Objectives: After renal transplantation, the patient is in an immunosuppressed state, requiring continuous administration of immunosuppressive agents to prevent rejection. While the immunosuppressed state can lead to increased susceptibility to infection and more severe viral infections, the risk of rejection and the long-term outcomes can be affected by reducing the dosage of immunosuppressive agents due to infection. In this study, we will evaluate the status of antibody gain and DNA quantitative values after renal transplantation for the EB virus (EBV), which is associated with the development of post-transplant lymphoproliferative disease, a unique post-transplantation condition.
Methods: EBV antibody (VCA-IgG, EBNA) gain and EBV-DNA quantitative values were cross-sectionally evaluated in post renal transplant patients under 18 years of age who visited our department from January 2022 to January 2023 (at the time of evaluation). EBV-DNA quantification was performed using whole blood and real-time PCR, and antibody titers were compared with those before transplantation.
Results: Thirty-four patients (21 boys) were included in this study, with a median age at evaluation of 13.0 (IQR 11.0-15.0) years and a median period of years since transplantation of 5.0 (IQR 3.0-8.0) years. Immunosuppressive agents used at the time of evaluation were tacrolimus in 31 cases, cyclosporine in 1, methylprednisolone in 30, mycophenolate mofetil in 26, everolimus in 8, azathioprine in 1, and rituximab was used previously in 9 cases. Pre-transplant EB virus antibodies were donor (D)+/recipient (R)+ in 12 cases, D+/R- in 19 cases, and D-/R- in 3 cases; in R+ 12 cases (35%), all were VCA-IgG positive. At the time of evaluation, 31 cases (91%) were R+, all VCA-IgG positive and 13 EBNA positive. The EBV-DNA quantification test was positive in 16 patients (47%) with a median value of 3.66 (IQR 3.19-4.33) LogIU/mL. One patient who was pre-transplant D+/R- developed PTLD, with an EBV-DNA of 2.18 LogIU/mL.
Conclusion: Many pre-transplant EBV antibody-negative recipients acquired VCA-IgG after transplantation, but the rate of EBNA antibody acquisition was low. EBV-DNA quantification was positive in about half of the cases, and the median value was also high, so it was difficult to predict the onset of PTLD. Establishment of cutoff values requires accumulation of cases.