From the Guidelines
Yes, minor antigen mismatches can cause a significant fall in hemoglobin (Hb) after blood transfusion, and it is crucial to recognize and manage this condition promptly to prevent life-threatening complications. This occurs through a process called delayed hemolytic transfusion reaction (DHTR), which typically develops within 21 days post-transfusion, as defined by the American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support 1. In this scenario, the recipient's immune system recognizes minor blood group antigens on donor red blood cells as foreign, producing antibodies that lead to premature destruction of transfused cells. Common minor antigens involved include Kidd, Duffy, Kell, and MNS blood group systems. Patients may present with unexplained anemia, jaundice, fever, and dark urine, and laboratory findings typically show decreased hemoglobin, elevated bilirubin, and sometimes hemoglobinuria.
Key Considerations
- Minor antigen mismatches can lead to hyperhemolysis, defined as a rapid hemoglobin decline to below the pretransfusion level and rapid decline of the posttransfusion HbA level 1.
- Immunosuppressive therapy should be initiated promptly in patients with life-threatening hemolysis, with first-line agents including IVIg and high-dose steroids, and second-line agent eculizumab 1.
- Prevention strategies include thorough antibody screening before transfusion and maintaining detailed transfusion history records, especially in patients requiring chronic transfusions who are at higher risk of developing these antibodies.
- If transfusion is warranted, extended matched red cells (C/c, E/e, K, Jka/Jkb, Fya/Fyb, S/s) should be considered to minimize the risk of DHTR 1.
Management and Prevention
- Supportive care should be initiated in all patients, including erythropoietin with or without IV iron 1.
- A shared decision-making process is critical in managing patients with DHTR, involving the hematologist, transfusion medicine specialist, and other healthcare professionals 1.
- Avoidance of further transfusion is recommended unless patients are experiencing life-threatening anemia with ongoing hemolysis, and phenotypically matched blood should be used for future transfusions 1.
From the Research
Minor Antigen Mismatch and Hemoglobin Levels
- A minor antigen mismatch can potentially cause a fall in Hemoglobin (Hb) after blood transfusion, as it may lead to an immune response against the transfused red blood cells 2.
- However, the severity of the reaction depends on various factors, including the type and amount of incompatible blood transfused, as well as the individual's immune response 2.
- In cases of minor ABO mismatch, acute hemolysis may not be detected due to the lack of residual plasma in leukocyte-reduced red cell concentrate (RCC-LR) 2.
Hyperhemolytic Transfusion Reactions
- Hyperhemolytic transfusion reactions (HHTR) are serious and potentially life-threatening complications of red blood cell transfusion, characterized by the destruction of both donor and host red blood cells 3, 4.
- HHTR can occur in patients with sickle cell disease and non-sickle cell disease patients, and may be triggered by minor antigen mismatches 3, 4.
- Treatment with intravenous immunoglobulin (IVIG) and steroids may be effective in correcting severe anemia and resolving hemolysis in HHTR cases 3, 4, 5.
Prevention and Management
- Prevention of ABO-incompatible transfusion is crucial, and can be achieved through the establishment of a management system of blood transfusion in hospitals, including a hospital transfusion committee and a responsible medical doctor 2.
- In cases where transfusion of incompatible units is necessary, prophylaxis with IVIG plus steroids and IVIG may be considered as a therapeutic option to prevent hemolytic transfusion reactions 5.