Survival of Post-Transplant Lymphoproliferative Disorder after Kidney Transplantation in Patients under Rapamycin Treatment.

Background: One of the important causes of mortality and morbidity in kidney transplanted patients is Post Transplant Lymphoproliferative Disease (PTLD), which is due to immunosuppression therapy and viral activity. It seems that Rapamycin, with dual antineoplastic and immunosuppressive effects, may have a pivotal role in the treatment of PTLD patients and preserving transplanted kidneys. Methods and Materials: Twenty patients with PTLD were enrolled. Immunosuppressive therapy was reduced or ceased, and Rapamycin was initiated at the time of PTLD diagnosis. We evaluated the effects of switching immunosuppressive drugs to Rapamycin on graft status, the response of tumor, and 6, 12 months, and 5-year survival in patients. Results: PTLD remission was achieved in 14 patients, while six patients died; no relapse was detected in recovered patients. The median of PTLD free time was 25 months, and the mean overall survival in patients with PTLD treated by Rapamycin was 84.8 (95% CI=61.3-108.23).The five-year survival rate was 67%, 12 months survival was 73.8%, and six months' survival was 80%. The response rate to Rapamycin and immunosuppression reduction alone was 46.6%. Four out of 13 Diffuse Large B-Cell Lymphoma patients achieved a complete response just only after the reduction of immunosuppressive drugs and the consumption of Rapamycin. Conclusion: The present study demonstrated the effectiveness of conversion from immunosuppressive medication, particularly of Calcineurin inhibitors to Rapamycin in PTLD patients. However, more research is needed to confirm the Rapamycin effect on patients with PTLD.