Diagnostic performance of noninvasive tests for cytomegalovirus ileocolitis: a systematic review and meta-analysis

Background/Aims: Diagnosis of cytomegalovirus (CMV) ileocolitis traditionally requires colonoscopy with tissue biopsy. Due to potential complications in high-risk patients, there is growing interest in serum and stool tests for diagnosing this condition. We aimed to evaluate the diagnostic accuracy of these noninvasive tests compared to traditional gold standards. Methods: Two independent reviewers performed a comprehensive search on MEDLINE and Embase from inception up to October 1, 2023. Prospective and retrospective studies evaluating the performance of serum CMV polymerase chain reaction (PCR), serum CMV antigen (Ag), and stool CMV PCR in diagnosing CMV ileocolitis were included. Tissue histopathology or tissue CMV PCR served as reference standards. Diagnostic performances of each serum and stool test were calculated based on a meta-analysis using random-effects model. Results: A total of 30 studies, comprising 23 studies of serum CMV PCR, 9 of serum CMV Ag, and 7 of stool CMV PCR, were included. The pooled sensitivity, specificity, and area under summary receiver operating characteristic curves were 62% (95% confidence interval [CI], 51%–72%), 90% (95% CI, 79%–96%), and 0.81 for serum CMV PCR, 38% (95% CI, 26%–51%), 94% (95% CI, 70%–99%), and 0.56 for serum CMV Ag, and 53% (95% CI, 35%–70%), 91% (95% CI,84%–95%), and 0.84 for stool CMV PCR. Conclusions: Serum and stool tests cannot replace colonoscopy for diagnosing CMV ileocolitis due to their low sensitivities but may be useful when colonoscopy is not feasible. Positive results can aid diagnosis, given their high specificities. Serum and/or stool CMV PCR are preferred over CMV Ag.