O-negative blood shortage management in a university hospital: Impact of transfusing RhD-positive red blood cells to RhD-negative patients

Optimizing O red blood cell concentrate usage in the emergency department in the era of patient blood management

BACKGROUND

Emergency transfusion may require the availability of O-negative red blood cell concentrates without pre-transfusion testing. At the Cliniques Universitaires Saint-Luc, the emergency department was used to having access to two decentralized O-negative red blood cell concentrates. This study aims to analyze the consumption of O-negative red blood cell concentrates in emergency situations both before and after the implementation of a novel strategy aiming at optimizing stocks. This strategy provides a combined allocation of one unit of O-positive red blood cell concentrate and one unit of O-negative red blood cell concentrate decentralized in the emergency department and reserve the transfusion of the negative unit only to under 45-year-old women and under 20-year-old men.

MATERIALS AND METHODS

A retrospective study was conducted of the transfusion and medical records of all patients who received immediate transfusions in the emergency department without pre-transfusion testing between 2008 and 2022.

RESULTS

A total of 193 patients received O red blood cell concentrates without pre-transfusion testing in emergency situations between 2008 and 2022. During the first 24 h of hospitalization, 354 O-negative units were transfused. Mean ratios of number of O-negative bags between 2008 and 2020 was 1.98 unit/patient. After implementation of the new strategy, the ratio in 2021 was 1.46 unit/patient and drastically decreased in 2022 to 0.79 unit/patient.

CONCLUSION

In situations of emergency, allocating O-negative units only for women younger than 45 years and men younger than 20 years could have saved 85% of O-negative red blood cell concentrates transfused (303/354) yet balancing the immunological risk. Limiting the number of delocalized units of O-negative red blood cell concentrates in the emergency department seems to lower O-negative consumption. With this strategy, the units spared could have been transfused to patients with greater needs (e.g., sickle cell patients or chronically transfused patients).

Prevention of Blood Incompatibility Related Hemagglutination: Blocking of Antigen A on Red Blood Cells Using In Silico Designed Recombinant Anti-A scFv

Critical blood shortages plague healthcare systems, particularly in lower-income and middle-income countries. This affects patients requiring regular transfusions and creates challenges during emergencies where universal blood is vital. To address these shortages and support blood banks during emergencies, this study reports a method for increasing the compatibility of blood group A red blood cells (RBCs) by blocking surface antigen-A using anti-A single chain fragment variable (scFv). To enhance stability, the scFv was first modified with the addition of interdomain disulfide bonds. The most effective location for this modification was found to be H44-L232 of mutant-1a scFv. ScFv was then produced from E.coli BL21(DE3) and purified using a three-step process. Purified scFvs were then used to block maximum number of antigens-A on RBCs, and it was found that only monomers were functional, while dimers formed through incorrect domain-swapping were non-functional. These antigen-blocked RBCs displayed no clumping in hemagglutination testing with incompatible blood plasma. The dissociation constant KD was found to be 0.724 μM. Antigen-blocked RBCs have the potential to be given to other blood groups during emergencies. This innovative approach could significantly increase the pool of usable blood, potentially saving countless lives.

Incidence of formation of anti-D between patients with and without a history of solid organ transplant

BACKGROUND AND OBJECTIVES

Solid organ transplant surgeries including liver transplants constitute a substantial risk of bleeding complications and given frequent national blood shortages, supporting D-negative transplant recipients with D-negative red blood cell products perioperatively can be difficult for the transfusion services. This study was designed to compare the incidence of alloimmunization after D-mismatched red cell transfusions between patients with and without a history of solid organ transplant at a single tertiary care hospital. The patients undergoing solid organ transplants are on strong immunosuppressive regimens perioperatively to help reduce the risk of rejection. We hypothesized that the use of these immunosuppressive agents makes these patients very less likely to mount an immune response and form anti-D antibodies when exposed to the D-positive red blood cell products perioperatively.

STUDY DESIGN AND METHODS

At our center, D-negative patients who received ≥1 unit of D-positive red blood cell products were identified using historical transfusion records. Antibody testing results were examined to determine the incidence of the formation of anti-D and any other red cell alloantibodies after transfusion and these results were compared between patients with and without a history of solid organ transplant.

RESULTS

We were able to identify a total of 22 patients over 10 years with D-negative phenotype who had undergone a solid organ transplant and had received D-positive red blood cell products during the transplant surgeries. We also identified a second group of 54 patients with D-negative phenotype who had received D-positive red blood cell products for other indications including medical and surgical. A comparison of the data showed no new anti-D formation among patients with a history of D mismatched transfusion during solid organ transplant surgeries.

CONCLUSION

Among our limited study population, we observed a very low likelihood of D alloimmunization among solid organ transplant recipients. A larger, prospective study could help further evaluate the need for prophylactic D matching for red cell transfusions during solid organ transplant surgeries.