Effects of cytomegalovirus infection on the prognosis of inflammatory bowel disease patients

The aim of the present study was to investigate the effects of cytomegalovirus (CMV) infection on the prognosis of inflammatory bowel disease (IBD). Various databases were searched using a combination of keywords associated with CMV infection and IBD. Subsequent to the selection of relevant studies in line with strict inclusion and exclusion criteria, a meta-analysis was conducted using the Stata 12.0 software. A total of 195 studies were initially retrieved, including 28 studies in Chinese and 167 in English. Following the exclusion of unsuitable studies, 7 cohort studies with 374 IBD patients were included in the meta-analysis. The results of the present study identified significant differences between patients with and without CMV infection regarding the disease duration of IBD [standardized mean difference, −0.81; 95% confidence interval (CI), −1.19 to −0.43; P<0.001], the efficacy of corticosteroid therapy [relative risk (RR), 1.24; 95% CI, 1.02–1.49; P=0.029], the colectomy rate (RR, 2.13; 95% CI, 1.03–4.40; P=0.042) and the incidence of severe IBD (RR, 1.32; 95% CI, 1.04–1.67; P=0.022). Considering the IBD onset area, patients with CMV infection may have higher susceptibility to pancolitis (RR, 1.31; 95% CI; 1.01–1.72; P=0.045); however, no difference in susceptibility to left-sided IBD was observed between patients with or without CMV infection (RR, 0.97; 95% CI, 0.72–1.30; P=0.828). In conclusion, CMV infection may be associated with the disease duration, efficacy of corticosteroid therapy, colectomy rate, severe IBD incidence and disease location of IBD; thus, the presence of CMV infection may be considered as an important biomarker for determining the prognosis of IBD.