Anti-D alloimmunization after D-mismatched allogeneic hematopoietic stem cell transplantation in patients with hematologic diseases

BACKGROUND:  The de novo development of anti-D after D-mismatched allogeneic hematopoietic stem cell transplantation (AHSCT) is a possibility that must be considered. The transfusion of D− blood components after AHSCT has been recommended but anti-D alloimmunization in this setting has been studied little. Thus, the aim of this study was to analyze anti-D formation after D-mismatched AHSCT. STUDY DESIGN AND METHODS:  Thirty patients with a hematologic disease who underwent D-mismatched AHSCT were retrospectively studied. Support therapy included red blood cells (RBCs) and platelet (PLT) concentrates (PCs) from whole-blood donations and PLTs from apheresis. After AHSCT, patients received D+ PCs without administering Rh immunoglobulin (RhIG). An antibody screening to detect anti-D was performed by low-ionic-strength saline-indirect antiglobulin test with the tube test. RESULTS:  Fifteen D+ patients received stem cells (SCs) of D− donors and 15 D− patients received SCs of D+ donors. After AHSCT, patients received a median of 11.5 (range, 0-32) D− RBC units. D+ patients received 682 (83%) of 825 PLT units from D+ donors, and D− patients received 573 (85%) of 678 PLT units from D+ donors. None of the 30 patients developed anti-D after a median follow-up of 32 weeks (range, 4-310 weeks). CONCLUSION:  Anti-D alloimmunization after performing a D-mismatched AHSCT is infrequent in patients with hematologic diseases although patients receive D−mismatched PLT transfusions without RhIG administration.