Is CMV DNAemia an early marker of CMV colitis in patients with active ulcerative colitis?

Cytomegalovirus (CMV) colitis is a serious concern worsening the prognosis of patients with ulcerative colitis (UC). We aimed to assess risk factors and prognostic impact of CMV colitis in patients with moderate-to-severe UC flare. We conducted a retrospective, observational, single-center study. Consecutive adult patients hospitalized for moderate-to-severe UC from January 2020 to June 2023 were included. The primary endpoint was a diagnosis of CMV-colitis according to immunohistochemistry on tissue biopsies. The secondary endpoint was the need for colectomy within 30 days. Overall, 135 patients were included. CMV colitis was diagnosed in n = 37 (27.4%): n = 19 (51.4%) endoscopically, the remaining on surgical specimens. Of them, n = 23 (62.2%) had positive CMV-DNAemia with a median value of 1,008 cp/mL (interquartile range 318-2,980). Differences between the two groups (CMV colitis vs non-CMV) included age (60 vs 41 years, P = 0.004), Charlson Comorbidity Index (1 vs 0, P = 0.003), steroid refractoriness (86.5% vs 62.2%, P = 0.007), and positive CMV-DNAemia (62.2% vs 10.1%, P < 0.001). At multivariable analysis, steroid-refractory disease, Charlson Comorbidity Index, and CMV-DNAemia were associated with CMV colitis. Overall, n = 54 (39.7%) patients underwent colectomy, and this was significantly more common in patients with CMV colitis vs non-CMV group (54.1% vs 34.4%, P = 0.049). Kaplan-Meier showed that antiviral therapy seems to have a relevant impact on colectomy (P < 0.001). CMV-DNA blood detection is independently associated with CMV-positive refractory UC. Since CMV colitis may increase the risk of colectomy and antiviral treatment seems to reduce such risk, prospective studies are needed to confirm the role of CMV-DNA blood detection to early diagnose CMV colitis. IMPORTANCE Cytomegalovirus (CMV) colonic reactivation worsens the prognosis of patients with active ulcerative colitis. Blood CMV-DNA reactivation is strongly associated with CMV colitis. Prompt diagnosis and treatment of CMV colitis can avoid surgery in most cases.