TCEP-HCl can resolve the daratumumab interference

Daratumumab (DARA) is a human CD38 IgG1 monoclonal antibody that has significant therapeutic effects on multiple myeloma (MM). However, DARA may interfere with the indirect antiglobulin test (IAT) used to test for MM. At present, there are defects in the popular strategies for IAT anti-human globulin reactions caused by anti-CD38 monoclonal antibody drugs. Tris(2-carboxyethyl)phosphine hydrochloride (TCEP-HCl) is a new and effective solution to eliminate DARA's interference with the IAT. To verify its effect, the following experiments were done. After TCEP-HCl was administered to red blood cells (RBCs), the expression level of CD38 antigen on RBCs was determined by flow cytometry. Serological experiments were performed to verify the effects of TCEP-HCl on different blood groups of RBCs. The results showed that DARA could cause false-positive reaction in IAT, and the CD38 antigen on the membranes of RBCs decreased after TCEP-HCl treatment. Serological results showed that TCEP-HCl did not damage other blood group antigens on RBCs, except for Kell antigens. Indirect antiglobulin tests appeared normal after treatment with the TCEP-HCl reagent. The conclusion is that TCEP-HCl can resolve daratumumab interference in the IAT.