Cytomegalovirus infection contributes to acute rejection in solid organ transplant recipients: a systematic review and meta-analysis.

Background: Solid organ transplant (SOT) recipients receive immunosuppressive drugs that predispose them to opportunistic infections, including cytomegalovirus (CMV) infection. In these patients, CMV infection can lead to life-threatening consequences, such as transplant rejection. This systematic review and meta-analysis investigated the role of CMV infection in the development of acute rejection in SOT recipients.

Methods: PubMed, Embase, Scopus, and Web of Science databases were systematically searched for eligible publications until Jan 31, 2025. English-language studies reporting the association between CMV infection and acute rejection in adult SOT recipients were included. Baseline characteristics, transplanted organs, and CMV infection and acute rejection status in SOT recipients were independently extracted by two reviewers. The pooled odds ratio (ORs) with a 95% confidence interval (CI) was calculated using the random effect model.

Results: Overall, 27 studies with 6308 SOT recipients entered the meta-analysis. Acute rejection was significantly higher in SOT recipients with CMV infection than those without CMV infection (OR = 2.02, 95%CI 1.64-2.49, I² = 40.44%). Acute rejection was significantly higher in recipients of liver (OR = 4.43, 95%CI 2.20-8.92, I² = 0.00%), kidney (OR = 2.22, 95%CI 1.70-2.89, I² = 48.72%), and lung (OR = 1.38, 95%CI 1.01-1.90, I² = 0.00%), if they were infected with CMV. While acute rejection was not significantly associated with CMV infection in heart transplant recipients (OR = 1.49, 95%CI 0.54-4.12, I² = 18.83%). Furthermore, Egger's test did not indicate any evidence of publication bias (P = 0.7440).

Conclusions: CMV infection approximately doubles the risk of acute rejection in SOT recipients. This association differs between various organs, with liver transplants indicating the highest risk, followed by kidney and lung transplants.