Prophylactic Red Cell Matching for Transfusion-dependent Thalassemia

Proposed Session Description: Patients with thalassemia may be exposed to many allogeneic red cell units throughout their lifetime. Those with transfusion-dependent thalassemia (TDT) receive red cell units every 2-4 weeks, while those with non-transfusion-dependent thalassemia (NTDT) may receive episodic transfusions, likely several in their lifetimes. Yet, the evidence guiding red cell matching practices remains surprisingly thin. Reported alloimmunization prevalence ranges from 3% to 42% across institutions worldwide. Prophylactic C, E, and K (CEK) antigen matching has been increasingly recommended and adopted, but whether it meaningfully reduces alloimmunization incidence across diverse TDT populations remains unclear.

This interprofessional session brings together a transfusion medicine physician and a hematologist who manages TDT patients to examine this problem from both sides of the clinical relationship. The transfusion medicine speaker will present: 1) existing alloimmunization data in this population, 2) current prophylactic matching guidelines, 3) variability in matching protocols, 4) existing data on impact of prophylactic matching on alloimmunization. The hematologist speaker will address: 1) the current transfusion practice for both TDT and NTDT, 2) the clinical consequences of alloimmunization for TDT patients (e.g., additional time and planning, risk of developing autoantibodies, risk of hemolytic reactions, increased transfusion burden from shorter red cell survival and worsening iron overload), 3) the logistical and financial impact of instituting extended matching protocol for these individuals (e.g., advanced planning, additional time requirements, delays for semi-emergent transfusions, additional costs) .

This session will explore whether prophylactic matching should be implemented for patients with TDT, the degree of matching and antigens to match for, and whether the utility of matching might vary across different populations or subgroups.