Both preoperative perinuclear antineutrophil cytoplasmic antibody and anti-CBir1 expression in ulcerative colitis patients influence pouchitis development after ileal pouch-anal anastomosis

Serologic markers associated with development of Crohn's disease after ileal pouch anal anastomosis for ulcerative colitis

BACKGROUND AND AIMS

One of the causes of pouch failure after ileal pouch anal anastomosis (IPAA) for ulcerative colitis (UC) is the development of de novo Crohn's disease (CD). Our aim was to clearly define factors associated with post-IPAA CD.

METHODS

We conducted a cross-sectional study to compare demographic, clinical, and serological characteristics of patients with and without post-IPAA CD. All subjects underwent testing for anti-neutrophil cytoplasm antibodies, anti-Saccaromyces cerevisiae antibodies, anti-outer membrane porin C antibodies, and anti-CBir1 flagellin (anti-CBir1). A multivariable model assessed factors associated with post-IPAA CD.

RESULTS

Thirty-nine subjects were enrolled in the study: 20 cases and 19 controls. Patients who developed post-IPAA CD were significantly younger (median 22 ± 9.9 vs. 30 ± 11.3, p = .027) at the time of UC diagnosis and exhibited more extraintestinal manifestations compared to controls (p = .023). No significant difference between the groups was found with respect to family history, smoking, duration of illness prior to colectomy, time to the onset of pouchitis, preoperative treatment, and indication for surgery. However, the post-operative serologic profile differed significantly with far more cases having elevated anti-CBir1 titers (p = .016, OR 8.81), the latter being the only independent predictor in the combined model.

CONCLUSIONS

Patients with Crohn's disease of the pouch were more likely to have elevated CBir1 antibodies titers than those with simple pouchitis and healthy pouches. The stability of the CBir1 antibodies (pre- and post-colectomy) must be further assessed to establish its value as an independent predictor for development of post-IPAA CD.

Pouchitis: what every gastroenterologist needs to know

Pouchitis is the most common complication among patients with ulcerative colitis who have undergone restorative proctocolectomy with ileal pouch-anal anastomosis. Pouchitis is actually a spectrum of diseases that vary in etiology, pathogenesis, phenotype, and clinical course. Although initial acute episodes typically respond to antibiotic therapy, patients can become dependent on antibiotics or develop refractory disease. Many factors contribute to the course of refractory pouchitis, such as the use of nonsteroidal anti-inflammatory drugs, infection with Clostridium difficile, pouch ischemia, or concurrent immune-mediated disorders. Identification of these secondary factors can help direct therapy.

Is pyloric gland metaplasia in ileal pouch biopsies a marker for Crohn's disease?

BACKGROUND

Approximately 5-10 % of ulcerative colitis (UC) patients who undergo ileal pouch-anal anastomosis (IPAA) will develop postoperative complications such as refractory pouchitis or a change in diagnosis to Crohn's disease (CD). Serological markers and histologic aspects of the pouch such as pyloric gland metaplasia (PGM) have been associated with a risk for these complications.

METHODS

Twenty-eight IPAA patients with either CD of the pouch or chronic pouchitis (cases) and 36 IPAA controls who experienced a normal postoperative course were originally consented. Of these 64 subjects, 22 cases and 17 controls had histopathologic and serologic data available and were subsequently enrolled. Demographic and clinical data were entered into a database, blood analyzed for serological markers (Prometheus Labs, San Diego, CA) and biopsies of the pouch and the afferent limb reviewed by two GI pathologists.

RESULTS

Of the cases, 55 % (12/22) had evidence of PGM in their pouch and/or small bowel biopsies, as compared to 12 % (2/17) of the controls (p = 0.006). Of 13 subjects with CD, 77 % (10/13) were found to have PGM versus subjects with chronic pouchitis in which 22 % (2/9) were found to have PGM (p = 0.03). There was a trend of ASCA positivity (both IgG and IgA, p = 0.20) and of higher ASCA titer levels (p = 0.07) with postoperative complications.

CONCLUSION

This study suggests that the presence of ileal pouch PGM is associated with postoperative complications and favors a diagnosis of CD over UC with chronic pouchitis.

The NOD2insC polymorphism is associated with worse outcome following ileal pouch-anal anastomosis for ulcerative colitis

BACKGROUND

Inflammatory complications after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) are common.

OBJECTIVE

To investigate whether genetic factors are associated with adverse pouch outcomes such as chronic pouchitis (CP) and a Crohn's disease-like (CDL) phenotype.

DESIGN

866 patients were recruited from three centres in North America: Mount Sinai Hospital (Toronto, Ontario, Canada), the Cleveland Clinic (Cleveland, Ohio, USA) and Penn State Milton S Hershey Medical Center (Hershey, Pennsylvania, USA). DNA and clinical and demographic information were collected. Subjects were classified into post-surgical outcome groups: no chronic pouchitis (NCP), CP and CDL phenotype.

RESULTS

Clinical and genetic data were available on 714 individuals. 487 (68.2%) were classified as NCP, 118 (16.5%) CP and 109 (15.3%) CDL. The presence of arthritis or arthropathy (p=0.02), primary sclerosing cholangitis (p=0.009) and duration of time from ileostomy closure to recruitment (p=0.001) were significantly associated with outcome. The NOD2insC (rs2066847) risk variant was the single nucleotide polymorphism (SNP) most significantly associated with pouch outcome (p=7.4×10(-5)). Specifically, it was associated with both CP and CDL in comparison with NCP (OR=3.2 and 4.3, respectively). Additionally, SNPs in NOX3 (rs6557421, rs12661812), DAGLB (rs836518) and NCF4 (rs8137602) were shown to be associated with pouch outcome with slightly weaker effects. A multivariable risk model combining previously identified clinical (smoking status, family history of inflammatory bowel disease), serological (anti-Saccharomyces cerevisiae antibody IgG, perinuclear antineutrophil cytoplasmic antibody and anti-CBir1) and genetic markers was constructed and resulted in an OR of 2.72 (p=8.89×10(-7)) for NCP versus CP/CDL and 3.22 (p=4.11×10(-8)) for NCP versus CDL, respectively.

CONCLUSION

Genetic polymorphisms, in particular, the NOD2insC risk allele, are associated with chronic inflammatory pouch outcomes among patients with UC and IPAA.

Characterization of the gut-associated microbiome in inflammatory pouch complications following ileal pouch-anal anastomosis

Introduction

Inflammatory complications following ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) are common and thought to arise through mechanisms similar to denovo onset inflammatory bowel disease. The aim of this study was to determine whether specific organisms in the tissue-associated microbiota are associated with inflammatory pouch complications.

Methods

Patients having previously undergone IPAA were recruited from Mount Sinai Hospital. Clinical and demographic information were collected and a pouchoscopy with biopsy of both the pouch and afferent limb was performed. Patients were classified based on post-surgical phenotype into four outcome groups: familial adenomatous polyposis controls (FAP), no pouchitis, pouchitis, and Crohn’s disease-like (CDL). Pyrosequencing of the 16S rRNA V1-V3 hypervariable region, and quantitative PCR for bacteria of interest, were used to identify organisms present in the afferent limb and pouch. Associations with outcomes were evaluated using exact and non-parametric tests of significance.

Results

Analysis at the phylum level indicated that Bacteroidetes were detected significantly less frequently (P<0.0001) in the inflammatory outcome groups (pouchitis and CDL) compared to both FAP and no pouchitis. Conversely, Proteobacteria were detected more frequently in the inflammatory groups (P=0.01). At the genus level, organisms associated with outcome were detected less frequently among the inflammatory groups compared to those without inflammation. Several of these organisms, including Bacteroides (P<0.0001), Parabacteroides (P≤2.2x10^-3), Blautia (P≤3.0x10^-3) and Sutterella (P≤2.5x10^-3), were associated with outcome in both the pouch and afferent limb. These associations remained significant even following adjustment for antibiotic use, smoking, country of birth and gender. Individuals with quiescent disease receiving antibiotic therapy displayed similar reductions in these organisms as those with active pouch inflammation.

Conclusions

Specific genera are associated with inflammation of the ileal pouch, with a reduction of typically ubiquitous organisms characterizing the inflammatory phenotypes.

Personalizing therapy for inflammatory bowel diseases

Inflammatory bowel diseases (IBDs; e.g., Crohn's disease [CD] and ulcerative colitis [UC]) are chronic immunologically mediated diseases characterized by frequent relapses, often requiring hospitalization and surgery. There is substantial heterogeneity in the progressive natural history of disease with cumulative accrual of bowel damage and impairment of functioning. Recent advances in therapeutics have significantly improved our ability to achieve disease remission; yet therapies remain expensive and are associated with significant side effects precluding widespread use in all patients with IBD. Consequently, algorithms for the management of patients with IBD require a personalized approach incorporating an individual's projected likely natural history, the probability of response to a specific therapeutic agent and an informed approach to management of loss of response to current therapies.

Serum antibodies associated with complex inflammatory bowel disease

BACKGROUND

Antibodies to microbial antigens have been associated with specific diagnoses and phenotypes of inflammatory bowel disease. We evaluated the prevalence of pANCA, IgA and IgG anti-Saccharomyces cerevisiae antibodies, anti-OmpC, and anti-flagellin in a large well-defined population of patients with Crohn's disease (CD) and ulcerative colitis (UC) and analyzed for various clinical outcomes.

METHODS

Samples were collected from 391 patients with CD, 207 patients with UC, and 62 healthy controls. Patients were phenotyped using the Montreal classification. Blinded serological analyses were performed for pANCA, IgA and IgG anti-Saccharomyces cerevisiae antibodies, anti-OmpC, and anti-flagellin.

RESULTS

In CD, increasing quantitative levels for antibodies were associated with a younger age of diagnosis, longer disease duration, increased surgeries, ileocolonic and perianal disease, and internal perforating behavior. In UC, they were associated with colectomy. An increasing number of seropositive antibodies in CD was associated with a younger age at diagnosis, increased disease duration, ileocolonic and perianal disease, internal penetrating and stricturing behavior, and increased surgeries. Multivariate analysis confirmed the association of antimicrobial antibodies with features of complicated CD and UC.

CONCLUSIONS

Increased serological markers are associated with a more aggressive CD phenotype and an increased need for colectomy in UC. This raises the possibility for use of these markers in patients at risk of complex disease.

Meta-analysis: serological markers and the risk of acute and chronic pouchitis

BACKGROUND

Serological markers such as anti-neutrophil cytoplasmic antibody (ANCA) and anti-Saccharomyces cerevisiae antibody (ASCA) may be associated with pouchitis after ileal pouch-anal anastomosis (IPAA).

AIM

To perform a systematic review with meta-analysis of studies evaluating the association of ANCA and ASCA status with risk of acute and chronic pouchitis after IPAA.

METHODS

We searched multiple databases (upto September 2012) for studies reporting ANCA and/or ASCA status along with risk of acute or chronic pouchitis after IPAA in adults with ulcerative colitis (UC). We abstracted odds ratio (OR) or raw data from the individual studies to calculate summary OR estimates with 95% CIs using random-effects model.

RESULTS

Eight studies reporting 184 cases of acute pouchitis and six studies reporting 151 cases of chronic pouchitis were included. The odds of chronic pouchitis were 76% higher in ANCA-positive patients than ANCA-negative (six studies; OR: 1.76; 95% CI: 1.19-2.61; P < 0.01). ASCA-positivity was not associated with the risk of chronic pouchitis (three studies; OR: 0.89; 95% CI: 0.49-1.59; P = 0.68). Neither ANCA (eight studies; OR: 1.54; 95% CI: 0.79-3.02; P = 0.21) nor ASCA-positivity (two studies; OR: 1.28; 95% CI: 0.25-6.54; P = 0.77) were associated with the risk of acute pouchitis.

CONCLUSIONS

The risk of chronic pouchitis after IPAA is higher in ANCA-positive patients, but the risk of acute pouchitis is unaffected by ANCA status. ASCA status was not associated with the risk of acute or chronic pouchitis. This information may be used to counsel UC patients regarding their risk of pouchitis after IPAA.

Surgical outcome of ileal pouch-anal anastomosis when used intentionally for well-defined Crohn's disease

BACKGROUND

Crohn's disease (CD) is considered a contraindication to ileal pouch--anal anastomosis (IPAA). In this study, we compare outcomes of CD and ulcerative colitis (UC) patients undergoing IPAA.

METHODS

Patients were considered to have CD before surgery based on a history of small bowel disease, perianal disease, noncrypt-associated granuloma, or pretreatment skip colonic lesions. Patients were prospectively assessed for pouchitis or CD. Postoperative CD (pouch inflammation into the afferent limb or pouch fistula) or pouch failure (need for permanent diversion) were assessed. Preoperative serum was assayed for IBD-associated antibodies using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Seventeen patients with preoperative CD were identified. Seven (41%) patients developed postoperative recurrent CD in the afferent limb (n = 3) or pouch fistulizing disease (n = 4). One patient (6%) required pouch excision. The incidence of postoperative CD was higher (P = 0.002) in preoperative CD patients (41%) than UC patients (11%). There was no significant difference in pouchitis or pouch failure. There was also no significant difference in any preoperative clinical feature between patients with or without postoperative CD. Afferent limb inflammation developed in three (50%) of the six patients with pANCA+/OmpC- expression compared to none of the 11 patients without this serologic profile (P = 0.03).

CONCLUSIONS

Although the intentional use of IPAA in CD has a higher incidence of postoperative disease vs. UC patients, there was no significant difference in pouch failure. Demographics, clinical features, and serologic factors do not predict outcome of CD patients undergoing IPAA. IBD serology may identify the phenotype manifestation of postoperative recurrent CD.

Bacteriology in the etiopathogenesis of pouchitis

BACKGROUND

Pouchitis is the most common long-term complication in ulcerative colitis that follows restorative proctocolectomy. Clinical evidence suggests that dysbiosis plays a key role in its pathogenesis.

METHODS

Current literature on the topic was reviewed. A therapeutic approach was proposed based on the literature along with personal experience from the subspecialty Pouchitis Clinic.

RESULTS

Pouchitis represents a disease spectrum in the reservoir, with ranging etiopathogenesis, clinical phenotypes, disease courses and prognoses. Dysbiosis plays a critical role in disease initiation and progress, with antibiotic therapy as the mainstay for treatment. On the other hand, superimposed infection from pathogens contributes to flare-up of the disease. Pouchitis can progress into an 'IBD-like' condition, requiring anti-inflammatory, immunomodulator or even biological therapy.

CONCLUSION

Pouchitis represents a unique form of IBD. Investigation on the evolution from an antibiotic-responsive phenotype to chronic antibiotic-refractory pouchitis may shed some light on the pathogenesis and therapeutic targets of IBD.

Have genomic discoveries in inflammatory bowel disease translated into clinical progress?

Inflammatory bowel disease (IBD) is a heterogeneous disease that can be challenging to diagnose and manage. As a result, significant efforts have been made in attempting to identify clinical, genomic, and serologic markers of disease that can aid in patient assessment and treatment. Recent genomic discoveries have the potential to change clinical practice by identifying those susceptible to IBD, predict natural history and guide choice of therapy. Panels of genetic and genomic markers are more likely to emerge as clinical tools, as opposed to individual allelic variants. Serology and biomarkers are already being used and guiding management but await integration with genomic panels before achieving their maximal potential. This article reviews the current state of IBD genetics and evolving molecular approaches that may have potential clinical impact.

Serological antibodies in inflammatory bowel disease: a systematic review

The diagnosis of inflammatory bowel disease (IBD) is traditionally based on a combination of clinical, endoscopic, histological, and radiological criteria. However, further testing is needed in cases of diagnostic uncertainty and in predicting disease course. This systematic review focuses on the potential for 10 serological antibodies to fill these roles: pANCA, ASCA, anti-OmpC, anti-CBir1, anti-I2, ALCA, ACCA, AMCA, anti-L, and anti-C. We discuss their prevalence in IBD and health; their role in disease diagnosis and risk stratification; their stability over time; their presence in unaffected relatives; their association with genetic variants; and differences across ethnic groups. Serological antibodies have some role in primary diagnosis and in differentiating between Crohn's disease and ulcerative colitis. In indeterminate colitis, preoperative measurement of serological antibodies can help to predict the likelihood of complications among patients undergoing pouch surgery. The combined presence and magnitude of a large panel of antibodies appear to be of value in predicting disease progression. There is currently insufficient evidence to recommend the use of antibody testing to predict responses to treatment or surgery in patients with IBD.

Evaluating pouch problems

IPAA is a technically demanding procedure that requires appropriate skills and expertise. Adverse sequelae of IPAA are common. Accurate diagnosis and classification of pouch disorders and associated complications are important for proper management and prognosis. Based on presenting symptoms, appropriate and combined diagnostic modalities should apply. A multidisciplinary approach involving gastroenterologists, colorectal surgeons, gastrointestinal pathologists, and gastrointestinal radiologists is advocated for diagnosis and treatment of pouch disorders.

Etiology of pouchitis

Restorative proctocolectomy with ileal-pouch anal anastomosis (RPC) is the operation of choice for ulcerative colitis (UC) patients requiring surgery. It is also used for patients with familial adenomatous polyposis (FAP). Pouchitis accounts for 10% of pouch failures. It is an idiopathic inflammatory condition that may occur in up to 50% of patients after RPC for UC. It is rarely seen in FAP patients after RPC. The etiology of pouchitis remains unclear. An overlap with UC is suggested by the frequency with which pouchitis affects patients with UC compared with FAP patients. There is significant clinical evidence implicating bacteria in the pathogenesis of pouchitis. Studies using culture and molecular methods demonstrate a dysbiosis of the pouch microbiota in pouchitis. Risk factors, genetic associations, and serological markers of pouchitis suggest that the interactions between the host immune responses and the pouch microbiota underlie the etiology of this idiopathic inflammatory condition. Here we present a detailed review of the data focusing on the pouch microbiota and the immune responses that support this hypothesis. We also discuss the contribution of luminal metabolic factors and the epithelial membrane in the etiology of this inflammatory process. The ileoanal pouch offers a unique opportunity to study the inter-relationships between the gut microbiota and host immune responses from before the onset of disease. For this reason the study of pouchitis could serve as a human model that significantly enhances our understanding of inflammatory bowel diseases in general.

ASCA IgG and CBir antibodies are associated with the development of Crohn's disease and fistulae following ileal pouch-anal anastomosis

BACKGROUND

For ulcerative colitis (UC) patients undergoing ileal pouch-anal anastomosis (IPAA), postoperative complications include chronic pouchitis and development of Crohn's disease (CD) of the pouch.

AIMS

The aim of this study was to determine if serologic markers obtained postoperatively are associated with the development of complications in UC patients after IPAA.

METHODS

A retrospective chart review was conducted of UC patients with IPAA were tested for expression of serologic markers. Complications abstracted from medical records included postoperative fistula, CD of the pouch, chronic pouchitis, and diversion or excision of the pouch.

RESULTS

142 patients were enrolled, 44 of whom developed complications. Positive serologic profiles for ASCA IgG and anti-CBir1 markers were found to be associated with the development of any complication, (P = 0.017 and P = 0.002, respectively). A positive anti-CBir1 test was also found to be associated with CD of the pouch and/or fistula formation (P < 0.001). Similarly, both ASCA IgG and anti-CBir1 titers were significantly associated with postoperative IPAA complications (P = 0.034 and P = 0.001, respectively), and anti-CBir1 titers were associated with CD of the pouch and/or fistula formation (P < 0.001). Complications developed after a median follow-up of 216 months (range 1-264).

CONCLUSIONS

ASCA IgG and anti-CBir1 markers were associated with the development of complications after IPAA, specifically fistulae and/or CD of the pouch. The ability to identify patients at high risk for adverse outcomes may allow for early aggressive therapy, which may decrease the rate of pouch failure. A prospective study of patients with preoperative serology is ongoing.

Antimicrobial antibodies are associated with a Crohn's disease-like phenotype after ileal pouch-anal anastomosis

BACKGROUND & AIMS

Pouchitis and Crohn's disease (CD)-like (CDL) complications of the pouch occur at rates near 50% and 20%, respectively, after colectomy with ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC). We investigated whether antimicrobial antibodies are associated with pouch outcome after IPAA.

METHODS

We studied clinical and endoscopic data from 399 individuals with UC who underwent colectomy with IPAA at Mount Sinai Hospital in Toronto, Canada; patients were classified as no pouchitis (NP), chronic pouchitis (CP), or CDL. Serum samples were analyzed from 341 patients for antibodies against Saccharomyces cerevisiae (ASCA), OmpC, CBir1, and perinuclear antineutrophil cytoplasmic antibody (pANCA).

RESULTS

Of the subjects, 70.7% had NP, 16.8% developed CP, and 12.5% developed CDL. Smoking was associated with CDL (P = .003). Ashkenazi Jewish individuals more commonly had CP (P = .008). Of patients with CDL, 53.5% and 14.0% had positive test results for anti-CBir1 and ASCA (immunoglobulin G), respectively, compared with 21.4% and 3.8% of those with NP and 28.3% and 5.0% of those with CP (P < .0001 and P = .03). Anti-CBir1 was associated with CDL, compared with NP (P = 2.8 × 10(-5); odds ratio [OR], 4.2; 95% confidence interval [CI], 2.2-8.3) or CP (P = .011; OR, 2.9; 95% CI, 1.3-6.6). ASCA immunoglobulin G was associated with CDL, compared with patients with NP (P = .01; OR, 4.1; 95% CI, 1.4-12.3). In a combined model, pANCA and the antimicrobial antibodies were associated with CP (P = .029) and CDL (P = 4.7 × 10(-4)).

CONCLUSIONS

Antimicrobial antibodies and pANCA are associated with inflammatory complications of the pouch. The CDL phenotype is associated with factors that characterize Crohn's disease, including smoking, anti-CBir1, and ASCA.

Acute and chronic pouchitis--pathogenesis, diagnosis and treatment

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the procedure of choice for the majority of patients with ulcerative colitis who require surgical treatment. Pouchitis, the most common long-term complication of the procedure, involves a spectrum of disease processes with heterogeneous risk factors, clinical features, disease courses and prognoses. In addition, clinical symptoms of pouchitis are not specific and often overlap with those of other inflammatory and functional pouch disorders, such as Crohn's disease of the pouch and irritable pouch syndrome. Pouchoscopy and biopsy, along with laboratory and radiographic evaluations, are often required for accurate diagnosis in patients with symptoms indicative of pouchitis. Dysbiosis has been implicated as a triggering factor for pouchitis, and concurrent infection with pathogens, such as Clostridium difficile, might contribute to disease relapse and exacerbation. Antibiotic therapy is the main treatment modality. However, the management of antibiotic-dependent and antibiotic-refractory pouchitis remains challenging. Secondary causes of pouchitis, such as ischaemia, NSAID use, the presence of concurrent primary sclerosing cholangitis and other systemic immune-mediated disorders, should be evaluated and properly managed.

Evaluation of upper and lower gastrointestinal histology in patients with ileal pouches

BACKGROUND

Inflammatory complications of ileal pouch-anal anastomosis (IPAA), including pouchitis and Crohn's disease (CD) of the pouch, are common in patients with restorative proctocolectomy for ulcerative colitis. It is not clear whether these inflammatory conditions can affect upper GI tract. The aim of the study was to evaluate correlation between duodenal and pouch histology in patients with healthy and diseased pouches.

METHODS

All IPAA patients who had esophagogastroduodenoscopy with biopsy after colectomy (N = 96) were included. H&E slides of gastric, duodenal, neo-terminal ileum, and pouch body biopsies were blindly re-reviewed by an expert GI pathologist for acute and chronic inflammation. Demographic and clinical variables and pouch outcome were analyzed.

RESULTS

There was a significant correlation between acute inflammation in the duodenum as measured by neutrophil infiltration score and the presence of chronic pouchitis (kappa coefficient = 0.21, P < 0.05). Intraepithelial lymphocytosis of the duodenum, though uncommon, only occurred in patients with irritable pouch syndrome, chronic pouchitis, or CD of the pouch. Crypt distortion of duodenal epithelium was only seen in patients with inflammatory or structural diseases of the pouch, including acute (18.2%) and chronic (5%) pouchitis, CD of the pouch (14.3%), and surgical complications of the pouch (14.4%).

CONCLUSION

Histologic evaluation of duodenal biopsy may provide additional information in patients with ileal pouches, as patients with normal histology of the pouch may have an abnormal duodenal histology.

Current and future role of serogenomics in ulcerative colitis

Ulcerative colitis (UC), a chronic inflammatory bowel disease, occurs in genetically susceptible individuals who mount inappropriate immune responses to endoluminal antigens. Serologic and genetic markers have shown great potential for clinical application in Crohn's disease (CD), particularly for prognostication. However, their use is not as well established in UC. The aim of this paper is to highlight the clinical relevance of these markers for diagnostics and prognostication in UC. This review identified studies that cited the use of serum and genetic biomarkers in UC when these biomarkers were used in diagnostic, prognostic, and therapeutic response prediction applications. Several serologic and genetic markers associated with UC were identified, and this review presents and summarizes these data, focusing on the biomarkers' established and emerging diagnostic and prognostic utility. Although more established in CD, the data provided by serologic and genetic testing in UC has the potential to enhance clinical decision making.

Predictors of aggressive inflammatory bowel disease

Inflammatory bowel disease comprises a group of conditions characterized by idiopathic inflammation of the gastrointestinal tract. The natural course of disease can range from an indolent course with prolonged periods of remission to aggressive, incapacitating disease. Predicting which patients are more susceptible to developing severe disease is important, especially when choosing therapeutic agents and treatment strategies. This paper reviews current evidence on the main demographic, clinical, endoscopic, histologic, serologic, and genetic markers that predict aggressive inflammatory bowel disease. In ulcerative colitis, we considered disease to be aggressive when patients had a high relapse rate, need for admission and/or surgery, development of colon cancer, or extraintestinal manifestations. We defined aggressive Crohn's disease as having a high relapse rate, development of penetrating disease, need for repeat surgery, or multiple admissions for flares. In Crohn's disease, involvement of the upper gastrointestinal tract and ileum, penetrating disease, early age at diagnosis, smoking, extensive ulceration of the mucosa, high titers of serum antibodies, and mutations of the NOD2 gene are markers of aggressive disease. In ulcerative colitis, patients with more extensive involvement of the colon (pancolitis) have more symptomatology and are at higher risk for needing a colectomy and developing colon cancer. Also, plasmocytic infiltration of the colonic mucosa and crypt atrophy predict treatment failure. As with diagnosis, no single method can predict disease aggressiveness. Multiple serologic and genetic tests are being developed to refine the accuracy of prediction. Endoscopic findings can also predict the future course of disease. At present, clinical manifestations are the most useful way to make therapeutic decisions.

Assessing inflammatory bowel disease-associated antibodies in Caucasian and First Nations cohorts

BACKGROUND

First Nation populations in Canada have a very low incidence of inflammatory bowel disease (IBD). Based on typical infections in this population, it is plausible that the First Nations react differently to microbial antigens with a different antibody response pattern, which may shed some light as to why they experience a low rate of IBD.

OBJECTIVE

To compare the positivity rates of antibodies known to be associated with IBD in Canadian First Nations compared with a Canadian Caucasian population.

METHODS

Subjects with Crohn's disease, ulcerative colitis (UC), rheumatoid arthritis (RA) (as an immune disease control) and healthy controls without a personal or family history of chronic immune diseases, were enrolled in a cohort study aimed to determine differences between First Nations and Caucasians with IBD or RA. Serum from a random sample of these subjects (n=50 for each of First Nations with RA, First Nations controls, Caucasians with RA, Caucasians with Crohn's disease, Caucasians with UC and Caucasians controls, and as many First Nations with either Crohn's disease or UC as could be enrolled) was analyzed in the laboratory for the following antibodies: perinuclear antineutrophil cytoplasmic antibody (pANCA), and four Crohn's disease-associated antibodies including anti-Saccharomyces cerevisiae, the outer membrane porin C of Escherichia coli, I2 - a fragment of bacterial DNA associated with Pseudomonas fluorescens, and the bacterial flagellin CBir-1. The rates of positive antibody responses and mean titres among positive results were compared.

RESULTS

For pANCA, First Nations had a positivity rate of 55% in those with UC, 32% in healthy controls and 48% in those with RA. The pANCA positivity rate was 32% among Caucasians with RA. The rates of the Crohn's disease-associated antibodies for the First Nations and Caucasians were comparable. Among First Nations, up to one in four healthy controls were positive for any one of the Crohn's disease-associated antibodies. First Nations had significantly higher pANCA titres in both the UC and RA groups than Caucasians.

DISCUSSION

Although First Nation populations experience a low rate of IBD, they are relatively responsive to this particular antibody panel.

CONCLUSIONS

The positivity rates of these antibodies in First Nations, despite the low incidence of IBD in this population, suggest that these antibodies are unlikely to be of pathogenetic significance.

Current and future role of biomarkers in Crohn's disease risk assessment and treatment

BACKGROUND

Crohn's disease (CD), a chronic inflammatory bowel disease (IBD), occurs in genetically susceptible individuals who develop aberrant immune responses to endoluminal bacteria. Recurrent inflammation increases the risk of several complications. Despite use of a traditional "step-up" therapy with corticosteroids and immunomodulators, most CD patients eventually require surgery at some time in their disease course. Newer biologic agents have been remarkably effective in controlling severe disease. Thus, "top-down," early aggressive therapy has been proposed to yield better outcomes, especially in complicated disease. However, safety and cost issues mandate the need for careful patient selection. Identification of high-risk candidates who may benefit from aggressive therapy is becoming increasingly relevant. Serologic and genetic markers of CD have great potential in this regard. The aim of this review is to highlight the clinical relevance of these markers for diagnostics and prognostication.

METHODS

A current PubMed literature search identified articles regarding the role of biomarkers in IBD diagnosis, severity prediction, and stratification. Studies were also reviewed on the presence of IBD markers in non-IBD diseases.

RESULTS

Several IBD seromarkers and genetic markers appear to be associated with complex CD phenotypes. Qualitative and quantitative serum immune reactivity to microbial antigens may be predictive of disease progression and complications.

CONCLUSION

The cumulative evidence provided by serologic and genetic testing has the potential to enhance clinical decision-making when formulating individualized IBD therapeutic plans.

Distinct microbiome in pouchitis compared to healthy pouches in ulcerative colitis and familial adenomatous polyposis

BACKGROUND

Pouchitis occurs in up to 50% of patients with ulcerative colitis (UC) undergoing ileal pouch anal anastomosis (IPAA). Pouchitis rarely occurs in patients with familial adenomatous polyposis (FAP) who undergo IPAA. Our aim was to compare mucosal and luminal flora in patients with UC-associated pouchitis (UCP), healthy UC pouches (HUC), and healthy FAP pouches (FAP).

METHODS

Nineteen patients were enrolled in this cross-sectional study (nine UCP, three HUC, seven FAP). Patients with active pouchitis were identified using the Pouchitis Disease Activity Index (PDAI). Ileal pouch mucosal biopsies and fecal samples were analyzed with a 16S rDNA-based terminal restriction fragment length polymorphism (TRFLP) approach. Pooled fecal DNA from four UCP and four FAP pouches were sequenced for further speciation.

RESULTS

TRFLP data revealed statistically significant differences in the mucosal and fecal microbiota between each group of patients. UCP samples exhibited significantly more TRFLP peaks matching Clostridium and Eubacterium genera compared to HUC and FAP pouches and fewer peaks matching Lactobacillus and Streptococcus genera compared to FAP. DNA Sanger sequencing of a subset of luminal samples revealed UCP having more identifiable sequences of Firmicutes (51.2% versus 21.2%) and Verrucomicrobia (20.2% versus 3.2%), and fewer Bacteroidetes (17.9% versus 60.5%) and Proteobacteria (9.8% versus 14.7%) compared to FAP.

CONCLUSIONS

The pouch microbial environment appears to be distinctly different in the settings of UC pouchitis, healthy UC, and FAP. These findings suggest that a dysbiosis may exist in pouchitis which may be central to understanding the disease.

Future therapeutic approaches for inflammatory bowel diseases

In this review, we speculate about future therapeutic approaches for inflammatory bowel diseases (IBDs), focusing on the need for better preclinical and clinical models and approaches beyond small molecules and systemically administered biologics. We offer ideas to change clinical trial programs and to use immunologic and genetic biomarkers to personalize medicine. We attempt to reconcile past therapeutic successes and failures to improve future approaches. Some of our ideas might be provocative, but we hope that the examples we provide will stimulate discussion about what will advance the field of IBD therapy.

Environmental influences on T regulatory cells in inflammatory bowel disease

Inflammatory bowel disease (IBD) is characterized by chronic, idiopathic inflammation of the intestine. The disease is thought to result from a combination of genetic and environmental factors which ultimately leads to a mucosal immune system that overreacts to normal constituents of the mucosal microbiota. The inflammation in IBD is primarily mediated by inappropriate production of proinflammatory cytokines by CD4(+) T effector cells, effects that are suppressed by CD4(+) T regulatory cells. Defects in both the function of T regulatory cells, and the ability of T effector cells to be suppressed, have been implicated in IBD. In this review we will discuss environmental factors, including cytokines, vitamins A and D, and commensal bacteria, which influence the phenotype and function of regulatory T cells and thereby alter the course of IBD. We will also discuss how these environmental signals can be manipulated therapeutically in order to improve the function of regulatory T cells and ultimately restore mucosal homeostasis in patients with IBD.

Serological markers for inflammatory bowel disease in AIDS patients with evidence of microbial translocation

BACKGROUND

Breakdown of the gut mucosal barrier during chronic HIV infection allows translocation of bacterial products such as lipopolysaccharides (LPS) from the gut into the circulation. Microbial translocation also occurs in inflammatory bowel disease (IBD). IBD serological markers are useful in the diagnosis of IBD and to differentiate between Crohn's disease (CD) and ulcerative colitis (UC). Here, we evaluate detection of IBD serological markers in HIV-infected patients with advanced disease and their relationship to HIV disease markers.

METHODS

IBD serological markers (ASCA, pANCA, anti-OmpC, and anti-CBir1) were measured by ELISA in plasma from AIDS patients (n = 26) with low CD4 counts (<300 cells/µl) and high plasma LPS levels, and results correlated with clinical data. For meta-analysis, relevant data were abstracted from 20 articles.

RESULTS

IBD serological markers were detected in approximately 65% of AIDS patients with evidence of microbial translocation. An antibody pattern consistent with IBD was detected in 46%; of these, 75% had a CD-like pattern. Meta-analysis of data from 20 published studies on IBD serological markers in CD, UC, and non-IBD control subjects indicated that IBD serological markers are detected more frequently in AIDS patients than in non-IBD disease controls and healthy controls, but less frequently than in CD patients. There was no association between IBD serological markers and HIV disease markers (plasma viral load and CD4 counts) in the study cohort.

CONCLUSIONS

IBD serological markers may provide a non-invasive approach to monitor HIV-related inflammatory gut disease. Further studies to investigate their clinical significance in HIV-infected individuals are warranted.

Serologic markers: impact on early diagnosis and disease stratification in inflammatory bowel disease

Inflammatory bowel disease (IBD) is difficult to diagnose, and differentiating between ulcerative colitis (UC) and Crohn's disease (CD) can be challenging. Overlapping symptoms of UC and CD often delay diagnosis, despite availability of endoscopic, radiologic, and histologic tools. This delay in diagnosis is quite common in clinical practice, which may also delay initiation of appropriate treatment. Abnormal immune responses found in IBD have led to the use of serum biomarkers (eg, anti-Saccharomyces cerevisiae antibody [ASCA], perinuclear antineutrophil cytoplasmic antibody [pANCA], antibodies to flagellin [anti-CBir1]) to improve diagnostic confidence in IBD. These biomarkers are beginning to be used to stratify patients with UC and CD according to disease phenotype and risk of complications. Associations between quantity and quality of immune reactivity and severe disease phenotypes are increasingly evident. This suggests that serologic panels of multiple IBD biomarkers can be used to identify the relative risk of progression to complicated disease behaviors, and that this information may ultimately impact therapeutic decisions. This review discusses the diagnostic process and challenges in IBD, with emphasis on the role that serologic markers may play in addressing these challenges.

Serologic and laboratory markers in prediction of the disease course in inflammatory bowel disease

The search for biologic markers that can assess the natural history and perhaps predict the course of individual's disease including response to treatments over time has become an important focus of inflammatory bowel disease research. The knowledge of an individual's prognosis can help physicians and patients make important management decisions and aid communication on risk and benefits of disease and treatment.

Secondary pouchitis: those with identifiable etiopathogenetic or triggering factors

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for the majority of patients with medically refractory ulcerative colitis (UC) or UC with dysplasia, or familial adenomatous polyposis. Various forms of pouchitis frequently occur after surgery. In fact, pouchitis is the most frequent long-term complication of IPAA in patients with UC, with a cumulative prevalence of up to 50%. The etiology and pathogenesis of pouchitis are not entirely clear. It is generally believed that the initiation and development of the disease process of pouchitis is associated with dysbiosis of pouch reservoir, as evidenced by a favorable response to antibiotic therapy. However, the majority of the patients do not show identifiable etiopathogenetic or triggering factors, therefore being labeled to have idiopathic pouchitis. In contrast, a subgroup of patients, particularly those with antibiotic-refractory pouchitis, may have obvious triggering factors for disease flare-up and progression and may be considered to have secondary pouchitis. Therefore, pouchitis can be classified on the basis of etiology into idiopathic and secondary causes. Approximately 20-30% of patients who present with chronic pouchitis have secondary identifiable and triggering factors, including cytomegalovirus or Clostridium difficile infection, ischemia, concurrent immune-mediated disorders, radiation, collagen deposition, and use of nonsteroidal anti-inflammatory drugs. Careful evaluation of these secondary causes of pouchitis that may contribute to resistance to antibiotics should be performed before the introduction of next-line medical therapy.

Pouchitis and pouch dysfunction

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the surgical treatment of choice for most patients with ulcerative colitis who require surgery. Although the surgical procedure offers a cure in some patients, postoperative inflammatory and noninflammatory complications are common. Pouchitis is the most common long-term complication of the procedure. Pouchitis represents a spectrum of disease processes with heterogeneous risk factors, clinical phenotypes, natural history, and prognosis. Accurate diagnosis and classification are important for proper treatment and prognosis.

Clinical significance of inflammatory markers

Inflammatory markers play a key role in the evaluation of patients with gastrointestinal symptoms. For patients presenting with nonspecific symptoms of abdominal pain and diarrhea, distinguishing inflammatory bowel disease from other disorders can be difficult, and invasive diagnostic procedures may be required. Inflammatory markers can be useful to differentiate patients who may require further workup from those who do not. Several serum, fecal, and other markers are reviewed for their use in clinical practice. Although no single ideal marker exists, a few show promise in diagnosing inflammatory disease, monitoring disease activity, and predicting relapse.

Diagnostic advances in inflammatory bowel disease (imaging and laboratory)

Autoimmune and antimicrobial antibodies currently play only an adjunctive role in the diagnosis of inflammatory bowel disease (IBD). Their sensitivity and specificity are not high enough to be relied upon alone to secure a diagnosis; however, their most promising role seems to be in identifying Crohn's disease patients at a higher risk of progression to intestinal complications. Serum C-reactive protein (CRP) correlates well with other measures of biologic activity but not as well with clinical activity. CRP can help predict IBD relapses, and in patients with severely active ulcerative colitis may indicate which patients are most likely to progress to colectomy. Similarly, fecal lactoferrin and calprotectin are reasonably accurate and noninvasive measures of disease activity, can predict relapse, and identify a high-risk group among acute severe colitis patients. Capsule endoscopy is a highly sensitive tool that can be used in patients with suspected Crohn's disease with a negative traditional workup, but lower specificity and the risk of capsule retention preclude first-line use. CT enterography can delineate the extent and severity of bowel inflammation and detect extraluminal findings. Magnetic resonance enterography is a radiation-free cross-sectional imaging alternative that is comparable to CT enterography in diagnostic accuracy.

Pouchitis and pouch dysfunction

Restorative proctocolectomy with ileal pouch-anal anastomosis has become the surgical treatment of choice for most patients with ulcerative colitis who require surgery. Although the surgical procedure offers a cure in some patients, postoperative inflammatory and noninflammatory complications are common. Pouchitis is the most common long-term complication of the procedure. Pouchitis represents a spectrum of disease processes with heterogeneous risk factors, clinical phenotypes, natural history, and prognosis. Accurate diagnosis and classification are important for proper treatment and prognosis.

Laboratory tests for patients with ileal pouch-anal anastomosis: clinical utility in predicting, diagnosing, and monitoring pouch disorders

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical treatment of choice for patients with medically refractory ulcerative colitis (UC) or UC-associated dysplasia, and for the majority of patients with familial adenomatous polyposis. Pouchitis and other complications of IPAA are common. There are scant data on laboratory markers for the evaluation and diagnosis of pouch disorders. The presence of immunogenotypic markers such as genetic polymorphisms of interleukin-1 (IL-1) receptor antagonist, NOD2/CARD15, Toll-like receptor, and tumor necrosis factor-alpha has been reported to be associated with pouchitis. Immunophenotypic/serologic markers such as perinuclear antineutrophil cytoplasmic antibody and anti-CBir1 have been investigated as possible markers for predicting and diagnosing pouchitis. Fecal markers including lactoferrin and calprotectin seem to be useful in distinguishing inflammatory from noninflammatory pouch disorders. In our practice, we have encountered a large number of pouch patients with Clostridium difficile infection. Laboratory evaluation provides information on the etiology and pathogenesis of pouchitis, and it also helps practicing clinicians with accurate diagnosis, differential diagnosis, disease stratification, and management of ileal pouch disorders.

Clinical guidelines for the management of pouchitis

When surgery is necessary in patients with ulcerative colitis, total proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the procedure of choice. Several inflammatory and noninflammatory complications can occur after IPAA. Pouchitis is the most common, occurring in approximately 50% of patients. Whereas "acute" pouchitis can be treated rapidly and successfully in the majority of patients, "refractory" and "chronic pouchitis" remain therapeutic challenges to patients and physicians. This article reviews the literature and offers consensus guidelines on issues related to the epidemiology, diagnosis, pathogenesis, risk factors, and treatment of pouchitis.

Pouchitis: lessons for inflammatory bowel disease

PURPOSE OF REVIEW

One of the significant limitations to the investigation of inflammatory bowel disease (IBD) in humans is the impossibility of studying this condition from the beginning of the disease process to understand the individual contribution of the various microbiological and immunological components to its pathogenesis. Pouchitis can serve as a human model for IBD, as the time of the pouch creation is known, which allows to prospectively study the events that might eventually lead to the development of a form of intestinal inflammation (i.e., pouchitis) that mimics IBD.

RECENT FINDINGS

A considerable amount of progress has been made in the last few years on the mechanisms underlying the pathogenesis of pouchitis. Recent literature suggests that pouchitis may present a spectrum of disease processes, with a wide range of causes, risk factors, clinical phenotypes, disease courses, and prognoses. Genetic, microbiological, and immunological profiles in pouchitis were evaluated.

SUMMARY

Ileal pouch and pouchitis represent a valuable human model to study the evolution of bacterial communities and host-bacteria interactions in IBD by sequentially monitoring microbiological and immunological profile before, during, and after pouch construction and before and after development and treatment of pouchitis.

Role of flagellin in Crohn's disease: emblematic of the progress and enigmas in understanding inflammatory bowel disease

Elevated immune responses to the enteric microbiota have long been associated with inflammatory bowel disease (IBD), especially Crohn's disease. In recent years there has been considerable progress in identifying a number of the specific bacterial and host molecules whose interactions mediate these responses. However, deciphering the role of these interactions in the pathophysiology of IBD remains a difficult challenge, in part due to the very complex nature of the epithelial cell / microbial / immune cell interactions that play a central role in maintaining the gut's well-being. This article reviews such progress and discusses these challenges in the context of focusing on 1 particular protein, bacterial flagellin.

Advances in epidemiology and diagnosis of inflammatory bowel diseases

The etiology of chronic inflammatory bowel diseases (IBD) remains unknown. Understanding IBD epidemiology helps to identify at-risk individuals, to appreciate the changing demographic profile of IBD, and to interpret theories of IBD pathogenesis. This article reviews recent advances in epidemiology and diagnostics. The importance of Clostridium difficile is highlighted. State-of-the-art IBD diagnostic modalities include serology, fecal markers, and advanced radiologic or endoscopic techniques. These include wireless capsule endoscopy, balloon enteroscopy, chromoendoscopy, high-magnification endoscopy, and MRI. The increasing number of available modalities requires appreciation of their indications, strengths, and limitations. This article discusses these issues relevant to the clinician.

Association between immune-associated disorders and adverse outcomes of ileal pouch-anal anastomosis

OBJECTIVES

Autoimmune disorders (ADs) frequently coexist with inflammatory bowel disease. The aim of the study was to determine whether coexisting AD in patients with ileal pouches increases the risk for chronic antibiotic-refractory pouchitis (CARP) and other inflammatory conditions of the pouch.

METHODS

A total of 622 patients seen in our Pouchitis Clinic were enrolled. We compared the prevalence of adverse outcomes of the pouch (including CARP, Crohn's disease of the pouch, and pouch failure) in patients with or without concurrent AD and assessed the factors for these adverse outcomes.

RESULTS

There were seven pouch disease categories: normal (N=60), irritable pouch syndrome (N=112), active pouchitis (N=131), CARP (N=67), Crohn's disease (N=131), cuffitis (N=83), surgical complications (N=36), and anismus (N=2). The prevalence of AD in these pouch disease categories was 4.5%, 12.5%, 9.2%, 13.4%, 10.7%, 3.8%, 1.5%, and 0%, respectively. The presence of at least one AD at time of pouch surgery was shown to be associated with a twofold increase in the risk for CARP (hazard ratio=2.29; 95% CI: 1.52, 3.46; P<0.001) and for pouch-associated hospitalization (hazard ratio=2.39; 95% CI: 1.59, 3.58; P<0.001). The presence of AD was not associated with increased risk for irritable pouch syndrome, active pouchitis, Crohn's disease, cuffitis, surgical complications, or pouch failure. Patients with Crohn's disease of the pouch had a 2.42 times higher risk for pouch failure (P=0.042) than these without. Active smoking or a history of smoking was shown to be associated with an increased risk for pouch-associated hospitalization and pouch failure.

CONCLUSIONS

AD appears to be associated with an increased risk for CARP, and the presence of the association between these AD and pouch disorders may stimulate further research on the link of these organ systems on an immunological basis.

Special issues in pediatric inflammatory bowel disease

The incidence of pediatric inflammatory bowel disease (IBD) is rising and recent advances in diagnostics and therapeutics have improved the care provided to these children. There are distinguishing features worth noting between early onset and adult onset IBD. Physical and psychosocial development remains a critical target for the comprehensive management of pediatric IBD. Children are not just little adults and consideration must be given to the stages of development and how these stages impact disease presentation and management. The final stage will be the transition from pediatric care to that of adult oriented care and special consideration must be given to make this a successful process. This review highlights special considerations in the management of the child with IBD.