Introduction: Human cytomegalovirus (CMV) infection are one of the most common complications in renal transplant patients. Graft survival rate was significantly lower in patients with CMV infection, with the incidence of CMV infection around 35% as reported. Guideline from the British Transplantation Society suggested in valganciclovir prophylaxis for patients at risk. For patients with CMV infection, most guidelines suggested valganciclovir treatment. However, several report suggested that reducing the dose mycophenolate mofetil and calcineurin inhibitor may be beneficial for such patients.
Method: In the study, the transplant recipients from a single center, Chang Gung Memorial Hospital from 2015~2024 were included. A total of 416 patients were included, which 387 cases have donors with positive test for Immunoglobulin G (IgG). The data of the patients were collected retrospectively through medical records. The patient’s basic characteristics including age, sex, Body mass index, renal function, CMV viral load were recorded. Biopsy proven rejection rate for the patients were calculated as our primary outcome.
Results: The patients with CMV infection after renal transplantation were classified to 2 groups. The first group had reduction of mycophenolate mofetil (MMF) and calcineurin inhibitor (CNI) dose right after confirmed CMV infection, while the second group did not. The patients renal function (Glomerular Filtration Rate) and biopsy proven rejection rate showed no statistically difference between the 2 groups. In the group with rapid reduction of MMF and CNI, lower CMV viral load was noted afterwards but without statistically significance. 
Conclusion: Rapid reduction of MMF and CNI may be potentially beneficial for renal transplant patients with CMV infection. Although no statistically significance was conducted from our study, it still offers a different approach to such patients. Further studies on the issue with larger patients numbers may be needed for better evaluation on the subject.