To investigate epidemiology of CMV-IgG in thoracic organ transplantation (TOT) donors and recipients, as well as the incidence of CMV infection and CMV disease in recipients and analyze the prognosis.

The study retrospectively analyzed the recipients who undergone TOT from January 1, 2003 to April 30, 2020 at the First Affiliated Hospital of Guangzhou Medical University. Clinical data were collected from the medical records which mainly included: serum CMV-immunoglobin (IgG) between donor (D) and recipient (R) pre-transplants, symptoms and signs, imaging performance, serum and bronchial alveolar lavage fluid levels of CMV-DNA and tissue biopsy.

With excluding of 13 cases of incomplete data, the study recruited 301 cases with TOT, comprising of 269 lung transplants, 19 heart transplants, and 16 heart and lung combined transplants. CMV-IgG information of donors and recipients were analyzed in the 301 cases. Serum CMV-IgG was positive in 87.0% (262/301) of recipients and 85.0% (256/301) of donors. According to the risk stratification of primary CMV infection, the proportions of high-risk (donor positive/recipient negative, D⁺ /R^-), intermediate-risk (donor positive/recipient positive), low-risk (donor negative/recipient positive) and very low-risk (donor negative/recipient negative) were 6.0% (18/301), 79.1% (238/301), 8.0% (24/301) and 7.0% (21/301), respectively, and there were no significant differences in the proportions of the above types in different types of transplant recipients (P>0.05 for all). Another 12 recipients were excluded from the further analysis who were died with 14 days post-transplantation, based on the exclusion criteria of this study. Thus, a total of 289 recipients were analyzed for the epidemiology of CMV infection and CMV diseases. There were 177 (61.2%) recipients whose serum CMV-DNA were positive at least once and 49 (17.0%) recipients who were diagnosed with CMV disease, with the incidence of CMV disease being presented highest in D⁺ R^- group. As of April 30, 2020, 289 recipients were followed up for 651 days (14-3 652 days). The all-cause mortality was 67.4% in CMV disease group and 35.8% in non-CMV disease group, respectively (χ²=15.4, P<0.05).

Only 6.0% recipients with TOT were at higher risk, and most of the recipients (87.0%) were at moderate-mild risk of primary CMV infection, based on the serological stratification. Most of the TOT recipients (61.2%) had at least once serum CMV-DNA positive post-operation, with 17% of the TOT recipients suffering from CMV disease. The all-cause mortality was significantly higher in CMV disease group than that of the non-CMV disease group.