Long-term evolution of disease behavior of Crohn's disease

Controversies in the treatment of Crohn’s disease: The case for an accelerated step-up treatment approach

The ideal treatment strategy for Crohn’s disease (CD) remains uncertain, as does the optimal endpoint of therapy. Top-down versus step-up describes two different approaches: early use of immunomodulators and biological agents in the former versus initial treatment with steroids in the latter, with escalation to immunomodulators or biological drugs in patients proven to be steroid refractory or steroid dependent. Top-down therapy has been associated with higher rates of mucosal healing. If mucosal healing proves to be associated with better long-term outcomes, such as a decreased need for hospitalization and surgery, top-down therapy may be the better approach for many patients. The main concern with the top-down approach is the toxicity of the immunomodulators and biological agents, which have been linked with infectious complications as well as an increased risk of lymphoma. It is unlikely that one strategy will be best for all patients given the underlying heterogeneity of CD presentation and severity. Ultimately, we must weigh the safety and efficacy of the therapies with the risks of the disease itself. Unfortunately our ability to risk stratify patients at diagnosis remains rudimentary. The purpose of this paper is to review the data that supports or refutes the differing treatment paradigms in CD, and to provide a rationale for an approach, termed the “accelerated step-up” approach, which attempts to balance the risks and benefits of our currently available therapies with the risk of disease related complications as we understand them in 2008.

Effect of infliximab on small bowel stenoses in patients with Crohn’s disease

AIM: To assess prospectively small bowel stenoses in Crohn’s disease (CD) patients treated with infliximab using Small Intestine Contrast Ultrasonography (SICUS).

METHODS: Twenty patients (M 12, age, 42.7 ± 11.8 years), 15 of whom showed obstructive symptoms indicating the presence of small bowel stenosis, and 5 without stenosis, were treated with infliximab (5 mg/kg at wk 0, 2, 6 and 5 mg/kg every 8 wk thereafter) for steroid refractoriness, fistulizing disease, or to avoid high-risk surgery. SICUS was performed at the induction phase and at regular time intervals during the follow-up period of 34.7 ± 16.1 mo (range 7-58). Small bowel stenoses were detected by SICUS, endoscopy and MRI.

RESULTS: In no case was progression of stenoses or the appearance of new ones seen. Of the 15 patients with stenosis, 5 stopped treatment after the induction phase (2 for no response, 3 for drug intolerance, one of whom showed complete regression of one stenosis). Among the remaining 10 patients, a complete regression of 8 stenoses (1 stenosis in 5 patients and 3 stenoses in one patient) was observed after 6-22 infliximab infusions.

CONCLUSION: In patients with CD treated with infliximab we observed: (a) No progression of small bowel stenosis and no appearance of new ones, (b) Complete regression of 1/22 stenosis after the induction phase and of 8/15 (53.3%) stenosis after 6-22 infusions during maintenance therapy.

Chronic enteric salmonella infection in mice leads to severe and persistent intestinal fibrosis

BACKGROUND & AIMS

Intestinal fibrosis and stricture formation are serious complications of Crohn's disease, often requiring surgical intervention. Unfortunately, the mechanisms underlying intestinal fibrosis development are poorly understood, in part because of the lack of relevant animal models. Here, we present a novel murine model of severe and persistent intestinal fibrosis caused by chronic bacterial-induced colitis.

METHODS

Mice were treated with streptomycin 24 hours prior to oral infection with Salmonella enterica serovar Typhimurium. Tissues were analyzed for bacterial colonization and inflammation, and fibrosis was assessed by Masson's trichrome staining and collagen quantification. Expression of the profibrotic cytokines transforming growth factor-beta1, connective tissue growth factor and insulin-like growth factor-I was determined, and the cell types present in fibrotic tissues were assessed by immunohistochemistry.

RESULTS

Infection led to chronic Salmonella colonization of the cecum and colon followed by edema, mucosal ulcerations, and severe transmural inflammation. This pathology was accompanied by significantly elevated expression of transforming growth factor-beta1, connective tissue growth factor, and insulin-like growth factor-I along with extensive type I collagen deposition in the cecal mucosa, submucosa, and muscularis mucosa of infected mice. Fibrosis was evident by 7 days postinfection, peaking at day 21 and still present at day 70. The fibrotic regions were found to be rich in fibroblasts and myofibroblasts.

CONCLUSIONS

These data demonstrate that chronic Salmonella infection of the murine gastrointestinal tract leads to severe tissue fibrosis. Because this model is highly reproducible and easy to perform, it provides great potential for investigating both host and bacterial contributions to intestinal fibrosis.

The role of CARD15 mutations and smoking in the course of Crohn's disease in a Mediterranean area

AIM

To evaluate the role of CARD15 mutations and smoking in the main events of Crohn's disease (CD).

PATIENTS AND METHODS

A total of 182 patients with CD were included in a prospective study in order to evaluate the role of CARD15 mutations and smoking in the main outcomes of disease course: first operation and surgical recurrence. The following variables were evaluated in a univariable and multivariable analysis: age, sex, site of disease, pattern, smoking habit, extraintestinal manifestations, duration of disease, and CARD15 mutation. The Kaplan-Meier method for survival curves and Cox model for multivariable analysis were, respectively, used.

RESULTS

A total of 110 patients were operated on and 32 were reoperated on. The 7-yr cumulative free rate of surgery was 42% (95% CI 34-51%). At multivariate analysis only stricturing and penetrating pattern were predictors of surgery (HR 1.7, 95% CI 1-2.8; HR 3.2, CI 1.8-5.5, respectively). The 7-yr cumulative free rate of reoperation was 75% (95% CI 0.52-0.88). At multivariable analysis in the model with any CARD15 mutation, only smoking habit at diagnosis (HR 3.6, 95% CI 1.4-9.1) was predictive of surgical recurrence. When single mutations were considered in the model smoking (HR 4.2, 95% CI 1.8-10.1) and L1007fs mutation (HR 2.9, 95% CI 1.1-7.3) were predictive of reoperation.

CONCLUSIONS

In CD, smoking predicts recurrence after surgery. The role of CARD15 mutations in the clinical course of CD remains undefined.

Dilation of colonic strictures by intralesional injection of infliximab in patients with Crohn's colitis

BACKGROUND

Intestinal stenosis is a frequent complication of Crohn's disease, often leading to repeated bowel obstruction and surgery. The prevalence of small bowel stenosis has ranged from 20% to 40% and from 7% to 15% in patients with colonic disease. Although balloon dilation is the initial preferred approach, many patients eventually restenose and require surgical resection or stricturoplasty. Infliximab, a chimeric IgG1 kappa monoclonal antibody against TNF-alpha, has been effective in the treatment of enteric as well as fistulous complications of Crohn's disease. Repeated systemic administration has been successful for active inflammatory disease yet has been reported to be ineffective in the treatment of strictures. Although the TREAT registry has shown systemic infliximab to be safe in the long term, there is concern regarding infectious as well as neoplastic complications.

METHODS

This report describes 3 patients refractory to all medical therapy including systemic infliximab.

RESULTS

In all 3 patients, dilation of a colonic stricture was accomplished by injection of infliximab, via the sclerotherapy technique, into the distal and medial portions of the stricture.

CONCLUSIONS

Infliximab was shown to be effective in the treatment of strictures in 3 patients.

C-reactive protein levels during a relapse of Crohn’s disease are associated with the clinical course of the disease

AIM: To explore if C-reactive protein (CRP) levels might serve as a prognostic factor with respect to the clinical course of Crohn’s disease and might be useful for classification.

METHODS: In this retrospective cohort study we enrolled 94 patients from the inflammatory bowel disease (IBD) database of the University Medical Centre Utrecht. CRP levels during relapse were correlated with the number of relapses per year. Severity of relapses was based on endoscopic reports and prednisone use. Furthermore, patients were categorized in a low or high CRP group based on their CRP response during relapse and demographic and clinical features were compared.

RESULTS: Overall, a positive correlation between CRP levels, number of relapses, and severity of relapse was found (respectively r_s = 0.31, P < 0.01 and r_s = 0.50, P < 0.001). Employing a cut-off level of 15 mg/L, the index CRP level was found to discriminate patients with respect to the number of relapses per year, as well as for severity of relapses (respectively 0.25 ± 0.16 vs 0.36 ± 0.24, P < 0.05 and 4.4 ± 1.2 vs 3.2 ± 1.1 on a 10-point visual analogue scale, P < 0.001 for the high CRP and low CRP groups respectively). In addition, the high CRP group showed more cumulative days of prednisone use per year (107 ± 95 vs 58 ± 48, P < 0.05), as well as a better response to infliximab (93 % vs 33 %, P = 0.06).

CONCLUSION: A higher CRP level during relapse seems to be associated with a more severe clinical course of disease.

Are we ready for top-down therapy for inflammatory bowel diseases: pro

Until the 1990s, inflammatory bowel diseases (IBD) were treated with conventional drugs, such as mesalazine, corticosteroids and thiopurines, which are effective in a proportion of IBD patients. Despite the introduction of immunosuppressive drugs, a significant number of IBD patients have a disabling disease course and, on average, a poor quality of life. The discovery of anti-TNF strategies and the development of biologics targeting several other pathways, important in the pathogenesis of ulcerative colitis and Crohn's disease, introduced a pivotal discussion. Central to this discussion is the question of whether these new therapies should be introduced early or late in the course of the disease. Important factors that are relevant for this discussion are quality of life, need for corticosteroids and surgery. This article aims to explore whether we are indeed ready for a top-down approach toward biologics.

Longitudinal concordance for clinical characteristics in a Swedish-Danish twin population with inflammatory bowel disease

BACKGROUND

The genetic influence on disease course in inflammatory bowel disease (IBD) remains unknown. We therefore aimed to study longitudinal concordance for clinical characteristics and longitudinal stability using the Montreal Classification in an IBD twin population.

METHODS

A total of 158 twins with ulcerative colitis (UC) (18 belonging to 9 concordant monozygotic pairs) and 141 twins with Crohn's disease (CD) (34 belonging to 17 concordant monozygotic pairs) were enrolled. Medical notes were scrutinized for clinical characteristics at diagnosis and after 10 years. Using the binominal distribution, we tested the hypothesis that clinical characteristics were independent within individuals in disease concordant monozygotic pairs.

RESULTS

In CD, location was identical in 11/17 monozygotic concordant pairs at diagnosis (P = 0.008) and in 11/16 pairs after 10 years (P = 0.02). Behavior at diagnosis was identical in 13/17 pairs (P = 0.03) and in 11/16 pairs after 10 years (P = 0.01). Monozygotic UC twins were concordant (within 5 years) for age at diagnosis (6/9 pairs; P < 0.001) and symptomatic onset (4/9 pairs; P = 0.02) but not for extent of disease at diagnosis or after 10 years. The Montreal Classification did not demonstrate longitudinal stability, either regarding location or behavior of CD or extent of UC.

CONCLUSIONS

The high phenotypic concordance, both at diagnosis and longitudinally, in monozygotic twins with CD supports a genetic influence not only on disease occurrence but also on disease course. This contrasts with UC, where the genetic impact appears less. Montreal Classification characteristics changed over time and should be used cautiously.

Health-related quality of life during natalizumab maintenance therapy for Crohn's disease

OBJECTIVES

We evaluated the effects of treatment on health-related quality of life (HRQoL) during a randomized controlled trial of natalizumab maintenance therapy (ENACT-2) using both disease-specific and generic measures.

METHODS

Crohn's disease patients who received natalizumab as induction therapy in ENACT-1 (N=724) and responded (N=339) were re-randomized to ENACT-2 in which they received natalizumab 300 mg (N=168) or placebo (N=171) every 4 wk for 48 additional wk. Outcome measures were the change from baseline on the inflammatory bowel disease questionnaire (IBDQ), the short form-36 (SF-36), the EuroQol-5D (EQ-5D), and a subject global assessment.

RESULTS

At entry into ENACT-1, scores indicated substantially impaired HRQoL for both the disease-specific and general measures. Natalizumab responders showed clinically meaningful improvement in HRQoL over the course of the ENACT-1 study. During maintenance therapy, IBDQ and SF-36 scale scores of patients who responded to natalizumab induction and were re-randomized to receive the drug in ENACT-2 (N=168) remained stable, while those re-randomized to placebo (N=171) worsened. At week 60, 48 wk after the initiation of maintenance therapy, the mean change from ENACT-1 baseline of all scales of the IBDQ and the SF-36 was significantly higher for those who continued to receive natalizumab (P<0.001 for all scales). The scores of patients who received maintenance natalizumab treatment were not statistically different from those of a cross-section of the U.S. population for 6 of 8 scales of the SF-36.

CONCLUSIONS

The substantial improvement in HRQoL experienced by patients who responded to natalizumab induction therapy was maintained during an additional 48 wk of maintenance therapy.

Effect of phenotype on health care costs in Crohn's disease: A European study using the Montreal classification

BACKGROUND

Crohn's disease (CD) is a chronic inflammation of the gastrointestinal tract associated with life-long high health care costs. We aimed to determine the effect of disease phenotype on cost.

METHODS

Clinical and economic data of a community-based CD cohort with 10-year follow-up were analyzed retrospectively in relation to Montreal classification phenotypes.

RESULTS

In 418 patients, mean total costs of health care for the behavior phenotypes were: nonstricturing-nonpenetrating 1690, stricturing 2081, penetrating 3133 and penetrating-with-perianal-fistula 3356 €/patient-phenotype-year (P<0.001), and mean costs of surgical hospitalization 215, 751, 1293 and 1275 €/patient-phenotype-year respectively (P<0.001). Penetrating-with-perianal-fistula patients incurred significantly greater expenses than penetrating patients for total care, diagnosis and drugs, but not surgical hospitalization. Total costs were similar in the location phenotypes: ileum 1893, colon 1748, ileo-colonic 2010 and upper gastrointestinal tract 1758 €/patient-phenotype-year, but surgical hospitalization costs differed significantly, 558, 209, 492 and 542 €/patient-phenotype-year respectively (P<0.001). By multivariate analysis, the behavior phenotype significantly impacted total, medical and surgical hospitalization costs, whereas the location phenotype affected only surgical costs. Younger age at diagnosis predicted greater surgical expenses.

CONCLUSIONS

Behavior is the dominant phenotype driving health care cost. Use of the Montreal classification permits detection of cost differences caused by perianal fistula.

Clinical course in Crohn's disease: results of a Norwegian population-based ten-year follow-up study

BACKGROUND & AIMS

Most studies concerning the clinical course in CD are retrospective or based on selected patient groups. Our aim was to assess the course of CD in a prospective population-based follow-up study and to identify possible prognostic risk factors for complications on the basis of information obtained at initial diagnosis.

METHODS

From 1990-1994, a population-based cohort of 843 new cases of inflammatory bowel disease was recruited in South-Eastern Norway. The cohort was systematically followed up at 1, 5, and 10 years after diagnosis.

RESULTS

Of 237 patients classified as CD, 197 completed the 10 years of follow-up, 18 died, and 22 were lost to follow-up. The cumulative relapse rate during the first 10 years was 90% (95% confidence interval, 86%-94%), and the cumulative probability of surgery was 37.9% (95% confidence interval, 31.4%-44.4%). Terminal ileal location (P < .001), stricturing (P = .004), penetrating behavior (P < .001), and age younger than 40 years (P = .03) at diagnosis were independent risk factors for subsequent surgery. A total of 53% (n = 105) of the patients had developed stricturing or penetrating disease at 10 years. A large proportion of patients (44%) were in clinical remission during the last 5 years of follow-up.

CONCLUSIONS

The prognosis for CD seems better than previously reported. The probability of surgery was low, and fewer than expected developed complicated disease behavior. Nevertheless, the cumulative relapse rate of 90% and the finding of prognostic risk factors for subsequent surgery might call for attention to early effective medical treatment strategies.

Early versus late surgery for ileo-caecal Crohn's disease

BACKGROUND

Surgical resection is almost inevitable in Crohn's disease. Surgery is usually performed for refractory or complicated disease: no studies appear to have been carried out, so far, to evaluate the potential benefits of performing surgery early in the course of the disease.

AIM

To compare the long-term course of Crohn's disease following ileo-caecal resection performed at the time of diagnosis (early surgery) or during the course of the disease (late surgery). Patients and methods Overall 207 patients with ileo-caecal Crohn's disease at their first resection were reviewed: 83 patients underwent surgery at the time of diagnosis (early surgery), while 124 underwent surgery 54.2 months (range 1-438) after diagnosis (late surgery). The mean follow-up after surgery was 147 months (range 12-534). The primary endpoint was clinical recurrence, defined as need for corticosteroids for symptomatic disease in the presence of endoscopic and/or radiologic recurrence. Secondary endpoints were need for immunosuppressants and surgical recurrence.

STATISTICAL ANALYSIS

Kaplan-Meier survival method and Cox proportional hazards regression model.

RESULTS

Within 10 years after surgery, the cumulative probability of clinical recurrence was significantly lower in the early surgery group (Log Rank test P = 0.01). A trend was observed regarding the need for immunosuppressants (P = 0.05). No difference was observed regarding surgical recurrence. At multivariate analysis, early surgery was the only independent variable associated with a reduced risk of clinical recurrence (Hazard ratio, HR = 0.57; 95% CI 0.35 to 0.92, P = 0.02), but not with need for immunosuppressants and surgical recurrence (HR = 0.51; 95% CI 0.20 to 1.30, P = 0.15; HR = 0.66; 95% CI 0.33 to 1.35, P = 0.25, respectively).

CONCLUSION

Early surgery prolongs clinical remission compared to surgery performed during the course of the disease, but the natural history of disease is not modified.

Medical management of Crohn's disease

The clinical course of Crohn's disease (CD) is characterized by unpredictable phases of disease activity and quiescence. The majority of CD patients experience mild to moderate disease or are in clinical remission over significant periods during the course of their disease. These patients can be treated conservatively with 5-aminosalicylates or budesonide depending on the disease location. Those patients with more severe forms of the disease who require corticosteroids should be treated more aggressively with early introduction of immunomodulator and/or biologic therapy, which may help to prevent the complications associated with CD. It has been suggested that therapies directed at mucosal healing may favorably modify the natural history of CD. As newer, more effective medications become available and new therapeutic approaches are introduced (top-down therapy), mucosal healing, and not solely clinical remission, may well become the preferred treatment objective.

The role of smoking in Crohn's disease as defined by clinical variables

The development of Crohn's disease (CD) is related to an interaction of genetic and environmental factors, with tobacco smoking being one of the most commonly studied environmental factors. In 1998, the Vienna classification was created to define CD by using three accepted clinical variables: age at diagnosis, disease behavior, and disease location. In this qualitative systematic review, articles examining the relationship between smoking and CD, using variables outlined in the Vienna classification, were identified utilizing multiple health databases. Current smoking was found to be associated with late-onset CD (> or =40 years old) and current smokers were more likely to progress to stricturing or penetrating type CD than were nonsmoking patients. Conflicting evidence exists regarding the relationship between smoking with respect to CD disease location. The Vienna classification is an important tool in permitting comparisons and predicting clinical course among CD cases, especially when smoking status is taken into account.

Application of the Montreal classification for Crohn's disease to a single clinician database of 1015 patients

Crohn's disease involves different gastrointestinal sites and may be characterized by high rates of strictures and penetrating complications. The present study applied the newly described Montreal schema of classification to a large, prospectively accumulated clinical database. In addition, age dependence was evaluated at diagnosis, with regard to disease location and disease behaviour. There were 1015 consecutively evaluated patients (449 male and 566 female). Disease was most often localized in the ileocolon and was usually complex with stricture formation or penetrating complications. For both sexes, with increasing age at diagnosis, Crohn's disease was less extensive, more often localized in the colon alone and characterized by less complex disease behaviour, especially with less penetrating disease complications. Using the Montreal classification for Crohn's disease, these results define the clinical features in a large, single clinician database and demonstrate age dependence in the phenotypic clinical expression of Crohn's disease.

The natural history of perianal Crohn's disease

Perianal lesions are exceedingly common in Crohn's disease and many patients have more than one type of lesion. Skin tags, fissures and haemorrhoids may persist over time and are usually managed expectantly or with topical therapy. Perianal and rectovaginal fistulas and associated abscesses often require both local and systemic therapy, and recurrence is common. In general, the clinical course of Crohn's disease is more aggressive in patients with perianal involvement. Established risk factors for perianal disease include colonic disease and young age at disease onset. Classification schema now recognize perianal fistulas as distinct from other forms of penetrating Crohn's disease. Genetic susceptibility factors for perianal disease may exist, but they remain incompletely delineated at present. There is hope that immunosuppressive and biotechnology medications will influence the natural history of perianal disease by preventing invasive surgeries, disease complications and recurrence, but this needs to be confirmed. Cancer, a rare complication of perianal disease, must be suspected when lesions persist despite therapy.

Quantifying exposure to diagnostic medical radiation in patients with inflammatory bowel disease: are we contributing to malignancy?

BACKGROUND

While potential risks of diagnostic medical radiation are acknowledged, actual exposure of patients in routine clinical practice is poorly documented.

AIM

To quantify such exposure to vulnerable abdominal organs in patients with inflammatory bowel disease who are already at risk of intestinal cancer.

METHODS

All incidences of exposure to diagnostic medical radiation were documented in a consecutive series of 100 patients with inflammatory bowel disease (62 Crohn's disease, 37 ulcerative colitis, 1 indeterminate colitis) attending a hospital-based clinic. Total effective dose (mSv) was calculated using published tables. Predictors of high or no irradiation were evaluated by multivariate logistic regression analysis.

RESULTS

Thirteen patients had no documented diagnostic irradiation. Twenty-three patients received an effective dose greater than 25 mSv. An at-risk effective dose >50 mSv was received by 11 patients. Dosage was higher in patients with Crohn's disease than ulcerative colitis (P = 0.02) and in patients undergoing surgery (P = 0.004). However, no predictive factors for high radiation dosage or for no exposure were identified.

CONCLUSIONS

At-risk irradiation from diagnostic medical radiation is common in patients with inflammatory bowel disease, and might potentially contribute to the elevated risk of intra-abdominal and other cancers. The level of irradiation should be considered in clinical decisions regarding abdominal imaging.

Are there any differences in phenotype or disease course between familial and sporadic cases of inflammatory bowel disease? Results of a population-based follow-up study

BACKGROUND

The influence of familial IBD on phenotype and course of disease in patients with CD and UC has not been studied in population-based cohorts.

AIM

To compare phenotype and course of disease between IBD patients with a first-degree relative with IBD and sporadic cases in a population-based cohort followed prospectively for 5 yr.

METHODS

Family history of IBD was registered at diagnosis and after 1 and 5 yr. Phenotype and course of disease were compared between sporadic and familial cases.

RESULTS

Data for 200 patients with CD and 454 with UC were sufficient for analysis. A first-degree relative with IBD was registered in 14.5% of CD patients and 10.1% of UC patients. The concordance for type of disease was 82% and 70% for CD and UC, respectively. No differences between familial and sporadic cases as regards localization and behavior of disease in CD patients or disease extent in UC patients were observed. In CD patients with colonic involvement, those in the familial group were significantly younger at diagnosis than the sporadic cases. No difference in disease severity in CD patients was observed between the familial and sporadic groups. In UC patients relapse was more frequent in familial cases, but no difference was observed in the need for surgery or medical treatment.

CONCLUSIONS

A family history of IBD does not seem to influence phenotype or to be an important prognostic factor for disease course in IBD patients.

The patient with recurrent (sub) obstruction due to Crohn's disease

Stricturing Crohn's disease (CD) occurs in 12-54% of the CD patient population and is associated with significant morbidity and impaired quality of life. The detailed pathophysiology of stricture formation has not been fully elucidated, but is primarily associated with luminal narrowing secondary to inflammation and the fibrosis that ensues during mucosal healing. The diagnosis of stricturing disease is based on clinical signs and symptoms along with imaging modalities. The advantages and shortcomings of each imaging modality are discussed. Treatment options are based on the differentiation between inflammatory versus fibrous-predominant strictures; whereas the former can potentially be managed with conservative medical treatment, the latter necessitates a mechanical solution through endoscopy or surgery. Indications, contra-indications and success rates of the different therapeutic approaches are discussed.

Inflammatory bowel disease: clinical aspects and established and evolving therapies

Crohn's disease and ulcerative colitis are two idiopathic inflammatory bowel disorders. In this paper we discuss the current diagnostic approach, their pathology, natural course, and common complications, the assessment of disease activity, extraintestinal manifestations, and medical and surgical management, and provide diagnostic and therapeutic algorithms. We critically review the evidence for established (5-aminosalicylic acid compounds, corticosteroids, immunomodulators, calcineurin inhibitors) and emerging novel therapies--including biological therapies--directed at cytokines (eg, infliximab, adalimumab, certolizumab pegol) and receptors (eg, visilizumab, abatacept) involved in T-cell activation, selective adhesion molecule blockers (eg, natalizumab, MLN-02, alicaforsen), anti-inflammatory cytokines (eg, interleukin 10), modulation of the intestinal flora (eg, antibiotics, prebiotics, probiotics), leucocyte apheresis and many more monoclonal antibodies, small molecules, recombinant growth factors, and MAP kinase inhibitors targeting various inflammatory cells and pathways. Finally, we summarise the practical aspects of standard therapies including dosing, precautions, and side-effects.

Clinical course in Crohn's disease: results of a five-year population-based follow-up study (the IBSEN study)

BACKGROUND

There are few population-based, prospective studies on the clinical course in patients with Crohn's disease (CD).

AIM

To extend the observation period in a population-based prospective study (the IBSEN study) to find out more about the initial 5-year clinical course in CD patients and to relate the findings to the Vienna classification.

METHODS

All patients diagnosed with inflammatory bowel disease (IBD) in southeastern Norway in the 4 years 1990-1993 were followed prospectively. The patients were invited to a systematic follow-up visit at their local hospital 1 and 5 years after inclusion in the study. The visits included a structured interview, a clinical examination and colonoscopy.

RESULTS

Out of 843 patients initially diagnosed with IBD, 200 patients with definite CD were alive and had sufficient data for analysis 5 years after diagnosis. Changes in disease localization and behaviour in relation to the Vienna classification were observed in 27 (13.5%) and 35 patients (17.5%), respectively. During the observation period, 56 patients (28%) underwent surgery with intestinal resection, and half of these had disease localized in the terminal ileum. At the time of the 5-year visit, oral sulfasalazin and 5-aminosalicylic acid (5-ASA) were the most frequently used medications (by 54% of the patients), while oral glucocorticosteroids and azathioprine were being used by 25% and 13%, respectively. Seventy-two percent of the patients had taken oral glucocorticosteroids at some time in the course of the 5-year period. The majority of the patients had intestinal symptoms at 5 years, but only 16% had symptoms that interfered with everyday activities. Fourteen percent of the patients had had a relapse-free 5-year course; however, relapse was not related to the initial Vienna classification. When the patients described the clinical course, 44% reported an improvement in symptoms during the follow-up period.

CONCLUSIONS

The 5-year clinical course in an unselected cohort of CD patients was mostly mild. The frequency of surgery was lower than that observed in other studies and only a minority of the patients had symptoms that interfered with everyday activities 5 years after the initial diagnosis. The Vienna classification predicted the risk of surgery, but did not predict symptoms at 5 years, relapses during the observation period or the course of disease as described by the patients.

Disease presentation and clinical course in black and white children with inflammatory bowel disease

OBJECTIVES

To compare the disease presentation, disease phenotype, and clinical course between black and white children with inflammatory bowel disease (IBD).

PATIENTS AND METHODS

A 10-year retrospective review was undertaken of the medical records of 245 pediatric patients with IBD studied at a tertiary care center.

RESULTS

In this patient population 24% were black and 76% were white. There were no differences between black and white patients in terms of anatomic distribution of IBD, symptom presentation, and extraintestinal manifestations. A family history of IBD (36.4% vs 17.5%; P = 0.006) was more common in white children. Mean erythrocyte sedimentation rate of black patients with Crohn disease was higher at diagnosis compared with whites (P < 0.001) and a greater proportion of African Americans presented with a body mass index z-score less than -2 (P < 0.009). At 12 months following diagnosis 22.5% of African American children had a hemoglobin level lower than 10 g/dL compared with 4.3% of whites (P = 0.001). African Americans had evidence of more complicating stricturing and penetrating Crohn disease behavior (51.3% vs 27.4%; P = 0.006). African Americans received significantly more corticosteroids and infliximab to treat their IBD compared with whites (P < 0.04).

CONCLUSIONS

This study suggests that for pediatric IBD, there may be racial differences in prevalence of family history and in disease phenotype.

Active and passive smoking in childhood is related to the development of inflammatory bowel disease

BACKGROUND

The highest prevalence of smoking in the United States is in Kentucky, where smoking typically begins in childhood. The state has many patients who suffer from inflammatory bowel diseases (IBD). The primary aim of this study was to assess whether exposure to active and/or passive tobacco smoke in childhood is related to the likelihood of developing IBD.

METHODS

Recruited into this prospective study were a total of 672 participants (253 patients with Crohn's disease [CD], 177 patients with ulcerative colitis [UC], and 242 controls), all of whom were asked to complete the Behavioral Risk Factor Surveillance Survey modified by the addition of 4 questions on childhood passive smoke exposure.

RESULTS

Survey response rate was 84%. CD and UC patients were more likely than controls to begin smoking regularly by ages 10 and 15, respectively, suggesting that becoming a regular smoker at a younger age may be associated with a subsequent diagnosis of IBD. Smoking by age 10 was associated with an earlier age at diagnosis with UC, but not with CD. CD patients were more likely than controls to have prenatal smoke exposure (odds ratio [OR], 1.72; 95% confidence interval [CI], 1.1-2.71) and were more likely to have passive smoke exposure during childhood, with 1 or both parents or other household members being smokers (OR, 2.04; 95% CI, 1.28-3.31).

CONCLUSIONS

Passive and active smoke exposure in childhood influences the development of IBD. A high incidence of this disease in a state with a high rate of cigarette smoking underscores the profound role of environmental factors in the etiology of these illnesses.

Treatment inferred disease severity in Crohn's disease: evidence for a European gradient of disease course

OBJECTIVE

Geographic differences in disease course of Crohn's disease (CD) might possibly be related to differences in genetic and environmental factors encountered in different parts of the world. The aim of this study was to assess differences in treatment regimens within a European cohort of CD patients as a reflection of disease course, and to identify associated phenotypic risk factors at diagnosis.

MATERIAL AND METHODS

A prospective European population-based inception cohort of 380 CD patients was studied. The patients were classified for phenotype according to the Vienna classification. Differences between Northern and Southern European centres in treatment over the first 10 years of disease were analysed using a competing risks survival analysis method.

RESULTS

Patients in the North were more likely to have had surgery (p<0.01), whereas patients in the South were more likely to have been treated medically (p<0.01). Phenotype at diagnosis was not predictive of differences in treatment regimens between North and South.

CONCLUSIONS

In this study, a difference in management of CD was observed between Northern and Southern European centres. This suggests that there may be a North-South disease severity gradient across Europe. Phenotypic differences between patients in the North and South did not explain this observed difference.

Does cigarette smoking influence the phenotype of Crohn's disease? Analysis using the Montreal classification

OBJECTIVES

The clinical subclassification of Crohn's disease by phenotype has recently been reevaluated. We have investigated the relationships between smoking habit, age at diagnosis, disease location, and progression to stricturing or penetrating complications using the Montreal classification.

METHODS

408 patients (157 male, median age 29.4 yr) were assessed. Data were collected on smoking habit, age at diagnosis, anatomical distribution, and disease behavior. Follow-up data were available on all patients (median 10 yr).

RESULTS

At diagnosis, ex-smokers (N = 53) were older than nonsmokers (N = 177) or current smokers (N = 178, medians 43.2 vs 28.3 or 28.9 yr, respectively, P < 0.001). Disease location differed according to smoking habit at diagnosis (chi(2)= 24.1, P= 0.02) as current smokers had less colonic (L2) disease than nonsmokers or ex-smokers (30%vs 45%, 50%, respectively). In univariate Kaplan-Meier survival analysis, smoking habit at diagnosis was not associated with time to development of stricturing disease, internal penetrating disease, perianal penetrating disease, or time to first surgery. Patients with isolated colonic (L2) disease were slower to develop strictures (P < 0.001) or internal penetrating disease (P= 0.001) and to require surgery (P < 0.001). Cox models with smoking habit as time-dependent covariates showed that, relative to ileal (L1) location of disease, progression to stricturing disease was less rapid for patients with colonic (L2) disease (HR 0.140, P < 0.001), but not independently affected by smoking habit. Progression to surgery was also slower for colonic (L2) than ileal (L1) disease location (HR 0.273, P < 0.001), but was independent of smoking habit.

CONCLUSIONS

Smoking habit was associated with age at diagnosis and disease location in Crohn's disease, while disease location was associated with the rate of development of stricturing complications and requirement for surgery. The pathogenic basis of these observations needs to be explained.

Fibrogenesis in Crohn's disease

INTRODUCTION

Over one-third of patients with Crohn's disease (CD) will develop an intestinal stricture and the great majority of these will require at least one surgical procedure. While the pathogenesis of inflammation in CD has been extensively investigated, knowledge of stricture pathogenesis remains limited. The aim of this review is to discuss the current understanding of fibrogenesis in CD and to outline potential directions in research and therapeutics.

METHODS

The electronic literature (January 1966 to May 2006) on CD-associated fibrosis was reviewed. Further references were obtained by cross-referencing from key articles.

RESULTS

CD-associated fibrosis results from chronic transmural inflammation and a complex interplay among intestinal mesenchymal cells, cytokines, and local inflammatory cells. The fibroblast is the key cell type mediating stricture formation. The cytoarchitecure of the bowel wall is altered with disruption of the muscularis mucosa, thickening of the muscularis propria, and deposition of collagen throughout. The cytokine TGF-beta appears critical in this process, acting to increase growth factor and extracellular matrix (ECM) production and dysregulate ECM turnover. Potential therapeutic interventions are likely to concentrate on modulating down-stream targets of TGF-beta.

CONCLUSIONS

Greater understanding of the biology of fibrostenosis is likely to yield significant advances in our ability to care for patients with stricturing CD. Potential dividends of this approach include identification of novel therapeutic targets and biomarkers useful for prognostication and therapeutic monitoring.

Impact of interobserver disagreement on phenotype-genotype associations in Crohn's disease

BACKGROUND

Nonvalidated definitions of disease-related parameters in inflammatory bowel disease cause variations in diagnosis and disease classification. We determined interobserver agreement on applications of definitions of the Vienna Classification variables and computed the potential influence of misclassification on genotype/phenotype associations.

METHODS

Ten records of patients with Crohn's disease (CD) were independently evaluated by 19 observers using a standardized inflammatory bowel disease documentation system, which included the Vienna Classification. Interobserver agreement (IOA) was calculated as a percentage of the observers' agreement with a predetermined reference observer and by Cohen's kappa. Randomized reclassifications were then computed with 10,000 simulation runs using the IOA results and published NOD2/CARD15 gene status. A chi-square independence test was calculated for each simulation run.

RESULTS

IOA for location and behavior was 70% (K = 0.57) and 95% (K = 0.91), respectively. IOA for location subgroups ranged from 48% to 88% and for behavior from 91% to 97%. By including the results of histopathology into the evaluation of location, the overall IOA increased significantly, to 80% (P = 0.019). Assuming a true genotype/phenotype association, the proportion of studies with nonsignificant findings (P > 0.05) because of the observed misclassification of location ranged from 13.3% to 63.8% and of behavior from 0.2% to 22.2%, depending on a study sample size of 500 or 150 patients respectively.

CONCLUSIONS

We concluded that there is appreciable interobserver disagreement on the location of CD according to the original Vienna Classification that may obscure true genotype/phenotype associations. Definitions of disease parameters have to be validated before being used as the bases for classifications.

Antibodies to saccharomyces cerevisiae in Crohn's disease: higher titers are associated with a greater frequency of mutant NOD2/CARD15 alleles and with a higher probability of complicated disease

BACKGROUND

Both antibodies to Saccharomyces cerevisiae (ASCA) and carriage of two mutated NOD2/CARD15 alleles are associated with ileal Crohn's disease (CD) and complications requiring bowel surgery. We assessed the ASCA titer as a marker of CD clinical behavior.

METHODS

In a cross-sectional study, we phenotyped 117 unrelated CD patients. Titers (Units, U) of ASCA IgG and IgA were measured and patients were genotyped for three high-risk NOD2/CARD15 alleles. Multiple logistic regression and Cox regression analyses were used to assess the association of factors to CD phenotype and time to surgery.

RESULTS

ASCA seropositivity was associated with younger age at diagnosis, ileal disease, and complicated (stricturing or penetrating) behavior. There was a dose-response between the number of mutant NOD2/CARD15 alleles and the prevalence and titers of ASCA. The ASCA titer and tobacco use were associated with ileal disease independently of NOD2/CARD15 status. The ASCA titer (odds ratio (OR): 2.7 per 25 U, 95% confidence interval (CI): 1.5-46.7) and ileal disease were associated with stricturing/penetrating behavior, independently of NOD2/CARD15 status. Patients with ileal CD and ASCA titers of 41 U and 60 U needed 10 and 5 years of disease, respectively, to accumulate a 50% risk of complications.

CONCLUSIONS

ASCA+ patients had a greater frequency of mutant NOD2/CARD15 alleles. Nonetheless, higher ASCA titers were associated with higher probabilities of ileal CD and stricturing/penetrating behavior independently of NOD2/CARD15 status. Higher ASCA titers were associated with more rapid development of complications. This quantitative marker may prove useful in risk-stratifying patients to more aggressive antiinflammatory therapies.

Review article: Altering the natural history of Crohn's disease--evidence for and against current therapies

BACKGROUND

The natural course of Crohn's disease is characterized by flare-ups altered with periods of remission. The majority of Crohn's disease patients need surgery within 10 years of diagnosis. Major advances in treatment options over the past years have made our treatment goals more ambitious and modification of the natural course has become the ultimate endpoint.

AIM

To review the evidence of existing therapies for Crohn's disease for changing the natural history.

METHODS

A Medline search was undertaken by using 'natural history', 'Crohn's disease', 'therapy' (corticosteroids, azathioprine, methotrexate, infliximab and enteral feeding), 'surgery', 'hospitalizations' and 'mucosal healing'.

RESULTS

Corticosteroids do not alter the disease course and maintenance therapy with corticosteroids should be avoided given their side effects. The immunomodulators azathioprine and methotrexate heal the mucosa but their onset of action is slow. Infliximab therapy introduces rapid mucosal healing and is associated with decreased hospitalizations and surgical interventions. Despite the fact that immunomodulators and infliximab are effective in maintaining clinical and endoscopic remission, there is little hard evidence at present that these therapies alter the natural history of the disease. The main reason being the fact that these therapies have so far been used only in refractory patients and that early initiation in the right patient is crucial in order to change the disease course.

CONCLUSION

Prospective studies should validate predictors of complicated disease and randomized studies in high-risk groups should be performed to answer if early introduction of immunomodulators or biological therapies slows down disease progression and alters natural history.

Homozygosity for the CARD15 frameshift mutation 1007fs is predictive of early onset of Crohn's disease with ileal stenosis, entero-enteral fistulas, and frequent need for surgical intervention with high risk of re-stenosis

OBJECTIVE

The identification of CARD15 as a susceptibility gene for Crohn's disease (CD) offers new possibilities for patient classification and risk assessment. The purpose of this study was to carry out a CARD15 sequence analysis in a large single-center IBD cohort and to investigate the impact of different genotypes on disease phenotypes.

MATERIAL AND METHODS

A total of 445 unrelated patients with IBD (68.1% CD, 28.5% ulcerative colitis (UC), 3.4% indeterminate colitis (IC)) were included in the study. Clinical data were recorded by detailed questionnaire and analysis of the charts. CARD15 variants (R702W, G908R, 1007fs (frameshift)) were identified by DNA sequence analysis.

RESULTS

CARD15 variants were found in 142 inflammatory bowel disease (IBD) patients (31.9%) including 120 CD patients (39.6%). In CD, the presence of two CARD15 variants was associated with ileal disease (p=0.008 versus wild-type (wt); OR 4.04; 95% CI 1.36-11.96) and a fibrostenotic phenotype (p=0.002 versus wt; OR 5.47; 95% CI 1.61-18.58). Subgroup analysis of 19 patients (4.3%) homozygous for the CARD15 variant 1007fs (3020ins C) revealed an association with onset of CD at an early age (p=0.014 versus wt), ileal involvement (p=0.001), and intestinal stenoses in all patients (p=0.001) frequently requiring surgery (73.7%; p=0.093). Of these patients 78.6% developed re-stenoses after surgical resection; 52.6% of the homozygotes were diagnosed as having entero-enteral fistulas.

CONCLUSIONS

Patients homozygous for the 1007fs mutation had an early disease onset with long-segment ileal stenoses and entero-enteral fistulas. They frequently needed surgical intervention and had a high risk of re-stenosis. Genotyping therefore appears to be an important diagnostic tool in identifying severely affected patients requiring individualized treatment strategies at an early stage of the disease.

Predictive value of the CARD15 variant 1007fs for the diagnosis of intestinal stenoses and the need for surgery in Crohn's disease in clinical practice: results of a prospective study

BACKGROUND AND AIM

The diagnostic and therapeutic relevance of CARD15 genotyping in Crohn's disease (CD) for daily clinical practice has not been investigated so far. We therefore analyzed whether CARD15 variants are independent predictive factors for small bowel stenosis in CD evaluated by magnetic resonance enteroclysis (MRE). On the basis of these findings, the potential implications for patient management were investigated.

METHODS

Eighty CD patients with clinical symptoms suggestive of small bowel stenosis were included. All patients were genotyped for the CARD15 variants c.2104C > T (p.R702W), c.2722G > C (p.G908R), and c.3019_3020insC (p.Leu1007fsX1008) and examined by MRE of the small bowel.

RESULTS

CARD15 variants were found in 40 (50%) patients. MRE identified 31 (38%) patients with small bowel stenoses. Twenty-five of the 40 (62%) patients with at least one CARD15 variant were diagnosed of intestinal stenosis by MRE (odds ratio [OR] = 9.44; confidence interval [CI] 3.21-27.77; P = 0.00028, Bonferroni corrected). Particularly, the presence of the 1007fs variant was associated with an increased risk of an intestinal stenosis (OR = 12.00, CI 3.47-41.54, P = 0.00042, Bonferroni corrected). Twenty-one of 31 (68%) patients with stenoses required surgical intervention, with 13 of these 21 (62%) patients carrying the 1007fs variant.

CONCLUSION

In the largest prospective study analyzing the diagnostic value of CARD15 variants in CD patients performed so far, we identified the 1007fs variant as strong predictor for intestinal stenoses with need for surgery in CD patients. Genotyping could therefore be an important diagnostic tool in clinical practice for identifying high-risk patients with specific diagnostic and therapeutic needs. Moreover, MRE is an excellent technique for diagnosing small bowel stenoses.

Smoking and inflammatory bowel disease: a meta-analysis

OBJECTIVE

To assess whether there is a true effect of smoking on the 2 most prevalent forms of inflammatory bowel disease (IBD): Crohn disease (CD) and ulcerative colitis (UC).

METHODS

For this meta-analysis, we searched multiple health care databases, including MEDLINE and EMBASE (January 1980 to January 2006), to examine the relationship between smoking and IBD. Keywords searched included smoking, Inflammatory bowel disease, Crohn's disease, and ulcerative colitis. Data were abstracted using predefined inclusion and exclusion criteria. An odds ratio (OR) was recalculated for each study using the random-effects model, and a combined OR was calculated.

RESULTS

A total of 245 articles were obtained through an electronic search of health care databases. Thirteen studies examined the relationship between UC and smoking, whereas 9 examined the relationship between CD and smoking. We found evidence of an association between current smoking and CD (OR, 1.76; 95% confidence interval [CI], 1.40-2.22) and former smoking and UC (OR, 1.79; 95% CI, 1.37-2.34). Current smoking had a protective effect on the development of UC when compared with controls (OR, 0.58; 95% CI, 0.45-0.75).

CONCLUSION

This is the first meta-analysis, to our knowledge, to evaluate the relationship between smoking and IBD using accepted quality standards for meta-analysis reporting. Our meta-analyses confirm that smoking is an important environmental factor in IBD with differing effects in UC and CD. By using predefined inclusion criteria and testing for homogeneity, the current analysis provides an estimate of the effect of smoking on both these forms of IBD.

The +1059G/C polymorphism in the C-reactive protein (CRP) gene is associated with involvement of the terminal ileum and decreased serum CRP levels in patients with Crohn's disease

BACKGROUND

Serum C-reactive protein (CRP) levels influence the response to anti-tumour necrosis factor (TNF) therapies.

AIM

To analyse the influence of the +1059G/C CRP polymorphism on CRP serum levels and disease susceptibility in patients with Crohn's disease (CD).

METHODS

Using restriction fragment length polymorphism (RFLP) analysis, genomic DNA from 241 CD patients and 199 unrelated controls was analysed for the +1059G/C substitution in the CRP gene and the common caspase-activation recruitment domain 15 (CARD15) variants.

RESULTS

Homozygous C/C carriers were detected only among CD patients (P = 0.066). Patients with ileal involvement (L1 and L3 phenotype) were found in only 58.4% of patients with the wildtype G/G genotype but in 88.2% of the heterozygous G/C carriers (OR 5.26; 95% CI 1.19-23.92) and four of the five C/C homozygous carriers (80%; OR 4.55; 95% CI 1.64-16.67; P = 0.008 for hetero- and homozygous carriers vs. wildtype) which was independent of the presence of CARD15 variants. Increased CD activity was associated with increased CRP serum levels (P < 0.005). For Crohn's disease activity index (CDAI) < 150, C/C homozygosity for the +1059 G/C polymorphism was associated with significantly lower CRP serum levels (P < 0.01).

CONCLUSIONS

The C allele of the CRP +1059G/C polymorphism is associated with decreased serum CRP levels and increased likelihood of disease involvement of the terminal ileum in CD patients.

Natalizumab: a promising treatment for Crohn's disease

A primary feature contributing to the pathology of Crohn's disease (CD) is inappropriate and persistent recruitment and migration of circulating leukocytes from the bloodstream to affected tissues and organs. These processes are mediated by interactions between alpha(4) integrin adhesion molecules expressed on leukocyte surfaces and cognate receptors on vascular endothelial cells. Natalizumab is a humanized immunoglobulin G(4) monoclonal antibody against alpha(4) integrins. Natalizumab has demonstrated efficacy in inducing and maintaining sustained remission in patients with moderately to severely active CD, including those intolerant of or unresponsive to infliximab. Maintenance therapy with natalizumab in adult patients allowed elimination of steroids in a significant number of patients and sustained patients' quality of life. Natalizumab has been well tolerated in the majority of patients. However, progressive multifocal leukoencephalopathy, a rare opportunistic infection associated with the JC polyomavirus, occurred in three natalizumab-treated patients; two multiple sclerosis patients and one CD patient. This article reviews the properties of natalizumab and addresses its potential benefits and risks in the treatment of CD.

Factors associated with disease evolution in Greek patients with inflammatory bowel disease

Background

The majority of Crohn's disease patients with B1 phenotype at diagnosis (i.e. non-stricturing non-penetrating disease) will develop over time a stricturing or a penetrating pattern. Conflicting data exist on the rate of proximal disease extension in ulcerative colitis patients with proctitis or left-sided colitis at diagnosis. We aimed to study disease evolution in Crohn's disease B1 patients and ulcerative colitis patients with proctitis and left-sided colitis at diagnosis.

Methods

116 Crohn's disease and 256 ulcerative colitis patients were followed-up for at least 5 years after diagnosis. Crohn's disease patients were classified according to the Vienna criteria. Data were analysed actuarially.

Results

B1 phenotype accounted for 68.9% of Crohn's disease patients at diagnosis. The cumulative probability of change in disease behaviour in B1 patients was 43.6% at 10 years after diagnosis. Active smoking (Hazard Ratio: 3.01) and non-colonic disease (non-L2) (Hazard Ratio: 3.01) were associated with behavioural change in B1 patients. Proctitis and left-sided colitis accounted for 24.2%, and 48.4% of ulcerative colitis patients at diagnosis. The 10 year cumulative probability of proximal disease extension in patients with proctitis and left-sided colitis was 36.8%, and 17.1%, respectively (p: 0.003). Among proctitis patients, proximal extension was more common in non-smokers (Hazard Ratio: 4.39).

Conclusion

Classification of Crohn's disease patients in B1 phenotype should be considered as temporary. Smoking and non-colonic disease are risk factors for behavioural change in B1 Crohn's disease patients. Proximal extension is more common in ulcerative colitis patients with proctitis than in those with left-sided colitis. Among proctitis patients, proximal extension is more common in non-smokers.

Immunogenetic phenotypes in inflammatory bowel disease

The currently accepted etiopathogenic hypothesis suggests that the chronic intestinal inflammation and related systemic manifestations characteristic of inflammatory bowel disease (IBD) are due to an overly aggressive or pathologic immune response to resident luminal bacterial constituents. Predisposing factors are genetic dysregulation of mucosal immune responses and/or barrier function, with onset triggered by environmental stimuli. These factors and their interactions may also be important determinants of disease phenotype and disease progression. The emergence of immunogenetic phenotypes lends support to the proposed hypothesis that susceptibility genes regulate distinct immune processes, driven by luminal antigens, expressed as specific immune phenotypes which in turn influence clinical phenotypes in IBD patients.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

Factors associated with the development of intestinal strictures or obstructions in patients with Crohn's disease

OBJECTIVE

Theoretical concern exists that rapid luminal healing in Crohn's disease (CD) with therapies like infliximab increases the risk of intestinal stenosis, stricture, or obstruction (SSOs).

METHODS

Data were analyzed from the ongoing observational TREAT (the Crohn's Therapy, Resource, Evaluation, and Assessment Tool) Registry and ACCENT I (A Crohn's Disease Clinical Trial Evaluating Infliximab in a New Long-Term Treatment Regimen) study. Investigators reported SSOs as adverse events or serious adverse events.

RESULTS

In TREAT, SSOs occurred at a significantly higher rate in patients treated with infliximab compared with patients who received other treatments only (1.95 events/100 patient-years vs 0.99 events/100 patient-years; p < 0.001). Using multivariable analyses, however, infliximab therapy was not associated with SSO development. CD severity at the time of event onset (hazard ratio (HR) = 2.35, 95% confidence internal (CI) 1.35-4.09); CD duration (HR = 1.02, 95% CI 1.00-1.04); ileal disease (HR = 1.56, 95% CI 1.04-2.36); and new corticosteroid use (HR = 2.85, 95% CI 1.23-6.57) were associated with SSOs. In ACCENT I, no increase in SSOs was reported in patients who received infliximab maintenance therapy compared with those who received episodic therapy, despite higher median cumulative infliximab exposure. Additionally, there was no increase in SSO development with rapid mucosal healing (healing at week 10).

CONCLUSIONS

Although unadjusted analyses suggested that patients who received infliximab were twice as likely to develop SSOs, multivariable analysis adjusting for other factors demonstrated that only disease duration, disease severity, ileal disease, and new corticosteroid use were significantly associated with SSO development.

Inflammatory bowel disease characteristics among African Americans, Hispanics, and non-Hispanic Whites: characterization of a large North American cohort

OBJECTIVES

Inflammatory bowel disease (IBD), comprising primarily of Crohn's disease (CD) and ulcerative colitis (UC), is increasingly prevalent in racial and ethnic minorities. This study was undertaken to characterize racial differences in disease phenotype in a predominantly adult population.

METHODS

Phenotype data on 830 non-Hispanic white, 127 non-Hispanic African American, and 169 Hispanic IBD patients, recruited from six academic centers, were abstracted from medical records and compiled in the NIDDK-IBD Genetics Consortium repository. We characterized racial differences in family history, disease location and behavior, surgical history, and extraintestinal manifestations (EIMs) using standardized definitions.

RESULTS

African American CD patients were more likely than whites to develop esophagogastroduodenal CD (OR = 2.8; 95% CI: 1.4-5.5), colorectal disease (OR = 1.9; 95% CI: 1.1-3.4), perianal disease (OR = 1.7; 95% CI: 1.03-2.8), but less likely to have ileal involvement (OR = 0.55; 95% CI: 0.32-0.96). They were also at higher risk for uveitis (OR = 5.5; 95% CI: 2.3-13.0) and sacroiliitis (OR = 4.0; 95% CI: 1.55-10.1). Hispanics had higher prevalence of perianal CD (OR = 2.9; 95% CI: 1.8-4.6) and erythema nodosum (3.3; 95% CI: 1.7-6.4). Among UC patients, Hispanics had more proximal disease extent. Both African American and Hispanic CD patients, but not UC patients, had lower prevalences of family history of IBD than their white counterparts.

CONCLUSIONS

There are racial differences in IBD family history, disease location, and EIMs that may reflect underlying genetic variations and have important implications for diagnosis and management of disease. These findings underscore the need for further studies in minority populations.

New genes in inflammatory bowel disease: lessons for complex diseases?

The chronic inflammatory bowel diseases Crohn's disease and ulcerative colitis are common causes of gastrointestinal disease in northern Europe, affecting as many as one in 250 people. Although mortality is low, morbidity associated with these diseases is substantial. We review the recent advances in the genetics of inflammatory bowel disease, with particular emphasis on the data that have been generated since the discovery of the CARD15 (NOD2) gene in 2001.

Crohn’s disease in adults: Observations in a multiracial Asian population

AIM: To determine the demography and clinical presentation of CD and secondly to determine any differences in the prevalence between the different ethnic groups in a multiracial Asian population.

METHODS: Patients with CD who were seen in 2001–2003 in the University of Malaya Medical Centre (UMMC) were enrolled in this study. Prevalence of disease was calculated for the group as a whole and by race with hospital admissions per ethnic group as the denominator.

RESULTS: Thirty-four patients were diagnosed to have CD. Basic demographic data of patients; male:female 17:17; mean age 29.1 years (±13.5 years); ethnic group: Malays 5 (14.7%), Chinese 12 (35.3%) and Indians 17 (50%). Twenty-six (76.5%) were diagnosed under the age of 40 and 8 (23.5%) were diagnosed over the age of 40. Location of the disease was as follows: ileocolonic 13 (38.2%), terminal ileum only 9 (26.5%), colon only 8 (23.5%), and upper gastrointestinal 4 (11.8%). Sixteen (47.1%) had penetrating disease, 9 (26.5%) had stricturing disease and 9 (26.5%) had non-penetrating and non-stricturing disease. The hospital admission prevalence of CD was 26.0 overall, Indians 52.6, Chinese 6.9, and Malays 9.3 per 10⁵ admissions per ethnic group. The difference between Indians and Malays: [OR 5.67 (1.97, 17.53) P < 0.001] was statistically significant but not between the Indians and the Chinese [OR 1.95 (0.89, 4.35) P = 0.700]. The difference between the Chinese and the Malays was also not statistically significant. [OR 2.90 (0.95, 9.42) P = 0.063].

CONCLUSION: The clinical presentation of CD is similar to the Western experience. Although the overall prevalence is low, there appears to be a clear racial predominance among the Indians.

Phenotype-stratified genetic linkage study demonstrates that IBD2 is an extensive ulcerative colitis locus

OBJECTIVES

The complete elucidation of genetic variants that contribute to inflammatory bowel disease (IBD) will likely include variants that increase risk to both Crohn's disease and ulcerative colitis as well as variants that increase risk for particular phenotypic subsets. The purpose of this study was to assess phenotypic subsets that contribute to the major IBD susceptibility loci.

METHODS

This linkage study encompassed 904 affected relative pairs, representing the largest combined phenotyped cohort to date, and allowing for meaningful subset analyses. Genetic linkage data were stratified by disease location and age at diagnosis.

RESULTS

We establish that some loci, notably the IBD3 and chromosome 3q linkage regions demonstrate contributions from both small intestine and colon cohorts, whereas others, notably the IBD1 (NOD2/CARD15) and IBD2 regions increase risk for small intestine or colon inflammation, respectively. The strongest linkage evidence in this study was for the subset of extensive ulcerative colitis in the region of IBD2 (lod 3.27; p < 0.001). Evidence for linkage in the region of NOD2/CARD15 (IBD1) was stronger for the subset of Crohn's patients with ileal disease (lod 2.56; p= 0.035) compared to the overall Crohn's group, consistent with previous findings that NOD2/CARD15 variants are associated with ileal disease.

CONCLUSIONS

Analyses incorporating disease location in IBD increase the power and enhance the accuracy of genomic localization. Our data provide strong evidence that extensive ulcerative colitis represents a pathophysiologic subset of IBD.

Clinically active Crohn's disease in the presence of a low C-reactive protein

OBJECTIVE

Clinical interest in C-reactive protein (CRP) -- a component of the innate immune system -- has focused mainly on its worth as an indicator of disease activity. There has been a resurgence of interest in CRP in the Crohn's disease (CD) literature because several trials of new treatments for active CD have been characterized by both a large proportion of patients with low CRP (<10 mg/l) at entry to the trials and by a negative therapeutic outcome. It is therefore of interest to study the clinical characteristics of patients who are thought to have at the same time both active CD and a low CRP.

MATERIAL AND METHODS

Patients were prospectively recruited as part of the Brisbane IBD clinical and research programme. Subjects were included in the low CRP group only if there were complete datasets for CRP on all occasions of active CD, and CRP was < 10 mg/l. Active disease was defined as CD activity index (CDAI)>200. The low CRP group was compared with patients in the raised CRP group for a range of clinical variables as well as the major NOD2 variants.

RESULTS

There were data sets for 223 CD patients, with a mean disease duration of 12 years. Of these, 22 patients fulfilled the criteria for low CRP. The low CRP group (group 1) showed significant differences for disease site (p<0.01) and for BMI (p=0.006) compared to the raised CRP group (group 2). Specifically, group 1 had a predominance of pure ileal disease (95% versus 53%) and lack of pure colonic disease (0% versus 24%) compared to group 2, and their BMI was significantly lower (20.3 kg/m(2) versus 25.0 kg/m(2)). Groups 1 and 2 did not differ with respect to Vienna behaviour at diagnosis, smoking, appendicectomy, extra-intestinal manifestations of CD, or NOD2 SNP variants. There was a trend for low CRP patients with previous ileal resection to evolve to a stricturing phenotype. Fat wrapping was noted in 11/13 (85%) of low CRP patients undergoing ileal resections.

CONCLUSIONS

Patients with CD and a persistently low CRP in the face of active disease were characterized by an almost exclusive ileal disease distribution and a low BMI, compared to those with a raised CRP. These patients had a similar frequency and distribution of NOD2/CARD15 variants. Stricturing (v inflammatory or penetrating) behaviour may explain some low CRP. Despite the abnormally low BMI, fat wrapping was noted in the majority of low CRP patients undergoing ileal resection.

Prior appendectomy and the phenotype and course of Crohn's disease

AIM

To determine whether prior appendectomy modifies the phenotype and severity of Crohn's disease.

METHODS

Appendectomy status and smoking habits were specified by direct interview in 2838 patients consecutively seen between 1995 and 2004. Occurrence of complications and therapeutic needs were reviewed retrospectively. Additionally, annual disease activity was assessed prospectively between 1995 and 2004 in patients who had not had ileocecal resection and of a matched control group.

RESULTS

Compared to 1770 non-appendectomized patients, appendectomized patients more than 5 years before Crohn's disease diagnosis (n=716) were more often females, smokers, with ileal disease. Cox regression showed that prior appendectomy was positively related to the risk of intestinal stricture (adjusted hazard ratio, 1.24; 95% confidence interval, 1.13 to 1.36; P=0.02) and inversely related to the risk of perianal fistulization (adjusted hazard ratio, 0.75; 95% confidence interval, 0.68 to 0.83; P=0.002). No difference was observed between the two groups regarding the therapeutic needs, except for an increased risk of surgery in appendectomized patients, attributable to the increased prevalence of ileal disease. Between 1995 and 2004, Crohn's disease was active during 50% of years in appendectomized patients (1318 out of 2637 patient-years) and 51% in non-appendectomized patients (1454 out of 2841 patient-years; NS).

CONCLUSION

Prior appendectomy is associated with a more proximal disease and has an increased risk of stricture and a lesser risk of anal fistulization. However, the severity of the disease is unaffected.

Eight novel CARD15 variants detected by DNA sequence analysis of the CARD15 gene in 111 patients with inflammatory bowel disease

We performed a limited DNA sequence analysis of the CARD15 gene in 89 patients with Crohn's disease (CD), 19 patients with ulcerative colitis (UC), and three patients with indeterminate colitis (IC), who were heterozygous carriers of one of the common CARD15 mutations [c.2104C>T (p.R702W), c.2722G>C (p.G908R), or c.3019_3020insC (p.Leu1007fsX1008)], the c.2462+10A>C variant, or of a new amino acid substitution in the 3'-end of exon 4. CARD15 exons 4, 5, 6, 8, and 11 were amplified by PCR and completely sequenced, thereby theoretically covering 73.9% of the described CARD15 variants and 96.6% of the mutated alleles. Using this approach, eight novel amino acid substitutions [c.1171C>T (p.R391C), c.1387C>G (p.P463A), c.2138G>A (p.R713H), c.2278C>T (p.R760C), c.2368C>T (p.R790W), c.2371C>T (p.R791W), c.2475C>G (p.N825K), and c.2546C>T (p.A849V)] were detected in six CD and two IC patients, and one UC patient. A severe disease phenotype was observed especially in patients who are compound-heterozygous for a common and a novel CARD15 mutation.

Serum immune responses predict rapid disease progression among children with Crohn's disease: immune responses predict disease progression

BACKGROUND AND AIM

Crohn's disease (CD) is a heterogeneous disorder characterized by diverse clinical phenotypes. Childhood-onset CD has been described as a more aggressive phenotype. Genetic and immune factors may influence disease phenotype and clinical course. We examined the association of immune responses to microbial antigens with disease behavior and prospectively determined the influence of immune reactivity on disease progression in pediatric CD patients.

METHODS

Sera were collected from 196 pediatric CD cases and tested for immune responses: anti-I2, anti-outer membrane protein C (anti-OmpC), anti-CBir1 flagellin (anti-CBir1), and anti-Saccharomyces-cerevisiae (ASCA) using ELISA. Associations between immune responses and clinical phenotype were evaluated.

RESULTS

Fifty-eight patients (28%) developed internal penetrating and/or stricturing (IP/S) disease after a median follow-up of 18 months. Both anti-OmpC (p < 0.0006) and anti-I2 (p < 0.003) were associated with IP/S disease. The frequency of IP/S disease increased with increasing number of immune responses (p trend = 0.002). The odds of developing IP/S disease were highest in patients positive for all four immune responses (OR (95% CI): 11 (1.5-80.4); p = 0.03). Pediatric CD patients positive for > or =1 immune response progressed to IP/S disease sooner after diagnosis as compared to those negative for all immune responses (p < 0.03).

CONCLUSIONS

The presence and magnitude of immune responses to microbial antigens are significantly associated with more aggressive disease phenotypes among children with CD. This is the first study to prospectively demonstrate that the time to develop a disease complication in children is significantly faster in the presence of immune reactivity, thereby predicting disease progression to more aggressive disease phenotypes among pediatric CD patients.