Current Practice of Mitigating Monoclonal Anti-CD38 Interference in Pretransfusion Compatibility Testing

ABSTRACT Monoclonal anti-CD38 is used in the treatment of patients with multiple myeloma (MM) who are refractory to proteasome inhibitors and immunomodulatory drugs. CD38 is highly expressed on malignant cells in MM; however, because CD38 is also expressed on red blood cells (RBCs), the drug interferes with a variety of blood compatibility tests that utilize the indirect antiglobulin test (IAT). Dithiothreitol (DTT) or trypsin may be employed to remove CD38 molecules from the RBC membrane prior to testing in order to circumvent the drug’s interference. However, numerous blood group antigens are also destroyed by DTT and trypsin, which could lead to the inability to detect certain clinically significant alloantibodies in pretransfusion compatibility testing. This study was undertaken to investigate the usage of various protocols for mitigating the drug’s interference in pretransfusion testing and strategies for providing blood products to patients undergoing anti-CD38 drug therapy in hospitals in the United States. ABBREVIATIONS Antihuman Globulin (AHG) Daratumumab (DARA) Dithiothreitol (DTT) Food and Drug Administration (FDA) Immunofixation Electrophoresis (IFE) Indirect Antiglobulin Test (IAT) Immunohematology Reference Laboratory (IRL) Laboratory Information System (LIS) Monoclonal antibody (mAb) Multiple Myeloma (MM) Red Blood Cell (RBC) Serum Protein Electrophoresis (SPEP) Index terms: CD38, Antibodies, Multiple Myeloma, Blood Banks, Blood Group Antigens