The microvascular thrombi of colonic tissue in ulcerative colitis. Dig Dis Sci. 2007 Sep;52(9):2236-40.

Mucosal microvascular thrombi in rectal biopsies were observed in some ulcerative colitis (UC). Heparin may be effective in steroid resistant UC in some studies, however, the new results of meta-analysis demonstrated a non-significant effect of heparin in controlled clinical trials, differing markedly from observational studies. The objective of this study was to identify colonic microvascular thrombi in larger cases with UC, and analyse its possible risk factors: age, gender, histologic score, extent of lesions and operation or biopsy specimens, and assess the significance of microvascular thrombosis in patients with UC. The microvascular thrombi were identified by immunohistochemical staining with anti-CD61 monoclonal antibody and Martius scarlet blue (MSB) staining in 40 colonic tissue samples of UC (31 biopsy specimens and nine operated cases) and 12 cases of normal colon tissue from operated colonic carcinoma. Logistic regression analysis was used to assess the relationship of age, gender, degree of histology, origin of the specimens, extent of lesions and microvascular thrombi examined. Microvascular thrombi were positive in 14 of 40 UC cases, and none in the controls. The presence of microvascular thrombi was related to operation specimens with odds ratio 11.667, P=0.0179, it might be also related to histologic score (OR=1.350) and extent of lesions (OR=1.619). These results suggest that microvascular thrombosis may be one of the important pathogenesis in some UC, and that the effect of anticoagulant treatment still needs to be assessed.

Colonic mucosal mast cell distribution at line of demarcation of active ulcerative colitis.Dig Dis Sci. 1992 Apr;37(4):490-5.

We examined the distribution of colonic mucosal mast cells in 25 patients with active ulcerative colitis, with a clear line of demarcation separating active inflammation from normal mucosa. Biopsies, at least one adjacent to the line of demarcation, one in inflamed mucosa, and one above were obtained during colonoscopy. Eight patients had elevated mast cells throughout the colon, and 12 had increased numbers at the line of demarcation of disease. Mean numbers of mast cells from these patients were 6.3 (+/- 2.1 SD) in active inflammation, 19.5 (+/- 7.1 SD) at the line of demarcation, and 15.8 (+/- 8.4 SD) in normal mucosa. Histologic inflammation decreased as mast cells increased. The accumulation of mast cells at the visible line of demarcation between normal and abnormal mucosa suggests mast cells play a critical role in either accelerating the process of inflammation or in suppressing continued extension of the disease.

Comparative histologic assessment of proctocolectomy specimens from Japanese and American patients with ulcerative colitis with or without dysplasia.Int J Surg Pathol. 2005 Jul;13(3):259-65.

There have been no reports of histologic differences in ulcerative colitis (UC) between Japanese and American patients. We therefore compared histology in proctocolectomy resection specimens between Japanese patients with UC (19 cases with and 21 without dysplasia) at the Kitasato University East Hospital and American patients with UC (21 cases with and 24 without dysplasia) at the University of Washington Medical Center. In cases of UC with, but not without dysplasia, cryptitis (p = 0.010) and epithelial apoptosis (p < 0.001) in the nondysplastic mucosa were more frequently observed in Japanese than in American cases, whereas lamina propria fibrosis was more prominent in American counterparts (p = 0.008). In patients with UC with dysplasia, the duration of disease was significantly longer in American than in Japanese patients (median, 17 vs 14 years, respectively; p = 0.038). This might, in part, explain the histologic variation. Another possibility for the differences is that the preoperative medications may have differed in the populations.

A study of the histological criteria for ulcerative colitis: retrospective evaluation of multiple colonic biopsies.J Gastroenterol. 1995 Apr;30(2):189-94.

It is clinically important to distinguish idiopathic inflammatory bowel disease (IBD) from other colitides, and ulcerative colitis (UC) from Crohn's disease (CD); however only a few histological criteria based on colonic biopsies have been established. We investigated 209 consecutive series of biopsies taken from 38 patients with UC, 12 with CD, and 105 with other colitides, to evaluate whether combinations of histological features, selected on the basis of our experience, and listed below, could be useful criteria for the differential diagnosis of IBD, and, more specifically, of UC: (A) chronic inflammation with a predominant increase of plasma cells, (B) crypt distortion, (C) crypt atrophy, (D) diffuse chronic inflammation within a biopsy and between biopsies, and (E) diffuse mucin depletion within a biopsy and between biopsies. Findings that fulfilled all or two of A-C distinguished IBD from the other colitides with high sensitivity (94.3%) and specificity (95.8%). When the findings fulfilled the additional criteria of D and/or E, UC was differentiated from CD or the other colitides with high sensitivity (86.4%) and specificity (99.3%).