Consecutive fecal calprotectin measurements to predict relapse in patients with ulcerative colitis receiving infliximab maintenance therapy.

BACKGROUND: This study examined whether fecal calprotectin can be used in daily practice as a marker to monitor patients with ulcerative colitis (UC) receiving infliximab maintenance therapy. METHODS: This prospective multicenter study enrolled adult patients with UC in clinical remission under infliximab maintenance therapy. Fecal calprotectin levels were measured every 4 weeks. Sigmoidoscopies were performed at inclusion and at study end. Relapse was defined as a clinical need for change in treatment or an endoscopic Mayo subscore of ≥2 at week 52. Sustained deep remission was defined as a partial Mayo score <3 at all points and an endoscopic Mayo score 0 at week 52. RESULTS: Full analysis was possible for 87 of 113 included patients with UC (77%). Of these patients, 30 (34.4%) were considered to be in sustained deep remission and 13 (14.9%) to have relapsed. Calprotectin levels in patients with sustained deep remission remained very low (median < 40 mg/kg at all time points). Patients who flared had significantly higher calprotectin levels (median > 300 mg/kg) already 3 months before the flare. Further receiver operator curve analysis suggested that a calprotectin level >300 mg/kg had a reasonable sensitivity (58.3%) and specificity (93.3%) to model flare. Two consecutive calprotectin measurements of >300 mg/kg with 1-month interval were identified as the best predictor of flare (61.5% sensitivity and 100% specificity). CONCLUSIONS: Fecal calprotectin can be used in daily practice to monitor patients with UC receiving infliximab maintenance therapy. Two consecutive measurements >300 mg/kg is more specific than a single measurement for predicting relapse.

Impact of medical therapies on inflammatory bowel disease complication rate.

Crohn's disease and ulcerative colitis are progressive diseases associated with a high risk of complications over time including strictures, fistulae, perianal complications, surgery, and colorectal cancer. Changing the natural history and avoiding evolution to a disabling disease should be the main goal of treatment. In recent studies, mucosal healing has been associated with longer-term remission and fewer complications. Conventional therapies with immunosuppressive drugs are able to induce mucosal healing in a minority of cases but their impact on disease progression appears modest. Higher rates of mucosal healing can be achieved with anti-tumor necrosis factor therapies that reduce the risk of relapse, surgery and hospitalization, and are associated with perianal fistulae closure. These drugs might be able to change the natural history of the disease mainly when introduced early in the course of the disease. Treatment strategy in inflammatory bowel diseases should thus be tailored according to the risk that each patient could develop disabling disease.

Hepatitis C of genotype 2: the role of medical invasive exams.

BACKGROUND AND AIM: Hepatitis C virus genotype 2 is the third in order of frequency in Belgium. The aim of this study was to better define the genotype 2 carriers' epidemiology characteristics. METHODS: In a database comprising 1726 viremic hepatitis C virus patient from the south part of Belgium, the files of 98 genotype 2 carriers were reviewed. RESULTS: There was a strong association between genotype 2 and the mode of transmission. The rate of contamination by invasive medical exams was very high (23%), and statistically different from the one of the others genotypes. Eligibility for antiviral therapies and the rate of sustained viral response were high. CONCLUSION: HCV genotype 2 was highly associated with transmission by invasive medical exams.

Current directions of biologic therapies in inflammatory bowel disease.

Crohn's disease (CD) and ulcerative colitis (UC) are chronic inflammatory bowel diseases which can be difficult to control with conventional therapies. A greater understanding of their pathophysiology has led to new therapies that target specific molecules of the inflammatory cascade. Three anti-tumor necrosis factor (TNF) monoclonal antibodies have been developed. Infliximab and adalimumab can induce clinical response and sustained remission in CD. Infliximab is also effective in UC. Certolizumab pegol gives good short-term results but long-term efficacy has yet to be determined in other clinical trials. Therapies that target leucocyte trafficking (anti-integrins) have also been developed and are associated with good clinical response in CD. Natalizumab (anti-α4 integrin antibody) is associated with important side effects and is not used anymore in gastroenterology in Europe but is still used in the USA. Vedolizumab (MLN0002), an anti-α4ß7 integrin antibody, has a good efficacy and safety profile. Monoclonal antibodies targeting other cytokines are also under development. For example, ustekinumab (CNTO 1275) inhibits interleukins 12 and 23. It is associated with a good clinical response in CD.

Do clinical factors help to predict disease course in inflammatory bowel disease?

While therapeutic strategies able to change the natural history of the disease are developing, it is of major importance to have available predictive factors for aggressive disease to try and target these therapeutic strategies. Clinical predictors have probably been the most broadly studied. In both Crohn's disease (CD) and ulcerative colitis (UC), age at diagnosis, disease location and smoking habit are currently the strongest predictors of disease course. A younger age at onset is associated with more aggressive disease both in CD and UC. Disease location in CD is associated with different types of complications: surgery and recurrence in upper gastrointestinal and proximal small bowel disease; and surgery in distal small bowel disease and peri-anal lesions in rectal disease. In UC, extensive colitis is clearly been associated with more severe disease. Finally, active smoking globally increases disease severity in CD but decreases it in UC. Besides these important factors, others may predispose to some specific disease evolution and complications, and are also reviewed in the present paper.

Anti-TNF and Crohn's disease: when should we stop?

When to stop anti-TNF therapy in Crohn's disease (CD)? This is a very important question both for patients and physicians. There is no published evidence to clearly and definitely answer this question. However data on natural history of CD, long term safety of biologics, outcome after immunosuppressors (IS) cessation and some preliminary studies on biologics cessation may help us to discuss this topic. One could argue that there is currently no good reason to stop anti-TNF therapy in a patient who is in stable remission and tolerate this drug very well. The decision to stop an anti-TNF treatment is thus currently based on a compromise between the benefits/risks and cost of such long term treatment. While it appears now clearly that prolonged anti-TNF therapy is associated with favourable outcome with sustained remission, reduced surgeries and hospitalisation as well as absence of significant increase in mortality or cancers, the cost-effectiveness which is probably favourable for short and mid-term treatment (up to one year), may be less optimal for very long term treatment. In this perspective however, prospective studies should be performed to adequately assess long term evolution, disease outcome, safety and global cost of strategies based on treatment reduction with IS maintenance alone or even full treatment cessation.

Genetic variation in the familial Mediterranean fever gene (MEFV) and risk for Crohn's disease and ulcerative colitis.

BACKGROUND AND AIMS: The familial Mediterranean fever (FMF) gene (MEFV) encodes pyrin, a major regulator of the inflammasome platform controlling caspase-1 activation and IL-1beta processing. Pyrin has been shown to interact with the gene product of NLRP3, NALP3/cryopyrin, also an important active member of the inflammasome. The NLRP3 region was recently reported to be associated with Crohn's disease (CD) susceptibility. We therefore sought to evaluate MEFV as an inflammatory bowel disease (IBD) susceptibility gene. METHODOLOGY AND RESULTS: MEFV colonic mucosal gene expression was significantly increased in experimental colitis mice models (TNBS p<0.0003; DSS p<0.006), in biopsies from CD (p<0.02) and severe ulcerative colitis (UC) patients (p<0.008). Comprehensive genetic screening of the MEFV region in the Belgian exploratory sample set (440 CD trios, 137 UC trios, 239 CD cases, 96 UC cases, and 107 healthy controls) identified SNPs located in the MEFV 5' haplotype block that were significantly associated with UC (rs224217; p = 0.003; A allele frequency: 56% cases, 45% controls), while no CD associations were observed. Sequencing and subsequent genotyping of variants located in this associated haplotype block identified three synonymous variants (D102D/rs224225, G138G/rs224224, A165A/rs224223) and one non-synonymous variant (R202Q/rs224222) located in MEFV exon 2 that were significantly associated with UC (rs224222: p = 0.0005; A allele frequency: 32% in cases, 23% in controls). No consistent associations were observed in additional Canadian (256 CD trios, 91 UC trios) and Scottish (495 UC, 370 controls) sample sets. We note that rs224222 showed marginal association (p = 0.012; G allele frequency: 82% in cases, 70% in controls) in the Canadian sample, but with a different risk allele. None of the NLRP3 common variants were associated with UC in the Belgian-Canadian UC samples and no significant interactions were observed between NLRP3 and MEFV that could explain the observed flip-flop of the rs224222 risk allele. CONCLUSION: The differences in association levels observed between the sample sets may be a consequence of distinct founder effects or of the relative small sample size of the cohorts evaluated in this study. However, the results suggest that common variants in the MEFV region do not contribute to CD and UC susceptibility.

Guillain-Barré syndrome following hepatitis E.

Guillain-Barré syndrome (GBS) is often triggered by a preceding bacterial or viral infection. Occasionally, it has been observed in association with acute hepatitis A, B and C, and three cases have been previously described in India in which GBS was associated with acute hepatitis E. A molecular mimicry mechanism is supposed to be involved in the pathogenesis of GBS triggered by infectious agents, although the nature of the shared epitopes has not been characterized in most instances, including that in the case of hepatotropic viruses. We report a case of GBS following acute hepatitis E in a European individual. The presence of antiganglioside GM2 antibodies in this patient suggested molecular mimicry involving ganglioside GM2 in the pathogenesis of GBS associated with hepatitis E.

Common variants in the NLRP3 region contribute to Crohn's disease susceptibility.

We used a candidate gene approach to identify a set of SNPs, located in a predicted regulatory region on chromosome 1q44 downstream of NLRP3 (previously known as CIAS1 and NALP3) that are associated with Crohn's disease. The associations were consistently replicated in four sample sets from individuals of European descent. In the combined analysis of all samples (710 father-mother-child trios, 239 cases and 107 controls), these SNPs were strongly associated with risk of Crohn's disease (P(combined) = 3.49 x 10(-9), odds ratio = 1.78, confidence interval = 1.47-2.16 for rs10733113), reaching a level consistent with the stringent significance thresholds imposed by whole-genome association studies. In addition, we observed significant associations between SNPs in the associated regions and NLRP3 expression and IL-1beta production. Mutations in NLRP3 are known to be responsible for three rare autoinflammatory disorders. These results suggest that the NLRP3 region is also implicated in the susceptibility of more common inflammatory diseases such as Crohn's disease.

Tailoring the treatment to the individual in Crohn's disease.

Crohn's disease is a heterogeneous disease with approximately 30-40% of patients having a simple benign history and the rest having a chronic progressive disease leading to complications, surgeries and potentially socio-professional marginalisation. Recent studies have shown that an early treatment with immunosuppressive treatment and/or anti-tumour necrosis factor agents could change the natural history of the disease and avoid the development of such disabling disease. The therapy should thus be tailored according to the risk of developing such disabling disease. Recent cohort studies have shown that clinical factors such as age at diagnosis, disease extent, disease location and behaviour at diagnosis were predictive for the development of severe or disabling disease and could be used in helping the physician to tailor therapy.

Predictors of severe Crohn's disease.

OBJECTIVE: A model based on clinical characteristics at diagnosis and predicting the early development of disabling Crohn's disease (CD) has recently been proposed in order to target patients for early intervention. The objectives of this study were to confirm the predictive factors established in a previous study and to establish the predictive factors for the development of severe disease characterized by the development of clinically significant non-reversible damage. MATERIAL AND METHODS: Our retrospective study comprised a total of 361 patients with CD from our clinical database with a follow-up of longer than 5 years. Clinical, demographic and biological factors associated with the development of disabling disease (according to predefined criteria) within 5 years after the diagnosis of CD and with the time to development of severe disease (according to predefined criteria) were successively studied by univariate and multivariate analyses. RESULTS: The rate of disabling CD within 5 years after diagnosis was 57.9%. Perianal lesions, the need for steroids to treat the first flare and ileo-colonic location, but not age below 40 years were confirmed as predictive markers. The rate of severe disease was 37.4%. Stricturing behaviour (HR: 2.11 (95% CI: 1.39-3.20)) and loss of weight (> 5 kg) (HR: 1.67 (95% CI: 1.14-2.45)) at diagnosis were independently associated with the time to development of severe disease. The predictive performances of the models generated were low. CONCLUSIONS: Disabling and severe CD developed in roughly one-third and two-thirds of our patients, respectively. Some clinical predictive markers could be found or even confirmed but their performances were low.

Sensitivity of intestinal fibroblasts to TNF-related apoptosis-inducing ligand-mediated apoptosis in Crohn's disease.

OBJECTIVE: Strictures and fistulas are common complications of Crohn's disease (CD). Collagen deposit and fibroblast proliferation can contribute to their development. Tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) binds two pro-apoptotic (TRAIL-R1, TRAIL-R2) and three anti-apoptotic (TRAIL-R3, TRAIL-R4, osteoprotegerin (OPG)) receptors. The aim of this work was to study TRAIL expression and the effects on intestinal fibroblasts (IFs) in CD. MATERIAL AND METHODS: Intestinal samples from 25 CD (with or without fibrostenosing areas) and 38 control patients (with or without inflammation) were used. TRAIL, TRAIL R2 and TRAIL R3 expression in the intestine and in human IFs was studied by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and immunostaining in IF and intestinal samples. TRAIL-induced IF cell death was studied in the presence or absence of OPG and cytokines. Western blots for poly ADP-ribose polymerase (PARP) and caspase-8 were performed to confirm apoptosis in IFs. RESULTS: Transcripts for TRAIL and its receptors were confirmed in the intestine. Immunostaining showed intestinal expression of TRAIL, TRAIL-R2 and TRAIL-R3 in fibroblasts, immune cells and epithelial cells, mainly in fibrostenosing areas. TRAIL-R3 mRNA expression was lower in IFs from fibrostenosing CD. The sensitivity of IFs to TRAIL-mediated apoptosis was higher in the fibrostenosing areas of CD. The effect of TRAIL was decreased by IL-6 and its soluble receptor and almost completely reversed by OPG in the CD patients involved. CONCLUSIONS: TRAIL is expressed in the intestine and influences fibroblast survival. Variations in TRAIL expression and in TRAIL-mediated apoptosis could be involved in the tissue remodelling associated with CD.

Genome-wide association defines more than 30 distinct susceptibility loci for Crohn's disease.

Several risk factors for Crohn's disease have been identified in recent genome-wide association studies. To advance gene discovery further, we combined data from three studies on Crohn's disease (a total of 3,230 cases and 4,829 controls) and carried out replication in 3,664 independent cases with a mixture of population-based and family-based controls. The results strongly confirm 11 previously reported loci and provide genome-wide significant evidence for 21 additional loci, including the regions containing STAT3, JAK2, ICOSLG, CDKAL1 and ITLN1. The expanded molecular understanding of the basis of this disease offers promise for informed therapeutic development.

Proteomics for prediction and characterization of response to infliximab in Crohn's disease: a pilot study.

OBJECTIVES: Infliximab is the first anti-TNFalpha accepted by the Food and Drug Administration for use in inflammatory bowel disease treatment. Few clinical, biological and genetic factors tend to predict response in Crohn's disease (CD) patient subcategories, none widely predicting response to infliximab. DESIGN AND METHODS: Twenty CD patients showing clinical response or non response to infliximab were used for serum proteomic profiling on Surface Enhanced Lazer Desorption Ionisation-Time of Flight-Mass Spectrometry (SELDI-TOF-MS), each before and after treatment. Univariate and multivariate data analysis were performed for prediction and characterization of response to infliximab. RESULTS: We obtained a model of classification predicting response to treatment and selected relevant potential biomarkers, among which platelet aggregation factor 4 (PF4). We quantified PF4, sCD40L and IL-6 by ELISA for correlation studies. CONCLUSIONS: This first proteomic pilot study on response to infliximab in CD suggests association between platelet metabolism and response to infliximab and requires validation studies on a larger cohort of patients.

Clinical and genetic factors associated with sacroiliitis in Crohn's disease.

BACKGROUND AND AIM: Radiographic sacroiliitis (SI), often asymptomatic, is considered the most frequent extra-intestinal manifestation (EIM) of Crohn's disease (CD). Data on the association of SI with other clinical features of CD are limited. Association of SI with CARD15 polymorphisms has recently been suggested. In a multicenter study, we investigated the association of SI in CD patients with clinical phenotypes, other EIM and CARD15 polymorphisms. METHODS: Radiographs of the sacroiliac joints were taken in 251 CD patients from three Belgian university hospitals and scored by two blinded rheumatologists. Clinical features were obtained from medical records. Forty-three percent of patients carried at least one CARD15 polymorphism. RESULTS: Sacroiliitis, defined as the presence of at least grade 2 unilateral changes, was diagnosed in 65 of the 244 scorable radiographs (27%). Only 16 of these patients were previously diagnosed with ankylosing spondylitis (AS). HLA-B27 positivity was observed in 53% of patients with AS and 7% of patients with radiographic SI. In univariate and multivariate analysis, associations between the presence of SI and peripheral arthritis (P = 0.005) and between AS and uveitis (P = 0.005) were found. No associations with other recorded clinical features or with CARD15 polymorphisms were observed. CONCLUSION: We confirm the high prevalence of radiographic sacroiliitis in a multicenter CD cohort. Uveitis is only associated with AS whereas all patients with SI are more prone to develop peripheral arthritis during their disease course, suggesting similar pathogenetic mechanisms in the development of these EIM. The previously reported association between SI and CARD15 polymorphisms was not confirmed.

An insertion-deletion polymorphism in the interferon regulatory Factor 5 (IRF5) gene confers risk of inflammatory bowel diseases.

The interferon regulatory factor 5 (IRF5) gene encodes a transcription factor that plays an important role in the innate as well as in the cell-mediated immune responses. The IRF5 gene has been shown to be associated with systemic lupus erythematosus and rheumatoid arthritis. We studied whether the IRF5 gene is also associated with inflammatory bowel diseases (IBD), Crohn disease (CD) and ulcerative colitis (UC). Twelve polymorphisms in the IRF5 gene were genotyped in a cohort of 1007 IBD patients (748 CD and 254 UC) and 241 controls from Wallonia, Belgium. The same polymorphisms were genotyped in a confirmatory cohort of 311 controls and 687 IBD patients (488 CD and 192 UC) from Leuven, Belgium. A strong signal of association [P = 1.9 x 10(-5), odds ratio (OR) 1.81 (1.37-2.39)] with IBD was observed for a 5 bp indel (CGGGG) polymorphism in the promoter region of the IRF5 gene. The association was detectable also in CD patients (P = 6.8 x 10(-4)) and was particularly strong among the UC patients [P = 5.3 x 10(-8), OR = 2.42 (1.76-3.34)]. The association of the CGGGG indel was confirmed in the second cohort [P = 3.2 x 10(-5), OR = 1.59 (1.28-1.98)]. The insertion of one CGGGG unit is predicted to create an additional binding site for the transcription factor SP1. Using an electrophoretic mobility shift assay, we show allele-specific differences in protein binding to this repetitive DNA-stretch, which suggest a potential function role for the CGGGG indel.

Noninvasive assessment of Crohn's disease intestinal lesions with (18)F-FDG PET/CT.

UNLABELLED: Pilot studies have shown good sensitivity and specificity for (18)F-FDG PET in detecting gastrointestinal lesions of Crohn's disease. The combination of (18)F-FDG PET with CT may further improve the localization and characterization of lesions with increased (18)F-FDG uptake. Our aim was to assess the use of (18)F-FDG PET/CT in evaluating the activity and location of Crohn's disease along the gastrointestinal tract. METHODS: After giving informed consent, 22 patients with Crohn's disease were prospectively studied. They underwent (18)F-FDG PET/CT, followed by ileocolonoscopy within 1 wk (mean, 2 d). The Crohn's disease activity index (CDAI) was calculated, and serum C-reactive protein (CRP) and fecal calprotectin were measured before endoscopy. The Crohn's disease endoscopy index of severity (CDEIS) was calculated during endoscopy. The global CDEIS score and endoscopic subscores for various ileocolonic segments were used for analysis. RESULTS: Globally, 95 intestinal and colonic segments in 22 patients were analyzed. (18)F-FDG PET/CT detected 35 of 48 endoscopically affected segments (sensitivity for the detection of endoscopic lesions, 72.9%). The sensitivity of (18)F-FDG PET/CT for the detection of severe endoscopic lesions (deep ulcers and strictures) was 100% (14/14). The global PET/CT score significantly correlated with CDEIS (r = 0.51; 95% confidence interval [CI], 0.09-0.77; P = 0.017), CDAI (r = 0.58; 95% CI, 0.17-0.80; P = 0.005), and CRP (r = 0.56; 95% CI, 0.19-0.81; P = 0.007). CONCLUSION: (18)F-FDG PET/CT was globally well correlated to the clinical, endoscopic, and biologic activity of Crohn's disease. Above all, this technique had a good sensitivity for the detection of intestinal and colonic segments with moderate to severe mucosal lesions. The potential impact of this promising tool on the global management of patients with Crohn's disease should be further evaluated in prospective studies.