[Application of Modified DTT Methods to Reduce the Interference of Daratumumab on Serological Detection].

Objective: To modified the classic dithiothreitol (DTT) method for treating red blood cells (RBCs) in Technical Manual of American Association of Blood Banks（AABB） and evaluate its application value in pre-transfusion examination of patients treated with daratumumab.
Methods: The classic 0.2 mol/L DTT method was improved in terms of PBS, DTT concentration, donor RBCs concentration (suspended/packed) and sample processing time. The modified DTT methods and AABB classic DTT method were applied to the blood matching tests of 12 multiple myeloma patients treated with daratumumab. The effect of treating panel RBCs with modified DTT methods on the detection of other irregular antibodies was evaluated by using antiserum and antibody reagents with known antibody properties.
Results: Two modified DTT methods were established (method 1: changed the concentration of DTT to 0.01 mol/L; method 2: changed the concentration of DTT to 0.02 mol/L and replaced the packed RBCs with 3% RBCs suspension). The optimal treatment time was 35 min for the modified DTT methods. At this time, the pan-agglutination caused by daratumumab was eliminated, but the detection of antibodies such as anti-E, anti-JK ^a , anti-M were not affected, and the titer of anti-K antibodies was only slightly decreased.
Conclusion: The modified DTT methods were effective, which can eliminate the interference of daratumumab while retaining the activity of the Kell blood group system, and can replace the current classic DTT method in AABB Technical Manual.