NOD2/CARD15 mutations correlate with severe pouchitis after ileal pouch-anal anastomosis

Pouchitis: pathophysiology and management

Pouchitis is an acute or chronic inflammatory disease of the ileal reservoir. It is common after restorative proctocolectomy with ileal pouch-anal anastomosis, and treatment of chronic antibiotic-refractory pouchitis has proven challenging. Most cases of acute pouchitis evolve into chronic pouchitis. The aetiology of acute pouchitis is likely to be partly related to the gut microbiota, whereas the pathophysiology of chronic pouchitis involves abnormal interactions between genetic disposition, faecal stasis, the gut microbiota, dysregulated host immunity, surgical techniques, ischaemia and mesentery-related factors. Pouchoscopy with biopsy is the most valuable modality for diagnosis, disease monitoring, assessment of treatment response, dysplasia surveillance and delivery of endoscopic therapy. Triggering or risk factors, such as Clostridioides difficile infection and use of non-steroidal anti-inflammatory drugs, should be modified or eradicated. In terms of treatment, acute pouchitis usually responds to oral antibiotics, whereas chronic antibiotic-refractory pouchitis often requires induction and maintenance therapy with integrin, interleukin or tumour necrosis factor inhibitors. Chronic pouchitis with ischaemic features, fistulae or abscesses can be treated with hyperbaric oxygen therapy.

The aetiology of pouchitis in patients with inflammatory bowel disease

Restorative proctocolectomy with ileal pouch-anal anastomosis is a treatment option for patients with refractory ulcerative colitis. Pouchitis is the most common complication, representing a spectrum of diseases ranging from acute antibiotic-responsive type to chronic antibiotic-refractory. Early accurate diagnosis using a combined assessment of symptoms, endoscopy and histology is important for both treatment and prognostication. Most patients respond well to antibiotic therapy; however, management of chronic antibiotic-refractory pouchitis remains a challenge, and treatment options are based on small studies. Pouchitis is thought to be driven by the interaction between genetics, the immune system and the environment but as yet a causal relationship has yet to be identified. Further longitudinal assessment of the pouch integrating new technologies may help us understand the factors driving pouchitis. This review outlines the currently understood risk factors and aetiology of pouchitis.

Digestive perianastomotic ulcerations after intestinal resection in children

Digestive perianastomotic ulceration (DPAU) is a rare complication after intestinal resection and anastomosis occurring at or near the anastomosis site. The purpose of this review is to summarize the characteristics of DPAU, including the etiology, diagnosis and differential diagnosis, clinical manifestations, treatment, and future research. All recent literature on DPAU was searched in PubMed, Embase, and Cochrane and then reviewed. The clinical manifestations of DPAU are mainly gastrointestinal symptoms such as bloody stool and chronic anemia. The diagnosis of DPAU is difficult. Specific diseases, such as Crohn's disease, must be ruled out before a diagnosis can be made. In addition, there are no clear treatment guidelines due to the high degree of heterogeneity in response to drugs and surgery. It is recommended to adjust medication in time and combine various treatment methods. In addition, the mechanism that causes DPAU is not well understood; however, several possible mechanisms have been proposed, such as scar tissue ischemia and underlying diseases. Moreover, there is a high risk of relapses, and a long-term follow-up is necessary. Numerous issues remain to be solved in this area; therefore, more randomized controlled trials and studies should be carried out to further understand this disease.

Inflammatory bowel disease-specific findings are common morphological changes in the ileal pouch with ulcerative colitis

Why inflammation is common in ileal pouches with ulcerative colitis (UC) is unclear. We therefore clarified the morphological changes in pouches and afferent limbs (AL) of patients with UC and explored the relationship between these findings. We evaluated the morphological findings (histological and endoscopic inflammation as the Pouchitis Disease Activity Index [PDAI] histology subscore [hPDAI] and endoscopy subscore [ePDAI], inflammatory bowel disease [IBD]-specific findings using the IBD score [S_IBD], colonic metaplasia using the colonic metaplasia score [CMS], and goblet cell [GC] ratio) in the pouch and AL of patients with UC. A total of 261 pouchoscopies were analyzed. The pouch body had a higher hPDAI (p < 0.001), S_IBD (p < 0.001), CMS (p < 0.001), GC ratio (p < 0.001), and ePDAI (p < 0.001) than the AL. The hPDAI was correlated with the S_IBD (Spearman's coefficient r = 0.538; p < 0.001), CMS (r = 0.687; p < 0.001), and the ePDAI (r = 0.552; p < 0.001), but not with GC ratio (r = 0.175; p < 0.001) or the pouch usage duration (r = -0.057; p = 0.107). The incidence of histological inflammation was higher in specimens showing basal plasmacytosis with severe mononuclear cell infiltration (BP) than in those without BP (odds ratio [OR] 6.790, p < 0.001), BP was commonly found with crypt hyperplasia (OR 3.414, p < 0.001) and the crypt length correlated with neutrophil infiltration (r = 0.469; p < 0.001). Histological inflammation, colonic metaplasia, the GC ratio, endoscopic inflammation, and IBD-specific findings were commonly present in the pouch than in the AL. Histological inflammation occurs with IBD-specific findings and colonic metaplasia, and these signify endoscopic inflammation.

Crohn's of the Pouch: Now What?

Total proctocolectomy and ileal pouch anal anastomosis (IPAA) is the gold standard surgical treatment for the majority (∼90%) of ulcerative colitis (UC) patients. In cases of carefully selected Crohn's colitis patients without small bowel or perianal involvement an "intentional IPAA" may be a viable option for disease resection and restoration of intestinal continuity. More commonly, Crohn's is incidentally found either in the resection specimen or, more commonly, when inflammatory complications subsequently arise after pouch construction for UC or indeterminate colitis. These incidental Crohn's pouches may be diagnosed early or late period post-IPAA. Crohn's may manifest within the pouch, in the proximal small bowel, and/or distally in the rectal cuff or anus. Like intestinal Crohn's, Crohn's disease of the pouch may be of an inflammatory, fibrostenosing, or fistulizing phenotype. Treatment depends on the phenotype and includes medical treatment, most commonly in the form of tumor necrosis factor inhibitor medications; however, the newer small molecules offer a potential treatment for these patients. Surgery first entails treating the sequelae of Crohn's and is typically staged. In up to 60% of Crohn's pouches, particularly in fistulizing disease and/or recalcitrant perianal disease, the pouch fails and must be defunctioned or excised. In patients with Crohn's pouches in situ long term, outcomes including quality of life are comparable to patients who underwent IPAA for UC.

Disease Monitoring of the Ileoanal Pouch: How to Utilize Biomarkers, Imaging, and Pouchoscopy

PURPOSE OF REVIEW

Restorative proctocolectomy with ileal pouch-anal anastomosis for ulcerative colitis has been associated with multiple short- and long-term complications. In this review, we examine the role of biomarkers, imaging, and pouchoscopy in the assessment of patients after ileal pouch-anal anastomosis, with a particular focus on the emergence of novel biomarkers and techniques for evaluating and risk stratifying patients after this procedure in the hopes of improving outcomes in this specific population.

RECENT FINDINGS

There are indications that that the incidence of pouchitis may be increasing in recent decades. Calprotectin and other non-invasive imaging tests such as ultrasound may offer advantages in distinguishing patients with inflammatory conditions of the pouch from other etiologies. In the search for other biomarkers that may identify patients at risk for inflammatory conditions of the pouch, the stool microbiota and metabolomics may play a key role in identifying those patients at greatest risk for complications. Advances in biomarkers, imaging, and standardized pouchoscopy scoring offer immediate improvements in clinical care and will prompt future research efforts.

Detection of mutations in NOD2/CARD15 gene in Arab patients with Crohn's disease

BACKGROUND

Mutations in NOD2/CARD15 gene have been linked to an increased risk of Crohn's disease (CD). The objective of this study is to determine NOD2/CARD15 gene mutations, and their association with the risk of CD in Arabs in Kuwait.

METHODS

Four NOD2 gene mutations, including Pro268Ser (SNP5), Arg702Trp (SNP8), Gly908Arg (SNP12), and Leu1007FsinsC (SNP13) were examined in Arab CD patients (n = 103) and control subjects (n = 100). The genomic DNA was isolated and used in polymerase chain reaction (PCR) with four sets of specific primers. The PCR-amplified DNA fragments were sequenced and analyzed for the NOD2 mutations. Logistic regression was used to estimate the adjusted odds ratios (aOR) and 95% confidence intervals (CI).

RESULTS

Of the four genotyped variants, the Arg702Trp (SNP8) and Leu1007FsinsC (SNP13) variants were not informative in our study sample due to minor allele frequency of <1%. The Pro268Ser (SNP5) mutation was detected in 17 (16.5%) CD patients and 32 (32.0%) controls. The Gly908Arg (SNP12) mutation was observed in 24 (23.3%) patients and 10 (10.0%) controls. In the dominant genetic risk model (i.e. carrying at least one minor allele), CD patients compared to controls were less likely to carry either the "CT" or "TT" genotype of variant Pro268Ser (SNP5; aOR = 0.43, 95% CI: 0.22-0.84). In contrast, CD patients compared to controls were more likely to carry the homozygous for the minor allele or the heterozygous genotypes of variant Gly908Arg (SNP12; aOR = 2.67, 95% CI: 1.19-5.97).

CONCLUSIONS

In this Arab population, carrying at least one copy of the minor allele of Gly908Arg (SNP12) mutation in NOD2 gene was associated with increased susceptibility to CD, while having the heterozygous or homozygous for the minor allele genotype of the Pro268Ser (SNP5) mutation provided protection against CD. Mutations in Arg702Trp (SNP8) and Leu1007FsinsC (SNP13) were not detected in this sample of the Arab population in Kuwait.

Determinants of Pouch-Related Symptoms, a Common Outcome of Patients With Adenomatous Polyposis Undergoing Ileoanal Pouch Surgery

Total proctocolectomy with ileal pouch anal anastomosis (IPAA) is performed in patients with adenomatous polyposis syndromes (APSs). Data regarding pouch outcomes in APS are scarce. The purposes of this study were to determine the prevalence of pouch-related symptoms in patients with APS and to identify the contributing factors.

A case of refractory pouchitis complicated by cytomegalovirus infection requiring administration of ganciclovir and infliximab

Pouchitis is a frequent complication of surgical treatment of ulcerative colitis (UC), and is typically treated using antimicrobials. If pouchitis is refractory to antimicrobials, screening for complications, such as cytomegalovirus (CMV) infection, is necessary. However, the optimal approach to management of pouchitis complicated by CMV infection is unclear. We report the case of a 41-year-old female patient with UC presenting with pouchitis associated with CMV infection; she had received subtotal colectomy/ileal pouch anal anastomosis (IPAA). She was admitted to hospital with persistent fever, epigastric discomfort, and watery diarrhea despite receiving antibiotics. Laboratory findings showed inflammation and reactivation of CMV infection accompanied by liver injury. The endoscopic findings showed inflammation of the pouch and ileal mucosa on the oral side with extensive and deep punched-out ulcers. Immunohistological staining of biopsy specimens from an ulcerated lesion demonstrated CMV infection. Therefore, we diagnosed the patient with pouchitis complicated by CMV infection. The patient was treated with ganciclovir and infliximab, which resolved her symptoms and led to the disappearance of CMV-positive cells. There has been no recurrence of pouchitis. CMV infection should be considered in patients with UC who develop refractory pouchitis.

Prevention and Medical Treatment of Pouchitis In Ulcerative Colitis

Approximately 50% of patients who have undergone IPAA surgery for Ulcerative Colitis (UC) develop at least 1 episode of pouchitis. Patients with pouchitis have a wide range of symptoms, endoscopic and histologic features, disease course, and prognosis. To date, there are no universally accepted diagnostic criteria in terms of endoscopy and histology; though, semi-objective assessments to diagnose pouchitis in patients with ileal pouch- anal anastomosis (IPAA) have been proposed using composite scores such as the Pouchitis Triad, Heidelberg Pouchitis Activity Score and Pouchitis Disease Activity Index (PDAI). In a systematic review that included four randomized trials evaluating five agents for the treatment of acute pouchitis, ciprofloxacin was more effective at inducing remission as compared with metronidazole. Rifaximin was not more effective than placebo, while budesonide enemas and metronidazole were similarly effective for inducing remission of acute pouchitis. Patients with pouchitis relapsing more than three times per year are advised maintenance therapy, and guidelines recommend ciprofloxacin or the probiotic VSL#3. In patients with antibiotic-refractory pouchitis, secondary factors associated with an antibiotic-refractory course should be sought and treated. In this review, we will discuss the prevention and management of pouchitis in Ulcerative Colitis patients.

Exposure to Anti-tumor Necrosis Factor Medications Increases the Incidence of Pouchitis After Restorative Proctocolectomy in Patients With Ulcerative Colitis

BACKGROUND

Pouchitis is the most frequent complication after IPAA in patients with ulcerative colitis. Antibiotics represent the mainstay of treatment, suggesting a crucial role of dysbiosis in the pathogenesis of this condition. Anti-tumor necrosis factor agents have been shown to adversely impact the gut microbiome and local host immunity.

OBJECTIVE

The aim of this study is to assess the effect of prior exposure to biologics on the development of pouchitis in patients who have ulcerative colitis.

DESIGN

This is a retrospective case-control study.

SETTINGS

This study was conducted at a tertiary-care IBD center.

PATIENTS

Consecutive patients with ulcerative colitis who underwent restorative proctocolectomy between 2000 and 2010 were included.

MAIN OUTCOME MEASURES

The primary outcome measured was the incidence of pouchitis.

RESULTS

Four hundred seventeen patients with ulcerative colitis who underwent IPAA were included. The incidence of pouchitis was 40.4%. There were no differences in patient demographics, disease-specific factors, surgical approach, and short-term postoperative complications between patients who developed pouchitis compared to those that did not. Patients exposed to anti-tumor necrosis factor agents or preoperative steroids were significantly more likely to develop pouchitis (anti-tumor necrosis factor: 47.9% vs 36.5%, p = 0.027; steroids: 41.7% vs 23.3%, p = 0.048). However, on multivariable analysis, only anti-tumor necrosis factor therapy was an independent predictor for pouchitis (p = 0.05). Pouchitis was not associated with adverse long-term outcomes.

LIMITATIONS

The retrospective design was a limitation of this study.

CONCLUSION

In a large cohort of patients undergoing IPAA for ulcerative colitis with at least a 5-year follow-up, anti-tumor necrosis factor exposure was the only independent risk factor for the development of pouchitis. These agents may "precondition" the pouch to develop pouchitis through alterations in the microbiome and/or local host immunity of the terminal ileum. See Video Abstract at http://links.lww.com/DCR/B19. LA EXPOSICIÓN A MEDICAMENTOS ANTI-TNF AUMENTA LA INCIDENCIA DE POUCHITIS DESPUÉS DE LA PROCTOCOLECTOMÍA RESTAURADORA EN PACIENTES CON COLITIS ULCEROSA:: La pouchitis es la complicación más frecuente después de la anastomosis anal de bolsa ileal en pacientes con colitis ulcerosa. Los antibióticos representan el pilar del tratamiento, lo que sugiere un papel crucial de la disbiosis en la patogénesis de esta afección. Se ha demostrado que los agentes anti-TNF tienen un impacto adverso en la microbiota intestinal y en la inmunidad local del huésped.El objetivo de este estudio es evaluar el efecto de la exposición previa a terapía biológica sobre el desarrollo de la pouchitis en pacientes con colitis ulcerosa.Estudio retrospectivo de casos y controles.Centro de tercer nivel de atención en enfermedades inflamatorias intestinales.Pacientes consecutivos con colitis ulcerosa que se sometieron a proctocolectomía restaurativa entre 2000-2010.Incidencia de pouchitis.Cuatrocientos diecisiete pacientes con colitis ulcerativa se sometieron a anastomosis anal de bolsa ileal. La incidencia de pouchitis fue del 40.4%. No hubo diferencias en la demografía del paciente, los factores específicos de la enfermedad, el abordaje quirúrgico y las complicaciones postoperatorias a corto plazo entre los pacientes que desarrollaron pouchitis en comparación con los que no lo hicieron. Los pacientes expuestos a agentes anti-TNF o esteroides preoperatorios fueron significativamente más propensos a desarrollar pouchitis (anti-TNF: 47.9% vs 36.5%, p = 0.027; esteroides: 41.7% vs 23.3%, p = 0.048). Sin embargo, en el análisis multivariable, solo la terapia anti-TNF fue un predictor independiente para la pouchitis (p = 0.05). La pouchitis no se asoció con resultados adversos a largo plazo.Diseño retrospectivo.En una gran cohorte de pacientes sometidos a anastomosis anal de bolsa ileal para la colitis ulcerosa con al menos 5 años de seguimiento, la exposición a terapía anti-TNF fue el único factor de riesgo independiente para el desarrollo de pouchitis. Estos agentes pueden "precondicionar" la bolsa para desarrollar una pouchitis a través de alteraciones en el microbioma y / o inmunidad local del huésped del íleon terminal. Vea el Resumen del video en http://links.lww.com/DCR/B19.

Recommendations of the Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) on pouchitis in ulcerative colitis. Part 1: Epidemiology, diagnosis and prognosis

Pouchitis is a common complication in ulcerative colitis patients after total proctocolectomy. This is an unspecific inflammation of the ileo-anal pouch, the aetiology of which is not fully known. This inflammation induces the onset of symptoms such as urgency, diarrhoea, rectal bleeding and abdominal pain. Many patients suffering from pouchitis have a lower quality of life. In addition to symptoms, an endoscopy with biopsies is mandatory in order to establish a definite diagnosis. The recommended index to assess its activity is the Pouchitis Disease Activity Index (PDAI), but its modified version (PDAIm) can be used in clinical practice. In accordance with the duration of symptoms, pouchitis can be classified as acute (<4 weeks) or chronic (>4 weeks), and, regarding its course, pouchitis can be infrequent (<4 episodes per year), recurrent (>4 episodes per year) or continuous.

Multiplex gene expression profile in inflamed mucosa of patients with Crohn’s disease ileal localization: A pilot study

BACKGROUND

Crohn’s disease (CD) is a complex disorder resulting from the interaction of genetic, environmental, and microbial factors. The pathogenic process may potentially affect any segment of the gastrointestinal tract, but a selective location in the terminal ileum was reported in 50% of patients.

AIM

To characterize clinical sub-phenotypes (colonic and/or ileal) within the same disease, in order to identify new therapeutic targets.

METHODS

14 consecutive patients undergoing surgery for ileal CD were recruited for this study. Peripheral blood samples from each patient were collected and the main polymorphisms of the gene Card15/Nod2 (R702W, G908R, and 1007fs) were analyzed in each sample. In addition, tissue samples were taken from both the tract affected by CD and from the apparently healthy and disease-free margins (internal controls). We used a multiplex gene assay in specimens obtained from patients with ileal localization of CD to evaluate the simultaneous expression of 24 genes involved in the pathogenesis of the disease. We also processed surgery gut samples with routine light microscopy (LM) and transmission electron microscopy (TEM) techniques to evaluate their structural and ultrastructural features.

RESULTS

We found a significant increase of Th17 (IL17A and IL17F, IL 23R and CCR6) and Th1 (IFN-γ) gene expression in inflamed mucosa compared to non-inflamed sites of 14 CD patients. DEFB4 and HAMP, two genes coding for antimicrobial peptides, were also strongly activated in inflamed ileal mucosa, suggesting the overwhelming stimulation of epithelial cells by commensal microbiota. IFN-γ and CCR6 were more expressed in inflamed mucosa of CD patients with ileal localization compared with patients with colonic localization suggesting a more aggressive inflammation process in this site. Morphological analysis of the epithelial lining of Lieberkün crypts disclosed enhanced release activity from goblet mucocytes, whereas the lamina propria contained numerous cells pertaining to various lines.

CONCLUSION

We observed that the expression of ileal genes related to Th1 and Th17 activity is strongly activated as well as the expression of genes involved in microbiota regulation.

Single Nucleotide Polymorphisms and Post-operative Complications Following Major Gastrointestinal Surgery: a Systematic Review and Meta-analysis

BACKGROUND

The human genome is an under-researched area of pre-operative risk stratification. Studies of genetic polymorphisms and their associations with acute post-operative complications in gastrointestinal surgery have reported statistically significant results, but have varied in methodology, genetic variations studied, and conclusions reached. To provide clarity, we conducted a systematic review and meta-analysis of single nucleotide polymorphisms and their association with post-operative complications after major gastrointestinal surgery.

METHODS

We performed a literature search using Ovid MEDLINE and Web of Science databases. Studies were included if they investigated genetic polymorphisms and their associations with post-operative complications after major gastrointestinal surgery. We extracted clinical and genetic data from each paper and assessed for quality against the STrengthening the REporting of Genetic Association Studies (STREGA) guidelines. Odds ratios were presented, with 95% confidence intervals, to assess strengths of association. We conducted a meta-analysis on TNF-α-308, which had been assessed in three papers.

RESULTS

Our search returned 68 papers, of which 5 were included after screening and full-text review. Twenty-two different single nucleotide polymorphisms (SNPs) were investigated in these studies. We found that all papers were genetic association studies, and had selected SNPs related to inflammation. The outcome investigated was most commonly post-operative infection, but also anastomotic leak and other non-infectious complications. Statistically significant associations were found for TNF-α-308, IL-10-819, PTGS2-765 and IFN-γ-874. There was significant variability in study quality and methodology. We conducted a meta-analysis on associations between the TNF-α-308 polymorphism and post-operative infection and report an OR of 1.18 (CI 0.27-5.21).

CONCLUSIONS

We found biologically plausible associations between SNPs involved in inflammation and post-operative infection, but the available data were too limited and of insufficient quality to reach definitive conclusions. Further work is needed, including genome-wide association studies (GWAS).

NOD2 Genetic Variants Predispose One of Two Familial Adenomatous Polyposis Siblings to Pouchitis Through Microbiome Dysbiosis

BACKGROUND AND AIMS

Individuals with familial adenomatous polyposis (FAP) may undergo a total proctocolectomy with ileal pouch-anal anastomosis (IPAA) to surgically treat their disease. Inflammation of the ileal pouch, termed pouchitis, is uncommon in FAP patients but prevalent in patients who received IPAA for ulcerative colitis, a type of inflammatory bowel disease (IBD).

METHODS AND RESULTS

We report on two FAP siblings, living in the same household, who underwent IPAA surgery within one week of each other. Their mother also had an IPAA for FAP. One sibling developed pouchitis while his brother and mother have remained pouchitis-free. We investigated the genetic and microbial factors that might explain the development of pouchitis in the one sibling. We surveyed DNA isolated from the two brothers and their parents for NOD2 IBD risk variants by Sanger sequencing. The composition of mucosa-associated bacteria was analyzed by 16S rRNA gene sequencing on terminal ileum and rectal tissue collected at the time of surgical resection from the two brothers. The sibling with pouchitis inherited the IBD-associated risk alleles for NOD2 (rs17221417 and rs2076756) from his healthy father. Both the mother and unaffected brother lacked these variants. Microbiome sequencing of the terminal ileum and rectum found reduced levels of potentially 'beneficial' bacteria (Faecalibacterium prausnitzii, Bacteroides, and Ruminococcaceae) in the sibling with pouchitis relative to his brother.

CONCLUSION

These findings suggest that the NOD2 signaling pathway may contribute to intrinsic bacterial dysbiosis which is pre-existing and which may then predispose individuals to pouchitis after IPAA surgery.

Alicaforsen in the treatment of pouchitis

Alicaforsen is a 20-base antisense oligonucleotide inhibiting ICAM-1 production, which is an important adhesion molecule involved in leukocyte migration and trafficking to the site of inflammation. Hitherto, alicaforsen has been granted orphan drug designation and is prescribed as an unlicensed medicine in accordance with international regulation for the treatment of pouchitis and left-sided ulcerative colitis. Given the positive results evolving from one open-label trial and one case series in patients with chronic refractory pouchitis, US FDA has agreed to a rolling submission for a license application for the treatment of pouchitis, which has been recently initiated. Whether alicaforsen leads to higher endoscopic and clinical remission rates as placebo and whether the response can be maintained in the long-term in larger studies is yet unknown. An ongoing multicenter international Phase III trial will definitely address these unanswered questions.

Pouchitis after ileal pouch-anal anastomosis in ulcerative colitis: Diagnosis, management, risk factors, and incidence

Restorative proctocolectomy with ileal pouch-anal anastomosis has been the surgical treatment of choice for patients with ulcerative colitis who require surgery. Quality of life after this procedure is satisfactory in most cases; however, pouchitis is a troublesome condition involving inflammation of the ileal pouch. When a patient presents with symptoms of pouchitis, such as increased bowel movements, mucous and/or bloody exudates, abdominal cramps, and fever, endoscopy is essential for a precise diagnosis. The proximal ileum and rectal cuff, as well as the ileal pouch, should be endoscopically observed. The reported incidence of pouchitis ranges from 14% to 59%, and antibiotic therapy is the primary treatment for acute pouchitis. Chronic pouchitis includes antibiotic-dependent and refractory pouchitis. Intensive therapy including antitumor necrosis factor antibodies and steroids may be necessary for antibiotic-refractory pouchitis, and pouch failure may occur despite such intensive treatment. Reported risk factors for the development of pouchitis include presence of extraintestinal manifestations, primary sclerosing cholangitis, non-smoking, and postoperative non-steroidal anti-inflammatory drug usage. In the present review, we focus on the diagnosis, endoscopic features, management, incidence, and risk factors of pouchitis in patients with ulcerative colitis who underwent ileal pouch-anal anastomosis.

Indications and surgical options for small bowel, large bowel and perianal Crohn's disease

Despite advancements in medical therapy of Crohn's disease (CD), majority of patients with CD will eventually require surgical intervention, with at least a third of patients requiring multiple surgeries. It is important to understand the role and timing of surgery, with the goals of therapy to reduce the need for surgery without increasing the odds of emergency surgery and its associated morbidity, as well as to limit surgical recurrence and avoid intestinal failure. The profile of CD patients requiring surgical intervention has changed over the decades with improvements in medical therapy with immunomodulators and biological agents. The most common indication for surgery is obstruction from stricturing disease, followed by abscesses and fistulae. The risk of gastrointestinal bleeding in CD is high but the likelihood of needing surgery for bleeding is low. Most major gastrointestinal bleeding episodes resolve spontaneously, albeit the risk of re-bleeding is high. The risk of colorectal cancer associated with CD is low. While current surgical guidelines recommend a total proctocolectomy for colorectal cancer associated with CD, subtotal colectomy or segmental colectomy with endoscopic surveillance may be a reasonable option. Approximately 20%-40% of CD patients will need perianal surgery during their lifetime. This review assesses the practice parameters and guidelines in the surgical management of CD, with a focus on the indications for surgery in CD (and when not to operate), and a critical evaluation of the timing and surgical options available to improve outcomes and reduce recurrence rates.

Review article: the pathogenesis of pouchitis

BACKGROUND

A total proctocolectomy followed by ileal pouch-anal anastomosis is a potentially curative surgery for ulcerative colitis or familial adenomatous polyposis. About 5-35% of patients with ulcerative colitis and 0-11% of patients with familial adenomatous polyposis develop subsequent inflammation of the ileal pouch termed pouchitis.

AIM

To provide a comprehensive analysis of the research studying the possible pathogenesis of pouchitis. The goals were to identify promising areas of investigation, to help focus clinicians, researchers and patients on how to better understand and then potentially manage ileal pouchitis, and to provide avenues for future research investigations.

METHODS

This review examined manuscripts from 1981 to 2015 that discussed and/or proposed hypotheses with supportive evidence for the potential underlying pathogenic mechanism for pouchitis.

RESULTS

The pathogenesis of pouchitis is not definitively understood, but various hypotheses have been proposed, including (i) recurrence of ulcerative colitis, (ii) dysbiosis of the ileal pouch microbiota, (iii) deprivation of nutritional short-chain fatty acids, (iv) mucosal ischaemia and oxygen-free radical injury, (v) host genetic susceptibility and (vi) immune dysregulation. However, none of these alone are able to fully explain pouchitis pathogenesis.

CONCLUSIONS

Pouchitis, similar to inflammatory bowel disease, is a complex disorder that is not caused by any one single factor. More likely, pouchitis occurs through a combination of both dysregulated host inflammatory mechanisms and interaction with luminal microbiota.

Nonbloody Diarrhea but Not Significant Weight Loss at Diagnosis Is Associated with the Development of Denovo Crohn's Disease After Ileal Pouch-anal Anastomosis for Ulcerative Colitis

BACKGROUND

Denovo Crohn's disease (CD) develops in 5% to 10% of patients after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC) leading to increased morbidity and rates of pouch failure. Initial nonbloody diarrhea and weight loss at diagnosis are independent risk factors for a change in diagnosis from UC to CD in nonsurgical patients. We investigated whether these features were risk factors for denovo CD in a longitudinal cohort of patients with UC undergoing IPAA.

METHODS

Prospective profiles of patients with UC undergoing IPAA followed over a 22-year period by 1 surgeon were analyzed. Denovo CD was diagnosed when mucosal inflammation (5 or more ulcers) involved the small bowel mucosa proximal to the ileal pouch any time after surgery and/or when a pouch fistula or other perianal complication developed more than 3 months after ileostomy closure. Patients with inflammatory bowel disease unclassified, acute pouchitis, chronic pouchitis, and those lost to follow-up were excluded from analysis. Cox regression analysis was performed for statistical significance.

RESULTS

Of the 199 study patients included in the analysis, denovo CD developed in 42 patients (21%). Patients who developed denovo CD had an increased incidence of nonbloody diarrhea (n = 12; 29%) compared with patients who had no evidence of pouch inflammation (n = 25; 16%) (P = 0.03). In contrast, the incidence of weight loss was not significantly increased in patients with denovo CD (n = 7; 17%) compared with patients who never had pouch inflammation (n = 16; 10%) (P = 0.12).

CONCLUSIONS

Initial nonbloody diarrhea is associated with denovo CD after IPAA. This association warrants close consideration before surgery.

The current place of probiotics and prebiotics in the treatment of pouchitis

Pouchitis is a common complication in patients undergoing restorative proctocolectomy for ulcerative colitis. Therapeutic attempts include manipulations of pouch flora composition. In this review, we bring together the evidence supporting the use of probiotics and prebiotics in pouchitis patients, to clarify the place of these treatments in current therapeutic regimens.

Complex host genetics influence the microbiome in inflammatory bowel disease

BACKGROUND

Human genetics and host-associated microbial communities have been associated independently with a wide range of chronic diseases. One of the strongest associations in each case is inflammatory bowel disease (IBD), but disease risk cannot be explained fully by either factor individually. Recent findings point to interactions between host genetics and microbial exposures as important contributors to disease risk in IBD. These include evidence of the partial heritability of the gut microbiota and the conferral of gut mucosal inflammation by microbiome transplant even when the dysbiosis was initially genetically derived. Although there have been several tests for association of individual genetic loci with bacterial taxa, there has been no direct comparison of complex genome-microbiome associations in large cohorts of patients with an immunity-related disease.

METHODS

We obtained 16S ribosomal RNA (rRNA) gene sequences from intestinal biopsies as well as host genotype via Immunochip in three independent cohorts totaling 474 individuals. We tested for correlation between relative abundance of bacterial taxa and number of minor alleles at known IBD risk loci, including fine mapping of multiple risk alleles in the Nucleotide-binding oligomerization domain-containing protein 2 (NOD2) gene exon. We identified host polymorphisms whose associations with bacterial taxa were conserved across two or more cohorts, and we tested related genes for enrichment of host functional pathways.

RESULTS

We identified and confirmed in two cohorts a significant association between NOD2 risk allele count and increased relative abundance of Enterobacteriaceae, with directionality of the effect conserved in the third cohort. Forty-eight additional IBD-related SNPs have directionality of their associations with bacterial taxa significantly conserved across two or three cohorts, implicating genes enriched for regulation of innate immune response, the JAK-STAT cascade, and other immunity-related pathways.

CONCLUSIONS

These results suggest complex interactions between genetically altered host functional pathways and the structure of the microbiome. Our findings demonstrate the ability to uncover novel associations from paired genome-microbiome data, and they suggest a complex link between host genetics and microbial dysbiosis in subjects with IBD across independent cohorts.

Clostridium difficile infection in the postcolectomy patient

Clostridium difficile infection (CDI) after total colectomy has been increasingly recognized over the past decade. C. difficile enteritis (CDE) is a rare occurrence, whereas C. difficile pouchitis (CDP) has been reported in approximately 10% of symptomatic patients seen at a referral center for pouch dysfunction. Similar to colonic CDI in the general population, antibiotic use and comorbid diseases may be risk factors for CDE. In contrast, the postoperative use of antibiotics does not seem to be associated with CDP, whereas male gender, recent hospitalization, and presurgery antibiotic use were shown to be risk factors for CDP. C. difficile is capable of colonizing all intestinal sites, including the ileal pouch. Similarities with the colon at physiological and cellular levels may contribute to the susceptibility of the ileal pouch to CDI. Postcolectomy CDI likely represents a disease spectrum from asymptomatic colonization to severe symptomatic infection. CDI should be considered in ostomy patients with fever and increased ileostomy output and in ileal pouch patients with a change in "normal" symptom pattern or chronic antibiotic-refractory pouchitis. Sensitive and specific methods for detection of CDI are available, and endoscopy is useful in evaluating the patient with suspected CDE or CDP, although pseudomembranes are typically absent. Vancomycin is used as the first-line therapy for CDP and may be warranted for patients with inflammatory bowel disease with CDE. Fecal microbiota transplantation has found its use in the management of severe or antibiotic refractory CDP, but this approach requires evaluation for the management of refractory CDE.

Auto-inflammatory diseases in ileal pouch patients with NOD2/CARD15 mutations

Pouchitis is common in ulcerative colitis patients undergoing total proctocolectomy with ileal pouch-anal anastomosis, and chronic antibiotic-refractory pouchitis occurs in a subgroup of the patients. Auto-inflammatory diseases are characterized by systemic inflammation, manifesting as periodic fever, rash, arthritis, and serositis. We describe two cases with ulcerative colitis and an ileal pouch, who presented with extra-intestinal manifestations and genetic features atypical for inflammatory bowel disease alone. Case 1 had a spectrum of clinical manifestations including refractory pouchitis, intermittent fevers, polyarthralgia, and pericarditis. Case 2 presented with oral ulcers, migratory oligoarthritis, and periodic papular rash. Genetic testing in both cases revealed mutations of the NOD2/CARD15 gene, including the IVS8⁺¹⁵⁸ mutation commonly detected among patients with NOD2-associated auto-inflammatory disease. Both of the patients demonstrated clinical improvement of these diverse systemic complaints following treatment with immunosuppressive and anti-inflammatory therapies.

Multi-omics analysis of inflammatory bowel disease

Crohn's disease and ulcerative colitis, known together as inflammatory bowel disease (IBD), are severe autoimmune disorders now causing gut inflammation and ulceration, among other symptoms, in up to 1 in 250 people worldwide. Incidence and prevalence of IBD have been increasing dramatically over the past several decades, although the causes for this increase are still unknown. IBD has both a complex genotype and a complex phenotype, and although it has received substantial attention from the medical research community over recent years, much of the etiology remains unexplained. Genome-wide association studies have identified a rich genetic signature of disease risk in patients with IBD, consisting of at least 163 genetic loci. Many of these loci contain genes directly involved in microbial handling, indicating that the genetic architecture of the disease has been driven by host-microbe interactions. In addition, systematic shifts in gut microbiome structure (enterotype) and function have been observed in patients with IBD. Furthermore, both the host genotype and enterotype are associated with aspects of the disease phenotype, including location of the disease. This provides strong evidence of interactions between host genotype and enterotype; however, there is a lack of published multi-omics data from IBD patients, and a lack of bioinformatics tools for modeling such systems. In this article we discuss, from a computational biologist's point of view, the potential benefits of and the challenges involved in designing and analyzing such multi-omics studies of IBD.

Clostridium difficile infection in patients with ileal pouches

Clostridium difficile (C. difficile) infection (CDI) following total proctocolectomy and ileal pouch-anal anastomosis has been increasingly recognized over the past 5 years. CDI of the ileal pouch has been recognized in ∼10% of symptomatic patients seen at a tertiary referral center for pouch dysfunction. In contrast to colonic CDI in the general population or in patients with inflammatory bowel disease, postoperative antibiotic exposure and the use of immunosuppressive agents or proton pump inhibitors do not appear to be associated with CDI of the pouch. Male gender, recent hospitalization, and presurgery antibiotic use were shown to be risk factors for ileal pouch CDI. The ileal pouch may be susceptible to CDI owing to similarities with the colon at physiological and structural levels. Postcolectomy CDI likely represents a spectrum of disease processes, varying from asymptomatic colonization to severe symptomatic infection. CDI should be considered in any patient with an ileal pouch presenting with a change in "normal" symptom pattern or treatment-refractory disease. Sensitive and specific methods for the detection of CDI are available, and pouchoscopy is a valuable tool in the evaluation of the patient with symptomatic CDI of the pouch. At a referral center for pouch dysfunction, vancomycin is used as the first-line therapy for ileal pouch CDI. Fecal microbiota transplantation may find use in the management of severe or antibiotic refractory CDI-related pouchitis.

NOD2 gene mutations in ulcerative colitis: useless or misunderstood?

PURPOSE

NOD2 mutations have been linked to an increased risk of Crohn's disease and to some of its phenotypes. The association between NOD2 mutations and susceptibility to ulcerative colitis (UC) remains somewhat controversial and potential correlations between these mutations and UC phenotype have not been studied.

AIM

To assess whether NOD2 mutations are a risk factor for UC in Portugal and if there are any genotype-phenotype correlations in these patients.

METHODS

The three main NOD2 mutations were searched in 200 patients with UC and in 202 healthy controls.

RESULTS

NOD2 mutations were present in 28 patients with UC (14.0 %) and in 27 controls (13.4 %) (p = 0.853). Mutation carriers were more likely to receive steroids during the first year of disease than non-carriers (54.2 % vs. 29.6 %, p = 0.018) and among these patients the need for intravenous administration was more frequent in those with the R702W polymorphism (90.0 % vs. 45.5 %, p = 0.014). In patients with severe colitis admitted for intravenous steroids, a greater proportion of mutation carriers was considered intravenous-steroid refractory and required salvage therapy (90.0 % vs. 38.1 %, p = 0.004). Patients with NOD2 mutation were submitted to colectomy more frequently than non-carriers (17.9 % vs. 4.1 %. p = 0.015). No correlation with the need for immunosuppressants/immunomodulators was found.

CONCLUSIONS

In the Portuguese population, NOD2 mutations do not increase the risk of UC but are associated with a more aggressive course including greater need of steroids in the first year, increased incidence of intravenous-steroid refractoriness and a higher colectomy rate.

The association between autoimmunity and pouchitis

: Restorative proctocolectomy with ileal pouch-anal anastomosis is commonly used in the management of ulcerative colitis. Inflammation of the ileal pouch reservoir, or pouchitis, is a common complication of ileal pouch-anal anastomosis that is incompletely understood. Risk factors including nonsmoker status and primary sclerosing cholangitis have been linked with pouchitis development, but the etiopathogenesis of pouchitis remains poorly defined. Pouchitis is more commonly a complication of ileal pouch-anal anastomosis performed in patients with ulcerative colitis, and similar to ulcerative colitis, chronic pouchitis is associated with extraintestinal manifestations and other diseases of immune origin, suggesting overlap in the disease pathogenesis. It is becoming apparent that pouchitis encompasses clinically distinct subtypes based on the response or lack of response to antibiotic therapy. There is also emerging evidence of the role of autoimmunity in a subgroup of patients with pouchitis, including patients with concurrent primary sclerosing cholangitis, seropositivity for immunoglobulin G4, or infiltration of immunoglobulin G4-expressing plasma cells in the pouch mucosa. The identification of underlying autoimmunity may have important clinical implications in the diagnosis, subclassification, and management of pouchitis.

Gene expression profiles of ileal inflammatory bowel disease correlate with disease phenotype and advance understanding of its immunopathogenesis

BACKGROUND

Pouchitis may develop in patients with ulcerative colitis undergoing pouch surgery. We aimed to evaluate the de novo inflammation developing in the ileal pouch, hypothesizing that it may be similar to ileitis in Crohn's disease (CD).

METHODS

Patients with ulcerative colitis pouch were prospectively recruited, stratified according to disease behavior into normal pouch, chronic pouchitis, and Crohn's-like disease of the pouch groups, and compared with controls. Gene expression analysis was performed using microarrays, validated by real-time polymerase chain reaction. Gene ontology and clustering were evaluated using bioinformatic tools.

RESULTS

Sixty-six subjects were recruited. Although in ulcerative colitis ileum there were no significant gene expression alterations, patients with normal pouch had 168 significant alterations (fold change ≥ 2, corrected P ≤ 0.05). In chronic pouchitis and Crohn's-like disease of the pouch, 490 and 1152 alterations were detected, respectively. High degree of overlap in gene expression alterations between the pouch subgroups was demonstrated. The magnitude of change correlated with pouch disease behavior. Gene expression profiles were more reflective of disease behavior compared with inflammatory indices. CD ileitis had 358 alterations, with a 90% overlap with pouchitis. Gene ontology analyses revealed multiple biological processes associated with pouch inflammation, including response to chemical stimulus, small molecule metabolic and immune system processes, and specific infection-related pathways such as Staphylococcus aureus, leishmaniasis, and tuberculosis.

CONCLUSIONS

Gene alterations in pouch inflammation and CD overlap, suggesting that inflammatory bowel diseases is a spectrum, rather than distinct diseases. Pouchitis may serve as a model of CD. The novel pathways associated with inflammatory bowel diseases may decipher pathophysiology and suggest targets for intervention.

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.

Chronic use of PPI and H2 antagonists decreases the risk of pouchitis after IPAA for ulcerative colitis

INTRODUCTION

Bacteria have been implicated in the development of pouchitis after ileal pouch anal anastomosis. The change in gastric pH with the use of proton pump inhibitors and H(2) antagonists may lead to alteration of enteric bacteria. We hypothesized that chronic use of these medications would decrease the incidence of pouchitis.

METHODS

Patients who had undergone ileal pouch anal anastomosis for ulcerative colitis were classified by history of pouchitis. Patients were further classified by their use of proton pump inhibitors, H(2) blockers, antacids, and other known risk factors for pouchitis.

RESULTS

Eighty-five patients were identified. There was a statistically significant increase in the use of daily acid suppression in patients without pouchitis. There was also a statistically significant increase in the use of antacids in patients without pouchitis. Occasional use of acid suppression did not alter the rate of pouchitis.

CONCLUSIONS

Our data suggest that the daily use of proton pump inhibitors, H(2) antagonists, or antacids is associated with a decreased risk of pouchitis in ulcerative colitis. Occasional use of these agents did not seem to afford the same protection. These data suggest that altering the pH of the gastrointestinal tract may influence the development of pouchitis.

Diagnosis and differential diagnosis of Crohn's disease of the ileal pouch

Approximately 20%-30% of patients with ulcerative colitis will eventually require colectomy despite recent advances in medical therapy. Ileal pouch-anal anastomosis has become the surgical treatment of choice. A subset of patients with ileal pouches can develop Crohn's disease or a Crohn's-disease-like condition of the ileal pouch after surgery. Diagnosis, differential diagnosis, and management of Crohn's disease of the ileal pouch have been challenging. A combined assessment of clinical history, endoscopy, histology, abdominal/pelvic imaging, and examination under anesthesia is often necessary for accurate diagnosis, disease classification, management, and prognosis. A multidisciplinary approach with gastroenterologists, colorectal surgeons, gastrointestinal pathologists, and radiologists is advocated.

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.

Genetic risk profiling and gene signature modeling to predict risk of complications after IPAA

BACKGROUND

Severe pouchitis and Crohn's disease-like complications are 2 adverse postoperative complications that confound the success of the IPAA in patients with ulcerative colitis. To date, approximately 83 single nucleotide polymorphisms within 55 genes have been associated with IBD.

OBJECTIVE

The aim of this study was to identify single-nucleotide polymorphisms that correlate with complications after IPAA that could be utilized in a gene signature fashion to predict postoperative complications and aid in preoperative surgical decision making.

DESIGN

One hundred forty-two IPAA patients were retrospectively classified as "asymptomatic" (n = 104, defined as no Crohn's disease-like complications or severe pouchitis for at least 2 years after IPAA) and compared with a "severe pouchitis" group (n = 12, ≥ 4 episodes pouchitis per year for 2 years including the need for long-term therapy to maintain remission) and a "Crohn's disease-like" group (n = 26, presence of fistulae, pouch inlet stricture, proximal small-bowel disease, or pouch granulomata, occurring at least 6 months after surgery). Genotyping for 83 single-nucleotide polymorphisms previously associated with Crohn's disease and/or ulcerative colitis was performed on a customized Illumina genotyping platform. The top 2 single-nucleotide polymorphisms statistically identified as being independently associated with each of Crohn's disease-like and severe pouchitis were used in a multivariate logistic regression model. These single-nucleotide polymorphisms were then used to create probability equations to predict overall chance of a positive or negative outcome for that complication.

RESULTS

The top 2 single-nucleotide polymorphisms for Crohn's disease-like complications were in the 10q21 locus and the gene for PTGER4 (p = 0.006 and 0.007), whereas for severe pouchitis it was NOD2 and TNFSF15 (p = 0.003 and 0.011). Probability equations suggested that the risk of these 2 complications greatly increased with increasing number of risk alleles, going as high as 92% for severe pouchitis and 65% for Crohn's disease-like complications.

CONCLUSION

In this IPAA patient cohort, mutations in the 10q21 locus and the PTGER4 gene were associated with Crohn's disease-like complications, whereas mutations in NOD2 and TNFSF15 correlated with severe pouchitis. Preoperative genetic analysis and use of such gene signatures hold promise for improved preoperative surgical patient selection to minimize these IPAA complications.

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.