Cytomegalovirus infection in ulcerative colitis: A prospective, comparative study on prevalence and diagnostic strategy

Background: Cytomegalovirus (CMV) infection has been reported in ulcerative colitis (UC), especially in severe, steroid-refractory disease. However, its role in steroid-refractoriness remains unknown. Our goals were to evaluate the prevalence of CMV disease in UC, the best diagnostic strategy, and the influence of disease activity and/or treatment in its development. Methods: Prospective, observational study including 114 subjects with active UC requiring intravenous steroids, steroid-refractory UC, inactive UC on mesalamine, inactive UC on azathioprine, and healthy controls. CMV antibodies, pp65-antigenemia, and rectal biopsies for hematoxylin and eosin staining, immunohistochemistry, and CMV-pp67 mRNA were performed. These procedures were repeated after medical treatment only in patients with active UC. CMV disease was defined by the presence of inclusion bodies and/or positive immunohistochemistry in colonic biopsies. Results: CMV disease was found in 6 steroid-refractory, CMV-IgG-positive UC patients but not among controls, inactive UC, or steroid-responding UC patients. In 5 out of the 6 patients, CMV disease was diagnosed after 7–10 days on cyclosporine. Conclusions: CMV disease in UC only affects seropositive, steroid-refractory UC patients. Steroid/cyclosporine treatment together with disease activity may predispose to latent colonic CMV reactivation. The impact of antiviral therapy on the clinical outcome of these patients remains to be elucidated. (Inflamm Bowel Dis 2008)