Cytomegalovirus Load in Inflamed Intestinal Tissue Is Predictive of Resistance to Immunosuppressive Therapy in Ulcerative Colitis

OBJECTIVES: Previous studies have suggested an association between cytomegalovirus (CMV) infection and steroid-refractory inflammatory bowel disease. In this study, the use of CMV DNA load during acute flare-ups of ulcerative colitis (UC) to predict resistance to immunosuppressive therapy was evaluated in intestinal tissue. METHODS: Forty-two consecutive patients (sex ratio M/F: 0.9, mean age: 43.6 years) hospitalized for moderate to severe UC and treated with IV steroids were included prospectively. A colonoscopy was performed for each patient at inclusion; colonic biopsy samples of the pathological tissue, and if possible, of the healthy mucosa, were tested for histological analysis and determination of CMV DNA load by real-time polymerase chain reaction assay. Patients were treated as recommended by the current guidelines. RESULTS: Sixteen patients were found positive for CMV DNA in inflamed intestinal tissue but negative in endoscopically healthy tissue; all of these patients were positive for anti-CMV IgG, three exhibited CMV DNA in blood, and none was positive for intestinal CMV antigen by immunohistochemistry detection. In the 26 remaining patients, no stigmata of recent CMV infection were recorded by any technique. By multivariate analysis, the only factor associated with CMV DNA in inflammatory tissue was the resistance to steroids or to three lines of treatment (risk ratio : 4.7; 95% confidence interval: 1.2-22.5). A CMV DNA load above 250 copies/mg in tissue was predictive of resistance to three successive regimens (likelihood ratio + = 4.33; area under the receiver-operating characteristic curve = 0.85). Eight UC patients with CMV DNA in inflamed tissue and therapeutic failure received ganciclovir; a clinical remission was observed in seven cases, with a sustained response in five of them. CONCLUSIONS: The CMV DNA load determined in inflamed intestinal tissue predicts resistance to steroid treatment and to three drug regimens in UC. Initiation of an early antiviral treatment in these patients might delay the occurrence of resistance to current treatments.