Prospective evaluation of a transfusion policy of D+ red blood cells into D- patients

BACKGROUND: Although D- patients should receive red blood cells (RBCs) from D- donors, the scarcity of D- blood components in certain situations makes the transfusion of D+ RBCs unavoidable. Therefore it is recommended that guidelines be developed in order to standardize transfusion policy in these scenarios. STUDY DESIGN AND METHODS: We have prospectively evaluated a policy for the use of D+ RBCs in 905 D- patients. The amount of D- RBCs saved as well as the incidence of hemolytic reactions and anti-D alloimmunization were assessed. RESULTS: 554 patients received D- RBCs while 351 received a total of 1032 D+ RBCs, all of them within our criteria for the acceptable use of D+ RBCs. This strategy allowed us to save 25.6 percent of D- RBCs (1032 out of 4024 RBCs requested). No hemolytic reactions were reported. The incidence of alloimmunization was 21.4 percent. Most patients who developed anti-D did so within the first 2 or 4 RBCs transfused (64% after the first 2 RBCs transfused and 88% after the first 4). In multivariate analysis the age of less than 77 years was the only predictor for alloimmuization (HR = 2.48 [95% Cl = 1.21-3.811; p = 0.014). CONCLUSION: The use of D+ RBCs in selected D-patients does not induce adverse reactions and allows the saving of a significant number of D- RBCs.