High prevalence of ulcerative appendicitis in patients with ulcerative colitis

BACKGROUND

Previous studies have indicated that the appendix may be a priming site of ulcerative colitis (UC). Appendectomy is inversely associated with the development of UC, and is suggested to have a beneficial effect on the disease course in patients with refractory disease.

OBJECTIVE

The aim of the current study was to assess histological features of appendices from patients with UC and their clinical relevance.

METHODS

Patients with UC in remission and active UC (therapy refractory) that underwent appendectomy between 2012 and 2019 were included. Histological features of UC appendices were compared to those of patients with acute appendicitis and colon carcinoma. The Robarts Histopathology Index (RHI) was used to assess appendiceal inflammation. In patients with active UC, histological and clinical characteristics were compared between patients with and without endoscopic response following appendectomy.

RESULTS

In total, 140 appendix specimens were assessed (n = 35 UC remission, n = 35 active UC, n = 35 acute appendicitis, n = 35 colon carcinoma). Histological features of appendices from UC patients looked like UC rather than acute appendicitis. The presence of active appendiceal inflammation was comparable between patients in remission versus active disease (53.7% vs. 46.3%, p = 0.45) and limited versus extensive disease (58.5% vs. 41.5%, p = 0.50). Endoscopic response (Mayo 0-1) following appendectomy, assessed in 28 therapy refractory patients, was more frequently seen in patients with higher RHI scores (RHI > 6: 81.8% vs. RHI ≤ 6: 9.1%, p = 0.03) and limited disease (proctitis/left sided 63.6% vs. pancolitis 36.4%, p = 0.02).

CONCLUSION

The presence of active appendiceal inflammation is common in UC and does not correlate with colonic disease activity. More than 50% of UC patients in remission showed active histological disease in the appendix. Favorable response to appendectomy for refractory UC was seen in cases with ulcerative appendicitis. These findings might support the role of the appendix as a pivotal organ in UC.

An International Consensus to Standardize Integration of Histopathology in Ulcerative Colitis Clinical Trials

BACKGROUND & AIMS

Histopathology is an emerging treatment target in ulcerative colitis (UC) clinical trials. Our aim was to provide guidance on standardizing biopsy collection protocols, identifying optimal evaluative indices, and defining thresholds for histologic response and remission after treatment.

METHODS

An international, interdisciplinary expert panel of 19 gastroenterologists and gastrointestinal pathologists was assembled. A modified RAND/University of California, Los Angeles appropriateness methodology was used to address relevant issues. A total of 138 statements were derived from a systematic review of the literature and expert opinion. Each statement was anonymously rated as appropriate, uncertain, or inappropriate using a 9-point scale. Survey results were reviewed and discussed before a second round of voting.

RESULTS

Histologic measurements collected using a uniform biopsy strategy are important for assessing disease activity and determining therapeutic efficacy in UC clinical trials. Multiple biopsy strategies were deemed acceptable, including segmental biopsies collected according to the endoscopic appearance. Biopsies should be scored for architectural change, lamina propria chronic inflammation, basal plasmacytosis, lamina propria and epithelial neutrophils, epithelial damage, and erosions/ulcerations. The Geboes score, Robarts Histopathology Index, and Nancy Index were considered appropriate for assessing histologic activity; use of the modified Riley score and Harpaz Index were uncertain. Histologic activity at baseline should be required for enrollment, recognizing this carries operational implications. Achievement of histologic improvement or remission was considered an appropriate and realistic therapeutic target. Current histologic indices require validation for pediatric populations.

CONCLUSIONS

These recommendations provide a framework for standardized implementation of histopathology in UC trials. Additional work is required to address operational considerations and areas of uncertainty.