Crypts in Asymmetric Fission in Endoscopic Biopsies from Swedish Patients With Inflammatory Bowel Disease

Abstract

Background/Aim: We previously found crypts in symmetric fission (CSF) and in asymmetric fission (CAF) in colectomy-specimens with ulcerative colitis. We now analyzed CSF and CAF (CSAF) in biopsies from 80 patients with inflammatory bowel disease (IBD) without dysplasia or carcinoma. Patients and Methods: One unselected doublebiopsy from affected endoscopic areas was investigated in the 80 cases. Results: A total of 353 crypts in fission were found. The median number of CAF/biopsy was 3.7 and for CSF/biopsy, 0.7 (p<0.00001). Conclusion: CSAF often occur in unselected biopsies from patients with IBD. Whereas the increased frequency of CSF might mirror a compensatory mechanism of crypt production in areas occupied by inflammation, CAF reflects a pathological aberration of cryptogenesis, probably generated by somatic mutations. The biological significance of CAF in IBD without dysplasia or carcinoma, deserves to be further investigated.

Crypts in Asymmetric Fission in Endoscopic Biopsies from German Patients With Inflammatory Bowel Disease

“…CSFs are the results of a homeostatic compensatory mechanism of boosted crypt production in mucosal areas previously occupied by chronic inflammation (2,9). Although the possible significance of CAF could not be assessed from these studies, their occurrence in the colonic mucosa of IBD patients appears to suggest a genuine pathologic aberration in cryptogenesis.…”

“…In the Swedish study (9), one unselected endoscopic biopsy from endoscopic affected areas in the colon was also investigated in the 80 IBD patients (40 with UC and 40 with CCs). Table II Thus, despite that German and Swedish populations dwell in disparate geographical areas, and are being subjected to different ecological factors, the proportions of CSF and CAF are similar, strongly suggesting that CF and in particular CAF, develop in IBD independently of the local environmental conditions in the two regions.…”

“…However, this description applies only to welloriented, upright crypts, often seen in sections from colectomy specimens (6), or mucosectomies (7). In contrast, endoscopic biopsies in normal donors reveal cross-cut crypts in a horizontal (tangential) plane, displaying ring-shaped cross-cut crypts, similar in outline and diameter (8,9).…”

“…Despite crypt branching being mentioned in most histologic reports in patients with IBD, only but few isolated histologic studies have described the various phenotypes of crypt branching in sections from colectomy specimens (6) or from endoscopic biopsies in IBD patients (8). In well-oriented, upright crypts in IBD, the point of crypt-branching (the starting "point" of crypt fission) may be found at any level along the height of the crypt, from the top to the bottom, but in IBD biopsies, the point of crypt fission is identified by back-to-back crypts being apart by an epithelial septum (9).…”

Crypts in Asymmetric Branching in Patients With Ulcerative Colitis in Remission

“…However, none of the aforementioned grading systems includes the histologic characteristics of branching crypts in UC. In previous publications, we described in detail, the histologic characteristics of crypt branching in UC (13)(14)(15)(16). These studies, based on single colonic biopsies in patients with UC showed two histologic phenotypes of branching crypts: i) crypts in symmetric branching (CSB) and ii) crypts in asymmetric branching (CAB).…”