Racial variation in the development of posttransplant lymphoproliferative disorders after renal transplantation.

Background: We previously reported that posttransplant lymphoproliferative disorders (PTLD) occurred more frequently in non-African American (AF) kidney transplant recipients. An in-depth analysis of racial differences in the development of PTLD has not been reported.

Methods: We assessed Medicare claims for PTLD in a retrospective cohort of 53,719 patients who underwent transplantation from January 2000 to September 2006 and followed up through December 2007.

Results: There were 719 (1.3%) patients with claims for PTLD. Non-AF recipient race (including all races analyzed separately, adjusted hazard ratio [AHR] 1.38, 95% confidence interval [CI] 1.13-1.68), recipient Epstein-Barr virus (EBV) immunoglobulin G (IgG) seronegative status (AHR 1.88, 95% CI 1.53-2.34), and de novo sirolimus (AHR 1.22, 95% CI 1.03-1.45) were associated with an increased risk of PTLD. Furthermore, de novo sirolimus showed a significant interaction with EBV IgG; among EBV IgG-negative recipients, sirolimus use was significant (P = 0.003), but among EBV IgG-positive recipients, it was not significant (P = 0.18). EBV IgG-seronegative status was significant in all races except for AFs, and racial differences were a significant effect modifier for EBV IgG status and risk of PTLD. Mortality subsequent to PTLD did not differ by race. CONCLUSIONS.: AF kidney transplant recipients were at lower risk for PTLD, irrespective of the recipient EBV IgG serostatus. On the contrary, recipient EBV IgG-seronegative status was associated with a higher risk of PTLD in the non-AF population. De novo sirolimus therapy was associated with increased risk of PTLD in EBV IgG-negative recipients, regardless of race.