Once the patient receives daratumumab dithiothreitol (DTT) is used to eliminate the CD38 antigen from the surface of the reagent RBCs thereby eliminating the antibody screen and panel panreactivity. In the meantime however, our institution’s Blood Bank has asked the clinical teams and pharmacy to notify the Blood Bank if a patient is going to receive daratumumab so that a baseline type and screen and RBC antigen phenotype or genotype is performed prior to initiating treatment. Potential future techniques to resolve interference, such as anti-idiotype antibodies to neutralize anti-CD38 in vitro, are on the horizon. Adsorptions: panreactivity cannot be eliminated.AHG crossmatch: positive with all RBC units tested.Antibody identification panel: all cells positive (autocontrol may be positive or negative).To summarize (adopted from AABB Bulletin #16-02): Thankfully, ABO/RhD testing is not affected. The daratumumab effect manifests as a warm autoantibody and will pan-react to any testing carried out including indirect (IAT) and direct antiglobulin tests (DAT), antihuman globulin (AHG) testing, and antibody screening and identification panels. However, it has been shown to result in false-positive screening test results in the blood bank in all media (saline, PEG, LISS). Thankfully, the anti-CD38 binding of RBCs has not been shown to cause severe hemolysis. So while the CD38 antibodies are busy destroying the malignant myelomatous plasma cells, they will also be binding onto RBCs. Daratumumab is a novel monoclonal antibody that targets CD38, an integral membrane protein expressed on both plasma cells and red blood cells (RBC). Daratumumab, also known as Darzalex, DARA, or Dara-T, is a new medication recently approved in the US by the FDA to treat multiple myeloma.