[Immunohistochemical study of colonic mucosa macrophages in children with Crohn's disease and ulcerative colitis].

Abstract

In this research the histological characteristics of the macrophages on the colonic mucosa in Crohn's disease and ulcerative colitis were quantified and analysed. Twelve Crohn's disease, 19 ulcerative colitis and 10 specimen of the rectal mucosa, representing the control group according to the followed model, were studied: I period (PI) = pre-treatment, II period (PII) = up two years of evolution and III period (PIII) = more than two years of evolution. The macrophages were identified in a colonic mucosa by the monoclonal CD68 through the immunoperoxidase method. The macrophages quantification was done by chromatic computer images analysis, that express the area (mm2) used by the CD68 positive cells, in percentage. The percentage of the area used by the macrophages was increased in both diseases, in all the studied periods, when compared with the control group, but without statistic significance. The macrophages' distribution inside the control group mucosa was subepithelial, while in the illness group, it reached all the mucosa that was concentrated on the basis of ulcers and all long the fissures. On the Crohn's disease the CD68 positive cells facilited the identification of the microgranulomas, sometimes unnoticed in the hematoxiline-eosine. Although there was no difference between patients and control group in the macrophages area, the difference in the distribution could suggest the macrophages' participation on the injure in both diseases although they do not permit a differential diagnosis because of the variety of the values. The CD68 did not identify the different functional status of the macrophages, but their position in the mucosa suggest that, in terms of fissures and ulcers, their mainly function should be the phagocitosis and in the other cases, they have been the cells that should show the antigens and that recruit the other inflammatory cells.