Cytomegalovirus and ulcerative colitis in pediatrics: association with severity and the outcome

The contribution of colonic cytomegalovirus (CMV) reactivation to ulcerative colitis (UC) exacerbations in children remains incompletely understood. This study aimed to determine the prevalence of CMV in pediatric UC exacerbations and to evaluate its clinical significance. We retrospectively analyzed pediatric patients with UC exacerbations who underwent colonoscopy between 2004 and 2021. CMV reactivation was assessed using tissue and blood CMV polymerase chain reaction (PCR) testing and histopathological examination. A total of 78 colonoscopic procedures from 68 pediatric patients with UC were included. Tissue CMV-PCR was positive in 11 of 78 specimens (14%), whereas blood CMV-PCR and histopathological evidence of CMV reactivation were detected in only two cases (3%). More than half of the patients with tissue CMV-PCR positivity (55%) exhibited corticosteroid resistance ( p = 0.008). Tissue CMV-PCR positivity was significantly associated with severe disease activity ( p = 0.03). No statistically significant associations were observed between tissue CMV-PCR positivity, CMV viremia, or histopathological CMV detection and colectomy ( p = 0.54, p = 0.17, and p = 0.23, respectively). Tissue CMV-PCR positivity was associated with severe disease activity and corticosteroid resistance but not colectomy. Tissue CMV-PCR results should therefore be interpreted alongside clinical and histopathological findings.