Optimized strategy to mitigate daratumumab interference in blood bank testing: Reducing cost and time

Area of Science:

• Hematology
• Transfusion Medicine
• Oncology

Background:

• Daratumumab (DARA) therapy in multiple myeloma (MM) patients can interfere with pretransfusion red blood cell (RBC) testing.
• Current guidelines recommend RBC phenotyping/genotyping before DARA, but lack standardized, cost-effective pretransfusion testing protocols.
• Previous studies reported low RBC alloimmunization risk and mitigation strategies but did not propose cost-effective solutions.

Purpose of the Study:

• To assess the RBC alloimmunization risk in MM patients treated with DARA.
• To propose a cost-effective algorithm for pretransfusion testing in DARA-treated patients.

Main Methods:

• Retrospective analysis of 850 MM patients receiving DARA and RBC transfusions over 9.4 years.
• Collected demographic data, serologic profiles (blood typing, Ab screen, Ab ID), RBC phenotype/genotype, and crossmatch data.
• Compared incidence of clinically significant antibody formation pre- and post-DARA against a control group (P < .05).

Main Results:

• 172 out of 850 (20%) MM patients on DARA received RBC transfusions.
• All patients exhibited a panagglutinin post-DARA; no new clinically significant alloantibodies were formed.
• An optimized pretransfusion strategy significantly reduced turnaround time and costs.

Conclusions:

• This extensive study demonstrates no increased RBC alloimmunization risk in DARA-treated, transfused MM patients.
• A novel pretransfusion testing strategy effectively mitigates DARA-related transfusion interference.
• The proposed strategy offers a cost-effective solution for pretransfusion testing in this patient population.