Immunosuppressive-Therapy Management and Day-14 Molecular Remission in Ulcerative Colitis Complicated by Cytomegalovirus Colitis: An Exploratory Prospective Cohort Study

Background and Objectives: Evidence regarding continuation versus withdrawal of immunosuppressive agents during antiviral treatment of cytomegalovirus (CMV) colitis complicating ulcerative colitis (UC) remains limited. We compared molecular remission, clinical outcomes, and relapse according to immunosuppressive-therapy management. Materials and Methods: This prospective, non-randomized, single-center cohort included 44 hospitalized adults with UC and CMV colitis treated with intravenous ganciclovir. Patients were managed according to a clinician-selected strategy of temporary discontinuation (n = 24) or continuation (n = 20) of immunosuppressive therapy. Molecular remission, the primary outcome, was defined as undetectable tissue CMV DNA at day 14. Results: Both groups demonstrated significant clinical and endoscopic improvement. The continuation group had higher residual CMV DNA levels at day 14 (p = 0.003) and more adverse events (p = 0.019). Clinical remission, endoscopic remission, and one-year relapse rates were comparable. Multivariable logistic regression showed that continuation of immunosuppressive therapy was associated with reduced molecular remission (OR 0.26, 95% CI 0.07–0.98; p = 0.045). Corticosteroid exposure was confined to the continuation group (7/20 vs. 0/24), raising the possibility of substantial residual confounding. Conclusions: In this exploratory cohort, clinician-selected continuation of immunosuppressive therapy was associated with a lower likelihood of day-14 molecular remission and more frequent adverse events, without demonstrable additional clinical or endoscopic benefit. However, the observed association may have been influenced by corticosteroid exposure and should not be interpreted as a class-wide effect of immunosuppressive therapy. These hypothesis-generating findings require confirmation in adequately powered multicenter studies before informing routine clinical practice.