Steroid-refractory inflammatory bowel disease is a risk factor for CMV infection

Patients with inflammatory bowel disease (IBD) show increased the prevalence of cytomegalovirus (CMV) infection due to the severity of the disease and the immunosuppressive treatments they receive. The aim of this study was to determine the prevalence of CMV infection in IBD patients and identify the risk factors for CMV infection with different demographic characteristics in IBD patients.

We enrolled 85 patients diagnosed with IBD (43 with ulcerative colitis (UC) and 42 with Crohn's disease (CD)) in this prospective study. The clinical disease activities of UC and CD were assessed using Truelove-Witts and Crohn's disease activity index (CDAI). CMV infection was assessed by detection of DNA using real-time polymerase chain reaction (PCR) in blood samples and quantitative PCR in colonic biopsy specimens and by detection of inclusion bodies using hematoxylin-eosin staining.

Thirteen patients with IBD exhibited concomitant CMV infection. CMV infection was not detected in any of the patients in remission. Viral loads measured in the colonic mucosa of infected patients ranged from 800-7000 genome copies/mL total extracted DNA. The mean serum CMV DNA level was 1694 ± 910 copies/mL (range: 800-3800). The rate of steroid resistance in CMV-positive cases was significantly higher than that in CMV-negative cases (p = 0.001). CD with acute exacerbation was a risk factor for CMV disease (p = 0.04). All of the CMV-positive patients received immunosuppressive treatments.

CMV infection should be suspected in steroid-resistant UC and CD. Antiviral treatment improved the clinical outcome in steroid-resistant IBD cases with serum CMV DNA levels above 1000 copies/mL.