Characteristics of extremely early-onset pouchitis after proctocolectomy with ileal pouch-anal anastomosis

Navigating Chronic Pouchitis: Pathogenesis, Diagnosis, and Management

Chronic pouchitis affects 13% to 17% of patients with ileal pouch-anal anastomosis and ulcerative colitis, and 20% with a history of acute pouchitis. It is classified by antibiotic responsiveness into chronic antibiotic-dependent pouchitis and chronic antibioticrefractory pouchitis. Pathogenesis of chronic pouchitis can range from microbially mediated to more antibiotic-resistant and immune-mediated processes. A diagnostic index combining clinical, endoscopic, and histologic components is essential for clinical practice and research. In chronic antibiotic-dependent pouchitis, remission is managed with microbiota- or immune-targeted therapies. For chronic antibiotic-refractory pouchitis, immune-directed therapy is primary, with vedolizumab recommended for first-line treatment. Other advanced therapies rely on less definitive evidence, and efficacy may be reduced by precolectomy exposure. This article reviews the pathogenesis, diagnosis, and management of chronic pouchitis.

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.

Association Between Pouchitis and Ulcerative Colitis–Related Gastroduodenitis After Restorative Proctocolectomy

Background

Ulcerative colitis (UC)–related disorders, which include pouchitis and gastroduodenitis (GDUC), can develop even after restorative proctocolectomy (RPC). However, the etiology of and predictive factors for these disorders remain unclear.

Aim

We analyzed the incidence and associations between pouchitis and GDUC.

Methods

UC patients who underwent RPC at the Hyogo College of Medicine between 2009 and 2012 were included in this study. The postoperative results of examinations and the clinical courses were analyzed.

Results

A total of 122 patients examined by endoscopy after RPC out of 188 patients who underwent follow-up at the outpatient clinic were included. Pouchitis developed in 56 of 188 patients. The cumulative incidence of pouchitis was 32.1% at 5 years. GDUC was identified in 14 of 122 patients. In the Cox regression analyses, GDUC was selected as an independent predictive factor for pouchitis (hazard ratio, 2.32; P = 0.025).

Conclusion

An association between GDUC and pouchitis after RPC was found. However, this association should be evaluated in a further study because both complications might exist coincidentally as components of a systemic immune disorder, and the etiology of each complication should be determined.

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.

Pouchitis Is a Common Complication in Patients With Familial Adenomatous Polyposis Following Ileal Pouch-Anal Anastomosis

BACKGROUND & AIMS

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgical procedure most commonly selected for patients with familial adenomatous polyposis (FAP) or ulcerative colitis that is refractive to medical treatment. Pouchitis is the most common complication in patients with ulcerative colitis after IPAA, but is thought to rarely occur in patients with FAP. We investigated the frequency of pouchitis and other pouch-related complications in patients with FAP after IPAA.

METHODS

We performed a retrospective cohort study of all patients with FAP who underwent IPAA at a single tertiary institution from 1992 through 2015 (n = 113). Patients were identified using International Classification of Diseases-9 diagnostic and current procedural terminology codes. We obtained relevant demographic and clinical data from patients' electronic medical records. The frequencies of pouchitis and pouch-related complications were determined.

RESULTS

Twenty-five patients (22.1%) developed pouchitis (mean time to pouchitis, 4.1 years) and 88 did not (77.9%). Patients with pouchitis showed a trend toward developing late (>90 days after IPAA) pouch-related complications (56.0% of patients with pouchitis developed late complications, compared with 36.4% without). In patients who developed pouchitis, the disease course was acute in 72.0% and chronic in 28.0%. Of those treated, 69.6% responded to antibiotics, 13.0% became dependent on antibiotics, and 13.0% developed antibiotic resistance.

CONCLUSIONS

Pouchitis is more prevalent in patients with FAP than previously believed. Although pouchitis seems to occur later in patients with FAP than in patients with ulcerative colitis, and have a milder course, it should be considered a common complication among patients with FAP following IPAA.

Gene expression alterations in ulcerative colitis patients after restorative proctocolectomy extend to the small bowel proximal to the pouch

OBJECTIVES

To evaluate molecular profiles in the small bowel (SB) mucosa proximal to the pouch in ulcerative colitis (UC) patients after pouch surgery.

DESIGN

Patients were prospectively recruited and stratified according to disease behaviour: normal pouch (NP), chronic pouchitis (CP), and Crohn's-like disease of the pouch (CLDP). Biopsies obtained from the pouch and the normal-appearing proximal SB (40 cm proximal to the anal verge) were compared to ileal biopsies from normal controls (NC). A histopathological score based on the degree of polymorphonuclear and mononuclear infiltrates was used to assess inflammation in the pouch and the proximal SB. Gene expression analysis was performed using microarrays, and validated by real-time PCR. Gene ontology and clustering were evaluated by bioinformatics.

RESULTS

Thirty-six subjects were recruited (age 18-71 years, 16 males). Histopathology scores demonstrated minimal differences in the normal-appearing proximal SB of all groups. Nonetheless, significant (fold change ≥2, corrected p [FDR] ≤ 0.05) molecular alterations in the proximal SB were detected in all groups (NP n=9; CP n=80; and CLDP n=230) compared with NC. The magnitude of DUOX2 alteration in the proximal SB was highest. An increase of 6.0, 9.8 and 21.7 folds in DUOX2 expression in NP, CP, CLDP, respectively was observed. This was followed by alterations in MMP1, SLC6A14 and PGC. Gene alterations in the proximal SB overlapped with alterations within the pouch (76% and 97% overlap in CP and CLDP, respectively). Gene ontology analysis in the proximal SB and pouch were comparable.

CONCLUSIONS

Significant gene expression alterations exist in an apparently unaffected proximal SB. Alterations in the pouch and the proximal SB were comparable, suggesting that inflammation may not be limited to the pouch, but that it extends to the proximal SB.