Immunohistological identification of epithelioid cell granulomas in Crohn's disease and its diagnostic values especially in the differentiation from ulcerative colitis.
We produced a monoclonal antibody against epithelioid cell granulomas (ECGs) by immunizing mice with a crude tissue extract of lymph nodes with sarcoidosis. The established antibody (ECM antibody) strongly reacted with epithelioid cells and Langhans' type giant cells of ECGs not only in cases of sarcoidosis, but also in cases of other granulomatous diseases such as tuberculosis and Crohn's disease. In this study, we used the ECM antibody to improve the histopathological diagnosis of Crohn's disease, in which the demonstration of ECGs is critical for diagnosis, but morphological identification of ECGs by hematoxyline and eosin (HE) staining is frequently difficult. When we examined the tissues removed at operation from 11 patients with Crohn's disease, we observed a total of 29 lesions of morphologically recognizable ECGs, all of which were immuonohistologically positive for the ECM antibody (granuloma pattern). In addition the ECM antibody revealed 43 nests of tiny inflammatory lesions (nested pattern) that could not be morphologically recognized as ECGs by HE staining only. Both the granuloma and nested patterns of ECM immunoreactivity were present in all cases of Crohn's disease we examined, but were absent in all 15 cases of ulcerative colitis that were used as controls. Thus, we concluded that the newly established ECM antibody is useful for detecting morphologically equivocal granulomatous Crohn's disease lesions, and should be helpful for the histopathological differentiation of this disease from other types of chronic inflammatory bowel diseases, such as ulcerative colitis.
Nakashima
H
H
Department of Pathology, Faculty of Medicine, Tokyo Medical and Dental University, Japan.
D000328:Adult; D000911:Antibodies, Monoclonal; D003093:Colitis, Ulcerative / Q000175:diagnosis* / Q000276:immunology; D003424:Crohn Disease / Q000175:diagnosis* / Q000276:immunology; D003937:Diagnosis, Differential; D004847:Epithelial Cells; D005260:Female; D006099:Granuloma / Q000276:immunology* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male
D000911:Antibodies, Monoclonal