Etiology and outcome of graft failure in pediatric hematopoietic stem cell transplant recipients

Purpose: To determine the incidence, etiology and outcome of graft failure in pediatric allogeneic bone marrow transplant (BMT) recipients. Patients and Methods: Patients with primary or secondary graft failure were identified by database review. A retrospective chart review was performed. Etiologic factors were identified and assessed for statistical significance. Results: 309 children underwent allogeneic BMT during the time interval studied. Four cases of primary graft failure and 7 cases of secondary graft failure occurred. Nonmalignant diagnosis, lower total nucleated cell (TNC) dose, and conditioning without total body irradiation were associated with a higher incidence of graft failure. Donor source, donor/recipient CMV status, CD34+ cell dose, and alloimmunization were not associated with graft failure. Conclusions: Graft failure is a relatively uncommon occurrence in pediatric patients. Autologous reinfusion may allow time to prepare the patient for a second transplant and decrease complications associated with aplasia. More immunosuppressive conditioning regimens may decrease the incidence of graft failure, particularly in patients with non-malignant diseases or those with lower stem cell doses. More frequent monitoring of chimerism by VNTR analysis may detect late graft failure earlier and allow for more rapid intervention.