Impact of cytomegalovirus on outcomes in acute severe ulcerative colitis: a retrospective observational study.

Background: Concomitant cytomegalovirus (CMV) is highly prevalent in acute severe ulcerative colitis (ASUC) but data for outcomes of CMV positivity in ASUC and the benefit of antiviral therapy remain unclear.

Objectives: We aim to determine the impact of CMV positivity, and antiviral therapy, on outcomes such as colectomy-free survival, length of hospital stay and readmission rate, among hospitalized patients with ASUC.

Design: This is a retrospective, multicentre study of patients admitted with ASUC.

Methods: CMV positivity was diagnosed from blood CMV DNA and inpatient colonic biopsies. Background demographics and disease characteristics, clinical characteristics and outcomes during admission and long-term outcomes were obtained from electronic medical records and compared according to the presence of CMV and the use of antiviral therapy.

Results: CMV was detected in 40 (24%) of 167 ASUC admissions. Previous steroid exposure was the only clinical predictor of CMV positivity on multivariate analysis. Outcomes of greater requirement for rescue therapy (60% versus 33%), longer hospital stay (14.3 versus 9.9 days) and higher readmission rates at 3 and 12 months were associated with CMV positivity. No difference was found in the rate of colectomy or colectomy-free survival. Antiviral therapy was not associated with a lower risk of colectomy but did extend the time to colectomy (126 versus 36 days).

Conclusion: CMV positivity was associated with worse outcomes of need for rescue therapy, hospital stay and readmissions. Antiviral therapy was not found to reduce the risk of colectomy but did extend the time to colectomy. Further prospective studies will be required to more clearly determine its benefit in patients with concomitant CMV and ASUC.