Pyloric gland metaplasia: Potential histologic predictor of severe pouch disease including Crohn's disease of the pouch in ulcerative colitis

Histologic Predictors of Clinical Outcomes and Healthcare Utilization in Patients With Ileal Pouch-Anal Anastomosis

BACKGROUND

The prognostic significance of histology in ileal pouch-anal anastomosis (IPAA) remains unclear. The aim of this study was to evaluate if histologic variables are predictive of IPAA clinical outcomes and healthcare utilization.

METHODS

This was a retrospective cohort study of patients with IPAA undergoing surveillance pouchoscopy at a tertiary care institution. Pouch body biopsies were reviewed by gastrointestinal pathologists, who were blinded to clinical outcomes, for histologic features of acute or chronic inflammation. Charts were reviewed for clinical outcomes including development of acute pouchitis, chronic pouchitis, biologic or small molecule initiation, hospitalizations, and surgery. Predictors of outcomes were analyzed using univariable and multivariable logistic and Cox regression.

RESULTS

A total of 167 patients undergoing surveillance pouchoscopy were included. Polymorphonuclear leukocytes (odds ratio [OR], 1.67), ulceration and erosion (OR, 2.44), chronic inflammation (OR, 1.97), and crypt distortion (OR, 1.89) were associated with future biologic or small molecule initiation for chronic pouchitis. Loss of goblet cells was associated with development of chronic pouchitis (OR, 4.65). Pyloric gland metaplasia was associated with hospitalizations (OR, 5.24). No histologic variables were predictive of development of acute pouchitis or surgery. In an exploratory subgroup analysis of new IPAA (<1 year), loss of goblet cells was associated with acute pouchitis (OR, 14.86) and chronic pouchitis (OR, 12.56). Pyloric gland metaplasia was again associated with hospitalizations (OR, 13.99).

CONCLUSIONS

Histologic findings may be predictive of IPAA outcomes. Pathologists should incorporate key histologic variables into pouchoscopy pathology reports. Clinicians may need to more closely monitor IPAA patients with significant histologic findings.

Risks Factors Associated with the Development of Crohn's Disease After Ileal Pouch-Anal Anastomosis for Ulcerative Colitis: A Systematic Review and Meta-Analysis

BACKGROUND

Following ileal pouch-anal anastomosis [IPAA] for ulcerative colitis [UC], up to 16% of patients develop Crohn's disease of the pouch [CDP], which is a major cause of pouch failure. This systematic review and meta-analysis aimed to identify preoperative characteristics and risk factors for CDP development following IPAA.

METHODS

A literature search of the MEDLINE, EMBASE, EMCare and CINAHL databases was performed for studies that reported data on predictive characteristics and outcomes of CDP development in patients who underwent IPAA for UC between January 1990 and August 2022. Meta-analysis was performed using random-effect models and between-study heterogeneity was assessed.

RESULTS

Seven studies with 1274 patients were included: 767 patients with a normal pouch and 507 patients with CDP. Age at UC diagnosis (weighted mean difference [WMD] -2.85; 95% confidence interval [CI] -4.39 to -1.31; p = 0.0003; I2 54%) and age at pouch surgery [WMD -3.17; 95% CI -5.27 to -1.07; p = 0.003; I2 20%) were significantly lower in patients who developed CDP compared to a normal pouch. Family history of IBD was significantly associated with CDP (odds ratio [OR] 2.43; 95% CI 1.41-4.19; p = 0.001; I2 31%], along with a history of smoking [OR 1.80; 95% CI 1.35-2.39; p < 0.0001; I2 0%]. Other factors such as sex and primary sclerosing cholangitis were found not to increase the risk of CDP.

CONCLUSIONS

Age at UC diagnosis and pouch surgery, family history of IBD and previous smoking have been identified as potential risk factors for CDP post-IPAA. This has important implications towards preoperative counselling, planning surgical management and evaluating prognosis.

Alterations in p53, Microsatellite Stability and Lack of MUC5AC Expression as Molecular Features of Colorectal Carcinoma Associated with Inflammatory Bowel Disease

Colitis-associated colorectal carcinoma (CAC) occurs in inflammatory bowel disease (IBD) because of the "chronic inflammation-dysplasia-cancer" carcinogenesis pathway characterized by p53 alterations in the early stages. Recently, gastric metaplasia (GM) has been described as the initial event of the serrated colorectal cancer (CRC) process, resulting from chronic stress on the colon mucosa. The aim of the study is to characterize CAC analyzing p53 alterations and microsatellite instability (MSI) to explore their relationship with GM using a series of CRC and the adjacent intestinal mucosa. Immunohistochemistry was performed to assess p53 alterations, MSI and MUC5AC expression as a surrogate for GM. The p53 mut-pattern was found in more than half of the CAC, most frequently stable (MSS) and MUC5AC negative. Only six tumors were unstable (MSI-H), being with p53 wt-pattern (p = 0.010) and MUC5AC positive (p = 0.005). MUC5AC staining was more frequently observed in intestinal mucosa, inflamed or with chronic changes, than in CAC, especially in those with p53 wt-pattern and MSS. Based on our results, we conclude that, as in the serrated pathway of CRC, in IBD GM occurs in inflamed mucosa, persists in those with chronic changes and disappears with the acquisition of p53 mutations.

Histopathology of Pouch and Para-Pouch Inflammatory and Neoplastic Disorders

BACKGROUND

Restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) is used to treat patients with ulcerative colitis or familial adenomatous polyposis who need colectomy. While this procedure substantially improves patient's quality of life and reduces cancer risk, it is associated with a variety of sequelae' including surgical complications, inflammatory disorders, and neoplasia. Pouchitis, cuffitis, and Crohn's disease of the pouch are the most common inflammatory disorders of the pouch and para-pouch.

OBJECTIVE

This study aimed to elaborate on the histopathology of common inflammatory and neoplastic disorders of the pouch and para-pouch.

DATA SOURCES

A Medline search for English language studies published between 1981 and 2021 using the PubMed search engine. The terms "ileal pouch-anal anastomosis," "pouchitis," "pouchitis activity score," "secondary pouchitis," "Crohn's disease of the pouch," "Crohn's-like conditions of the pouch," "pre-pouch ileitis," "cuffitis," "pouch adenocarcinoma," and "pouch neoplasia" were used.

STUDY SELECTION

The published human studies that reported histopathology of common inflammatory and neoplastic disorders of the ileal pouch were selected and reviewed.

CONCLUSIONS

Histologic examination plays an essential role in confirming inflammation in pouchitis, identifying etiology and clues for secondary pouchitis, and diagnosing neoplasia. A standardized, simple, and reproducible histologic grading system for pouchitis is needed. Pouch and para-pouch glandular dysplasia diagnosis is challenging and should always be reviewed by at least one gastrointestinal pathologist.

Appendiceal inflammation in colectomy is independently correlated with early pouchitis following ileal pouch anal anastomosis in ulcerative colitis and indeterminate colitis

BACKGROUND

Appendiceal inflammation in colectomy is one of the histologic predictors of pouchitis in ulcerative colitis (UC) following ileal pouch anal anastomosis (IPAA). Fecal calprotectin level has been shown to increase 2 months prior to the onset of pouchitis. We evaluated whether inflammation and calprotectin expression in appendiceal specimens correlate with early-onset pouchitis in UC and indeterminate colitis (IC).

MATERIALS AND METHODS

IPAA (2000-2018) cases with appendix blocks available in colectomy specimens were identified (n = 93, 90 UC, 3 IC). Histologic features thought to predict pouchitis were evaluated. The degree of appendiceal inflammation was scored. Calprotectin immunostain was performed on the appendix blocks and the extent of mucosal staining was quantified. Electronic medical records were reviewed for demographics, smoking history, clinical pouchitis, time of onset of pouchitis, and clinical and endoscopic components of the Pouchitis Disease Activity Index (PDAI) score. Follow-up pouch biopsies were reviewed and scored to generate histologic PDAI score, when available.

RESULTS

Among the patients with clinical pouchitis (n = 73), moderate to severe appendiceal inflammation independently correlated with earlier pouchitis compared to no/mild inflammation (median time to pouchitis 12.0 vs. 23.8, log rank p = 0.016). Calprotectin staining correlated with inflammatory scores of the appendix (Spearman's rho, r = 0.630, p < 0.001) but not with early pouchitis (p > 0.05).

CONCLUSIONS

The presence of moderate to severe appendiceal inflammation at the time of colectomy was associated with a shorter time to pouchitis following IPAA. Calprotectin immunostain may be used to demonstrate the presence of inflammation in the appendix but its role in predicting early pouchitis remains limited.