Absence of Cytomegalovirus from the Gastrointestinal Tract of Patients with Active Crohn's Disease

Background: Cytomegalovirus (CMV) infection reportedly is detectable in the gastrointestinal mucosa of patients with chronic inflammatory bowel disease. One view is that CMV infection is of clinical significance in patients with Crohn's disease with severe colitis not responding to steroid therapy. In this study, we evaluated the prevalence of CMV infection in our own patients with Crohn's disease treated with colon resection. Patients and Methods: The study included 16 consecutive patients with Crohn's disease with colitis who underwent surgery for colonic disease. Histology and immunohistochemistry were used to examine the CMV infection in their surgical specimens by means of enzymatic antigen retrieval, mouse monoclonal antibody, clone CMV01, and a sensitive polymer detection system. Results: All 16 patients underwent colon resection, three of them undergoing emergency surgery. No CMV infection was found in their surgical specimens. Conclusion: CMV infection seems not to play a major role in the pathogenesis of Crohn's colitis requiring surgery. However, further prospective studies with larger number of patients are needed to determine the role of CMV in active Crohn's colitis. Cytomegalovirus (CMV), belonging to the herpesvirus family, infects 40% to 100% of the adult population worldwide (1). CMV infection may be latent, but its diagnosis requires the presence of clinical signs and symptoms of infectious disease (fever, leucopenia) and detection of end-organ involvement (1). CMV colitis is usually detected in recipients of allograft transplantation and AIDS patients, but it may reportedly also cause colitis in previously healthy immunocompetent persons (2). Some studies suggest that CMV may also be involved in pathogenesis of refractory and complicated inflammatory bowel disease (IBD) (3-5). CMV has reportedly occurred in ileal and colonic mucosa of patients with active ileocolonic Crohn's disease (6, 7). In the treatment of complicated Crohn's disease, surgery plays a significant role (8). About 30% of patients with Crohn's disease of our hospital referral area have undergone surgery (9). It has been suggested, however, that antiviral treatment of CMV infection in Crohn's colitis can diminish the need for surgery (10). At present, only a few studies of Crohn's colitis relate to CMV. The aim of the present study was to determine the prevalence of CMV infection in the intestinal mucosa of patients with Crohn's disease who underwent colon resection.