Pouchitis: pathophysiology and management

Comparative Effectiveness of Bile Acid Sequestrants and Antibiotics in the Management of Acute Pouchitis: A Matched Cohort Study from the United States

BACKGROUND AND AIMS

Bile acid sequestrants (BAS) are an emerging option for treatment of pouchitis. We aimed to compare BAS monotherapy, antibiotics, and combination therapy with both in the treatment of pouchitis after ileal pouch-anal anastomosis (IPAA) for ulcerative colitis (UC).

METHODS

We conducted a retrospective cohort study using the US-Collaborative TriNetX database to identify patients with acute pouchitis and UC. Treatment groups were divided into BAS (cholestyramine, colesevelam, colestipol), antibiotics (ciprofloxacin and/or metronidazole), and combination therapy of both BAS and antibiotics. Primary outcomes were failure of initial therapy (early relapse or nonresponse) and the development of recurrent pouchitis in the first 12 months after an initial episode of pouchitis.

RESULTS

Our analysis included 1,136 patients (mean age: 37.8 ± 15.4 years, and 45.9% female) of whom 727 (64%) were diagnosed with recurrent pouchitis. After adjusting for confounders by propensity-score matching, there was no significant difference in the odds of early relapse or nonresponse with BAS compared with antibiotic monotherapy (aOR: 0.74; 95% CI: 0.40-1.38; p = 0.34) or combination therapy (aOR: 0.94; 95% CI: 0.47-1.88; p = 0.86). Patients treated with BAS had a statistically significant lower recurrent pouchitis rate (aHR: 0.57; 95% CI: 0.42-0.79; p < 0.001) compared with patients treated with antibiotics. Patients treated with BAS had a statistically significant longer time (median: 225 days) to recurrent pouchitis (p < 0.001) compared to antibiotics (median: 99 days).

CONCLUSION

Using real-world evidence regarding treatment of pouchitis compared to standard antibiotic therapy, BAS monotherapy was not inferior for initial treatment response and significantly prolonged time to recurrent pouchitis.

Management of J-pouch Complications

Most patients with a restorative proctocolectomy with ileal pouch-anal anastomosis do well; however, properly identifying acute and chronic complications are paramount to managing and correcting these complications to allow for optimal pouch function and avoid pouch failure. Inflammatory conditions like pouchitis may require ongoing medical therapy, but surgical intervention may be needed to correct any underlying septic complication and to repair any structural disorders. Patients with signs of pouch failure may be candidates for pouch augmentation or redo pouch surgery and should be referred to high-volume centers before pouch excision is offered if the patient wishes to avoid a permanent ileostomy.

Mirikizumab for the treatment of chronic antibiotic-refractory pouchitis

The current standard of care for the definitive surgical treatment of complicative ulcerative colitis is a continence-preserving proctocolectomy with the creation of an ileal pouch anal anastomosis. In addition to structural and functional disorders, pouchitis of the J-pouch is a common phenomenon, typically well responsive to antimicrobial therapy. However, sometimes chronic antibiotic-refractory pouchitis occurs, most often due to not completely understood multifactorial pathomechanisms. While high-quality evidence is available only for anti-integrin therapy, the role of advanced therapy, i.e., cytokine-antibodies or small molecules in the treatment of chronic antibiotic-refractory pouchitis (CARP), is emerging.This case demonstrates a successful induction treatment of CARP with the novel p19-selective IL-23-targeted antibody mirikizumab.

Histopathologic Evaluation and Single-Cell Spatial Transcriptomics of the Colon Reveal Cellular and Molecular Abnormalities Linked to J-Pouch Failure in Patients with Inflammatory Bowel Disease

Background and Aims

Total abdominal colectomy (TAC) with a staged ileal pouch-anal anastomosis (IPAA) is a common surgical treatment for ulcerative colitis (UC). However, a significant percentage of patients experience pouch failure, leading to morbidity. This retrospective case-control study identified histopathological features of the TAC specimen associated with pouch failure and investigated the molecular mechanisms of this susceptibility using single-cell spatial transcriptomics.

Methods

We analyzed a cohort of 417 patients who underwent IPAA between 2000-2010 at the University of Chicago Medical Center for up to 18 years. Histological examination of TAC specimens focused on disease activity, depth of inflammation, and specific features, including granulomas and deep ulcers. A subset of patients was profiled using single-cell spatial transcriptomics to map gene expression and immune cell interactions in relation to the risk of pouch failure.

Results

The 18-year pouch failure risk was 23%, with post-procedure diagnosis of CD as a major risk factor (HR = 4.3, 95% CI: 2.3-8.1) as well as high-risk histologic features, including deep chronic inflammation (HR = 21, 95% CI: 11-41) and severe disease activity (HR = 14, 95% CI: 5.7-32) in TAC specimens. Spatial transcriptomics showed immune infiltration of T and myeloid cells, reduced myocyte-glial interactions, and cytokine signaling pathways such as IL-10, IL-1β, and type I/II interferons, associated with an increased risk of pouch failure.

Conclusion

Histological features and spatial molecular profiling are predictive of IPAA failure. These findings support the use of histologic evaluation and targeted molecular analysis of the TAC specimen to identify high-risk patients and improve IPAA outcomes.

Pouchitis unveiled: exploring clinical features, diagnosis, and cutting-edge treatments

Last decades led to a revolution in the management of ulcerative colitis (UC), due to the development of novel advanced therapies and the identification of increasingly ambitious therapeutic goals. Nevertheless, a subset of patients, refractory to available therapies, still requires proctocolectomy with ileal pouch-anal anastomosis (IPAA). Pouchitis, an inflammatory condition of the ileal pouch, is the most common long-term complication of IPAA, affecting almost one-half of patients in the first 10 years after surgery. Symptoms of pouchitis include increased stool frequency, urgency, and abdominal discomfort, significantly affecting patients' quality of life. Traditionally the mainstay treatment of acute pouchitis involves the use of antibiotics, but one-fifth of patients develop chronic pouchitis (CP), which may be dependent or resistant to antibiotics, posing significant challenges in the management of this condition. Currently, there is still no consensus on the optimal management for CP, though recent progress in understanding the pathophysiology of pouchitis has paved the way for innovative therapeutic approaches, based on biological therapies and small molecules. This review aims to discuss the recent advanced therapies available for pouchitis and provide a comprehensive review on the topic to guide physicians in their clinical practice.

Diagnosis and Medical Treatment of Acute and Chronic Idiopathic Pouchitis in Inflammatory Bowel Disease

Despite the decreased rates in inflammatory bowel disease (IBD) colectomies due to high advances in therapeutic options, a significant number of patients still require proctocolectomy with ileal pouch-anal anastomosis (IPPA) for ulcerative colitis (UC). Pouchitis is the most common complication in these patients, where up to 60% develop one episode of pouchitis in the first two years after UC surgery with IPAA with severe negative impact on their quality of life. Acute cases usually respond well to antibiotics, but 15% of patients will still develop a refractory disease that requires the initiation of advanced immunosuppressive therapies. For chronic idiopathic pouchitis, current recommendations suggest using the same therapeutic options as for IBD in terms of biologics and small molecules. However, the available data are limited regarding the effectiveness of different biologics or small molecules for the management of this condition, and all evidences arise from case series and small studies. Vedolizumab is the only biologic agent that has received approval for the treatment of adult patients with moderately to severely active chronic refractory pouchitis. Despite the fact that IBD treatment is rapidly evolving with the development of novel molecules, the presence of pouchitis represents an exclusion criterion in these trials. Recommendations for the approach of these conditions range from low to very low certainty of evidence, resulting from small randomized controlled trials and case series studies. The current review focuses on the therapeutic management of idiopathic pouchitis.