The Impact of Cytomegalovirus Infection on Ulcerative Colitis Relapse: A Multicenter Retrospective Cohort Study.

Cytomegalovirus (CMV) infection exacerbates intestinal inflammation in ulcerative colitis (UC) patients, yet the effect of CMV infection on UC relapse has not been fully elucidated. This study aimed to investigate the impact of CMV infection on UC relapse and identify associated risk factors. This multicenter retrospective cohort study included UC patients who visited research centers from January 2016 to December 2020. Univariate and multivariate Cox regression analyses were conducted to explore risk factors for UC relapse. Propensity score matching was used to balance the differences in the clinical characteristics between the groups. A total of 298 UC patients participated in this study, including 19 with CMV colitis, 37 with CMV viremia, and 242 CMV-negative patients. The 2-year cumulative recurrence rate was higher in patients with CMV colitis than that in CMV-negative patients (84.21% vs 51.65%, p = 0.01). Univariate and multivariate Cox regression analyses confirmed that fecal calprotectin ≥ 250 µg/g, Montreal classification E3, CMV colitis, duration > 48 months, and serum albumin < 30 g/L were independent risk factors for UC relapse at 2 years, whereas the use of biologics for induction of remission was identified as an independent protective factor. Our study suggests that the risk of relapse increases among UC patients with CMV colitis over two years. Risk factors for UC relapse at 2 years include fecal calprotectin ≥ 250 μg/g, Montreal classification E3, CMV colitis, UC duration > 48 months, and albumin < 30 g/L, whereas the use of biologics during induction is a protective factor.