A morphometric study on intestinal mucosal biopsies in inflammatory bowel disorders.

To study a few simple morphometric features and conventional existing histological parameters in ileal and segmental colorectal mucosal biopsies from patients with Crohn’s disease, intestinal Tuberculosis, Ulcerative Colitis and normal controls in order to identify features that will aid in the diagnosis and differentiation of these disorders. METHODS: We studied 30 cases each of clinically confirmed CD, ITB, UC and controls. It was a retrospective study performed on biopsies between January 2008 and January, 2015. H&E stained slides were retrieved from the archives of Dept of General Pathology. A total 480 biopsies from 120 cases were evaluated (4 biopsies from ileum, caecum/ascending colon, transverse/descending colon and sigmoid/rectum were studied in each case). 22 histological parameters were evaluated. Height of mucosa, crypts, and villi were measured in 5 well oriented fields. The mean plasma cell count of 5 consecutive OIFs and the mean eosinophil count in 5 consecutive HPFs were evaluated. All histological parameters were evaluated by 2 investigators. ICC was studied on 40 cases. Statistical analysis was performed for all variables and P-value less than 0.05 was considered significant. RESULTS: Controls: All biopsies were normal expect for mild chronic inflammation in caecum/ascending colon and mild architectural alteration and fibrosis in recto-sigmoid biopsies. The mean height of ileal villi and mucosa were 475.4±31μm and 569.13μm ±27.2μm. Mean height of crypt and mucosa from caecum (321.8±19μm & 333.3±21.4μm) increased to 351.53±50.19μm & 375.07±53.05μm in the rectosigmoid, respectively. The mean plasma cell count/OIF and eosinophils/HPF were 3.5, 6.6, 4.3, 3.7 and 2.3, 5.6, 3.2, 2.6 from ileum to distal segments respectively. Crohn’s disease: The percentage of involved biopsies decreased from proximal to distal segments. The prevalence of architectural alteration, chronic inflammation and activity showed the same trend. Mucosal heights were higher than controls. Mean plasma cell count ranged from 12-14/OIF in all segments and mean eosinophil count ranged from 5.3-8.7, with a peak in caecum/ascending colon. 46% of biopsies showed non-necrotizing granulomas. No case had granulomas >200μm or >4 granulomas/site. Intestinal TB: Ileum and caecum/ascending colon were most commonly involved. Architectural alteration, chronic inflammation, activity, ulcers, fibrosis were more common and more severe than in CD in the same sites. Rectal sparing and <10 plasma cells/OIF in rectum were features in favour of ITB over CD. Granulomas >400μm, >4 granulomas/ site, deep ulceration at the site of granulomatous inflammation and rectal sparing identified 100% cases of ITB. Ulcerative Colitis: There was a distal predominance of disease with the highest severity in all observed histological parameters. Ileum was involved in 10% cases and recto-sigmoid in 97%. UC showed a 50% increase in mucosal height compared to controls in the recto-sigmoid with a concomitant 900-1000% increase in mean plasma cell count/ OIF: highest among all diseases in our study. UC showed the highest mean percentages of crypt distortion, crypt branching and crypt abscesses. Crypt atrophy, pseudovillous change and Paneth cell metaplasia were more common in UC as compared to CD and ITB