Faecal microbiota signatures of IBD and their relation to diagnosis, disease phenotype, inflammation, treatment escalation and anti-TNF response in a European Multicentre Study (IBD-Character).

METHOD: We examined faecal samples, using the GA-map™ Dysbiosis Test, to associate gut microbiota composition with Crohn's disease (CD) and ulcerative colitis (UC) and to identify markers for future biomarker identification. We conducted a prospective case-control study (EU-ref. no. 305676) in an inception cohort of 324 individuals (64 CD, 84 UC, 116 symptomatic non-IBD controls and 44 healthy controls) across five European centres and examined 54 predetermined bacterial markers. We categorized patients according to the Montreal Classification and calculated the dysbiosis index (DI). Non-parametric tests were used to compare groups and the Bonferroni correction to adjust for multiple comparisons. RESULTS: The fluorescent signals (FSSs) for Firmicutes and Eubacterium hallii were lower in inflammatory bowel disease (IBD) vs. symptomatic controls (p<.05). FSS for Firmicutes, Lachnospiraceae, Eubacterium hallii and Ruminococcus albus/bromii were lower, whereas the signal for Bacteroides Fragilis was higher in UC vs. symptomatic controls (p<.05). FSS was higher for Bifidobacterium spp., Eubacterium hallii, Actinobacteria and Firmicutes among patients with ulcerative proctitis, compared to extensive colitis (p<.05). In CD, we observed no association with disease location. The DI correlated with faecal-calprotectin in both CD and in UC (p<.001). In terms of treatment escalation and anti-TNF response, differences were observed for some bacterial markers, but none of these associations were statistically significant. CONCLUSION: Our data reveal that the GA-map™ Dysbiosis Test holds the potential to characterize the faecal microbiota composition and to assess the degree of dysbiosis in new-onset IBD. On the other hand, our results cannot demonstrate any proven diagnostic or predictive value of this method to support clinical decision making.

MicroRNAs: new players in IBD.

MicroRNAs (miRNAs) are small non-coding RNAs, 18-23 nucleotides long, which act as post-transcriptional regulators of gene expression. miRNAs are strongly implicated in the pathogenesis of many common diseases, including IBDs. This review aims to outline the history, biogenesis and regulation of miRNAs. The role of miRNAs in the development and regulation of the innate and adaptive immune system is discussed, with a particular focus on mechanisms pertinent to IBD and the potential translational applications.

Two stage genome-wide search in inflammatory bowel disease provides evidence for susceptibility loci on chromosomes 3, 7 and 12.

Crohn's disease (CD) and ulcerative colitis (UC), the chronic inflammatory bowel diseases (CIBD), are common causes of gastro-intestinal disease in the Western world, with a combined prevalence of 100-200/100,000 (ref. 1). Epidemiological studies, particularly concordance rates in twin pairs and siblings, strongly implicate genetic susceptibility in the pathogenesis of CIBD. In fact, the relative contribution of genetic factors to the pathogenesis of CD may be greater than in schizophrenia, asthma or hypertension, and at least equivalent to that in insulin-dependent diabetes. Systematic screening of the entire human genome now provides a strategy for the identification of susceptibility genes in complex polygenic disorders. We undertook a two-stage genome search for susceptibility genes in inflammatory bowel disease involving 186 affected sibling pairs from 160 nuclear families. We provide strong evidence for the presence of susceptibility loci for both CD and UC on chromosome 3, 7 and 12. We obtained the highest lod score (5.47; P = 2.66 x 10(-7) with the marker D12S83 and lod scores of 3.08 and 2.69 for D7S669 and D3S1573, respectively. Our data suggest that CD and UC are closely related, but distinct, polygenic disorders that share some, but not all, susceptibility genes.

New IBD genetics: common pathways with other diseases.

Complex disease genetics has been revolutionised in recent years by the advent of genome-wide association (GWA) studies. The chronic inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis have seen notable successes culminating in the discovery of 99 published susceptibility loci/genes (71 Crohn's disease; 47 ulcerative colitis) to date. Approximately one-third of loci described confer susceptibility to both Crohn's disease and ulcerative colitis. Amongst these are multiple genes involved in IL23/Th17 signalling (IL23R, IL12B, JAK2, TYK2 and STAT3), IL10, IL1R2, REL, CARD9, NKX2.3, ICOSLG, PRDM1, SMAD3 and ORMDL3. The evolving genetic architecture of IBD has furthered our understanding of disease pathogenesis. For Crohn's disease, defective processing of intracellular bacteria has become a central theme, following gene discoveries in autophagy and innate immunity (associations with NOD2, IRGM, ATG16L1 are specific to Crohn's disease). Genetic evidence has also demonstrated the importance of barrier function to the development of ulcerative colitis (HNF4A, LAMB1, CDH1 and GNA12). However, when the data are analysed in more detail, deeper themes emerge including the shared susceptibility seen with other diseases. Many immune-mediated diseases overlap in this respect, paralleling the reported epidemiological evidence. However, in several cases the reported shared susceptibility appears at odds with the clinical picture. Examples include both type 1 and type 2 diabetes mellitus. In this review we will detail the presently available data on the genetic overlap between IBD and other diseases. The discussion will be informed by the epidemiological data in the published literature and the implications for pathogenesis and therapy will be outlined. This arena will move forwards very quickly in the next few years. Ultimately, we anticipate that these genetic insights will transform the landscape of common complex diseases such as IBD.

Sarcoidosis complicating treatment with natalizumab for Crohn's disease.

Natalizumab is a humanised monoclonal antibody targeting the lymphocyte adhesion molecule a4 integrin, with proven efficacy in multiple sclerosis (MS) and Crohn's disease (CD). The development of sarcoidosis with extrapulmonary involvement is reported in two patients with refractory CD who had received maintenance therapy with natalizumab. This complication has not been previously reported. It is hypothesised that the effect of natalizumab in altering lymphocyte mucosal trafficking may underlie the development of sarcoidosis in these patients.

Serum proteomic profiling at diagnosis predicts clinical course, and need for intensification of treatment in inflammatory bowel disease.

BACKGROUND: Success in personalized medicine in complex disease is critically dependent on biomarker discovery. We profiled serum proteins using a novel proximity extension assay [PEA] to identify diagnostic and prognostic biomarkers in inflammatory bowel disease [IBD]. METHODS: We conducted a prospective case-control study in an inception cohort of 552 patients [328 IBD, 224 non-IBD], profiling proteins recruited across six centres. Treatment escalation was characterized by the need for biological agents or surgery after initial disease remission. Nested leave-one-out cross-validation was used to examine the performance of diagnostic and prognostic proteins. RESULTS: A total of 66 serum proteins differentiated IBD from symptomatic non-IBD controls, including matrix metallopeptidase-12 [MMP-12; Holm-adjusted p = 4.1 × 10-23] and oncostatin-M [OSM; p = 3.7 × 10-16]. Nine of these proteins are associated with cis-germline variation [59 independent single nucleotide polymorphisms]. Fifteen proteins, all members of tumour necrosis factor-independent pathways including interleukin-1 (IL-1) and OSM, predicted escalation, over a median follow-up of 518 [interquartile range 224-756] days. Nested cross-validation of the entire data set allowed characterization of five-protein models [96% comprising five core proteins ITGAV, EpCAM, IL18, SLAMF7 and IL8], which define a high-risk subgroup in IBD [hazard ratio 3.90, confidence interval: 2.43-6.26], or allowed distinct two- and three-protein models for ulcerative colitis and Crohn's disease respectively. CONCLUSION: We have characterized a simple oligo-protein panel that has the potential to identify IBD from symptomatic controls and to predict future disease course. Further prospective work is required to validate our findings.

Whole Blood Profiling of T-cell-Derived microRNA Allows the Development of Prognostic models in Inflammatory Bowel Disease.

BACKGROUND: MicroRNAs [miRNAs] are cell-specific small non-coding RNAs that can regulate gene expression and have been implicated in inflammatory bowel disease [IBD] pathogenesis. Here we define the cell-specific miRNA profiles and investigate its biomarker potential in IBD. METHODS: In a two-stage prospective multi-centre case control study, next generation sequencing was performed on a discovery cohort of immunomagnetically separated leukocytes from 32 patients (nine Crohn's disease [CD], 14 ulcerative colitis [UC], eight healthy controls) and differentially expressed signals were validated in whole blood in 294 patients [97 UC, 98 CD, 98 non-IBD, 1 IBDU] using quantitative PCR. Correlations were analysed with phenotype, including need for early treatment escalation as a marker of progressive disease using Cox proportional hazards. RESULTS: In stage 1, each leukocyte subset [CD4+ and CD8+ T-cells and CD14+ monocytes] was analysed in IBD and controls. Three specific miRNAs differentiated IBD from controls in CD4+ T-cells, including miR-1307-3p [p = 0.01], miR-3615 [p = 0.02] and miR-4792 [p = 0.01]. In the extension cohort, in stage 2, miR-1307-3p was able to predict disease progression in IBD (hazard ratio [HR] 1.98, interquartile range [IQR]: 1.20-3.27; logrank p = 1.80 × 10-3), in particular CD [HR 2.81; IQR: 1.11-3.53, p = 6.50 × 10-4]. Using blood-based multimarker miRNA models, the estimated chance of escalation in CD was 83% if two or more criteria were met and 90% for UC if three or more criteria are met. INTERPRETATION: We have identified and validated unique CD4+ T-cell miRNAs that are differentially regulated in IBD. These miRNAs may be able to predict treatment escalation and have the potential for clinical translation; further prospective evaluation is now indicated.

Fecal calprotectin predicts the clinical course of acute severe ulcerative colitis.

OBJECTIVES: Calprotectin is a granulocyte neutrophil-predominant cytosolic protein. Fecal concentrations are elevated in intestinal inflammation and may predict relapse in quiescent inflammatory bowel disease. We aim to investigate fecal calprotectin (FC) as a biomarker in predicting the clinical course of acute severe ulcerative colitis (ASUC). METHODS: In 90 patients with ASUC requiring intensive in-patient medical therapy (January 2005-September 2007), we investigated the discriminant ability of FC to predict colectomy and corticosteroid and infliximab nonresponse. All patients received parenteral corticosteroids as first-line treatment; 21 (23.3%) were also treated with infliximab (5 mg/kg), after failure of corticosteroid therapy. RESULTS: Of 90 patients, 31 (34.4%) required colectomy, including 11 (52.4%) of those treated with infliximab. Overall FC was high (1,020.0 microg/g interquartile range: 601.5-1,617.5). FC was significantly higher in patients requiring colectomy (1,200.0 vs. 887.0; P=0.04), with a trend toward significance when comparing corticosteroid nonresponders and responders (1,100.0 vs. 863.5; P=0.08), as well as between infliximab nonresponders and responders (1,795.0 vs. 920.5; P=0.06). Receiver-operator characteristic curve analysis yielded an area under the curve of 0.65 to predict colectomy (P=0.04), with a maximum likelihood ratio of 9.23, specificity 97.4%, and sensitivity 24.0% at a cutoff point of 1,922.5 microg/g. Kaplan-Meier analyses showed that using 1,922.5 microg/g over a median follow-up of 1.10 years, 87% of patients will need subsequent colectomy. CONCLUSIONS: This is the first data set to demonstrate that FC levels are dramatically elevated in severe UC. These data raise the possibility that this biomarker can predict response to first or second-line medical therapy in this setting.

Anti-Saccharomyces cerevisiae antibodies status is associated with oral involvement and disease severity in Crohn disease.

OBJECTIVES: To determine anti-Saccharomyces cerevisiae antibodies (ASCA) status and its relation to disease phenotype in patients with inflammatory bowel disease (IBD). PATIENTS AND METHODS: A total of 301 Scottish patients with early-onset IBD-197 Crohn disease (CD), 76 ulcerative colitis (UC), 28 indeterminate colitis (IC)-and 78 healthy control individuals were studied. ASCA status (IgA, IgG) was determined by enzyme-linked immunosorbent assay. ASCA status was then analyzed in relation to CD phenotype. RESULTS: Patients with CD had a higher prevalence of ASCA than patients with UC and healthy controls: 82/197 versus 12/76, odds ratio (OR) 3.80 (1.93-7.50) and 82/197 versus 6/78, OR 8.56 (3.55-20.62), respectively. Univariate analysis showed that positive ASCA status was associated with oral CD (17/25 vs 59/153, OR 3.39 [1.38-8.34]), perianal CD (39/77 vs 38/108, OR 1.89 [1.04-3.44]) and the presence of granulomata (63/132 vs 15/52, OR 2.25 [1.13-4.48]) and also with markers of disease severity: raised C-reactive protein (44/90 vs 12/49, OR 2.95[1.36-6.37]), hypoalbuminemia (44/85 vs 20/74, OR 2.28[1.19-4.37]), and surgery (27/49 vs 54/147, OR 2.11 [1.10-4.06]). From multivariate analysis, the presence of oral disease (adjusted P = 0.001, OR 22.22 [3.41-142.86]) and hypoalbuminemia (adjusted P = 0.01, OR 4.78 [1.40-16.39]) was found to be independently associated with ASCA status. No association was demonstrated between ASCA and IBD candidate genes. CONCLUSIONS: Patients with CD had a higher prevalence of ASCA than did other patients with IBD. ASCA status described patients with CD who had a specific phenotype, showing an association with markers of disease severity and oral CD involvement.

Gender-stratified analysis of DLG5 R30Q in 4707 patients with Crohn disease and 4973 controls from 12 Caucasian cohorts.

BACKGROUND: DLG5 p.R30Q has been reported to be associated with Crohn disease (CD), but this association has not been replicated in most studies. A recent analysis of gender-stratified data from two case-control studies and two population cohorts found an association of DLG5 30Q with increased risk of CD in men but not in women and found differences between 30Q population frequencies for males and females. Male-female differences in population allele frequencies and male-specific risk could explain the difficulty in replicating the association with CD. METHODS: DLG5 R30Q genotype data were collected for patients with CD and controls from 11 studies that did not include gender-stratified allele counts in their published reports and tested for male-female frequency differences in controls and for case-control frequency differences in men and in women. RESULTS: The data showed no male-female allele frequency differences in controls. An exact conditional test gave marginal evidence that 30Q is associated with decreased risk of CD in women (p = 0.049, OR = 0.87, 95% CI 0.77 to 1.00). There was also a trend towards reduced 30Q frequencies in male patients with CD compared with male controls, but this was not significant at the 0.05 level (p = 0.058, OR = 0.87, 95% CI 0.74 to 1.01). When data from this study were combined with previously published, gender-stratified data, the 30Q allele was found to be associated with decreased risk of CD in women (p = 0.010, OR = 0.86, 95% CI 0.76 to 0.97), but not in men. CONCLUSION: DLG5 30Q is associated with a small reduction in risk of CD in women.

Regional variation in gene expression in the healthy colon is dysregulated in ulcerative colitis.

OBJECTIVE: To investigate differential intestinal gene expression in patients with ulcerative colitis and in controls. DESIGN: Genome-wide expression study (41,058 expression sequence tags, 215 biopsies). SETTING: Western General Hospital, Edinburgh, UK, and Genentech, San Francisco, USA. PATIENTS: 67 patients with ulcerative colitis and 31 control subjects (23 normal subjects and 8 patients with inflamed non-inflammatory bowel disease biopsies). INTERVENTIONS: Paired endoscopic biopsies were taken from 5 specific anatomical locations for RNA extraction and histology. The Agilent microarray platform was used and confirmation of results was undertaken by real time polymerase chain reaction and immunohistochemistry. RESULTS: In healthy control biopsies, cluster analysis showed differences in gene expression between the right and left colon. (chi(2) = 25.1, p<0.0001). Developmental genes, homeobox protein A13 (HOXA13), (p = 2.3x10(-16)), HOXB13 (p<1x10(-45)), glioma-associated oncogene 1 (GLI1) (p = 4.0x10(-24)), and GLI3 (p = 2.1x10(-28)) primarily drove this separation. When all ulcerative colitis biopsies and control biopsies were compared, 143 sequences had a fold change of >1.5 in the ulcerative colitis biopsies (0.01>p>10(-45)) and 54 sequences had a fold change of <-1.5 (0.01>p>10(-20)). Differentially upregulated genes in ulcerative colitis included serum amyloid A1 (SAA1) (p<10(-45)) the alpha defensins 5 and 6 (DEFA5 and 6) (p = 0.00003 and p = 6.95x10(-7), respectively), matrix metalloproteinase 3 (MMP3) (p = 5.6x10(-10)) and MMP7 (p = 2.3x10(-7)). Increased DEFA5 and 6 expression was further characterised to Paneth cell metaplasia by immunohistochemistry and in situ hybridisation. Sub-analysis of the inflammatory bowel disease 2 (IBD2) and IBD5 loci, and the ATP-binding cassette (ABC) transporter genes revealed a number of differentially regulated genes in the ulcerative colitis biopsies. CONCLUSIONS: Key findings are the expression gradient in the healthy adult colon and the involvement of novel gene families, as well as established candidate genes in the pathogenesis of ulcerative colitis.

Detailed assessment of NOD2/CARD15 exonic variation in inflammatory bowel disease in Scotland: implications for disease pathogenesis.

The high incidence of Scottish Crohn's disease (CD) is not explained by the common three NOD2/CARD15 variants. We aimed to identify population-specific NOD2/CARD15 coding variants. A total of 1478 (320 inflammatory bowel disease patients <16 years, 343 adult CD patients, 542 parents and 273 controls). All NOD2/CARD15 exons were sequenced in 24 CD patients. Sequencing identified 18 single-nucleotide polymorphisms (SNPs) including 4 non-synonymous coding SNPs altering the structure of the Leucine-rich region--two were well established (1007-/C and 908G/R). Two other variants, valine955isoleucine (955V/I) and methionine863valine (863M/V), were genotyped in all subjects. 863M/V carriage was not significantly higher in CD patients vs controls (1.35 vs 0.37%, P=0.27). 955V/I carriage was no higher in CD or ulcerative colitis patients (12.8 and 15.8%, respectively) compared to controls (16.2%). Transmission disequilibrium test analysis was negative. 955V/I carriage was higher in indeterminate colitis patients (n=29) compared to controls (41.4 vs 16.2%, P=0.001, OR=3.6 (1.6-8.2)). Population-specific NOD2/CARD15 exonic variants do not account for the high-CD prevalence in Scotland.

Autophagy gene ATG16L1 influences susceptibility and disease location but not childhood-onset in Crohn's disease in Northern Europe.

BACKGROUND: The rs2241880A/G variant of the ATG16L1 gene has been associated with susceptibility to ileal Crohn's disease (CD) in adults. Our aim was to assess whether germline variation of ATG16L1 acts as an independent determinant of susceptibility to childhood-onset CD in the high-incidence Scottish population. METHODS: In all, 2195 subjects (361 children (inflammatory bowel disease [IBD] diagnosis <17 years), their parents (n = 634), 855 adult IBD patients, and 345 controls were genotyped. Case-control analysis was powered to detect effect sizes with an odds ratio (OR) >1.39 in pediatric CD. Case-control analysis, transmission disequilibrium testing (TDT), analysis of variance (ANOVA) of growth parameter z-scores, Kruskal-Wallis test (age at diagnosis), and multifactorial genotype-phenotype analysis (Montreal classification) were performed. 7.8% of pediatric CD patients and 37.2% of adult CD patients had pure ileal disease. RESULTS: We confirmed the association of the rs2241880G-allele with adult-onset CD (60.7% versus controls 53.9%, P = 0.01, OR 1.32, 95% confidence interval [CI] 1.07-1.63) in contrast to childhood-onset CD (54.1% versus controls, P = 0.95, OR 1.01, 95% CI 0.80-1.26). TDT analysis was negative. Genotype-phenotype analysis demonstrated an association of pure ileal disease with the rs2241880G-allele (P = 0.02, OR 1.34, 95% CI 1.03-1.74). Using binary logistic regression analysis we confirmed the effect of rs2241880 genotype (GG) on ileal disease versus colonic disease (P = 0.03, OR 2.43, 95% CI 1.05-5.65). ATG16L1 genotype did not influence age at CD diagnosis. ANOVA of z-scores of height, weight, and body mass index (BMI) at CD diagnosis in children showed no association with genotype. CONCLUSIONS: The ATG16L1 variant is associated with susceptibility to adult CD in Scotland, but not early-onset disease. These contrasting effects are primarily driven by differences in disease location between early-onset and adult-onset disease.

MDR1 deficiency impairs mitochondrial homeostasis and promotes intestinal inflammation.

The multidrug resistance-1 (MDR1) gene encodes an ATP-dependent efflux transporter that is highly expressed in the colon. In mice, loss of MDR1 function results in colitis with similarities to human inflammatory bowel diseases (IBD). Here, we show that MDR1 has an unexpected protective role for the mitochondria where MDR1 deficiency results in mitochondrial dysfunction with increased mitochondrial reactive oxygen species (mROS) driving the development of colitis. Exogenous induction of mROS accelerates, while inhibition attenuates colitis in vivo; these effects are amplified in MDR1 deficiency. In human IBD, MDR1 is negatively correlated to SOD2 gene expression required for mROS detoxification. To provide direct evidential support, we deleted intestinal SOD2 gene in mice and showed an increased susceptibility to colitis. We exploited the genome-wide association data sets and found many (∼5%) of IBD susceptibility genes with direct roles in regulating mitochondria homeostasis. As MDR1 primarily protects against xenotoxins via its efflux function, our findings implicate a distinct mitochondrial toxin+genetic susceptibility interaction leading to mitochondrial dysfunction, a novel pathogenic mechanism that could offer many new therapeutic opportunities for IBD.

The contribution of the DLG5 113A variant in early-onset inflammatory bowel disease.

OBJECTIVE: To assess the contribution of the 113 G-->A missense mutation within the discs, large homolog 5 (DLG5) gene in childhood-onset inflammatory bowel disease (IBD) in Scotland. STUDY DESIGN: Two-hundred and ninety-six children with IBD were studied. Parental DNA was also collected for transmission disequilibrium testing (TDT) analysis. Genotyping was performed by TaqMan. Genotype-phenotype analysis was also undertaken. Socioeconomic status was assigned using a deprivation category (DepCat) score 1 through 7 (1 = most affluent). RESULTS: TDT analysis demonstrated a significant association with IBD (P = .045). On unifactorial analysis, 113A carriage was associated with: (1) higher social class (DepCat 1 compared with 2-7, and 1-2 compared with 3-7) (66.7% vs 22.6%, P = .0005, OR 6.84 [1.99-23.55] and 37.2% vs 22.2%, P = .03, OR 2.08 [1.04-4.17], respectively); (2) higher height centile (>75th centile vs <75th centile) (42.9% vs 23.1%, P = .01, OR 2.50 [1.18-5.28]); and (3) male sex in Crohn's disease (CD) (29.3% vs 16.9%, P = .04, OR 2.04 [1.01-4.11]). Multifactorial analysis demonstrated that higher social class (DepCat 1) was independently associated with carriage of variants of 113A (P = .001, OR = 6.92 [2.24-21.33]). CONCLUSIONS: DLG5 113A is associated with increased susceptibility to IBD in Scottish children. The effect may be most marked for those children living in relative affluence.

Contribution of the NOD1/CARD4 insertion/deletion polymorphism +32656 to inflammatory bowel disease in Northern Europe.

BACKGROUND: NOD1/CARD4 and NOD2/CARD15 are both intracellular pattern-recognition receptors. The NOD1/CARD4 gene lies within a previously described inflammatory bowel disease (IBD) locus (7p14). An association has been suggested between the NOD1/CARD4+32656 deletion*1 variant of a complex deletion*1/insertion*2 polymorphism and IBD in 1 recent study in Europe. Our aim was to assess the influence of NOD1/CARD4+32656 on disease susceptibility and phenotype in the Scottish and Swedish IBD populations. METHODS: A total of 3,962 individuals (1,791 IBD patients, 522 parents, 1,649 healthy controls) from 2 independent populations (Scotland and Sweden) were genotyped for NOD1/CARD4+32656 A/C by TaqMan and direct sequencing. Case-control, Transmission Disequilibrium Testing (TDT) and detailed genotype-phenotype (Montreal) analyses were performed. The case-control analysis had 80% power to detect an effect size of odds ratio (OR) 1.21 for IBD. RESULTS: In case-control analyses in Scottish and Swedish patients, none of the genotypes studied in IBD, Crohn's disease (CD) or ulcerative colitis (UC), differed significantly from controls (deletion*1 allelic frequency 73.9%, 73.6%, 73.9%, and 73.6%, respectively: all P > 0.8). No epistatic interaction with NOD2/CARD15 was seen for CD susceptibility. TDT analysis in our Scottish early onset cohort was negative. CONCLUSIONS: This variant allele of NOD1/CARD4+32656 is not associated with a strong effect on susceptibility to IBD in children and adults in Northern Europe. A gene-wide haplotype-based approach may be preferable to analysis of individual variants to assess the contribution of the NOD1/CARD4 gene to IBD.

A retrospective analysis of the efficacy and safety of infliximab as rescue therapy in acute severe ulcerative colitis.

BACKGROUND: Forty per cent of patients with acute severe ulcerative colitis will not respond to intravenous corticosteroids and require second-line medical therapy or colectomy. A recent controlled trial has suggested that infliximab may be effective as rescue therapy. AIM: To assess the value of infliximab as rescue therapy for acute severe colitis in a retrospective cohort of ulcerative colitis patients in Scotland. METHODS: All patients satisfied Truelove and Witts criteria on admission, failed to respond to intravenous corticosteroids and received infliximab (5 mg/kg) as rescue therapy. Response was defined as need for colectomy at hospital discharge and by 90 days. RESULTS: A total of 39 patients (median age 31.7 years) were treated. 26/39 (66%) responded, avoiding colectomy during the acute admission, and were followed up for a median of 203 days (Interquartile range = 135.5-328.5). Hypoalbuminaemia was a consistent predictor of non-response on univariate and multivariate analysis. At day 3 of intravenous steroids, 9/18 (50.0%) with serum albumin <34 g/L had urgent colectomy vs. 1/13 (7.7%) >or=34 g/L (P = 0.02, OR = 12.0, C.I. 1.28-112.7). Two serious adverse events occurred - one death due to Pseudomonas pneumonia, and one post-operative fungal septicaemia. CONCLUSIONS: Infliximab represents a moderately effective rescue therapy for patients with acute severe ulcerative colitis. Serious adverse events, including death, do occur and should be discussed with patients prior to therapy.

The efficacy of corticosteroid therapy in inflammatory bowel disease: analysis of a 5-year UK inception cohort.

BACKGROUND: Corticosteroids remain the mainstay of first-line therapy in active inflammatory bowel disease. AIMS: To determine the clinical outcome after the first corticosteroid-therapy and to identify factors which predict response/failure. METHODS: 216 (136 ulcerative colitis and 80 Crohn's disease) patients were identified in this 5-year inception cohort. The outcomes of early (30 days) and late (1 year) responses were used. Multivariate analyses were performed to identify factors associated with outcome. RESULTS: 86 (63%) and 60 (75%) ulcerative colitis and Crohn's disease required corticosteroid therapy, respectively. In ulcerative colitis, at 30 days, 69 (51%), 42 (31%) and 25 (18%) patients demonstrated complete response, partial response and no response, respectively. For Crohn's disease, these outcomes were observed in 32 (40%), 28 (35%) and 20 (25%). After 1 year, 75 (55%), 23 (17%) and 29 (21%) patients with ulcerative colitis demonstrated prolonged response, corticosteroid-dependence or required surgery, respectively. For Crohn's disease, these outcomes were observed in 30 (38%), 19 (24%) and 27 (35%) patients. Extensive ulcerative colitis was a predictor of surgery (P = 0.001, OR: 15.2). In Crohn's disease, inflammatory disease behaviour was negatively associated with surgery (P = 0.02, OR: 0.13). CONCLUSION: Although corticosteroids are effective, dependence/resistance remains common. Patients with extensive ulcerative colitis and fistulizing/stricturing Crohn's are most at risk of failing corticosteroid therapy.

Gut mucosal DAMPs in IBD: from mechanisms to therapeutic implications.

Endogenous damage-associated molecular patterns (DAMPs) are released during tissue damage and have increasingly recognized roles in the etiology of many human diseases. The inflammatory bowel diseases (IBD), ulcerative colitis (UC) and Crohn's disease (CD), are immune-mediated conditions where high levels of DAMPs are observed. DAMPs such as calprotectin (S100A8/9) have an established clinical role as a biomarker in IBD. In this review, we use IBD as an archetypal common chronic inflammatory disease to focus on the conceptual and evidential importance of DAMPs in pathogenesis and why DAMPs represent an entirely new class of targets for clinical translation.