A nationwide database study on colectomy and colorectal cancer in ulcerative colitis: what is the role of appendectomy?

AIM

Although has been suggested that an appendectomy has a positive effect on the disease course in patients with ulcerative colitis (UC), recent studies indicate a potential increase in risk of colectomy and colorectal cancer (CRC). This study aimed to evaluate the rates of colectomy and CRC after appendectomy in UC patients using a nationwide prospective database [the Initiative on Crohn and Colitis Parelsnoer Institute - Inflammatory Bowel Disease (ICC PSI-IBD) database].

METHOD

All UC patients were retrieved from the ICC PSI-IBD database between January 2007 and May 2018. Primary outcomes were colectomy and CRC. Outcomes were compared in patients with and without appendectomy, with a separate analysis for timing of appendectomy (before or after UC diagnosis).

RESULTS

A total of 826 UC patients (54.7% female; median age 46 years, range 18-89 years) were included. Sixty-three (7.6%) patients had previously undergone appendectomy: 24 (38.1%) before and 33 (52.4%) after their diagnosis of UC. In multivariate analysis, appendectomy after UC diagnosis was associated with a significantly lower colectomy rate compared with no appendectomy [hazard ratio (HR) 0.16, 95% C: 0.04-0.66, P = 0.011], and the same nonsignificant trend was seen in patients with an appendectomy before UC diagnosis (HR 0.35, 95% CI 0.08-1.41, P = 0.138). Appendectomy was associated with delayed colectomy, particularly when it was performed after diagnosis of UC (P = 0.009). No significant differences were found in the CRC rate between patients with and without appendectomy (1.6% vs 1.2%; P = 0.555).

CONCLUSION

Appendectomy in established UC is associated with an 84% decreased risk of colectomy and a delay in surgery. Since the colon is in situ for longer, the risk of developing CRC remains, which underscores the importance of endoscopic surveillance programmes.

Systematic Review: Histological Scoring of Strictures in Crohn's Disease

BACKGROUND AND AIMS

In Crohn's disease, many patients develop a stricture, which can due to inflammation, fibrosis and muscular changes or all at the same time. Determining the predominant component has therapeutic consequences but remains challenging. To develop imaging techniques that assess the nature of a stricture, a gold standard is needed and histopathology is considered as such. This paper provides an overview of published histological scoring systems for strictures in Crohn's disease.

METHODS

A systematic literature review according to PRISMA guidelines was performed of histological scoring indices that assessed whether a stricture was inflammation-predominant or fibrosis-predominant. Multiple libraries were searched from inception to December 2018. Two reviewers independently assessed abstracts and full-texts.

RESULTS

Sixteen articles were identified as suitable for this systematic review. A large number of parameters were reported. Extent of neutrophil infiltration and extent of fibrosis in the bowel wall were most frequently described to reflect severity of inflammation and fibrosis, respectively. Among the 16 studies, only two described a numerical scoring system for the inflammatory and fibrotic component separately. Smooth muscle changes were scored in a minority of studies.

CONCLUSIONS

Multiple scoring systems have been developed. There was large heterogeneity in scoring per parameter and construction of numerical scoring systems. Therefore, we feel that none of the systems is suitable to be used as gold standard. We offer an overview of histological parameters that could be incorporated in a future histological scoring index for strictures.

Anti-TNF therapy in IBD exerts its therapeutic effect through macrophage IL-10 signalling

OBJECTIVE

Macrophage interleukin (IL)-10 signalling plays a critical role in the maintenance of a regulatory phenotype that prevents the development of IBD. We have previously found that anti-tumour necrosis factor (TNF) monoclonal antibodies act through Fcγ-receptor (FcγR) signalling to promote repolarisation of proinflammatory intestinal macrophages to a CD206+ regulatory phenotype. The role of IL-10 in anti-TNF-induced macrophage repolarisation has not been examined.

DESIGN

We used human peripheral blood monocytes and mouse bone marrow-derived macrophages to study IL-10 production and CD206+ regulatory macrophage differentiation. To determine whether the efficacy of anti-TNF was dependent on IL-10 signalling in vivo and in which cell type, we used the CD4+CD45Rb^high T-cell transfer model in combination with several genetic mouse models.

RESULTS

Anti-TNF therapy increased macrophage IL-10 production in an FcγR-dependent manner, which caused differentiation of macrophages to a more regulatory CD206+ phenotype in vitro. Pharmacological blockade of IL-10 signalling prevented the induction of these CD206+ regulatory macrophages and diminished the therapeutic efficacy of anti-TNF therapy in the CD4+CD45Rb^high T-cell transfer model of IBD. Using cell type-specific IL-10 receptor mutant mice, we found that IL-10 signalling in macrophages but not T cells was critical for the induction of CD206+ regulatory macrophages and therapeutic response to anti-TNF.

CONCLUSION

The therapeutic efficacy of anti-TNF in resolving intestinal inflammation is critically dependent on IL-10 signalling in macrophages.

Prospective cohort study of appendicectomy for treatment of therapy-refractory ulcerative colitis

Introduction

Appendicectomy may reduce relapses and need for medication in patients with ulcerative colitis, but long-term prospective data are lacking. This study aimed to analyse the effect of appendicectomy in patients with refractory ulcerative colitis.

Methods

In this prospective multicentre cohort series, all consecutive patients with refractory ulcerative colitis referred for proctocolectomy between November 2012 and June 2015 were counselled to undergo laparoscopic appendicectomy instead. The primary endpoint was clinical response (reduction of at least 3 points in the partial Mayo score) at 12 months and long-term follow-up. Secondary endpoints included endoscopic remission (endoscopic Mayo score of 1 or less), failure (colectomy or start of experimental medication), and changes in Inflammatory Bowel Disease Questionnaire (IBDQ) (range 32–224), EQ-5D™ and EORTC-QLQ-C30-QL scores.

Results

A total of 28 patients (13 women; median age 40·5 years) underwent appendicectomy. The mean baseline IBDQ score was 127·0, the EQ-5D™ score was 0·65, and the EORTC-QLQ-C30-QL score was 41·1. At 12 months, 13 patients had a clinical response, five were in endoscopic remission, and nine required a colectomy (6 patients) or started new experimental medical therapy (3). IBDQ, EQ-5D™ and EORTC-QLQ-C30-QL scores improved to 167·1 (P < 0·001), 0·80 (P = 0·003) and 61·0 (P < 0·001) respectively. After a median of 3·7 (range 2·3–5·2) years, a further four patients required a colectomy (2) or new experimental medical therapy (2). Thirteen patients had a clinical response and seven were in endoscopic remission. The improvement in IBDQ, EQ-5D™ and the EORTC-QLQ-C30-QL scores remained stable over time.

Conclusion

Appendicectomy resulted in a clinical response in nearly half of patients with refractory ulcerative colitis and a substantial proportion were in endoscopic remission. Elective appendicectomy should be considered before proctocolectomy in patients with therapy-refractory ulcerative colitis.

A JAK1 Selective Kinase Inhibitor and Tofacitinib Affect Macrophage Activation and Function

BACKGROUND

Janus kinases (JAKs) mediate cytokine signaling involved in inflammatory bowel disease. The pan-JAK inhibitor tofacitinib has shown efficacy in the treatment of ulcerative colitis. However, concerns regarding adverse events due to their wide spectrum inhibition fueled efforts to develop selective JAK inhibitors. Given the crucial role of myeloid cells in intestinal immune homeostasis, we evaluated the effect of pan-JAK and selective JAK inhibitors on pro- and anti-inflammatory macrophage polarization and function (M1/M2) and in experimental colitis.

METHODS

Murine bone marrow-derived macrophages or human monocytes were treated using JAK1 and JAK3 selective inhibitors (JAK1i;JAK3i) and tofacitinib and were evaluated by transcriptional, functional, and metabolic analyses. In vivo, oral administration of JAK1i and tofacitinib (10 or 30 mg/kg) was tested in both acute and acute rescue dextran sodium sulfate (DSS) colitis.

RESULTS

Both tofacitinib and JAK1i but not JAK3i effectively inhibited STAT1 phosphorylation and interferon gamma-induced transcripts in M1 polarized macrophages. Strikingly, transcriptional profiling suggested a switch from M1 to M2 type macrophages, which was supported by increased protein expression of M2-associated markers. In addition, both inhibitors enhanced oxidative phosphorylation rates. In vivo, JAK1i and tofacitinib did not protect mice from acute DSS-induced colitis but ameliorated recovery from weight loss and disease activity during acute rescue DSS-induced colitis at the highest dose.

CONCLUSION

JAK1i and tofacitinib but not JAK3i induce phenotypical and functional characteristics of anti-inflammatory macrophages, suggesting JAK1 as the main effector pathway for tofacitinib in these cells. In vivo, JAK1i and tofacitinib modestly affect acute rescue DSS-induced colitis.

Patterns of anti-TNF use and associated treatment outcomes in inflammatory bowel disease patients: results from an analysis of Dutch health insurance claims data

INTRODUCTION

Real-life patterns of anti-tumour necrosis factor (anti-TNF) use remain largely unknown. We aimed to investigate survival rates, clinical outcomes and costs of anti-TNF agents in a large population of patients with inflammatory bowel disease (IBD).

METHODS

Health insurance data from 22,082 IBD patients were provided by Achmea Healthcare. Time to anti-TNF discontinuation, treatment intensification, corticosteroid initiation and hospitalisation were analysed in patients starting on anti-TNF treatment from January 2008 until December 2014. Treatment regimens were analysed at different time points.

RESULTS

In this cohort, 855 and 1199 subjects started infliximab and adalimumab treatment, respectively. The median time to anti-TNF discontinuation was 600 days (IQR 156-1693). The proportion of subjects receiving intensified treatment increased over time (infliximab at 3 vs. 24 months: 22.2% vs. 33.6%, p = 0.01; adalimumab at 3 vs. 24 months: 10.5% vs. 19.3%, p < 0.001). Cessation of anti-TNF treatment was less common in Crohn's disease patients (HR 0.79, p = 0.001) and in patients receiving intensified treatment (HR 0.62, p = 0.001). Immunomodulator use was associated with a longer time to corticosteroid initiation (HR 0.80, p = 0.048), but not with longer drug survival (HR 0.99, p = 0.617). Hospitalisation was more common in Crohn's patients (HR 1.49, p = 0.011). Corticosteroid initiation was lower in Crohn's patients (HR 0.57, p < 0.001) and in patients using infliximab (HR 0.55, p < 0.001).

CONCLUSIONS

Discontinuation of anti-TNF therapy occurred earlier than previously reported and was associated with a diagnosis of ulcerative colitis and non-intensified anti-TNF treatment. Immunomodulator use at the start of anti-TNF treatment was associated with a longer time to corticosteroid initiation, but not with longer drug survival.

Randomised non-inferiority trial: 1600 mg versus 400 mg tablets of mesalazine for the treatment of mild-to-moderate ulcerative colitis

BACKGROUND

High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC).

AIM

To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations.

METHODS

Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored.

RESULTS

At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low.

CONCLUSIONS

Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).

Short- and medium-term outcomes following primary ileocaecal resection for Crohn's disease in two specialist centres

BACKGROUND

Despite improvements in medical therapy, the majority of patients with Crohn's disease still require surgery. The aim of this study was to report safety, and clinical and surgical recurrence rates, including predictors of recurrence, after ileocaecal resection for Crohn's disease.

METHODS

This was a cohort analysis of consecutive patients undergoing a first ileocaecal resection for Crohn's disease between 1998 and 2013 at one of two specialist centres. Anastomotic leak rate and associated risk factors were assessed. Kaplan-Meier estimates were used to describe long-term clinical and surgical recurrence. Univariable and multivariable regression analyses were performed to identify risk factors for both endpoints.

RESULTS

In total, 538 patients underwent primary ileocaecal resection (40·0 per cent male; median age at surgery 31 (i.q.r. 24-42) years). Median follow-up was 6 (2-9) years. Fifteen of 507 patients (3·0 per cent) developed an anastomotic leak. An ASA fitness grade of III (odds ratio (OR) 4·34, 95 per cent c.i. 1·12 to 16·77; P = 0·033), preoperative antitumour necrosis factor therapy (OR 3·30, 1·09 to 9·99; P = 0·035) and length of resected bowel specimen (OR 1·06, 1·03 to 1·09; P < 0·001) were significant risk factors for anastomotic leak. Rates of clinical recurrence were 17·6, 45·4 and 55·0 per cent after 1, 5 and 10 years respectively. Corresponding rates of requirement for further surgery were 0·6, 6·5 and 19·1 per cent. Smoking (hazard ratio (HR) 1·67, 95 per cent c.i. 1·14 to 2·43; P = 0·008) and a positive microscopic resection margin (HR 2·16, 1·46 to 3·21; P < 0·001) were independent risk factors for clinical recurrence. Microscopic resection margin positivity was also a risk factor for further surgery (HR 2·99, 1·36 to 6·54; P = 0·006).

CONCLUSION

Ileocaecal resection achieved durable medium-term remission, but smoking and resection margin positivity were risk factors for recurrence.

Suppression of anti-drug antibodies to infliximab or adalimumab with the addition of an immunomodulator in patients with inflammatory bowel disease

BACKGROUND

Loss of response to anti-tumour necrosis factor (TNF) therapy in patients with inflammatory bowel disease (IBD) is often caused by anti-drug antibody formation with neutralisation of drug effect. Addition of an immunomodulator has been suggested to reduce immunogenicity, leading to regained response.

AIM

To investigate whether addition of an immunomodulator to anti-TNF monotherapy could lead to anti-drug antibody suppression and regained clinical response in IBD patients.

METHODS

We retrospectively collected measurements of infliximab or adalimumab serum concentrations and anti-drug antibodies to identify anti-drug positive patients with loss response who were given an immunomodulator.

RESULTS

Anti-drug antibodies against infliximab and adalimumab were detected in 98/376 (26%) and in 61/226 (27%) patients, respectively. Immunomodulators were given to 17/159 patients. Clinical response was recaptured in 6/10 patients receiving a thiopurine and in all (7/7) patients receiving methotrexate. In 7/8 patients on infliximab, serum concentrations increased (median 2.84 μg/mL; IQR: 1.19-4.98) and in 6/9 patients on adalimumab (median 3.10 μg/mL; IQR: 1.45-4.45). This was accompanied by a decrease in anti-drug antibodies to undetectable levels (median 11 months for both anti-TNF agents). In 23 patients, no immunomodulator was added but anti-TNF interval was shortened (17/23) or dosage was increased (6/23), which resulted in a clinical response in 10/17 and 2/6 patients, respectively.

CONCLUSION

In 77% of IBD patients with loss of response due to immunogenicity, addition of immunomodulator resulted in undetectable anti-drug antibody levels, increased serum drug concentrations and regained clinical response. This strategy should be considered in this patient population before switching to other agents.

Risk factors for proximal disease extension and colectomy in left-sided ulcerative colitis

OBJECTIVE

The primary objective of this study was to assess proximal disease extension of ulcerative colitis (UC) over time, with disease behaviour pattern and risk factors for proximal disease extension and colectomy as secondary aims.

METHODS

All cumulative incident cases diagnosed with UC at the Academic Medical Center between January 1990 and December 2009 were studied. The cumulative risk of colectomy was calculated by Kaplan-Meier analysis. The Cox proportional hazards regression was used to identify risk factors associated with proximal disease extension and colectomy.

RESULTS

In total, 506 UC patients were included with a median age of 33 years (IQR 23-41) at diagnosis. Ninety-five (18.8%) patients underwent colectomy during follow-up. Median follow-up was 10 years (IQR 5-15). Initial disease extent was evaluable in 416 patients, of whom 142 (34.1%) had proctitis, 155 (37.3%) left-sided colitis and 119 (28.6%) pancolitis. Proximal disease extension was observed in 120 (28.8%) patients during follow-up (51 proctitis to left-sided colitis, 39 proctitis to extensive colitis and 30 left-sided to extensive colitis). Disease behaviour was evaluable in 378 patients, of whom 244 (64.6%) had less than one relapse per year. Younger age at diagnosis (HR 0.98, 95% CI 0.96-0.99) and continuous active disease (HR 2.18, 95% CI 1.27-3.73) were independent risk factors for proximal disease extension. The cumulative risk of colectomy did not change over time between patients diagnosed before and after the year 2000 (p = 0.341). Continuous active disease (HR 7.05, 95% CI 4.23-11.77), systemic steroids (HR 3.25, 95% CI 1.37-7.71) and cyclosporine treatment (HR 2.80, 95% CI 1.66-4.72) were independent risk factors for colectomy, whereas proctitis at diagnosis (HR 0.43, 95% CI 0.22-0.86) carried a lower risk.

CONCLUSION

In one-third of UC patients, left-sided disease at diagnosis will extend proximally during 10 years of follow-up. Proximal disease extension was not a risk factor for colectomy, but the risk of colectomy is rather determined by continuous disease activity, and use of systemic steroids and cyclosporine.

Low prevalence of Blastocystis sp. in active ulcerative colitis patients

Ulcerative colitis (UC) is thought to originate from a disbalance in the interplay between the gut microbiota and the innate and adaptive immune system. Apart from the bacterial microbiota, there might be other organisms, such as parasites or viruses, that could play a role in the aetiology of UC. The primary objective of this study was to compare the prevalence of Blastocystis sp. in a cohort of patients with active UC and compare that to the prevalence in healthy controls. We studied patients with active UC confirmed by endoscopy included in a randomised prospective trial on the faecal transplantation for UC. A cohort of healthy subjects who served as donors in randomised trials on faecal transplantation were controls. Healthy subjects did not have gastrointestinal symptoms and were extensively screened for infectious diseases by a screenings questionnaire, extensive serologic assessment for viruses and stool analysis. Potential parasitic infections such as Blastocystis were diagnosed with the triple faeces test (TFT). The prevalence of Blastocystis sp. were compared between groups by Chi-square testing. A total of 168 subjects were included, of whom 45 had active UC [median age 39.0 years, interquartile range (IQR) 32.5–49.0, 49 % male] and 123 were healthy subjects (median age 27 years, IQR 22.0–37.0, 54 % male). Blastocystis sp. was present in the faeces of 40/123 (32.5 %) healthy subjects and 6/45 (13.3 %) UC patients (p = 0.014). Infection with Blastocystis is significantly less frequent in UC patients as compared to healthy controls.

Clinical trial: Preliminary efficacy and safety study of a new Budesonide-MMX® 9 mg extended-release tablets in patients with active left-sided ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a chronic inflammatory disease with relapses. Many patients need systemic corticosteroids to induce clinical remission.

AIM

Efficacy and safety of Budesonide-MMX® 9 mg tablets, a new oral, extended-release formulation, were evaluated in patients suffering from active, left-sided UC with colitis activity index (CAI) <14.

METHODS

36 patients were treated once daily for 4 weeks with Budesonide-MMX® 9 mg tablets or placebo. In an additional 4-week period, all patients received Budesonide-MMX®. CAI, endoscopic index and histology were assessed after 4 and 8 weeks. Primary end-point was remission, and/or CAI reduction by 50% after 4 weeks. Morning cortisol was assayed after 4 and 8 weeks, and a short ACTH-test was performed at week 8.

RESULTS

32 patients were analysed. After 4 weeks, 47.1% of the patients in the Budesonide-MMX® 9 mg tablets group achieved the primary end-point vs. 33.3% of patients on placebo. In addition, 47.1% of budesonide patients and another 33.3% of placebo recipients improved without remission by 4 weeks. The CAI reduction was significant with Budesonide (p<0.0001) tablets and not with placebo (p=0.1). Neither morning cortisol nor pituitary-adrenal axis was more frequently suppressed with Budesonide tablets than with placebo.

CONCLUSIONS

Budesonide-MMX® 9 mg tablets induced a fast and significant clinical improvement of active left-sided UC without suppression of adrenocortical functions and without important toxicity EudraCT number 2004-000896-33.

Adalimumab sustains clinical remission and overall clinical benefit after 2 years of therapy for Crohn's disease

BACKGROUND

In the randomized, double-blind, placebo-controlled CHARM trial, adalimumab was more effective than placebo in maintaining clinical remission for patients with moderate-to-severe Crohn's disease (CD) through 56 weeks.

AIM

To substantiate the long-term safety and clinical benefits of adalimumab through 2 years of therapy in CHARM and its open-label extension (ADHERE).

METHODS

Patients entering ADHERE on blinded therapy received adalimumab 40 mg every other week (eow). Patients who had already moved to open-label adalimumab eow or weekly in CHARM continued their regimens. Data were analysed by originally randomized treatment group at CHARM baseline (adalimumab 40 mg eow, adalimumab 40 mg weekly, or placebo), regardless of whether patients entered ADHERE or received open-label adalimumab (eow or weekly).

RESULTS

After up to 2 years of therapy, 37.6%, 41.9% and 49.8% of patients originally randomized to placebo, adalimumab eow and adalimumab weekly, respectively, were in clinical remission. All groups experienced sustained improvements on the Inflammatory Bowel Disease Questionnaire. Decreasing hazard rates for both all-cause and CD-related hospitalizations were observed over time. Over a 2-year period, the rates of serious adverse events and malignancies (33.3 and 1.1 events/100-patient-years respectively) were similar to those observed during the overall adalimumab CD clinical development programme.

CONCLUSIONS

Adalimumab demonstrated sustained maintenance of clinical remission, improvements in quality of life and reductions in hospitalization during long-term treatment for CD, with no new safety concerns identified.

Top-down therapy for Crohn's disease: rationale and evidence

Several trials have shown that early treatment of Crohn's disease with immunomodulators and anti-TNF agents leads to superior clinical outcome including healing of the mucosa. Evidence is mounting that this endpoint is associated with a reduced risk of complications and a reduced need for surgeries and hospitalizations. In the SONIC trial, treatment with the combination of azathioprine and infliximab was the most potent anti-inflammatory therapy in Crohn's disease patients with evidence of active inflammation who had never been exposed to immunomodulators or biologics. These findings have introduced a trend towards earlier initiation of immunomodulator therapy, comparable to what is being done in rheumatoid arthritis. Given the fact that subsets of patients have a favorable disease course without immunomodulator therapy and given the significant potential toxicity of these medications, however, it is becoming a challenge to the gastroenterologists to try and identify patients with an unfavorable disease prognosis and treat these early and aggressively. The key to successful management of Crohn's disease appears to lie in careful timing and selection of the appropriate interventions.

IL-15 is highly expressed in inflammatory bowel disease and regulates local T cell-dependent cytokine production

IL-15 shares biological activities but no significant sequence homology with IL-2. It induces T cell recruitment to sites of inflammation, T cell proliferation, and cytokine production and rescue from apoptosis. The aim of this study was to investigate expression of IL-15 and its effects on proinflammatory cytokine production in inflammatory bowel disease (IBD). Immunohistochemistry demonstrated local IL-15 production by macrophages in inflamed mucosa from IBD patients. Isolated lamina propria mononuclear cells from these patients but not from controls produced IL-15 when stimulated with LPS or IFN-gamma. Moreover, lamina propria T cells (LP-T) from IBD patients were more responsive to IL-15 as compared with controls, and IL-15 alone without a primary T cell stimulus induced IFN-gamma and TNF production by isolated IBD LP-T cells, especially by LP-T cells from patients with Crohn's disease. LP-T cells from IBD patients could induce CD40-CD40 ligand (CD40L) interaction-dependent TNF and IL-12 production by monocytes in a coculture system. This capacity of LP-T cells was strongly enhanced by preincubation in IL-15 and was the result of higher CD40L expression after culture in IL-15. These data indicate that IL-15 is overexpressed in the inflamed mucosa in IBD and that IL-15 enhances local T cell activation, proliferation, and proinflammatory cytokine production by both T cells and macrophages, the latter via a CD40-CD40L interaction-dependent mechanism. Treatment directed against IL-15 may have therapeutic potential in IBD.

Hyperexpression of CD40 ligand (CD154) in inflammatory bowel disease and its contribution to pathogenic cytokine production

CD40 ligand (CD40L or CD154), a type II membrane protein with homology to TNF, is transiently expressed on activated T cells and known to be important for B cell Ig production and for activation and differentiation of monocytes and dendritic cells. Both Crohn's disease and ulcerative colitis are characterized by local production of cytokines such as TNF and by an influx of activated lymphocytes into inflamed mucosa. Herein, we investigated whether CD40L signaling participates in immune responses in these diseases. Our results demonstrated that CD40L was expressed on freshly isolated lamina propria T cells from these patients and was functional to induce IL-12 and TNF production by normal monocytes, especially after IFN-gamma priming. The inclusion of a blocking mAb to CD40L or CD40 in such cocultures significantly decreased monocyte IL-12 and TNF production. Moreover, lamina propria and peripheral blood T cells from these patients, after in vitro activation with anti-CD3, showed increased and prolonged expression of CD40L as compared with controls. Immunohistochemical analyses indicated that the number of CD40+ and CD40L+ cells was significantly increased in inflamed mucosa, being B cells/macrophages and CD4+ T cells, respectively. These findings suggest that CD40L up-regulation is involved in pathogenic cytokine production in inflammatory bowel disease and that blockade of CD40-CD40L interactions may have therapeutic effects for these patients.

Infliximab (Remicade), a new biological treatment for Crohn's disease

Tumour necrosis factor plays a pivotal role in Crohn's disease intestinal inflammation. Blocking this cytokine by means of the chimeric monoclonal antibody infliximab has led to a rapid reduction in mucosal inflammation. More than 65% of refractory Crohn's disease patients treated with infliximab showed a remarkable improvement in their symptoms, which was maintained by repeated infusions every 2 months up to 44 weeks. Patients with draining enterocutaneous fistulae also benefited from infliximab treatment, with more than 60% of fistulae healed after 3 infusions. Adverse events following infliximab infusions were mild and transient, occurring with the same frequency in infliximab and placebo-treated patients. In conclusion, infliximab appears to offer a promising novel therapeutic agent for refractory and fistulizing Crohn's disease. Long-term risks and benefits remain to be determined.

Tumor necrosis factor alpha antibody (infliximab) therapy profoundly down-regulates the inflammation in Crohn's ileocolitis

BACKGROUND & AIMS

Anti-tumor necrosis factor alpha monoclonal antibody treatment (infliximab) reduces clinical signs and symptoms in patients with Crohn's disease. The effects of infliximab on mucosal histopathologic abnormalities in Crohn's ileocolitis were studied.

METHODS

Thirteen patients with steroid-refractory Crohn's disease were treated with a single infusion of infliximab (5-20 mg/kg), and 5 were treated with placebo. Ileal and colonic biopsy specimens of all patients were collected before and 4 weeks after therapy. Severity of inflammation was assessed by a histological score. Immunohistochemical stainings with antibodies against HLA-DR, CD68, tumor necrosis factor alpha, intercellular adhesion molecule 1, lymphocyte function-associated antigen, CD4, CD8, and interleukin 4 were performed.

RESULTS

Total histological activity score was reduced significantly in both ileitis and colitis after infliximab. This is caused by a virtual disappearance of the neutrophils and a reduction of mononuclear cells. Mucosal architecture returned to normal in 4 patients at 4 weeks. The number of lamina propria mononuclear cells decreased because of a global reduction of CD4(+) and CD8(+) T lymphocytes and CD68(+) monocytes. Aberrant colonic epithelial HLA-DR expression completely disappeared. The percentage of intercellular adhesion molecule 1 and lymphocyte function-associated antigen 1-expressing and interleukin 4- and tumor necrosis factor-positive lamina propria mononuclear cells sharply decreased.

CONCLUSIONS

Infliximab dramatically decreases histological disease activity in Crohn's ileocolitis. Signs of active inflammation nearly disappear accompanied by a profound down-regulation of mucosal inflammatory mediators.

Early lesions of recurrent Crohn's disease caused by infusion of intestinal contents in excluded ileum

BACKGROUND & AIMS

Postoperative recurrence of Crohn's disease may be triggered by agents in the fecal stream. The aim of this study was to examine intestinal mucosal inflammation induced by contact with intestinal fluids in surgically excluded ileum.

METHODS

The effects of infusion of intestinal luminal contents into excluded ileum in 3 patients with Crohn's disease who had undergone a curative ileocolonic resection with ileocolonic anastomosis and temporary protective proximal loop ileostomy were studied by histopathology and electron microscopy.

RESULTS

Contact with intestinal fluids for 8 days induced focal infiltration of mononuclear cells, eosinophils, and polymorphonuclear cells in the lamina propria, small vessels, and epithelium in the excluded neoterminal ileum that was previously normal. Epithelial HLA-DR expression increased, and mononuclear cells expressed the KP-1 antigen associated with activation. Marked up-regulation of RFD-7, RFD-9, intercellular adhesion molecule 1, and lymphocyte function-associated antigen 1 was observed after infusion, reflecting epithelioid transformation and transendothelial lymphocyte recruitment. At the ultrastructural level, dilatation of the endoplasmic reticulum and Golgi apparatus occurred in epithelial cells, where also basally located transport vesicles were identified.

CONCLUSIONS

Intestinal contents trigger postoperative recurrence of Crohn's disease in the terminal ileum proximal to the ileocolonic anastomosis in the first days after surgery.

Duration of recurrent ileitis after ileocolonic resection correlates with presurgical extent of Crohn's disease

Crohn's disease of the terminal ileum recurs in a predictable sequence proximal to the ileocolonic anastomosis after surgical resection. To confirm the suspicion that the duration of recurrent ileitis correlates with the extent of presurgical disease, this study investigated 23 consecutive patients with recurrent Crohn's disease symptoms who had undergone ileocaecal resections between 1982 and 1992 at our institution and had both preoperative and postoperative small bowel follow through studies available for comparison. All films were reviewed by a blinded gastrointestinal radiologist using uniform criteria. Symptomatic recurrence was reported at a mean (SEM) of 29 (25) months after resection. Presurgical length of inflammation averaged 26 (15) (8-57) cm and at recurrence 24 (14) (7-55) cm. The correlation coefficient (r) between pre and postsurgical extent of ileal disease was 0.70 (p < 0.0001). Seven patients had sequential small bowel series after 20 (10) (7-36) months without intervening surgery. The extent of measured inflammation between examinations correlated with r = 0.995 (p < 0.0001), showing the consistency of the measurement process. The close correlation between the duration of postoperative recurrence with the extent of presurgical disease is another example of individual patterns of recurrent Crohn's disease and is an additional factor to be considered when contemplating surgical resections.

Mucosal expression by B7-positive cells of the 60-kilodalton heat-shock protein in inflammatory bowel disease

BACKGROUND/AIMS

Heat-shock protein (Hsp) 60 is an immunodominant antigen of mycobacteria and other microorganisms that is highly homologous to its human counterpart. Hsp60 may provide a link between immunity to invading microorganisms and autoimmune diseases.

METHODS

Expression of Hsp60 was studied by immunohistochemistry in gut resection specimens of patients with Crohn's disease (n = 14), ulcerative colitis (n = 7), acute self-limited colitis (infective type) (n = 5), and controls (n = 9) using the monoclonal antibodies LK1 and LK2.

RESULTS

A strong staining positivity for Hsp60 was observed in numerous mononuclear cells of the mucosa and submucosa in ileum and colon tissue biopsy specimens of patients with Crohn's disease from inflamed and healthy areas. In ulcerative colitis, Hsp60 expression was limited to the mucosa. In biopsy specimens from patients with acute self-limited colitis and controls, Hsp60-positive cells were absent or only present in low numbers and staining intensity was weak. Differentiation between mammalian and bacterial Hsp60 showed expression of the human homologue. Double staining for B7 and Hsp60 showed that Hsp60 was expressed by B7-positive cells.

CONCLUSIONS

Human Hsp60 is strongly expressed by B7-positive antigen-presenting mononuclear cells in the mucosa of patients with inflammatory bowel disease and might play a role in the initiation or maintenance of the inflammatory process.

Postoperative recurrence of Crohn's disease: pathogenesis and prevention

Postoperative recurrence of Crohn's disease is very common and almost invariably appears at the ileal side of the ileocolonic anastomosis. Luminal factors are believed to play an essential role in triggering the earliest inflammatory events. The characteristics of recurrent disease are often very similar to those of the original presentation before surgery. Several 5-ASA preparations as well as antibiotics such as metronidazole have been shown to affect incidence and/or severity of recurrence of Crohn's disease.

Pericholangitis and sclerosing cholangitis are risk factors for dysplasia and cancer in ulcerative colitis

Known risk factors for the development of dysplasia and cancer in ulcerative colitis (UC) patients are: 1) increased extent and duration of disease and 2) increased age at symptom onset. This case-control study was performed to determine whether cholestatic liver disease is associated with neoplastic transformation. Twenty-nine UC patients with extensive disease of long duration and dysplasia or cancer detected in a cancer surveillance program were pair-matched to UC patients without neoplasia from a large inflammatory bowel disease registry matched on extent of disease, sex, and calendar year of disease onset. Of the 29 cases, 10 were found to have cholestatic liver disease; nine with pericholangitis and one with primary sclerosing cholangitis (PSC). Two controls had PSC. Cholestatic liver disease was a significant risk factor for the development of dysplasia or cancer (odds ratio 9.00, 95% confidence interval 1.14-71.0). Increased age at symptom onset also was found to be a significant risk factor for neoplasia (odds ratio 1.04 for each additional year, 95% confidence interval 1.00-1.08) that did not exhibit confounding or interacting effects with cholestatic liver disease. The degree of neoplasia (low-grade dysplasia, high-grade dysplasia, or cancer) did not appeared to affect the results. Therefore, cholestatic liver disease, either pericholangitis or PSC, was significantly associated with the development of dysplasia or cancer in UC patients and should be considered an important risk factor for neoplastic transformation.