Objective: To eliminate the interference of daratumumab (DARA) in the titer determination of IgG antiA/antiB antibodies, resolve the discrepancy between test results and theoretical expectations, and obtain accurate and reliable test results. Methods: A group A blood sample with a positive IgG antiA titer result was confirmed to have a recent history of DARA administration. After removal of IgM antibodies from the plasma, IgG antiA/antiB titers were determined using the antiglobulin test card with a serial twofold dilution method, following pretreatment of reagent red blood cells with a rabbit antihuman CD38 functional monoclonal antibody. Results: Without pretreatment with the rabbit antihuman CD38 functional monoclonal antibody, the IgG antiA titer of the sample was 128. After pretreatment, the IgG antiA titer became negative. Conclusion: Based on the red blood cell CD38 antigen masking strategy, pretreatment of red blood cells with a rabbit antihuman CD38 functional monoclonal antibody can eliminate the interference of DARA on the titer determination of IgG antibodies, thereby providing accurate diagnostic evidence and decision support for clinical treatment.