Review article: is clinical remission the optimum therapeutic goal in the treatment of Crohn's disease?

Baitouweng Decoction Ameliorates Ulcerative Colitis in Mice Partially Attributed to Regulating Th17/Treg Balance and Restoring Intestinal Epithelial Barrier

Ulcerative colitis (UC) is a chronic intestinal disease with unclear pathogenesis. With an increasing global prevalence over the past two decades, UC poses a serious threat to public health. Baitouweng decoction (BTW), a traditional Chinese medicine, has been shown to have good clinical efficacy for treating intestinal inflammation. Yet, the efficacy of BTW in UC and the underlying mechanism remain unclear. The current study aimed to determine whether BTW suppressed intestinal inflammation in mice and the potential mechanism. We used a dextran sulfate sodium (DSS)-induced murine colitis model to test the anti-inflammatory efficacy of BTW. Clinical symptoms were scored by the disease activity index (DAI), and the colon length and pathological changes in colon tissue were also used to further evaluate the efficacy of BTW. Precisely how BTW affected immune function and the intestinal barrier of UC mice was also examined. BTW significantly reduced DAI score and colonic pathological damage. BTW regulated the balance between T helper (Th)17 and regulatory T (Treg) cells, decreased interleukin (IL)-1β, IL-6, and tumor necrosis factor-α, and increased IL-10 levels. BTW reduced intestinal permeability of UC mice, increased expression of tight junction proteins (occludin and zonula occludens-1), and decreased expression of phospho-nuclear factor (p-NF)-κB and phospho-extracellular signal-regulated kinase (p-ERK) in the colon. BTW inhibited the ERK/p-NF-κB signaling pathway and suppressed expression of cyclo-oxygenase-2 and inducible NO synthase in lipopolysaccharide-activated RAW 264.7 cells. BTW significantly promoted the synthesis of short-chain fatty acids in the gut, particularly acetate, propionate, isobutyric acid, and isovalerate. The results suggest that BTW can protect against DSS-induced UC. The mechanism may be partially attributed to regulating the balance of Th17/Treg cells and restoring the intestinal epithelial barrier.

Histologic scoring indices for evaluation of disease activity in Crohn's disease

BACKGROUND

Histologic assessment of mucosal disease activity has been increasingly used in clinical trials of treatment for Crohn's disease. However, the operating properties of the currently existing histologic scoring indices remain unclear.

OBJECTIVES

A systematic review was undertaken to evaluate the development and operating characteristics of available histologic disease activity indices in Crohn's disease.

SEARCH METHODS

Electronic searches of MEDLINE, EMBASE, PubMed, and the Cochrane Library (CENTRAL) databases from inception to 20 July 2016 were supplemented by manual reviews of bibliographies and abstracts submitted to major gastroenterology meetings (Digestive Disease Week, United European Gastroenterology Week, European Crohn's and Colitis Organisation).

SELECTION CRITERIA

Any study design (e.g. randomised controlled trial, cohort study, case series) that evaluated a histologic disease activity index in patients with Crohn's disease was considered for inclusion. Study participants included adult patients (> 16 years), diagnosed with Crohn's disease using conventional clinical, radiographic or endoscopic criteria.

DATA COLLECTION AND ANALYSIS

Two authors independently reviewed the titles and abstracts of the studies identified from the literature search. The full text of potentially relevant citations were reviewed for inclusion and the study investigators were contacted as needed for clarification. Any disagreements regarding study eligibility were resolved by discussion and consensus with a third author.Two authors independently extracted and recorded data using a standard form. The following data were recorded from each eligible study: number of patients enrolled; number of patients per treatment arm; patient characteristics: age and gender distribution; description of histologic disease activity index utilized; and outcomes such as content validity, construct validity, criterion validity, responsiveness, intra-rater reliability, inter-rater reliability, and feasibility.

MAIN RESULTS

Sixteen reports of 14 studies describing 14 different numerical histological indices fulfilled the inclusion criteria.Inter-rater reliability was assessed in one study. For the Naini and Cortina Score, estimates of correlation were 'almost perfect', ranging from r = 0.94 to 0.96. The methodological quality of this study with respect to reliability was 'good'.With respect to validity, correlation estimates between various histological scoring systems and Crohn's disease activity as measured by objective markers of inflammation (including C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin and fecal lactoferrin); endoscopic disease activity scores; clinical disease activity scores; and quality of life questionnaires were reported. Comparisons between histologic scoring indices and endoscopic scoring indices ranged from no correlation to 'substantial' (r = 0.779). The methodological quality of the studies that explored validity ranged form 'poor' to 'good'.Responsiveness data were available in seven studies. After subjects were administered a treatment of known efficacy, statistically significant change in the index score was demonstrated in five studies with respect to six indices. Two studies failed to indicate whether there was statistically significant change in the index score post-treatment. With regard to methodological quality, six of the studies were rated as 'poor' and one of the studies was rated as 'fair'.Feasibility was assessed by one study. The Naini and Cortina Score was shown to be simple to use and feasible for every given case.

AUTHORS' CONCLUSIONS

Currently there is no fully validated histological scoring index for evaluation of Crohn's disease activity. Development of a validated histological scoring index for Crohn's disease is a clinical and research priority.

Real-time monitoring of trans-epithelial electrical resistance in cultured intestinal epithelial cells: the barrier protection of water-soluble dietary fiber

OBJECTIVES

In this study we aimed to verify a real-time trans-epithelial electrical resistance (TEER) monitoring system in a Caco-2 monolayer and to investigate the therapeutic effect of partially hydrolyzed guar gum (PHGG), a dietary fiber, against interferon (IFN)-γ-induced intestinal barrier dysfunction using this monitoring system.

METHODS

We measured TEER using a real-time monitoring system and evaluated epithelial paracellular permeability using fluorescein isothiocyanate-conjugated dextran (4 kDa; FD4) in Caco-2 monolayers treated with IFN-γ for 48 h. The expression and distribution of tight junction (TJ)-associated proteins, ZO-1 and occludin, were analyzed by Western blot and immunocytochemistry, respectively. In some experiments PHGG was added prior to IFN-γ treatment in order to investigate its protective effect on barrier function.

RESULTS

IFN-γ treatment significantly decreased TEER and increased FD4 flux across Caco-2 monolayers, indicating a great influence of IFN-γ on the intestinal epithelial paracellular permeability. In contrast, the pretreatment of PHGG significantly reduced the IFN-γ-induced increment of FD4 flux without affecting TEER. Neither IFN-γ nor PHGG treatment affected the expressions of TJ-associated proteins, while immunocytochemistry showed that IFN-γ-induced redistribution of occludin was clearly restored by PHGG.

CONCLUSIONS

Real-time TEER monitoring enabled us to evaluate the dynamic changes of intestinal epithelial barrier function. PHGG may have a protective effect against IFN-γ-induced barrier dysfunction by attenuating the paracellular hyperpermeability; thus, its promotion as a functional food is anticipated.

Synergy Between Immunosuppressive Therapy and Enteral Nutrition in the Management of Childhood Crohn's Disease

Induction of a remission in children with Crohn's disease is increasingly successful. However this success is dependent on what measure we use to define "remission." Achieving a clinical remission is possible in >70% of children with Crohn's disease at diagnosis, while a mucosal or even immunological remission may occur in <50%. The importance of what ;degree of remission' should be achieved during maintenance therapy is discussed. Does early aggressive management with immunomodulators or biological agents indeed alter the natural history of the disease, and is it possible to give a prognosis based on either a snap-shot of endoscopic appearance, or a mucosal cytokine profile? The potential benefits of using a 6-8 week course of exclusive enteral nutrition as an induction therapy in combination with azathioprine/6-mercaptopurine are discussed. Whole protein formulae are safe and effective at achieving a clinical remission, however they are not a long-term maintenance strategy. Given the relative safety of these immunosuppressants and their efficacy in children treated at diagnosis, it is now more important than ever to predict which individuals will benefit from use of immunomodulators very early in the disease process. There is brief mention of enteral nutrition as maintenance therapy. Given the very limited data available, it is still not possible to recommend long-term nutrition supplementation as a maintenance therapy in all children. However, some children may respond to repeated shorter cycles of exclusive enteral nutrition in the absence of other therapeutic options.

Clinical importance of faecal calprotectin variability in inflammatory bowel disease: intra-individual variability and standardisation of sampling procedure

OBJECTIVE

Faecal (f-) calprotectin is a biomarker of intestinal inflammation. Previous studies have described intra-individual day-to-day variability of this biomarker in patients with inflammatory bowel disease (IBD) and morning samples have been suggested for standardisation purposes. With this project, we investigated if day-to-day variability differed from diurnal variability. Additionally, we evaluated a new extraction method for f-calprotectin analysis.

METHODS

Fifty patients provided three faeces samples from morning - evening - morning on two consecutive days. Nineteen patients provided two faeces samples from the same bowel movement, one conventional spot sample, and one sample with a device for patient-administered sampling and extraction.

RESULTS

The two morning samples differentiated between mucosal inflammation and mucosal healing with same level of agreement as the two samples from the same day (kappa 0.76), using an f-calprotectin cut-off level of 259 μg/g. Although large intra-individual variation in f-calprotectin values, there were no significant day-to-day (p = 0.096) or diurnal variation (p = 0.78). Used by laboratory technicians, the new extraction device correlated significantly with the conventional extraction method (p < 0.001), Spearman's rank correlation coefficient 0.95. Of the 19 patients testing patient administered extraction, two patients provided samples leading to considerably higher f-calprotectin levels than conventional sampling procedure.

CONCLUSIONS

The reliability of f-calprotectin morning samples is equal to the reliability of samples from different bowel movements on the same day. The new extraction method is reliable when used by laboratory technicians, but larger studies are recommended to evaluate patient administered extraction.

Comparison of three commercial fecal calprotectin ELISA test kits used in patients with Inflammatory Bowel Disease

OBJECTIVE

Fecal calprotectin is a noninvasive marker of intestinal inflammation used to distinguish between functional and organic bowel diseases and to evaluate disease activity among patients with Inflammatory Bowel Disease (IBD). The goal of this study was to compare three different ELISA tests measuring calprotectin in their accuracy to detect IBD and to distinguish between IBD patients with active or inactive disease.

MATERIAL AND METHODS

This study includes in total 148 fecal samples, 96 from patients with a previously confirmed IBD diagnosis and 52 from healthy controls, aged from 25 to 86 and 18 to 67 years, respectively. Disease activity in the patients was established using the following clinical activity indices: the Simple Clinical Colitis Activity Index (SCCAI), the Harvey Bradshaw Index (HBI) and the Modified Pouchitis Disease Activity Index (MPDAI). Three ELISA calprotectin tests (EK-CAL, CALPRO and HK325) were performed on fecal specimens and results compared.

RESULTS

The CALPRO calprotectin ELISA test was shown to have the best specificity of 96% compared to the HK325 and the EK-CAL calprotectin ELISA tests with 28% specificity and 74% specificity, respectively. A significant correlation between clinical activity indices and fecal calprotectin was found in patients with ulcerative colitis (p < 0.05***) and in patients with an ileoanal pouch (p < 0.05), but not in patients with Crohn's disease (p = 0.11).

CONCLUSION

The CALPRO ELISA test performed best in measuring calprotectin in feces.

Current evidence supporting mucosal healing and deep remission as important treatment goals for inflammatory bowel disease

Mucosal healing (MH) is now considered as a major treatment goal in clinical trials and clinical practice for patients with inflammatory bowel disease (IBD). MH is associated with sustained clinical remission, steroid-free remission, and reduced rates of hospitalization and surgery. There is a well-known disconnect between clinical symptoms and mucosal lesions that is more pronounced in CD. More stringent therapeutic goals have been discussed recently such as deep remission defined as clinical remission associated with MH. Recent international guidelines from the IOIBD recommended deep remission as a treatment goal in clinical practice. However there is no validated definition of deep remission in IBD. Also, the efficacy of available drugs to induce and maintain deep remission in IBD is poorly known. Finally, whether deep remission is the best way to modify the course of IBD and whether it should be achieved before considering drug de-escalation have to be formally evaluated in upcoming disease-modification trials.

Comprehensive magnetic resonance enterography of Crohn's disease in the pediatric population: technique, interpretation, and management

Magnetic resonance enterography (MRE) plays a critical role in the management of Crohn's disease in the pediatric population. The ability to provide dynamic assessment of disease burden, complications, and therapeutic response without ionizing radiation makes it an ideal tool for younger patients requiring frequent follow-up. With a growing array of available treatment options, a sound understanding of MRE is critical in directing management aimed at curbing the physical and emotional morbidity associated with the lifelong condition. The goal of this article is to provide a practical overview of MRE in the pediatric population. This includes a review of our technique, approach to interpretation, pictorial collection of findings, and discussion of the role MRE plays in management.

Current and future role of MR enterography in the management of Crohn disease

OBJECTIVE

The purpose of this article is to explore the future role of MRI in assessing the global disease burden of Crohn disease and monitoring treatment response.

CONCLUSION

MR enterography is increasingly used to evaluate disease activity in Crohn disease, and scoring methods have been validated. Current MRI protocols may be extended to allow the assessment of inflammation and fibrosis.

Bovine colostrum increases pore-forming claudin-2 protein expression but paradoxically not ion permeability possibly by a change of the intestinal cytokine milieu

An impaired intestinal barrier function is involved in the pathogenesis of inflammatory bowel disease (IBD). Several nutritional factors are supposed to be effective in IBD treatment but scientific data about the effects on the intestinal integrity remain scarce. Bovine colostrum was shown to exert beneficial effects in DSS-induced murine colitis, and the present study was undertaken to explore the underlying molecular mechanisms. Western blot revealed increased claudin-2 expression in the distal ileum of healthy mice after feeding with colostrum for 14 days, whereas other tight junction proteins (claudin-3, 4, 10, 15) remained unchanged. The colostrum-induced claudin-2 induction was confirmed in differentiated Caco-2 cells after culture with colostrum for 48 h. Paradoxically, the elevation of claudin-2, which forms a cation-selective pore, was neither accompanied by increased ion permeability nor impaired barrier function. In an in situ perfusion model, 1 h exposure of the colonic mucosa to colostrum induced significantly increased mRNA levels of barrier-strengthening cytokine transforming growth factor-β, while interleukine-2, interleukine-6, interleukine-10, interleukine-13, and tumor-necrosis factor-α remained unchanged. Thus, modulation of the intestinal transforming growth factor-β expression might have compensated the claudin-2 increase and contributed to the observed barrier strengthening effects of colostrum in vivo and in vitro.

Mechanism of IL-1β modulation of intestinal epithelial barrier involves p38 kinase and activating transcription factor-2 activation

The defective intestinal epithelial tight junction (TJ) barrier has been postulated to be an important pathogenic factor contributing to intestinal inflammation. It has been shown that the proinflammatory cytokine IL-1β causes an increase in intestinal permeability; however, the signaling pathways and the molecular mechanisms involved remain unclear. The major purpose of this study was to investigate the role of the p38 kinase pathway and the molecular processes involved. In these studies, the in vitro intestinal epithelial model system (Caco-2 monolayers) was used to delineate the cellular and molecular mechanisms, and a complementary in vivo mouse model system (intestinal perfusion) was used to assess the in vivo relevance of the in vitro findings. Our data indicated that the IL-1β increase in Caco-2 TJ permeability correlated with an activation of p38 kinase. The activation of p38 kinase caused phosphorylation and activation of p38 kinase substrate, activating transcription factor (ATF)-2. The activated ATF-2 translocated to the nucleus where it attached to its binding motif on the myosin L chain kinase (MLCK) promoter region, leading to the activation of MLCK promoter activity and gene transcription. Small interfering RNA induced silencing of ATF-2, or mutation of the ATF-2 binding motif prevented the activation of MLCK promoter and MLCK mRNA transcription. Additionally, in vivo intestinal perfusion studies also indicated that the IL-1β increase in mouse intestinal permeability required p38 kinase-dependent activation of ATF-2. In conclusion, these studies show that the IL-1β-induced increase in intestinal TJ permeability in vitro and in vivo was regulated by p38 kinase activation of ATF-2 and by ATF-2 regulation of MLCK gene activity.

Fecal calprotectin concentration predicts outcome in inflammatory bowel disease after induction therapy with TNFα blocking agents

BACKGROUND

Fecal calprotectin (FC) concentration is a useful surrogate marker for mucosal healing (MH) during tumor necrosis factor alpha (TNFα)-blocking therapy for inflammatory bowel disease (IBD). Our aim was to evaluate whether a normal FC after induction therapy with TNFα antagonist predicts the outcome of IBD patients during maintenance therapy.

METHODS

Sixty IBD patients (34 Crohn's disease [CD], 26 ulcerative colitis [UC]), treated with TNFα antagonists, either infliximab (n = 42) or adalimumab (n = 18), and having a documented FC level at baseline and after induction therapy were included. Disease activity was evaluated by partial Mayo score without endoscopy or Harvey-Bradshaw index at baseline, after induction, and at 12 months during maintenance therapy.

RESULTS

After induction, FC was normalized (≤ 100 μg/g) in 31 patients (52%, median 42 μg/g, range 0-97), whereas the level remained elevated in 29 patients (48%, median 424 μg/g, range 116-5859). At ≈12 months, 26/31 (84%, 18 CD, 8 UC) of the patients with normal FC after induction were in clinical remission, whereas only 11/29 (38%, 9 CD, 2 UC) of those with an elevated (≥ 100 μg/g) postinduction FC were in clinical remission, P < 0.0001. After induction therapy with TNFα antagonists, a cutoff concentration of 139 μg/g for FC had a sensitivity of 72% and a specificity of 80% to predict a risk of clinically active disease after 1 year.

CONCLUSIONS

A normal FC after induction therapy with TNFα antagonists predicts sustained clinical remission in the majority of patients on scheduled therapy with active luminal disease.

Fecal M2-PK in children with Crohn's disease: a preliminary report

BACKGROUND AND AIMS

Although active inflammatory changes in chronic Crohn's disease (CD) can be detected with serum inflammatory markers, these have low specificity and sensitivity. Stool markers of inflammation, such as M2-pyruvate kinase (M2-PK), permit more direct assessment of mucosal inflammation. The aim of this study was to assess levels of M2-PK in children with active CD and to compare to levels in healthy control children.

METHODS

Fecal levels of M2-PK were measured by immunoassay using stored stool samples from children with untreated (active) CD and healthy control children. Correlations between M2-PK levels and disease activity scores and serum inflammatory markers were performed. Comparison was also made between M2PK and a second fecal inflammatory marker, S100A12.

RESULTS

Mean fecal M2-PK levels were higher in the 17 patients with active CD than in the 21 healthy controls (p = 0.0007). M2-PK levels did not correlate with disease activity scores or serum inflammatory markers. There was a trend for children with ileocolonic disease to have higher levels of M2-PK in their stool compared to those with colonic disease or isolated ileal disease. Fecal M2PK did not correlate with fecal S100A12 in children with active CD.

CONCLUSION

Fecal M2-PK is increased in children with active CD, indicating that this marker may be a useful non-invasive marker for gut inflammation. Further studies of M2PK are required in additional settings with larger cohorts of children with CD and with comparison to other stool markers.

How to guide therapeutic decisions in a patient-tailored approach to treatment of IBD?

Therapeutic decisions in the treatment of IBD involve the initial choice of therapy(ies) and designing a long-term strategy for the individual patient. Putting forward clear therapeutic aims is therefore critical in order to assess treatment success and to guide the sequential use of therapies. Although the ultimate goal of therapy is to achieve steroid-free remission and avoid complications and surgeries, the first therapeutic intervention will achieve these aims only in a minority of patients. Depending on the requirements and successes of each stage of therapy, interim goals are pursued which may be small steps towards the total control of the disease. A patient-tailored approach does not necessarily conflict with algorithm-based decision-making; indeed, they are complementary. The former allows the skipping of some steps in the algorithm, based on the individual patient characteristics. The latter supplies a basis for the rational sequential use of drugs. Many physicians use an accelerated step-up approach in the treatment of IBD, although it has not yet been established whether this is associated with a better outcome. Whether or not an endoscopic or (and) CT or MRI assessment is conducted, the therapeutic approach should be based on mucosal activity and the location and extent of the disease. Treatments that do not heal (or at least improve) ulcers are not to be continued if they have been given a reasonable time to work. Biomarkers like C-reactive protein and calprotectin can be useful surrogates in this setting.

Monitoring inflammatory bowel disease activity: clinical activity is judged to be more relevant than endoscopic severity or biomarkers

BACKGROUND

There is increasing evidence for the clinical relevance of mucosal healing (MH) as therapeutic treatment goal in inflammatory bowel disease (IBD). We aimed to investigate by which method gastroenterologists monitor IBD activity in daily practice.

METHODS

A questionnaire was sent to all board-certified gastroenterologists in Switzerland to specifically address their strategy to monitor IBD between May 2009 and April 2010.

RESULTS

The response rate was 57% (153/270). Fifty-two percent of gastroenterologists worked in private practice and 48% worked in hospitals. Seventy-eight percent judged clinical activity to be the most relevant criterion for monitoring IBD activity, 15% chose endoscopic severity, and 7% chose biomarkers. Seventy percent of gastroenterologists based their therapeutic decisions on clinical activity, 24% on endoscopic severity, and 6% on biomarkers. The following biomarkers were used for IBD activity monitoring: CRP, 94%; differential blood count, 78%; fecal calprotectin (FC), 74%; iron status, 63%; blood sedimentation rate, 3%; protein electrophoresis, 0.7%; fecal neutrophils, 0.7%; and vitamin B12, 0.7%. Gastroenterologists in hospitals and those with ≤ 10 years of professional experience used FC more frequently compared with colleagues in private practice (P=0.035) and those with > 10 years of experience (P<0.001).

CONCLUSIONS

Clinical activity is judged to be more relevant for monitoring IBD activity and guiding therapeutic decisions than endoscopic severity and biomarkers. As such, the accumulating scientific evidence on the clinical impact of mucosal healing does not yet seem to influence the management of IBD in daily gastroenterologic practice.

Colon capsule endoscopy: Advantages, limitations and expectations. Which novelties?

Since the first reports almost ten years ago, wireless capsule endoscopy has gained new fields of application. Colon capsule endoscopy represents a new diagnostic technology for colonic exploration. Clinical trials have shown that colon capsule endoscopy is feasible, accurate and safe in patients suffering from colonic diseases and might be a valid alternative to conventional colonoscopy in selected cases such as patients refusing conventional colonoscopy or with contraindications to colonoscopy or when colonoscopy is incomplete. Despite the enthusiasm surrounding this new technique, few clinical and randomized controlled trials are to be found in the current literature, leading to heterogeneous or controversial results. Upcoming studies are needed to prove the substantial utility of colon capsule endoscopy for colon cancer screening, especially in a low prevalence of disease population, and for other indications such as inflammatory bowel disease. Possible perspectives are critically analysed and reported in this paper.

Cellular and molecular mechanism of interleukin-1β modulation of Caco-2 intestinal epithelial tight junction barrier

Interleukin-1β (IL-1β) is a prototypical multifunctional cytokine that plays an important role in intestinal inflammation of Crohn's disease and other inflammatory conditions of the gut. Previous studies have shown that IL-1β causes an increase in intestinal epithelial tight junction (TJ) permeability both in in vivo animal and in vitro cell culture model systems. The IL-1β-induced increase in intestinal epithelial TJ permeability has been postulated to be an important pathogenic mechanism contributing to intestinal inflammation. However, the signalling pathways and the molecular processes that mediate the IL-1β modulation of intestinal epithelial TJ barrier remain unclear. Here, we show that the IL-1β-induced increase in Caco-2 monolayer TJ permeability was mediated by activation of extracellular signal-regulated kinases 1/2 (ERK1/2) signalling pathway and that inhibition of ERK1/2 activity inhibits the IL-1β-induced increase in Caco-2 TJ permeability. The activation of ERK1/2 pathway caused a downstream activation of nuclear transcription factor Elk-1. The activated Elk-1 translocated to the nucleus and binds to the cis-binding motif on myosin light chain kinase (MLCK) promoter region, triggering MLCK gene activation, MLCK mRNA transcription and MLCK protein synthesis and MLCK catalysed opening of the intestinal epithelial TJ barrier. These studies provide novel insight into the cellular and molecular processes that mediate the IL-1β-induced increase in intestinal epithelial TJ permeability.

Literature review and recommendations for clinical application of Colon Capsule Endoscopy

Colon Capsule Endoscopy represents a new diagnostic technology for colonic exploration. Despite the great enthusiasm around this new technique, only few studies are available in the literature, and reported results are still controversial and non-homogeneous. Current preparation protocols have led to discordant results. In January 2010, the first Italian Meeting on Colon Capsule Endoscopy was held. Aim of this Meeting was to critically evaluate the available results obtained by Colon Capsule Endoscopy in clinical studies, in order to identify the proper test indications, to propose a shared preparation protocol and Colon Capsule Endoscopy procedure. Studies published in literature were extensively reviewed and analysed during the Meeting. The available evidence served to propose recommendations for preparation protocols, proper test indications and Colon Capsule Endoscopy procedure. Possible perspectives were also critically analysed and are reported in this paper.

Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis

OBJECTIVE

To evaluate whether including a test for faecal calprotectin, a sensitive marker of intestinal inflammation, in the investigation of suspected inflammatory bowel disease reduces the number of unnecessary endoscopic procedures.

DESIGN

Meta-analysis of diagnostic accuracy studies.

DATA SOURCES

Studies published in Medline and Embase up to October 2009. Interventions reviewed Measurement of faecal calprotectin level (index test) compared with endoscopy and histopathology of segmental biopsy samples (reference standard). Inclusion criteria Studies that had collected data prospectively in patients with suspected inflammatory bowel disease and allowed for construction of a two by two table. For each study, sensitivity and specificity of faecal calprotectin were analysed as bivariate data to account for a possible negative correlation within studies.

RESULTS

13 studies were included: six in adults (n=670), seven in children and teenagers (n=371). Inflammatory bowel disease was confirmed by endoscopy in 32% (n=215) of the adults and 61% (n=226) of the children and teenagers. In the studies of adults, the pooled sensitivity and pooled specificity of calprotectin was 0.93 (95% confidence interval 0.85 to 0.97) and 0.96 (0.79 to 0.99) and in the studies of children and teenagers was 0.92 (0.84 to 0.96) and 0.76 (0.62 to 0.86). The lower specificity in the studies of children and teenagers was significantly different from that in the studies of adults (P=0.048). Screening by measuring faecal calprotectin levels would result in a 67% reduction in the number of adults requiring endoscopy. Three of 33 adults who undergo endoscopy will not have inflammatory bowel disease but may have a different condition for which endoscopy is inevitable. The downside of this screening strategy is delayed diagnosis in 6% of adults because of a false negative test result. In the population of children and teenagers, 65 instead of 100 would undergo endoscopy. Nine of them will not have inflammatory bowel disease, and diagnosis will be delayed in 8% of the affected children.

CONCLUSION

Testing for faecal calprotectin is a useful screening tool for identifying patients who are most likely to need endoscopy for suspected inflammatory bowel disease. The discriminative power to safely exclude inflammatory bowel disease was significantly better in studies of adults than in studies of children.

Clinical implications of mucosal healing for the management of IBD

Mucosal healing (MH) has emerged as an important treatment goal for patients with IBD. Historically, the therapeutic goals of induction and maintenance of clinical remission seemed insufficient to change the natural history of IBD. Evidence has now accumulated to show that MH can alter the course of IBD, as it is associated with sustained clinical remission, and reduced rates of hospitalization and surgical resection. In patients with ulcerative colitis, MH may represent the ultimate therapeutic goal because inflammation is limited to the mucosa. In patients with Crohn's disease, which is a transmural disease, MH could be considered as a minimum therapeutic goal. This Review focuses on the definition of MH and discusses the ability of each available IBD medication to induce and maintain MH. The importance of achieving MH is also discussed and literature that demonstrates improvement of disease course with MH is reviewed. Finally, we discuss how best to integrate the treatment end point of MH into clinical practice for the management of patients with IBD.

Ulcerative colitis: correlation of the Rachmilewitz endoscopic activity index with fecal calprotectin, clinical activity, C-reactive protein, and blood leukocytes

BACKGROUND

The accuracy of noninvasive markers for the detection of endoscopically active ulcerative colitis (UC) according the Rachmilewitz Score is so far unknown. The aim was to evaluate the correlation between endoscopic disease activity and fecal calprotectin, Clinical Activity Index, C-reactive protein (CRP), and blood leukocytes.

METHODS

UC patients undergoing colonoscopy were prospectively enrolled and scored independently according the endoscopic and clinical part of the Rachmilewitz Index. Patients and controls provided fecal and blood samples for measuring calprotectin, CRP, and leukocytes.

RESULTS

Values in UC patients (n = 134) compared to controls (n = 48): calprotectin: 396 ± 351 versus 18.1 ± 5 μg/g, CRP 16 ± 13 versus 3 ± 2 mg/L, blood leukocytes 9.9 ± 3.5 versus 5.4 ± 1.9 g/L (all P < 0.001). Endoscopic disease activity correlated closest with calprotectin (Spearman's rank correlation coefficient r = 0.834), followed by Clinical Activity Index (r = 0.672), CRP (r = 0.503), and leukocytes (r = 0.461). Calprotectin levels were significantly lower in UC patients with inactive disease (endoscopic score 0-3, calprotectin 42 ± 38 μg/g), compared to patients with mild (score 4-6, calprotectin 210 ± 121 μg/g, P < 0.001), moderate (score 7-9, calprotectin 392 ± 246 μg/g, P = 0.002), and severe disease (score 10-12, calprotectin 730 ± 291 μg/g, P < 0.001). The overall accuracy for the detection of endoscopically active disease (score ≥4) was 89% for calprotectin, 73% for Clinical Activity Index, 62% for elevated CRP, and 60% for leukocytosis.

CONCLUSIONS

Fecal calprotectin correlated closest with endoscopic disease activity, followed by Clinical Activity Index, CRP, and blood leukocytes. Furthermore, fecal calprotectin was the only marker that reliably discriminated inactive from mild, moderate, and highly active disease, which emphasizes its usefulness for activity monitoring.

Questions and answers on the role of fecal lactoferrin as a biological marker in inflammatory bowel disease

Among the available fecal biomarkers for the diagnosis and monitoring of inflammatory bowel disease (IBD), only calprotectin and lactoferrin have translated into useful clinical tools. Lactoferrin can be detected using simple and cheap techniques and it has excellent stability in feces over a long period of time. Fecal lactoferrin has a good diagnostic precision for separating organic and functional intestinal disease. However, a negative fecal lactoferrin test should be interpreted merely as the absence of significant neutrophilic intestinal inflammation. The mean sensitivity and specificity of the fecal lactoferrin determination for the diagnosis of IBD is 80% and 82%, respectively. Some studies have suggested a lower accuracy of lactoferrin when compared with calprotectin for the diagnosis of IBD, indicating that more studies on this topic are necessary. A parallel between fecal lactoferrin levels and IBD activity estimated with clinical, endoscopic, and histological parameters has been confirmed. However, this correlation seems to be lower in Crohn's disease than in ulcerative colitis, mainly when Crohn's disease patients with purely ileal disease are considered. Fecal lactoferrin determination may be useful in predicting impending clinical relapse in IBD patients. Fecal lactoferrin may be a helpful noninvasive diagnostic tool for monitoring therapeutic efficacy, mainly on mucosal healing, as a decreasing concentration of lactoferrin can be interpreted as a marker of therapeutic response. Finally, in patients with Crohn's disease who have undergone ileocolonic resection, those with higher lactoferrin fecal levels might be more prone to postsurgical recurrence.

Immunomodulation does not alter histology in resected Crohn's disease

BACKGROUND

The use of immunomodulators (Azathioprine, 6-Mercaptopurine and Methotrexate) and biological agents (Infliximab and adalimumab) for the treatment of Crohn's disease (CD) has increased in the recent years with the aim of treating the inflammatory component of the disease and hoping to change the natural history of the disease. The aim of this study was to determine if the use of immunomodulators or biological agents in the 2 years prior to resection affects the histopathological characteristics of the patient's disease.

METHODS

A retrospective review was conducted over a 10-year period (1996-2005) of patients who underwent resection for CD. Clinical case notes and histology specimens were reviewed. Patients treated with Azathioprine, 6-Mercaptopurine, Methotrexate or Infliximab for more than 3 months within the 2 years preceding surgery were deemed to have been immunomodulated. The results were also analysed by Montreal phenotype.

RESULTS

A total of 165 patients were identified. 52 patients had been treated with either immunomodulator or biological agent. Of 20 histological features examined, only muscular hypertrophy approached significance (P = 0.05), Montreal A and Montreal L phenotypes were the same regardless on immunomodulators, however, there was a significant difference (P = 0.03) with regard to Montreal B in patients with stricturing disease being more likely to have received an immunomodulator.

CONCLUSIONS

In this cohort of patients requiring resection for CD, those with stricturing disease were more likely to receive immunomodulators or biologics than those without stricturing disease. However, there were no significant histological differences in the resected specimens between those who did and those who did not receive these drugs.

Questions and answers on the role of faecal calprotectin as a biological marker in inflammatory bowel disease

Faecal calprotectin has been proposed as a non-invasive surrogate marker of intestinal inflammation in inflammatory bowel disease. Close correlation between faecal calprotectin concentration and faecal leukocyte excretion quantified with (111)indium has been described. This faecal marker can be detected using simple and cheap techniques. Faecal calprotectin has a good diagnostic precision for separating organic and functional intestinal diseases. However, the specificity for the diagnosis of inflammatory bowel disease is lower than desirable, as several diseases other than inflammatory bowel disease -- specially colorectal neoplasia and gastrointestinal infection -- can also increase faecal calprotectin. High concentration of calprotectin in faeces is a strong argument to carry out a colonoscopy in order to rule out the presence of inflammatory bowel disease or other organic pathologies. Parallelism between faecal calprotectin levels and inflammatory bowel disease activity has been confirmed, although this faecal marker appears to better reflect the disease activity in ulcerative colitis than in Crohn's disease. Faecal calprotectin's capacity to predict inflammatory bowel diseases relapse is promising. It has been suggested that, in inflammatory bowel disease patients receiving treatment, a normalization or decrease in faecal calprotectin concentrations is an accurate indicator of endoscopic healing. Greater faecal calprotectin concentration has been shown in asymptomatic first-degree relatives of patients with inflammatory bowel disease, suggesting that there is a high prevalence of subclinical intestinal inflammation in them.

Fecal calprotectin, lactoferrin, and endoscopic disease activity in monitoring anti-TNF-alpha therapy for Crohn's disease

BACKGROUND

Fecal calprotectin and lactoferrin are promising noninvasive biomarkers for intestinal inflammation. In Crohn's disease (CD), during anti-TNF-alpha (TNF-alpha) treatment, the clinical significance of these markers has, however, been insufficiently explored.

METHODS

Among CD patients receiving anti-TNF-alpha therapy we assessed the role of fecal calprotectin and lactoferrin as surrogate markers for mucosal healing. Before and 3 months after the beginning of anti-TNF-alpha induction, 15 patients underwent ileocolonoscopy with scoring of the Crohn's Disease Index of Severity (CDEIS). Fecal samples for calprotectin and for lactoferrin measurements were collected and the Crohn's Disease Activity Index (CDAI) was calculated at the time of the endoscopies and 2 and 8 weeks after the first treatment.

RESULTS

The median CDEIS fell from 13.0 to 4.8 (P = 0.002) and CDAI from 158 to 68 (P = 0.005). Accordingly, the median fecal calprotectin concentration fell from 1173 microg/g to 130 microg/g (P = 0.001) and fecal lactoferrin from 105.0 microg/g to 2.7 microg/g (P = 0.001). Of the 15 patients, 11 (73%) showed an endoscopic response to treatment and 5 of these achieved endoscopic remission (CDEIS < 3). In those 5 patients the fecal calprotectin concentration declined from 1891 mug/g (range 813-2434) to 27 microg/g (13-130) and lactoferrin from 92.4 microg/g (35.5-235.6) to 1.9 microg/g (0.0-2.1).

CONCLUSIONS

Compared to pretreatment values, concentrations of fecal calprotectin and lactoferrin after the anti-TNF-alpha treatment were significantly lower. During anti-TNF-alpha therapy these fecal neutrophil-derived proteins may thus be useful surrogate markers for mucosal healing.

Faecal calprotectin as reliable non-invasive marker to assess the severity of mucosal inflammation in children with inflammatory bowel disease

BACKGROUND

An accurate monitoring of mucosal inflammation is important for an effective management of patients with inflammatory bowel disease. Intestinal inflammation can be detected by faecal calprotectin level determination.

AIM

To comparatively evaluate the accuracy of faecal calprotectin, clinical scores, common serum markers and endoscopy in the assessment of the severity of intestinal mucosa inflammation in children with inflammatory bowel disease.

METHODS

Fifty-eight paediatric patients (mean age 13.9 years, 95% CI 2.9-14.8; male 28) with confirmed inflammatory bowel disease (26 Crohn's disease, 32 ulcerative colitis) were enrolled. Before endoscopy, all patients underwent a complete evaluation including: clinical scores, erythrocyte sedimentation rate, C-reactive protein and faecal calprotectin determination. The severity of mucosal inflammation was assessed using specific endoscopic and histologic scores.

RESULTS

Faecal calprotectin showed a high correlation (r=0.655) with the histologic grade of mucosal inflammation, similar to that observed for endoscopy (r=0.699), and it resulted the most accurate tool (sensitivity 94%, specificity 64%, positive predictive value 81%, negative predictive value 87%) to detect the presence of active mucosal inflammation when compared to clinical scores and common serum markers. In patients with apparent clinical and laboratory remission the accuracy of faecal calprotectin resulted further improved (sensitivity 100%, specificity 80%, positive predictive value 67%, negative predictive value 100%).

CONCLUSIONS

A more accurate assessment of the severity of mucosal inflammation can be achieved by the determination of faecal calprotectin levels compared to other common clinical and laboratory indices. This non-invasive and objective method could be particular useful in patients with apparent clinical and laboratory remission.

Crohn's disease activity assessed by fecal calprotectin and lactoferrin: correlation with Crohn's disease activity index and endoscopic findings

BACKGROUND

Correlation of endoscopic Crohn's disease activity with fecal calprotectin and lactoferrin is insufficiently studied. We evaluated the clinical significance of these neutrofil-derived proteins in assessment of Crohn's disease activity by comparing them with endoscopic disease activity and with Crohn's disease activity index (CDAI) and serum CRP.

METHODS

A total of 77 CD patients underwent one or more ileocolonoscopies (n = 106) with scoring of Crohn's disease index of severity (CDEIS). Patients provided stool samples for calprotectin and lactoferrin measurements and blood samples for CRP. Clinical activity was based on the CDAI.

RESULTS

Both fecal calprotectin and lactoferrin correlated significantly with CDEIS (Spearman's r 0.729 and 0.773, P < 0.001). With a cutoff level of 200 microg/g for a raised fecal calprotectin concentration, sensitivity was 70%, specificity 92%, positive predictive value (PPV) 94%, and negative predictive value (NPV) 61% in predicting endoscopically active disease (CDEIS >/= 3). A fecal lactoferrin concentration of 10 microg/g as the cutoff value gave a sensitivity, specificity, PPV, and NPV of 66%, 92%, 94%, and 59%. Sensitivity of CDAI >/= 150 to detect endoscopically active disease was only 27%, specificity 94%, PPV 91%, and NPV 40%. A raised serum CRP (> 5 mg/l) gave a sensitivity, specificity, PPV, and NPV of 48%, 91%, 91%, and 48%.

CONCLUSIONS

For evaluation of Crohn's disease activity, based on endoscopic findings, more sensitive surrogate markers than is CDAI or CRP are fecal calprotectin and lactoferrin. These prove to be useful tools for estimation of disease activity in Crohn's disease.

Research and clinical challenges in paediatric inflammatory bowel disease

Inflammatory bowel disease in childhood has become the subject of intense scientific debate during the last two decades, when there has been a significant rise in its incidence. There is a commonly agreed view that the disorder in children has peculiarities both in terms of underlying mechanisms and clinical management. This review highlights the emerging pathophysiologic concepts and clinical issues in paediatric inflammatory bowel disease and their effects on the management of children with this disorder are discussed. Particular emphasis is given to the link between the improvement of the research in the pathogenetic mechanisms and the development of novel therapeutic strategies able to promote a change in the natural course of the disorder.

"New drugs: kids come first": children should be included in trials of new biological treatments

The advent of biological therapies has dramatically revolutionized the treatment options for refractory inflammatory bowel disease (IBD). Of all the biologics evaluated to date, infliximab, an anti-tumor necrosis factor-alpha monoclonal chimeric antibody, has been shown to be an extremely potent drug for acute and maintenance treatment of both adult and pediatric patients with severe IBD, especially in those with Crohn's disease, whereas other biological agents are undergoing evaluation in several clinical trials. Although infliximab has preferentially been used as rescue therapy for IBD patients refractory to traditional drugs, clinical and immunological arguments seem to indicate that the biological agents are an advantageous treatment for children with IBD when given early in the course of the disease. This, however, requires multicenter randomized controlled trials to prove.

Review article: appropriate use of corticosteroids in Crohn's disease

BACKGROUND

Corticosteroids are a well-established treatment for active Crohn's disease and have been widely used for decades. It has become apparent, however, that a proportion of patients either fails to respond to corticosteroids or is unable to withdraw from them without relapsing. Furthermore, their use is associated with a range of side effects, such that long-term treatment carries unacceptable risk.

AIM

To review the evidence regarding the appropriate use of corticosteroids in Crohn's disease, along with their side effects, safety and alternatives.

METHODS

To collect relevant articles, a PubMed search was performed from 1966 to November 2006 using the terms 'steroid', 'corticosteroid', 'glucocorticoid', 'prednisolone', 'prednisone', 'methylprednisolone', 'hydrocortisone', 'dexamethasone' and 'budesonide' in combination with 'Crohn(s) disease'. Relevant articles were reviewed, as were their reference lists to identify further articles.

RESULTS

When used correctly, corticosteroids are a highly effective, well tolerated, cheap and generally safe treatment for active Crohn' disease. Nevertheless, approximately 50% of recipients will either fail to respond (steroid-resistant) or will be steroid dependent at 1 year. Newer alternatives to corticosteroids are not, however, without risk themselves and, moreover, are not necessarily available universally.

CONCLUSIONS

Steroids are used widely to treat Crohn's disease, a situation that is unlikely to change in the near future. Accordingly, efforts should be made to ensure that they are used correctly and that their side effects are minimized. Reference is made to recently published guidelines and a simplified 'users guide' is presented.

Long-term outcome of Crohn's disease following corticosteroid-induced remission

INTRODUCTION

Corticosteroids are the gold standard in the treatment of moderate to severe Crohn's disease but are often associated with severe and potentially dangerous side effects. Despite an initial clinical response many patients become steroid dependent or require further steroid courses in the long term. The aim of the present study was to assess the probability of the need for further steroid treatment in Crohn's disease patients following steroid-induced remission and to establish if clinical variables can predict further steroid needs. PATIENTS AND All

METHODS

patients at their first steroid course and with corticosteroid-induced remission, defined as a Crohn's Disease Activity Index (CDAI) <150, 4 wk after steroid weaning, were studied and observed at follow-up for 12 months. The main outcome was clinical relapse requiring further steroid treatment. Statistical analysis was performed using the Kaplan-Meier method and multivariable Cox proportional hazard regression model taking into consideration gender, age at diagnosis, disease location and behavior, smoking habits, CDAI score before steroid treatment, and C reactive protein values at steroid weaning, as covariates.

RESULTS

A total of 77 patients with steroid-induced remission were included. One-year follow-up was available in 75 of the 77 patients (97.4%). During follow-up 49 of 75 patients (65.3%) maintained remission or presented mild relapse not requiring steroids while 26 of 75 patients (34.6%) had moderate to severe relapse requiring further steroid treatment. The cumulative probability of a course free from steroids was 93.3%, 82.6%, 78.6%, and 66.6% at 3, 6, 9, and 12 months, respectively. At multivariate analysis, increased C reactive protein at steroid weaning and penetrating complications were independent risk factors for further steroid requirement (OR 5.57, 95% CI 1.20-25.91, P= 0.001 and OR 4.20, 95% CI 1.76-10.04, P= 0.005, respectively).

CONCLUSION

Despite an initial clinical response and successful steroid tapering, 35% of patients required further steroid treatment within 1 yr. An increased C reactive protein value, at steroid weaning, despite clinical remission, and penetrating complications may predict further steroid requirement in already steroid responsive patients.

Diagnostic precision of fecal calprotectin for inflammatory bowel disease and colorectal malignancy

OBJECTIVES

Fecal calprotectin (FC) is a relatively new marker of intraluminal intestinal inflammation. Using meta-analytical techniques, the study aimed to evaluate the diagnostic precision of FC for inflammatory bowel disease (IBD) and colorectal cancer (CRC) in adults and children.

METHODS

Quantitative meta-analysis was performed on prospective studies, comparing FC levels against the histological diagnosis. Sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver-operating characteristic (sROC) curves and subgroup analysis were undertaken. Study quality and heterogeneity were evaluated.

RESULTS

Thirty studies of 5,983 patients were included. FC levels in patients with IBD were higher by 219.2 micrograms per gram (microg/g) compared with normal patients (P < 0.001). sROC curve analysis showed a sensitivity of 0.95 (95% CI 0.93-0.97), specificity of 0.91 (95% CI 0.86-0.91), and an area under the curve (AUC) of 0.95 for the diagnosis of IBD. Patients with colorectal neoplasia had nonsignificantly higher FC levels by 132.2 microg/g compared with noncancer controls (P= 0.18). Sensitivity and specificity of FC for the diagnosis of CRC were 0.36 and 0.71, respectively, with an AUC of 0.66. The diagnostic precision of FC for IBD was higher in children than adults with better accuracy at a cutoff level of 100 microg/g versus 50 microg/g. Sensitivity analysis and metaregression analysis did not significantly alter the results.

CONCLUSIONS

FC cannot be recommended as a screening test for CRC in the general population. FC appeared to offer a good diagnostic precision in distinguishing IBD from non-IBD diagnoses, with higher precision at a cutoff of 100 microg/g.

Novel treatment options for inflammatory bowel disease: targeting alpha 4 integrin

The aetiology of inflammatory bowel disease (IBD) is complex and many aspects still remain unclear. However, significant progress has been made in understanding the pathogenesis of chronic inflammation in the intestine, and new insights have been gained recently. A better understanding of the immunopathology of IBD has led to the development of novel biological agents to target crucial molecules and processes in the inflammatory cascade. The development of novel therapies in the management of IBD has moved from empirical to scientific rational translation from bench to bedside. Lymphocyte infiltration into the intestinal tract in Crohn's disease (CD) is mediated by interaction between alpha4 integrin expressed on lymphocytes and its specific ligand mucosal vascular addressin cell adhesion molecule-1, expressed on the endothelial cells of the microvasculature in the inflamed intestinal tract. Development of monoclonal antibodies against alpha4 integrin permitted the targeting of lymphocyte trafficking into the intestine as a novel therapeutic intervention. Natalizumab, a recombinant humanised monoclonal antibody against alpha4 integrin, was effective in CD in a phase II randomised controlled trial. The highest response rate and remission rate were 71% and 44%, respectively, at 6 weeks after two infusions of natalizumab 3mg administered 4 weeks apart. Natalizumab was well tolerated in this trial. The phase III trial results are encouraging, although the primary efficacy endpoint of response at week 10 was not achieved. The maintenance of response and remission trial, ENACT (Evaluation of Natalizumab as Continuous Therapy)-2, has reported impressive efficacy in maintaining response and remission in those who responded in the initial induction of remission (ENACT-1) trial. This was associated with an improvement in quality-of-life parameters. A second humanised monoclonal antibody, MLN-02 (LDP-02), developed against alpha4beta7 has also shown evidence of efficacy in ulcerative colitis and CD. Although the clinical trials showed that inhibition of alpha4 integrin was well tolerated, use of natalizumab in multiple sclerosis and CD has raised serious concerns about the association with progressive multifocal leukoencephalopathy (PML) in a small number of patients, and the drug has been withdrawn from the market pending further safety evaluation. PML is caused by polyoma JC virus infection, is progressive and generally fatal, and is recognised to occur in patients with severe immunosuppression. Initial safety evaluation suggests that PML is very rare, despite its occurrence in one patient with CD receiving open-label natalizumab treatment.

C-reactive protein and monitoring the activity of Crohn's disease

Biological treatments (anti-tumor necrosis factor-a antibody, mitogen-activated protein kinase inhibitors) and azathioprine given to patients with Crohn's disease (CD) provide the opportunity for mucosal healing. This fact has given rise to the question of whether clinical relief or mucosal healing is the treatment goal in CD. If only clinical relief is sought, current indexes should be reevaluated. In this study, investigators explored the relationship between findings of endoscopic activity, Crohn's Disease Activity Index (CDAI) scores, and C-reactive protein (CRP). This study attempted to clarify the relationship between a high CDAI score (CDAI >150), raised serum CRP, and endoscopic activity in patients with CD. This retrospective study included 115 patients with Crohn's ileocolitis and colitis. CDAI score, CRP level, and mucosal lesions were compared with the chi2 test. The relation between endoscopic activity and raised CRP was significant (P=.001), unlike the association of endoscopic activity with CDAI (P=.287). Mucosal activity was most intense in patients who had both a high CDAI and a raised CRP (84%). No significant difference in endoscopic activity was noted, however, between patients with raised CRP + high CDAI, raised CRP + low CDAI, normal CRP + high CDAI, and normal CRP + low CDAI (P=.113). CRP seemed to be more sensitive than CDAI in the evaluation of patients with CD. The relationship between high CDAI, raised CRP, and the presence of colonoscopic mucosal activity was poor. Therefore, CDAI and CRP are not viewed by the authors as reliable measures of CD activity.

Fecal calprotectin remains high during glucocorticoid therapy in children with inflammatory bowel disease

OBJECTIVE

Fecal calprotectin is a promising marker for the assessment of gastrointestinal inflammation. Fecal calprotectin levels were followed-up in children with inflammatory bowel disease (IBD) who were introduced to glucocorticoid therapy. The aim of this study was to assess whether the changes in fecal calprotectin levels reflect therapeutic responses.

MATERIAL AND METHODS

Fecal calprotectin was measured by enzyme immunoassay in 57 children (mean age 9.8 years, range 0.9-18 years) who underwent colonoscopies (IBD n=31, non-IBD disease n=13, normal n=13) and followed-up in 15 children (mean age 13 years, range 3.6-18 years) who were introduced to glucocorticoid therapy because of active IBD at 0, 2, and 4 weeks and at 4-week intervals until one month after discontinuation of the therapy.

RESULTS

Fecal calprotectin was <100 microg/g in 70% of the children with normal findings on colonoscopy or a non-IBD disease. Fecal calprotectin was >100 microg/g in all but one child with active IBD and in 13/15 of those children who were introduced to glucocorticoids by the clinicians. Fecal calprotectin values decreased within 4 weeks in line with clinical improvement in 7 children and normalized in 4/15 children during the follow-up. Fecal calprotectin increased in 5/8 of the non-steroid-dependent children after discontinuation of glucocorticoids.

CONCLUSIONS

Fecal calprotectin is a sensitive marker for chronic colitis. In active disease treated with glucocorticoids, fecal calprotectin levels declined in line with the clinical improvement but seldom fell within the normal range, which suggests ongoing inflammation in a clinically silent disease. The measurement of fecal calprotectin may provide new tools for the assessment of the level of gut inflammation in children with chronic colitis in the follow-up of clinical responses.

Control of systemic and local inflammation with transforming growth factor beta containing formulas

Enteral nutrition therapy with liquid diet has been shown to be effective in achieving clinical remission in intestinal Crohn's disease. The mechanism of action of this therapy, however, is still poorly understood. As part of our assessment of the action of 3 related polymeric enteral therapies, we have used a variety of techniques to document the histological and cytokine responses, in the mucosa and, systemically, to these treatments. The feeds studied (AL110, Modulen IBD and ACD004 [Nestle, Vevey, Switzerland]) all have casein as the protein source, are lactose free and are rich in transforming growth factor beta (TGF-beta). They have all been shown to induce clinical remission associated with mucosal healing. In the case of Modulen IBD, as well as mucosal macroscopic and histological healing there was a fall in mucosal proinflammatory cytokines: interleukin-1 mRNA in colonic and ileal, interleukin-8 mRNA in the colon and interferon gamma mRNA in the ileum, but a rise in the regulatory cytokine TGF-beta mRNA in the ileum. These results indicate that these formulas are influencing the disease process itself, and thus suggest that the clinical remission achieved is a result of a reduction in inflammation, rather than a consequence of some other nutrition effect.

Mesenteric pulsatility index analysis predicts response to azathioprine in patients with Crohn's disease

OBJECTIVE

Mesenteric blood flow measurement has been found to predict relapse after steroid-induced remission in patients with Crohn's disease (CD) and ulcerative colitis (UC). Therefore, we assessed prospectively the possible relationship between changes in mesenteric blood flow and prognosis in chronically active patients with need of immunosuppressive therapy with azathioprine (AZA) or 6-mercaptopurine (6-MP).

METHODS

Doppler ultrasound (DUS) measurements of the pulsatility index (PI) of the superior mesenteric artery (SMA) and inferior mesenteric artery (IMA) were performed in 52 patients with chronically active inflammatory bowel disease (CD 31 patients; UC 21 patients) before beginning therapy with AZA/6-MP (US1) and during clinical remission (CD activity index <150, Truelove index score I) (US2). Patients were weaned from concomitant therapy with corticosteroids as soon as possible and were followed up for 12 months.

RESULTS

After 1 year, 16 patients with CD (51.6%) and 13 patients with UC (61.9%) were in remission, whereas 23 patients had recurrent disease or had undergone surgery. A decreased SMA PI at US2 predicted clinical relapse in all patients with CD [100%; P < 0.001; mean (+/-SD) 77 +/- 67 d after US1], but only 4 of 8 patients (50%; difference not significant; mean 84 +/- 75 d after US1) with UC. Conversely, an increase of SMA PI was associated with sustained remission in the majority of CD patients (12/16 patients; 75%; P < 0.002), but in only 7 of 13 patients (54%) with UC. Flow measurements in the IMA and postprandial values for both arteries were less reliable.

CONCLUSION

Repeated DUS measurements of the SMA PI predict response to AZA/6-MP in patients with chronic active CD.

Ameliorative effect of IDS 30, a stinging nettle leaf extract, on chronic colitis

BACKGROUND AND AIMS

Anti-TNF-alpha antibodies are very effective in the treatment of acute Crohn's disease, but are limited by the decline of their effectiveness after repeated applications. The stinging nettle leaf extract, IDS 30, is an adjuvant remedy in rheumatic diseases dependent on a cytokine suppressive effect. We investigated the effect of IDS 30 on disease activity of murine colitis in different models.

METHODS

C3H.IL-10-/- and BALB/c mice with colitis induced by dextran sodium sulphate (DSS) were treated with either IDS 30 or water. Mice were monitored for clinical signs of colitis. Inflammation was scored histologically, and faecal IL-1beta and mucosal cytokines were measured by ELISA. Mononuclear cell proliferation of spleen and Peyer's patches were quantified by 3H-thymidine.

RESULTS

Mice with chronic DSS colitis or IL-10-/- mice treated with IDS 30 clinically and histologically revealed significantly (p < 0.05) fewer signs of colitis than untreated animals. Furthermore, faecal IL-1beta and mucosal TNF-alpha concentrations were significantly lower (p < 0.05) in treated mice. Mononuclear cell proliferation after stimulation with lipopolysaccharide was significantly (p < 0.001) reduced in mice treated with IDS 30.

CONCLUSIONS

The long-term use of IDS 30 is effective in the prevention of chronic murine colitis. This effect seems to be due to a decrease in the Th1 response and may be a new therapeutic option for prolonging remission in inflammatory bowel disease.

Canine inflammatory bowel disease: retrospective analysis of diagnosis and outcome in 80 cases (1995-2002)

The case records of 80 dogs in which idiopathic inflammatory bowel disease (IBD) had been diagnosed were reviewed, and owners were contacted for follow-up information using a telephone questionnaire. The types of IBD encountered were lymphocytic (n=6), lymphocytic-plasmacytic (n=38), eosinophilic (n=6) and mixed inflammation (n=30). Prednisolone, sulphasalazine, metronidazole and tylosin were the most frequently prescribed medications. At follow-up, 21 dogs (26 per cent) were classified as being in remission (for a median of 14 months), 40 dogs (50 per cent) had intermittent clinical signs (for a median of 17 months) and three dogs (4 per cent) had uncontrolled disease (for a median of 19 months). Ten dogs (13 per cent) had been euthanased due to refractory IBD and four of these had entered remission for a median of 21 months prior to developing severe relapse and refractoriness to further treatment. Six dogs (8 per cent) had been euthanased or had died for reasons unrelated to IBD. Hypoalbuminaemia at the time of diagnosis was significantly associated with a negative outcome (P=0.0007). No association was found between the site (P=0.75), type (P=0.44) and severity (P=0.75) of disease. Dietary change to single protein and carbohydrate commercial diets had no association with outcome (P=0.12). Owner assessment of quality of life at follow-up was significantly associated with outcome (P=0.006).

Infliximab heals intestinal inflammatory lesions and restores growth in children with Crohn's disease

BACKGROUND

Infliximab has recently emerged as an efficacious agent for patients with severe Crohn's disease. There are only few studies on the use of infliximab in children with Crohn's disease: most of them are retrospective and deal only with the clinical response to the drug.

AIM

We aimed at assessing the efficacy of infliximab in children and adolescents with severe Crohn's disease recruited consecutively and followed up prospectively at a single centre. Clinical response, intestinal inflammation and growth pattern were evaluated.

PATIENTS

Eighteen patients entered into the trial (median age: 13 years, range: 6-18). They were referred because of severe symptoms with unsatisfactory response to conventional drugs.

METHODS

All patients received a baseline schedule of three intravenous infusions of infliximab (0, 2 and 6 weeks), 5 mg/kg. Paediatric Crohn's Disease Activity Index, nutritional and activity serum variables, and ileocolonoscopy (with histology) were evaluated before and 8 weeks after beginning the therapy. All patients had long-term administration of azathioprine (2 mg/kg per day). After the baseline schedule, eight patients had a retreatment infusion of infliximab (5 mg/kg) every 8 weeks. Weight and height Z scores were measured before starting the baseline infusion programme and after 6 months.

RESULTS

After 8 weeks of therapy, there was a dramatic improvement in Paediatric Crohn's Disease Activity Index, in nutritional and activity blood parameters, as well as in endoscopic and histological scores; 10 patients had a clinical remission (Paediatric Crohn's Disease Activity Index < or = 10), 12 patients had an inflammatory remission (decrease in both endoscopic and histological scores for > or = 50% as compared to baseline values). In all patients corticosteroids were stopped within 4 weeks after beginning infliximab therapy. After 6 months of therapy, Paediatric Crohn's Disease Activity Index was markedly lower than the pre-treatment value; however, it was significantly lower in patients on retreatment than in those who received only three infusions of infliximab. Furthermore, a significant increase in both weight and height Z scores was observed 6 months after beginning of the baseline infusion programme. Moreover, weight and height gain was significantly higher in patients on retreatment rather than in those treated only with three baseline infusions of infliximab. Mild infusion reactions controlled by slowing infusion rate were observed in four patients. No delayed hypersensitivity-like reactions were seen.

CONCLUSIONS

In children with severe Crohn's disease, infliximab is a safe and valuable treatment in inducing remission, in healing inflammatory lesions of the gut, as documented by endoscopy and histology, and in promoting growth. Retreatment infusions of infliximab may be suggested in childhood-onset Crohn's disease to maintain remission and reverse growth failure.

Evaluation of new therapies for inflammatory bowel disease

The pathophysiology of inflammatory bowel disease (IBD) is gradually being unravelled and new therapies are being developed to target the disturbed biological processes. This article outlines the clinical features of IBD, its current therapy and pathogenesis. The difficulties for clinical pharmacologists and gastroenterologists associated with designing, executing and interpreting clinical trials in IBD are then discussed. The final section reviews methods that can used to demonstrate the pharmacological actions of new treatments in patients with IBD. It is emphasized that proof of the therapeutic efficacy of a novel agent with a specific mechanism of action yields not only clinical benefit to patients with IBD, but also indicates the importance of the targeted biochemical pathway in the pathogenesis of the disease.

The AF-1 domain of the orphan nuclear receptor NOR-1 mediates trans-activation, coactivator recruitment, and activation by the purine anti-metabolite 6-mercaptopurine

NOR-1/NR4A3 is an "orphan member" of the nuclear hormone receptor superfamily. NOR-1 and its close relatives Nurr1 and Nur77 are members of the NR4A subgroup of nuclear receptors. Members of the NR4A subgroup are induced through multiple signal transduction pathways. They have been implicated in cell proliferation, differentiation, T-cell apoptosis, chondrosarcomas, neurological disorders, inflammation, and atherogenesis. However, the mechanism of transcriptional activation, coactivator recruitment, and agonist-mediated activation remain obscure. Hence, we examined the molecular basis of NOR-1-mediated activation. We observed that NOR-1 trans-activates gene expression in a cell- and target-specific manner; moreover, it operates in an activation function (AF)-1-dependent manner. The N-terminal AF-1 domain delimited to between amino acids 1 and 112, preferentially recruits the steroid receptor coactivator (SRC). Furthermore, SRC-2 modulates the activity of the AF-1 domain but not the C-terminal ligand binding domain (LBD). Homology modeling indicated that the NOR-1 LBD was substantially different from that of hRORbeta, a closely related AF-2-dependent receptor. In particular, the hydrophobic cleft characteristic of nuclear receptors was replaced with a very hydrophilic surface with a distinct topology. This observation may account for the inability of this nuclear receptor LBD to efficiently mediate cofactor recruitment and transcriptional activation. In contrast, the N-terminal AF-1 is necessary for cofactor recruitment and can independently conscript coactivators. Finally, we demonstrate that the purine anti-metabolite 6-mercaptopurine, a widely used antineoplastic and anti-inflammatory drug, activates NOR-1 in an AF-1-dependent manner. Additional 6-mercaptopurine analogs all efficiently activated NOR-1, suggesting that the signaling pathways that modulate proliferation via inhibition of de novo purine and/or nucleic acid biosynthesis are involved in the regulation NR4A activity. We hypothesize that the NR4A subgroup mediates the genotoxic stress response and suggest that this subgroup may function as sensors that respond to genotoxicity.

Review article: maintenance treatment of Crohn's disease

The aetiology of Crohn's disease is unknown and therefore no curative treatments are available for the disease. The natural history of Crohn's disease is characterized by recurrent flare-ups of symptoms. Several drug treatments are effective in inducing clinical remission. However, no drug treatments are available in order to prevent clinical relapses, although several drug regimens may delay clinical flare-ups. Crohn's disease treatment for maintaining clinical remission needs to be tailored in relation to specific characteristics of each patient. The frequency of clinical relapse indeed shows marked variations in subgroups of patients, as the likelyhood of relapse is higher in patients in clinical remission for less than 6 months. Treatment strategies for maintaining remission may therefore differ among inactive patients. In chronically active, steroid-dependent or steroid-refractory Crohn's disease patients immunomodulatory drugs (azathioprine 2-2.5 mg/kg by mouth, 6-mercaptopurine 1-1.5 mg/kg by mouth, or methotrexate 15-25 mg/i.m./week) should be added to oral mesalazine (2.4 g/day), while in long-term inactive Crohn's disease patients mesalazine alone may be effective in delaying relapse. Recently, treatment with anti-tumour necrosis factor-alpha monoclonal antibodies (Infliximab or CDP571) has shown efficacy in delaying relapse in responsive patients. One other issue which needs to be considered before selecting drug treatments for maintaining remission in Crohn's disease, is that Crohn's disease activity is currently assessed on the basis of standard clinical scores which may not appropriately reflect the biological activity of the disease. Clinical remission as defined by standardized scores may include heterogeneous subgroups of patients showing different endoscopic and histological activity or persistence of activated immunocompetent cells within the gut. Several sub-clinical markers of relapse have indeed been reported in quiescent Crohn's disease, although their usefulness in clinical practice in currently uncertain.

99mTc-interleukin-2 and (99m)Tc-HMPAO granulocyte scintigraphy in patients with inactive Crohn's disease

Crohn's disease (CD) is a chronic inflammatory bowel disease that may involve the whole gut. Marked intestinal T cell and macrophage activation is a key feature of the disease. Polymorphonuclear cell infiltration is also observed in the diseased gut, mainly during active inflammation. Scintigraphic detection of granulocytes and activated lymphocytes infiltrating the gut wall may be useful in identifying a subgroup of patients with clinically inactive CD who are undergoing early clinical relapse. The aims of the present study were (a) to compare the effectiveness of scintigraphy with (99m)Tc-labelled interleukin-2 ((99m)Tc-IL2) and with (99m)Tc-HMPAO labelled granulocytes ((99m)Tc-WBC) in detecting the presence and extent of bowel inflammation in patients with long-term inactive CD (>12 months) and (b) to assess the accuracy of these techniques in predicting future disease relapse. We studied 29 patients with ileal and/or colonic CD in stable clinical remission (Crohn's Disease Activity Index <150 for at least 12 months) using both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy in order to evaluate the extent of acute and chronic inflammation in the bowel. Planar and single-photon emission tomography images were acquired in each patient at 1 h p.i. For quantitative analysis of (99m)Tc-IL2 uptake, the abdomen was divided into 32 regions of interest. Despite the absence of symptoms, 18 patients (62%) showed a positive (99m)Tc-IL2 and 18 (62%) a positive (99m)Tc-WBC scan. Only 12 patients (41.4% of the total group) were positive on both scans, and the sites of IL2 and granulocyte bowel uptake were usually located in different segments, indicating that in CD, acute and chronic inflammation can be present in different sites. As far as the prognostic role of the two scans in predicting future disease relapse is concerned, both (99m)Tc-IL2 and (99m)Tc-WBC scintigraphy showed a high negative predictive value (1.00 and 0.91, respectively) but a weak positive predictive value (0.44 and 0.39, respectively). Nevertheless, Kaplan-Meier curves generated between scintigraphic findings and time free from disease relapse were statistically different only for (99m)Tc-IL2 scintigraphy (log-rank test, P=0.013). These results indicate that (99m)Tc-IL2 scintigraphy can be useful in selecting CD patients in clinical remission who could benefit from preventive therapy to avoid disease relapse.

Fecal alpha 1-antitrypsin clearance as a marker of clinical relapse in patients with Crohn's disease of the distal ileum

BACKGROUND

Crohn's disease (CD) shows a chronic relapsing course but no marker of relapse is currently available. However, fecal alpha 1-antitrypsin (alpha 1-AT) clearance (alpha 1-ATCl) is an indicator of protein loss and increases during active inflammation. We assessed the usefulness of fecal alpha 1-ATCl in predicting clinical relapse in patients with inactive ileal CD.

DESIGN

In a prospective longitudinal study, 26 patients with inactive ileal CD (Crohn's disease activity index (CDAI) < 150) (18 males, mean age 43 +/- 10, range 23-58) were enrolled. Fecal alpha 1-ATCl and concentration, daily stool weight and serum alpha 1-AT were measured at baseline (visit 1), after 1 week (visit 2) and 3 weeks (visit 3) in 24/26 patients (two drop-outs) (short-term study). In six of these 26 patients, fecal alpha 1-ATCl was also measured every 3 months for 1 year (long-term study). All patients were clinically assessed every 3 months for 1 year and every 6 months for 2 years. Ten healthy volunteers were tested as controls.

METHODS

Serum and fecal alpha 1-AT concentration was quantified by radial immunodiffusion.

RESULTS

The median fecal alpha 1-ATCl value at baseline was higher in inactive patients undergoing clinical relapse (CDAI > 200) in the next 6 months than in those remaining in remission at 6 months (P = 0.03). Fecal alpha 1-ATCl showed a 75% sensitivity, 85% specificity, 50% positive predictive value and 94% negative predictive value in predicting CD relapse in the next 6 months. In the long-term follow-up, fecal alpha 1-ATCl values increased at 12 months compared with both baseline and 6 month values (P = 0.005; P = 0.009). Fecal alpha 1-ATCl was higher in patients with raised C-reactive protein (P = 0.039).

CONCLUSIONS

Results from our study suggest that fecal alpha 1-ATCl is an indicator of clinical relapse in patients with CD of the distal ileum under regular surveillance.