Colectomy risk score predicts pouchitis in patients with ulcerative colitis

Normal Ileal Mucus Is Inadequate for Epithelial Protection in Ileal Pouch Mucosa

BACKGROUND

Clinical, nonspecific pouchitis is common after restorative proctocolectomy for ulcerative colitis, but its cause is unknown. A possible lack of protection for the ileal mucosa in its role as a reservoir for colonic-type bacteria may be the missing piece in defining the causes of pouchitis.

OBJECTIVE

The study aimed to review the causes of pouchitis and introduce the hypothesis that inadequate mucus protection in the pouch, combined with a predisposition to abnormal inflammation, is the most common cause of nonspecific pouchitis.

DATA SOURCES

Review of PubMed and MEDLINE for articles discussing pouchitis and intestinal mucus.

STUDY SELECTION

Studies published from 1960 to 2023. The main search terms were "pouchitis," and "intestinal mucus," whereas Boolean operators were used with multiple other terms to refine the search. Duplicates and case reports were excluded.

MAIN OUTCOME MEASURES

Current theories about the cause of pouchitis, descriptions of the role of mucus in the physiology of intestinal protection, and evidence of the effects of lack of mucus on mucosal inflammation.

RESULTS

The crossreference of "intestinal mucus" with "pouchitis" produced 9 references, none of which discussed the role of mucus in the development of pouchitis. Crossing "intestinal mucus" with "pouch" resulted in 32 articles, combining "pouchitis" with "barrier function" yielded 37 articles, and "pouchitis" with "permeability" yielded only 8 articles. No article discussed the mucus coat as a barrier to bacterial invasion of the epithelium or mentioned inadequate mucus as a factor in pouchitis. However, an ileal pouch produces a colonic environment in the small bowel, and the ileum lacks the mucus protection needed for this sort of environment. This predisposes pouch mucosa to bacterial invasion and chronic microscopic inflammation that may promote clinical pouchitis in patients prone to an autoimmune response.

LIMITATIONS

No prior studies address inadequate mucus protection and the origin of proctitis. There is no objective way of measuring the autoimmune tendency in patients with ulcerative colitis.

CONCLUSIONS

Studies of intestinal mucus in the ileal pouch and its association with pouchitis are warranted.

Acute Severe Ulcerative Colitis Is Associated With an Increased Risk of Acute Pouchitis

BACKGROUND

Pouchitis occurs in up to 80% of patients after total proctocolectomy (TPC) with ileal pouch-anal anastomosis (IPAA) and has been associated with microbial and host-related immunological factors. We hypothesized that a more robust immune response at the time of colectomy, manifested by acute severe ulcerative colitis (ASUC), may be associated with subsequent acute pouchitis.

METHODS

This was a retrospective cohort analysis of all patients with UC or indeterminate colitis complicated by medically refractory disease or dysplasia who underwent TPC with IPAA at Mount Sinai Hospital between 2008 and 2017 and at least 1 subsequent pouchoscopy. Acute pouchitis was defined according to the Pouchitis Disease Activity Index. Cox regression was used to assess unadjusted relationships between hypothesized risk factors and acute pouchitis.

RESULTS

A total of 416 patients met inclusion criteria. Of the 165 (39.7%) patients who underwent urgent colectomy, 77 (46.7%) were admitted with ASUC. Acute pouchitis occurred in 228 (54.8%) patients a median of 1.3 (interquartile range, 0.6-3.1) years after the final surgical stage. On multivariable analysis, ASUC (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.04-2.17) and a greater number of biologics precolectomy (HR, 1.57; 95% CI, 1.06-2.31) were associated with an increased probability of acute pouchitis, while older age at colectomy (HR, 0.98; 95% CI, 0.97-0.99) was associated with a decreased probability. Time to pouchitis was significantly less in patients admitted with ASUC compared with those not (P = .002).

CONCLUSION

A severe UC disease phenotype at the time of colectomy was associated with an increased probability of acute pouchitis.

Efficacy of Switching to Adalimumab for Maintenance of Remission Following Induction Therapy with Tacrolimus in Patients with Ulcerative Colitis

BACKGROUND

Tacrolimus (TAC) effectively induces remission in refractory ulcerative colitis (UC). However, TAC therapy usually lasts for 3 months. Although azathioprine (AZA) is often used in maintenance therapy, the relapse rate remains high. Herein, we evaluated the efficacy of adalimumab (ADA) for remission maintenance in patients with UC after induction therapy with TAC.

METHODS

We prospectively enrolled patients with moderate-to-severe UC who achieved clinical remission after 3 months of TAC therapy with endoscopic non-mucosal healing (Cohort A). After TAC discontinuation, the remission maintenance rate up to 1 year after starting ADA therapy was examined. We retrospectively enrolled patients with UC treated with TAC (Cohort B). Among patients in clinical remission after TAC treatment for 3 months, those who received AZA as remission maintenance therapy after TAC discontinuation constituted the AZA group. Patients in Cohort A who received ADA and AZA as remission maintenance therapy after TAC discontinuation constituted the ADA + AZA group. We compared the remission maintenance rates in the AZA and ADA + AZA groups for up to 5 years after TAC discontinuation.

RESULTS

In Cohort A, of the 46 patients with UC treated with TAC, 17 were eligible for analysis after receiving ADA as remission maintenance therapy. A notable 88.2% (15/17) were still in remission 1 year after starting ADA. The ADA + AZA group (n = 16) exhibited a significantly higher relapse-free rate than the AZA group (n = 26) (p < 0.05; log-rank test).

CONCLUSION

switching to ADA for remission maintenance in patients with refractory UC who achieved clinical remission with TAC is clinically useful.

Curable leakage in stapled IPAA has little effect on the long-term pouch function

PURPOSE

This study aimed to evaluate the frequency and grade of anastomotic leakage (AL) in stapled ileal pouch-anal anastomosis (IPAA) and its long-term impact on the pouch functions.

METHODS

A longitudinal cohort study was conducted on UC patients who underwent stapled IPAA at Yokohama City University Medical Center between 2007 and 2018. The diagnosis and grading of AL were performed in accordance with the recommendations of the International Study Group of Rectal Cancer. We assessed the functional pouch rate, late complication, pouch survival rate, bowel function (bowel movements per day, soiling, spotting, difficulty in distinguishing feces from flatus) and pouch inflammation (pouchitis disease activity index; PDAI) in the long-term period.

RESULTS

Two hundred seventy-six patients were analyzed. Twenty-three (8.3%; grade B/C; 13/10) patients were diagnosed with AL, but a functional pouch was achieved in all the twenty-three patients. Anastomotic stricture was significantly more common in patients with AL (AL group) than in patients without AL (non-AL group; AL/non-AL: 13.0/3.2%, p = 0.020). There were no differences in other late complications. Furthermore, the pouch survival rate did not differ between the AL and non-AL groups (100.0/97.9%/10 years, p = 0.494). There were no differences between the groups in bowel movements per day, spotting, soling, difficulty in distinguishing feces from flatus, or PDAI postoperatively.

CONCLUSIONS

Curable AL may not affect late complications (except anastomotic stricture), pouch survival, the bowel function, or pouch inflammation over the long term. Perioperative management to prevent the severity of AL is as important as preventing its occurrence.