MUCOSAL INFLAMMATION IN PEDIATRIC DIVERSION COLITIS - A QUANTITATIVE-ANALYSIS

Background: Diversion colitis commonly occurs in bypassed segments of colorectum, and has been described qualitatively in Hirschsprung's dis ease patients with colostomies. The objective of this study was to cha racterize quantitatively the changes in the inflammatory tell populati on in the mucosa of children with diversion colitis. Methods: Paraffin blocks of well-oriented, full-thickness colorectal tissues were obtai ned from 15 children with diversion colitis (all with Hirschsprung's d isease), four pediatric controls and four adult controls. Sections wer e immunostained for B and T lymphocytes, macrophages, IgG, IgM, and Ig A. Measurements were made referent to a standard length of muscularis mucosae. Lymphoid follicles were counted and the areas occupied by B a nd T cells were determined by image analysis. Cells in the interfollic ular lamina propria were counted separately, but IgA-containing plasma cells were too abundant to enumerate. Results: Pediatric diversion co litis was characterized by enlarged and more numerous lymphoid follicl es with approximately four times as many B lymphocytes and twice as ma ny T lymphocytes in the follicular compartment of the mucosa when comp ared to pediatric controls. The interfollicular mucosa was thickened ( 499 +/- 27 versus 380 +/- 56 mu m) and contained approximately six lim es as many B cells and eight times as many T cells as controls. Macrop hages and plasma cells containing IgG and IgM were not significantly i ncreased. Conclusions: These findings extend the qualitative observati ons of increased follicular and lamina propria lymphoid tissue in bypa ssed segments of colon, and are consistent with the hypothesis of pers istent antigenic stimulation of the mucosa-associated lymphoid tissue. (C) 1997 Lippincott-Raven Publishers.