The Absence of Large Ulcer Predicts Latent Cytomegalovirus Infection in Ulcerative Colitis with Positive Mucosal Viral Assay

Objective Although many studies have shown that cytomegalovirus (CMV) infection is an exacerbating factor in patients with ulcerative colitis (UC), there is no valid method to distinguish CMV infection requiring therapy from that disappearing without therapy. The aim of this study was to describe whether or not the endoscopic feature of a large ulcer predicts the necessity of antiviral therapy against CMV infection in active UC patients with positive mucosal viral assay. Methods Active UC patients in whom CMV infection was detected by mucosal polymerase chain reaction (PCR) assay were enrolled in this prospective observational clinical study. Patients with a large ulcer (ulcerated group) were treated with antiviral and UC therapy. Patients without a large ulcer (non-ulcerated group) were treated with only UC therapy. We prospectively evaluated the clinical and endoscopic findings in all of the patients 2 months after starting this protocol, and observed their outcomes during one year. Results In the ulcerated group (n=10), 3 patients still had active disease at 2 months and underwent colectomy. Although the other 7 patients achieved remission at 2 months, 4 of the 7 patients had a flare-up, and the remaining 3 patients maintained remission. All of the patients in the non-ulcerated group (n=10) attained remission without antiviral therapy at 2 months, and maintained remission. Conclusion In active UC patients with positive CMV DNA by mucosal PCR assay, the absence of a large ulcer suggests latent CMV infection, and requires no antiviral therapy.