Maintenance immunosuppressive regimens and cytomegalovirus infection: Association with delayed kidney graft function

Transplant success depends on adherence to maintenance immunosuppression and effective prevention of opportunistic infections; however, selecting the most appropriate regimen remains challenging. This cohort study evaluated the association between maintenance immunosuppressive regimens and cytomegalovirus (CMV) infection, as well as renal function, in kidney transplant recipients at different time points after transplantation. All patients aged ≥18 years who underwent transplantation between March 2019 and May 2022 were included. Data on sex, age, donor (D) and recipient (R) CMV serostatus, viremia, immunosuppressive regimens, serum creatinine, and estimated glomerular filtration rate (eGFR) were obtained from medical records. The study was approved by the institutional ethics committee (no. 5,896,752). A p -value <0.05 was considered statistically significant. A total of 155 patients were included; 114 (73.5%) were male, with a mean age of 49.59 (±13.84) years, and 143 (92.3%) had an intermediate serological risk (D−/R+ or D+/R+). Eighty-three patients (53.5%) were receiving sirolimus, whereas 72 (46.5%) were receiving mycophenolate. Mycophenolate use was associated with a higher frequency of viremia at 15, 30, and 45 days ( p < 0.001). Viral load was not associated with renal function parameters. Mycophenolate increased the likelihood of viremia >5000 copies/mL within 6 months by 12.17-fold ( p < 0.001) compared with sirolimus. Additionally, the likelihood of delayed graft function was 2.9-fold higher ( p = 0.016) among women receiving mycophenolate. Serum creatinine and eGFR are not sensitive markers of renal dysfunction associated to CMV infection, and typically stabilize after 30 days post-transplant. Mycophenolate is a risk factor for CMV infection within the first 6 months, particularly at 45 days, and its use in women may delay improvement in renal function. • A high frequency of CMV viremia was observed at 30 and 45 days post-transplantation. • Creatinine and eGFR are not affected by CMV viremia. • Mycophenolate is associated with high frequency of viremia. • Female sex and use of mycophenolate increase the risk of delayed graft function.