Daratumumab (Dara), an anti-CD38 monoclonal antibody, was approved by the U.S. Food and Drug Administration (FDA) in 2015 for use in patients with hematologic malignancies. Compared to normal lymphoid and myeloid cells, multiple myeloma cells express high levels of CD38 making these cancerous cells targets for Dara. Dara, however, also binds to RBCs which express CD38, thus interfering with antibody screens, antibody identification, and other serological tests. The AABB recommends a baseline type, antibody screen and phenotype or genotype before patients start taking Dara, but little data exists as to whether these patients have an increased risk of alloimmunization. In order to better understand the transfusion needs and the alloimmunization risk of these patients, researchers at the Mayo Clinic performed a retrospective chart review on 244 patients on Dara from September 2015 to December 2018 and compared RBC transfusion and RBC alloantibody formation rates to a control group of patients. Of the 244 patients taking Dara, 145 (59.4%) received a RBC transfusion and antibody screens were performed on 97/145 patients at least two weeks following the transfusion. New alloantibodies were detected in four patients (2.8% of the total transfused; 4.1% of the patients with follow-up antibody screens) at an incidence similar to transfused hematology patients not taking Dara. These results support current typing, matching, and transfusion practices for patients with multiple myeloma taking Dara.
Reference:
