Elimination of ALX148 Interference in Pretransfusion Testing by RBC Alloadsorption: Two Case Reports / 대한수혈학회지

ABSTRACT

The anti-CD47 monoclonal antibody, one of the immune checkpoint inhibitors, can interfere with pretransfusion testing by binding to the cluster of differentiation 47 (CD47) proteins expressed on the surface of red blood cells (RBCs). We report the experience of mitigating interference in the pretransfusion test in two patients treated with ALX148, an anti-CD47 monoclonal antibody, by using multiple RBC alloadsorption. Two patients with a history of advanced head and neck squamous cell carcinoma were referred for a pretransfusion and cross-matching test. The blood group type of the two patients was B, RhD＋, but antibody screening, autocontrol, direct globulin, and cross-matching of the RBC units showed high-intensity agglutination. Medical records revealed that the patients were enrolled in an anti-CD47 monoclonal antibody clinical trial. To eliminate interference by the drug, we attempted alloadsorption using pooled O, RhD＋ RBCs, and the patient’s plasma in the ratio of 41. After three alloadsorption sessions using pooled allogeneic RBCs, the antibody screening and cross-matching issues of the globulin phase were resolved. The method used in this case is meaningful in that it can be easily used when drug interference occurs in a blood bank. (Korean J Blood Transfus 2023;3426-31)