Risk factors for post‐transplant lymphoproliferative disorder after Thymoglobulin‐conditioned hematopoietic cell transplantation

Epstein‐Barr virus ( EBV )‐induced post‐transplant lymphoproliferative disorder ( PTLD ) occurs frequently when rabbit antithymocyte globulin ( ATG ) is used in hematopoietic cell transplant ( HCT ) conditioning. We retrospectively studied 554 patients undergoing ATG ‐conditioned myeloablative HCT . Strategies used to minimize mortality due to PTLD were either therapy of biopsy‐diagnosed PTLD in the absence of EBV DNA emia monitoring (n = 266) or prompt therapy of presumed PTLD (based on clinical/radiologic signs and high EBV DNA emia, in the setting of weekly EBV DNA emia monitoring) (n = 199). Both strategies resulted in similar mortality due to PTLD (0.7% vs 1% at 2 years, P  = .43) and similar overall survival (63% vs 67% at 2 years, P  = .23) even though there was a trend toward higher PTLD incidence with the prompt therapy. Donor positive with recipient negative EBV (D+R−) serostatus was a risk factor for developing PTLD . Older patient age, HLA ‐mismatched donor, and graft‐versus‐host disease were not associated with increased risk of PTLD . In summary, in ATG ‐conditioned HCT , D+R− serostatus, but not older age, mismatched donor or GVHD is a risk factor for developing PTLD . EBV DNA emia monitoring may be a weak risk factor for developing/diagnosing PTLD ; the monitoring coupled with prompt therapy does not improve survival.