Post‐transplant Lymphoproliferative Disorders: Determination of Donor/Recipient Origin in a Large Cohort of Kidney Recipients

Although in previous studies most post‐transplant lymphoproliferative disorders (PTLD) were reported to derive from recipient cells, some cases derived from donor lymphocytes have been reported. To provide a better description of the features and outcome of PTLD according to the origin of the lymphoma, we performed histologic and molecular studies of PTLD in kidney recipients. Forty‐three specimens were analyzed by histochemistry, fluorescent hybridization of the Y chromosome and analysis of multiple short tandem repeat microsatellite loci. Sixteen tumors were shown to be of donor origin and 27 of recipient origin. Time to PTLD was shorter in donor‐derived PTLDs (20±27 vs. 69±67 months, p = 0.013). Ten‐year patient survival was similar among patients with recipient‐ and donor‐derived PTLD, but when PTLD‐related mortality was analyzed, there was a trend to better survival in patients with donor lymphomas. Among the 21 PTLDs localized in the allograft, 14 lymphomas were of donor origin and seven of recipient origin. No difference was found between the two groups. Our analysis of the origin of PTLDs in the largest cohort studied to date with a description of the clinical and histological characteristics of donor and recipient PTLDs should lead to a better understanding of lymphomagenesis. Analyzing the origin of the tumor cells in post‐transplant lymphomas occurring in 43 kidney recipients, the authors show that 16 tumors were of donor and 27 were of recipient origin.