Evaluating colonic biopsy specimens to distinguish acute self-limited colitis from inflammatory bowel disease: No final answer yet

Abstract

The authors’ objective in this study was to evaluate whether examination of histologic features in rectal mucosal biopsy specimens could reliably distinguish acute self-limited colitis (ASLC, defined as a single episode of diarrheal disease with no recurrence for a minimum of 2 years’ follow-up) from acute onset inflammatory bowel disease (AOIBD) of <3 months’ duration. The study design was a retrospective blinded review of coded rectal mucosal specimens by two independent observers (C.S., R.H.) using a standardized checklist of histologic features. The results of this review were then correlated with clinical outcome based on a minimum of 2 years’ follow-up (mean follow-up, -5 years). The study population included 52 patients ultimately shown to have ASLC, 51 with AOIBD, and 30 with chronic inflammatory bowel disease of >4 months’ duration. When the data were analyzed, the most characteristic histologic features of ASLC were normal crypt architecture and acute inflammation in the lamina propria, whereas AOIBD featured (singly or in combination) diffusely abnormal crypt architecture (including crypt branching, distortion, and atrophy); mixed acute and chronic inflammation in the lamina propria, numerous plasma cells, lymphoid aggregates, or increased lymphocytes at the base of the lamina propria just above the muscularis mucosae (or a combination of these); isolated giant cells; epithelioid granulomas; goblet cell mucin depletion; and reactive epithelial hyperplasia. Findings in the AOIBD group were identical to those in the patients with chronic IBD. In a multivariate analysis, normal architecture and acute inflammation were independent indicators of ASLC, whereas branched crypts, mixed acute and chronic inflammation in the lamina propria, basal plasmacytosis, and isolated giant cells were independent markers of AOIBD. Overall, the histologic features had a >90% predictive value in distinguishing ASLC from AOIBD, even if the biopsies were obtained a week or more after the onset of symptoms. The authors conclude that evaluation of rectal mucosal specimens is a useful adjunct in evaluating patients with acute onset diarrheal diseases.