IMMUNOCYTOCHEMICAL EVIDENCE OF LISTERIA, ESCHERICHIA-COLI, AND STREPTOCOCCUS ANTIGENS IN CROHNS-DISEASE

Background/Aims: Infectious agents have long been suspected of playing a role in the initiation of Crohn's disease. The objective of this st udy was to search for likely microbial agents in diseased tissues usin g immunocytochemical techniques. Methods: Intestines and mesenteric ly mph node specimens of 21 patients from two French families with a high frequency of Crohn's disease and from Connecticut were studied. The m icrobial agents searched for included Bacteroides vulgatus, Borrelia b urgdorferi, Escherichia coil, Listeria monocytogenes, Streptococcus sp p., bovine viral diarrhea virus, influenza A virus, measles virus, par ainfluenza virus, and respiratory syncytial virus. Results: Seventy-fi ve percent of the patients with Crohn's disease (12 of 16) were positi vely labeled with the antibody to Listeria. Macrophages and giant cell s immunolabeled for this antigen were distributed underneath ulcers, a long fissures, around abscesses, within the lamina propria, in granulo mas, and in the germinal centers of mesenteric lymph nodes. In additio n, 57% (12 of 21) of the cases contained the E. coli antigen, and 44% (7 of 16) contained the streptococcal antigen. The immunolabeling for the latter two agents also occurred within macrophages and giant cells , distributed in a pattern similar to that of Listeria antigen. Conclu sions: The results suggest that Listeria spp., E. coil, and streptococ ci, but not measles virus, play a role in the pathogenesis of Crohn's disease.