400 mg each) or placebo for 52 weeks. The primary endpoint was the proportion of patients in whom remission was maintained throughout the 52 weeks. Secondary endpoints were time to relapse, changes of Crohn's Disease Activity Index (CDAI), and IBD Questionnaire (IBDQ) scores.
The trial was prematurely terminated due to insufficient discrimination of drug and placebo with regard to the primary efficacy endpoint. A total of 82 patients were randomized to Boswelan (n=42) or placebo (n=40). Sixty-six patients could be analyzed for efficacy. 59.9% of the actively treated patients and 55.3% of the placebo group stayed in remission (P=0.85). The mean time to diagnosis of relapse was 171 days for the active group and 185 days for the placebo group (P=0.69). With respect to CDAI, IBDQ, and laboratory measurements of inflammation, no advantages in favor of active treatment were detected. Regarding safety concerns, no disadvantages of taking the drug compared to placebo were observed.
The trial confirmed good tolerability of a new Boswellia serrata extract, Boswelan, in long-term treatment of CD. However, superiority versus placebo in maintenance therapy of remission could not be demonstrated.
Full-text available · Article · Aug 2010 · Inflammatory Bowel Diseases
[Show abstract][Hide abstract]ABSTRACT: Identification of dysplasia in inflammatory bowel disease represents a major challenge for both clinicians and pathologists. Clear diagnosis of dysplasia in inflammatory bowel disease is sometimes not possible with biopsies remaining "indefinite for dysplasia." Recent studies have identified molecular alterations in colitis-associated cancers, including increased protein levels of alpha-methylacyl coenzyme A racemase, p53, p16 and bcl-2. In order to analyze the potential diagnostic use of these parameters in biopsies from inflammatory bowel disease, a tissue microarray was manufactured from colons of 54 patients with inflammatory bowel disease composed of 622 samples with normal mucosa, 78 samples with inflammatory activity, 6 samples with low-grade dysplasia, 12 samples with high-grade dysplasia, and 66 samples with carcinoma. In addition, 69 colonoscopic biopsies from 36 patients with inflammatory bowel disease (28 low-grade dysplasia, 8 high-grade dysplasia, and 33 indefinite for dysplasia) were included in this study. Immunohistochemistry for alpha-methylacyl coenzyme A racemase, p53, p16 and bcl-2 was performed on both tissue microarray and biopsies. p53 and alpha-methylacyl coenzyme A racemase showed the most discriminating results, being positive in most cancers (77.3% and 80.3%) and dysplasias (94.4% and 94.4%) but only rarely in nonneoplastic epithelium (1.6% and 9.4%; P < .001). Through combining the best discriminators, p53 and alpha-methylacyl coenzyme A racemase, a stronger distinction between neoplastic tissues was possible. Of all neoplastic lesions, 75.8% showed a coexpression of alpha-methylacyl coenzyme A racemase and p53, whereas this was found in only 4 of 700 nonneoplastic samples (0.6%). alpha-methylacyl coenzyme A racemase/p53 coexpression was also found in 10 of 33 indefinite for dysplasia biopsies (30.3 %), suggesting a possible neoplastic transformation in these cases. Progression to dysplasia or carcinoma was observed in 3 of 10 p53/alpha-methylacyl coenzyme A racemase-positive, indefinite-for-dysplasia cases, including 1 of 7 cases without and 2 of 3 cases with p53 mutation. It is concluded that combined alpha-methylacyl coenzyme A racemase/p53 analysis may represent a helpful tool to confirm dysplasia in inflammatory bowel disease.
[Show abstract][Hide abstract]ABSTRACT: Genetic predisposition as a cause of inflammatory bowel disease (IBD) has been proven by both family and twin studies and genetic variants associated with the disease have been identified. The aim of our study was to determine the concordance rates for IBD in German twin pairs and to evaluate clinical characteristics of concordant and discordant twin pairs.
Patients with IBD were asked to participate and complete a questionnaire that contained questions about zygosity, demographic data, and medical history.
A total of 189 twin pairs in which at least 1 member had IBD were recruited (68 monozygotic and 121 dizygotic pairs). Within monozygotic pairs, 11 out of 31 (35%) were concordant for Crohn's disease (CD) and 6 out of 37 (16%) for ulcerative colitis (UC). Two of the 58 (3%) dizygotic pairs with CD and 1 out of 63 (2%) dizygotic pairs with UC were concordant for the disease. In 14 out of 20 (70%) discordant monozygotic CD pairs and 25 out of 31 (81%) discordant monozygotic pairs with UC, the first-born was affected by IBD. For discordant dizygotic twins, the first in birth order had IBD in 33 out of 56 (59%) pairs with CD and 40 out of 62 (64.5%) pairs with UC.
This study confirms a stronger genetic influence in CD than in UC. The high preponderance in being affected of the first-born twin and the fact that concordance was only 35% for CD and 16% for UC monozygotic twins highlight the important role of environmental trigger factors.
[Show abstract][Hide abstract]ABSTRACT: Interleukin-11 has shown benefit in animal inflammatory bowel disease models. Recently, recombinant human interleukin-11 (rhIL-11) has been observed to induce remission in a subset of patients with mild to moderate Crohn's disease (CD). The present study compared the efficacy of rhIL-11 versus prednisolone in remission induction in CD.
Patients with active CD were randomly assigned to receive either subcutaneous rhIL-11 (1 mg once weekly) and prednisolone placebo tablets, or active prednisolone (60 mg/day) and rhIL-11 placebo, for 12 weeks. Prednisolone/placebo was tapered after week 1, and patients were assessed every second week.
Fifty-one patients received medication: 13/27 (rhIL-11) and 17/24 (prednisolone) completed 12 weeks of treatment. Remission rates (intent to treat) for rhIL-11 versus prednisolone were 4% versus 46% at week 4 (p < 0.001) and 19% versus 50% at week 6 (p < 0.05). Response to treatment (deltaCDAI > 100) was seen in 19% (rhIL-11) versus 63% (prednisolone) after 4 weeks (p < 0.002) and 37% versus 63% after 6 weeks (p = 0.1). After 12 weeks of treatment, it was observed that 22% (rhIL-11) versus 21% (prednisolone) had remained in remission. Frequent side effects of rhIL-11 included fever (n = 3), rash (4), arthralgia/arthritis (3), nausea/vomiting (3), and headache (6).
rhIL-11 is well tolerated but significantly inferior when compared to prednisolone in short-term remission induction in patients with active CD. In this patient cohort, both treatments appeared to be poor in maintaining remission over a period of 3 months.
Full-text available · Article · Apr 2006 · The American Journal of Gastroenterology
[Show abstract][Hide abstract]ABSTRACT: We performed a randomized, double-blind, placebo-controlled, multicenter trial to investigate the efficacy and safety of recombinant interferon-beta-1a (rIFN-beta-1a) in outpatients with active steroid-refractory ulcerative colitis.
Ninety-one randomized patients subcutaneously received 3 MIU rIFN-beta-1a (group A, n = 32), 1 MIU rIFN-beta-1a (group B, n = 30), or placebo (group C, n = 29) 3 times a week over a period of 8 weeks in addition to standard therapy. An intention-to-treat analysis was performed to evaluate the efficacy and safety of treatment. Results: In all 3 groups, the median prestudy clinical activity index (CAI) was 10. In 18 of 32 patients (56%) in group A, in 11 of 30 patients (36%) in group B, and in 10 of 29 patients (34%) in group C, a reduction of the CAI of 6 points or greater (response) was achieved (differences were not statistically significant). Complete response (reduction of CAI to < or =4) was achieved in 56%, 30%, and 38% of patients in groups A, B, and C, respectively. Compared with baseline, the median endoscopic index had been reduced by 5, 3, and 4 points in groups A, B, and C, respectively. Steroid reduction was 12 mg in group A, 6 mg in group B, and 10 mg in group C. Identical side effects occurred in all 3 groups. Seven serious adverse events were reported (1 in group A and 6 in group C). All were unrelated to therapy as judged by the investigating physicians.
rIFN-beta-1a was safe but not significant, at the dosage and/or duration of treatment used, in steroid-refractory ulcerative colitis. Further studies are indicated.
Full-text available · Article · Jun 2005 · Clinical Gastroenterology and Hepatology
[Show abstract][Hide abstract]ABSTRACT: ISIS-2302, an antisense oligonucleotide directed against intercellular adhesion molecule 1, was effective in steroid refractory Crohn's disease in a pilot trial. The aim of this study was to investigate safety and efficacy of ISIS-2302 in chronic active Crohn's disease (CACD).
A dose-interval, multicenter, placebo-controlled trial was conducted in 75 patients with steroid-refractory CACD (Crohn's Disease Activity Index [CDAI], 200-400). The primary endpoint was steroid-free remission (CDAI <150) at week 14.
Only 2 of 60 (3.3%) ISIS-2302-treated and no placebo patients reached the primary endpoint. Steroid-free remission at week 26 (secondary endpoint) was reached in 8 of 60 (13.3%) active treatment and 1 of 15 (6.7%) placebo patients. A greater proportion of ISIS-2302-treated than placebo patients achieved a steroid dose <10 mg/day at weeks 14 and 26 (48.3% vs. 33.3% and 55.0% vs. 40.0%, respectively, and a glucocorticoid dose of 0 mg [prednisone equivalent] at week 26 [23.3% vs. 6.7%, respectively]). Treatment with ISIS-2302 was safe. The most common side effects were injection site reactions in the active treatment group (23% in ISIS-2302-treated patients vs. none in placebo patients). No statistically significant differences in the frequency of side effects were detected between dose groups.
The trial did not prove clinical efficacy of ISIS-2302 based on the primary endpoint. Positive trends were observed in some of the secondary endpoints.
Full-text available · Article · May 2001 · Gastroenterology
[Show abstract][Hide abstract]ABSTRACT: Expression of tumour necrosis factor-alpha (TNF-alpha) is increased in patients with Crohn's disease. Nuclear factor kappa B (NFkappaB) controls transcription of inflammation genes. Treatment with monoclonal antibodies to TNF (infliximab) in refractory Crohn's disease results in a remission rate of 30-50% after 4 weeks. We aimed to assess the clinical and immunological mechanism of failure to respond to infliximab.
24 patients with steroid refractory, chronic active Crohn's disease (Crohn's disease activity index [CDAI]>200), who showed an inflammatory manifestation in the sigmoid colon, had a single infusion of infliximab (5 mg/kg bodyweight) and were followed up for 16 weeks. Secretion capacity for TNF-alpha was assessed in whole-blood cytokine assays and nuclear concentrations of NFkappaB p65 were determined in colonic mucosal biopsy samples.
21 (88%) of 24 patients were in remission (CDAI<150) after 1 week, ten (42%) at 4 weeks, five (21%) at 8 weeks, and two (8%) of 24 at 12 and 16 weeks. Six (29%) of 21 patients who reached remission in week 1 relapsed at week 4, 13 (62%) at week 8, 17 (81%) at week 12, and 19 (90%) at week 16. Infliximab downregulated secretion of TNF-alpha in all patients to undetectable concentrations (day 1 after infusion). Relapsers were characterised by a rise in TNF-alpha secretion capacity and by increase of mucosal nuclear NFkappaB p65 before reactivation of clinical symptoms.
Infliximab greatly improved clinical symptoms in 88% of patients with Crohn's disease after 1 week. Response in some patients was of short duration. Reactivation of the mucosal and the systemic immune system preceded clinical relapse.
[Show abstract][Hide abstract]ABSTRACT: Inflammatory bowel disease (IBD) has a definite genetic component as documented by epidemiological and linkage evidence. It shows an earlier onset of disease in children of affected patients than in their parents. This has lead to speculations about genetic anticipation in this disorder. 2,007 IBD patients with sporadic disease and 472 multiplex familial cases (including 103 affected parents and 99 children of affected patients) were evaluated with a multi-item questionnaire as part of a study of inflammatory bowel disease genetics. The Mann-Whitney U-test and the general linear model were used for analysis. Clinical characteristics such as presence of fistulae, stenoses, extraintestinal manifestations, and other parameters, which are related to the severity of the disease, were found to be similar between familial and sporadic cases of IBD (corrected P > or = 0.31 for all tests). The mean-age-of onset in children of affected patients was 19.4 years earlier than in their parents. However, the age of the parental cohort was significantly higher (27 years) and the diagnostic interval also longer (1.7 years). If these confounders are corrected in a general linear model, no significant difference is evident for the age-of-onset between the groups (P > or = 0.52). There is no evidence for genetic anticipation in inflammatory bowel disease. The absence of genetic anticipation is consistent with the clinical similarity of familial and sporadic inflammatory bowel disease. This finding justifies the primary genetic analysis of familial disease under the assumption that their genetic background will be representative for all presentations of IBD.
Article · Jun 2000 · American Journal of Medical Genetics
[Show abstract][Hide abstract]ABSTRACT: Mycophenolate mofetil (MMF) is a new immunosuppressant with pharmacodynamic properties comparable to azathioprine. Recent reports found MMF to be effective in inflammatory bowel disease (IBD).
An open-label prospective and uncontrolled multicentre 6 month trial of MMF in combination with steroids was conducted in 24 chronic active IBD patients. A daily steroid demand of >/= 10 mg prednisone in the preceding 2 months and a Crohn's disease activity index (CDAI) > 150, or moderate to severe activity according to Truelove, served as criteria for chronic activity. The treatment consisted of a steroid pulse and tapering protocol in combination with MMF 2 g/day. A prednisone dose of 5 mg/day was maintained during months 4-6. The primary end-point was induction and maintenance of remission.
Only 10 of 24 patients had achieved remission after 3 months. All but one Crohn's disease patient had relapsed by the end of the study at 6 months. Depression and migraine necessitated drug withdrawal in two patients.
In conclusion, MMF 2 g/day was unable to induce and maintain remission for a period of 6 months in 23 of 24 chronic active IBD patients. Further controlled investigations are required in view of recent conflicting reports.
Full-text available · Article · Mar 2000 · Alimentary Pharmacology & Therapeutics
[Show abstract][Hide abstract]ABSTRACT: The chimeric anti-TNF antibody Remicade (Infliximab) has recently been approved for human use by the FDA and is now available on the market. Since there is considerable interest in this kind of treatment among patients with Crohn's disease, an international working group has summarized the presently available information about efficacy, side effects and possible problems of this treatment. Studies show that Remicade is effective in the treatment of active Crohn's disease, maintaining remission and fistulae. The working group does not see Infliximab as a first-line treatment for Crohn's disease. It may be used in active phase recurrent disease, chronic active disease and fistulae if standard treatment was not successful. For the surveillance special attention has to be given to the unknown malignancy rate of Infliximab. Infusion should be performed in an institution, routinely performing intravenous infusions and a two-hour surveillance of the patients should be guaranteed to recognize anaphylactic reactions or acute side effects. There is presently no information indication that the combination with immunosuppressants might increase risks or side effects of this treatment. Due to the limited information available the working group would prefer to use Remicade in studies only and recommends central collection and documentation of all data on efficacy and side effects for the next year.
Article · Jul 1999 · Zeitschrift für Gastroenterologie
[Show abstract][Hide abstract]ABSTRACT: Concentrations of proinflammatory cytokines are increased in the intestinal mucosa of patients with active Crohn's disease. Experimental immunotherapeutic interventions with anticytokine agents in refractory Crohn's disease show that tumour necrosis factor alpha (TNF alpha) may be an important mediator of inflammation. We investigated the relation between production of TNF alpha and interleukin 1beta by mononuclear cells of the colonic lamina propria in patients with remitting Crohn's disease and the risk of relapse.
We followed up 137 patients with Crohn's disease in steroid-induced remission for 1 year. Secretion of proinflammatory cytokines (tumour necrosis factor alpha [TNF alpha] and interleukin 1beta) was assessed after short-term culture of human lamina propria mononuclear cells.
Increased secretion of TNF alpha and interleukin 1beta were predictive for acute relapses within the next year. Site and extent of disease, baseline demographics, and serum acute-phase proteins had little predictive value.
TNF alpha is important as a target molecule for immune interventions in Crohn's disease. The capacity to produce TNF alpha or interleukin 1beta may identify patients who would benefit from anti-inflammatory remission maintenance.
[Show abstract][Hide abstract]ABSTRACT: Inflammatory bowel disease (IBD) is a complex disorder of unknown etiology. Epidemiological investigations suggest a genetic basis for IBD. Recent genetic studies have identified several IBD linkages. The significance of these linkages will be determined by studies in large patient collections. The aim of this study was to replicate IBD linkages on chromosomes 12 and 16 in a large European cohort.
Three hundred fifty-nine affected sibling pairs from 274 kindreds were genotyped using microsatellite markers spanning chromosomes 12 and 16. Affection status of the sibling pairs was defined as Crohn's disease (CD) or ulcerative colitis (UC).
Nonparametric statistical analyses showed linkage for both chromosomes. Two-point results for chromosome 12 peaked at D12S303 (logarithm of odds [LOD], 2.15; P = 0.003) for CD and at D12S75 (LOD, 0.92; P = 0.03) for UC. Multipoint analyses produced a peak LOD of 1.8 for CD. Chromosome 16 showed linkage for CD at marker D16S415 (LOD, 1.52; P = 0.007). Multipoint support peaked above markers D16S409 and D16S411 (LOD, 1.7).
These data are consistent with linkage of IBD to chromosomes 12 and 16. The replication of genetic risk loci in a large independent family collection indicates important and common susceptibility genes in these regions and will facilitate identification of genes involved in IBD.