(P-TS-58) Multiple rapid allo-immunizations and severe DHTR after massive transfusion of RhD-positive RBC in a RhD-negative recipient: case report and literature review

Background/Case Studies: Delayed hemolytic transfusion reaction (DHTR) is defined by the National Health Safety Network (NHSN) as a reaction that occurs between 24 hours and 28 days after cessation of transfusion, with and newly identified red blood cell antibody and signs of hemolysis, increased LDH and bilirubin, and a positive direct antiglobulin test (DAT). Several studies have reported the incidence of DHTR at approximately 1 in 800 patients. Red cell antibodies in the Rh, Kell, Duffy, and Kidd blood group systems have been reported to be most common antibodies causing DHTR. We report an unusual case of rapid alloimmunization with multiple, sequential antibodies leading to severehemolysis in a RhD-negative male patient shortly after massive transfusion of RhD-positive red cells with no prior transfusion history.

Study

Design/Methods: A 21-year-old male patient, in a motor vehicle related accident with major pelvic fractures and internal soft tissue injury. He received 30, O-RhD positive RBCs, 23 fresh frozen plasma, 7 apheresis platelets, and 4 bags of pooled cryoprecipitate over 24 hours. On day 5, his antibody screen was negative, but required two O-RhD negative units upon a sudden drop in hemoglobin and >2g/dL rise in bilirubin. Type and screen, DAT, antibody identification, and elution studies were performed using standard blood bank and reference lab techniques.

Results/Findings: On day 11, a strong anti-D was detected in the plasma and the DAT was positive for IgG(3+) and C3 (1+). On day 17, anti-Jka was identified in the plasma, and the anti-D was identified in the eluate. Patient received 2 additional O, RhD-negative, Jk (a-), RBC due to worsening anemia and ongoing evidence of hemolysis. On day 19, anti-E was identified in the plasma. To provide phenotype matched blood, red cell genotyping was performed which offered the C- E- K- Fya- Jka- S- phenotype. On day 26, a warm autoantibody was detected and the anti-Jka in the eluate. Finally, anti-C and anti-K were identified on day 29. His hemolysis gradually improved, and the DAT converted to negative. A clinical timeline of patient's progress has been shown in Figure 1.

Conclusions: While DHTR can be life threatening, it usually takes several days to weeks to present, especially in a massive trauma situation. Our patient was a hyper-responder that produced multiple alloantibodies- anti-D, anti-C, anti-E, anti-K, anti-Jka, and a warm autoantibody in < 4 weeks’ time span. With negative history of any prior exposure to RBC antigens, patient’s rapid alloimmunization with multiple sequential antibodies and rapid hemolysis was unusual.

Importance of research: In trauma setting, use of group O RhD-positive RBC and LTOWB can be expected except in women of childbearing age or patients with known anti-D. Current literature suggests that the overall risk of alloimmunization with massive transfusion in trauma setting, while variably reported, is not critically high. However, when DHTR occurs, it can be life threatening as seen in this case. Currently, there is no clear indication on how early and frequently patients should be monitored for signs of DHTR.