From the Guidelines
Delayed transfusion reactions should be managed promptly with immunosuppressive therapy, including first-line agents such as IVIg and high-dose steroids, to prevent life-threatening hemolysis and improve patient outcomes. The management of delayed transfusion reactions involves a comprehensive approach, including stopping any ongoing transfusions, obtaining blood samples for laboratory testing, and providing supportive care 1. Patients with delayed transfusion reactions often present with a significant drop in hemoglobin within 21 days posttransfusion, associated with new red cell alloantibody, hemoglobinuria, or accelerated HbS% increase 1.
Key considerations in the management of delayed transfusion reactions include:
- Initiating immunosuppressive therapy promptly in patients with life-threatening hemolysis 1
- Using first-line immunosuppressive agents such as IVIg and high-dose steroids 1
- Considering second-line agents such as eculizumab 1
- Avoiding further transfusion unless patients are experiencing life-threatening anemia with ongoing hemolysis 1
- Providing supportive care, including erythropoietin with or without IV iron 1
The pathophysiology of delayed transfusion reactions involves the development of antibodies against minor blood group antigens present in the donor blood, which can lead to significant hemolysis 1. Prevention strategies include careful cross-matching and maintaining detailed transfusion records to avoid future exposure to incompatible blood products 1. Patients with a history of delayed transfusion reactions should receive leukocyte-reduced blood products and be monitored closely during subsequent transfusions 1.
In terms of specific treatment, a dose of 375 mg of rituximab/m2 repeated after 2 weeks, methylprednisolone or prednisone at 1 to 4 mg/kg per day, and IVIg at 0.4 to 1 g/kg per day for 3 to 5 days have been used to treat hemolytic transfusion reactions 1. However, the optimal treatment approach may vary depending on the individual patient's circumstances and the severity of the reaction. A shared decision-making process is critical in the management of delayed transfusion reactions, taking into account the potential benefits and harms associated with specific immunosuppressive therapies 1.
From the Research
Definition and Symptoms of Delayed Transfusion Reactions
- Delayed hemolytic transfusion reactions (DHTRs) are defined as immune-mediated hemolysis of allogeneic donor red cells that occurs approximately 3 to 5 days after transfusion 2
- Symptoms of DHTRs may include a drop in hemoglobin and hematocrit, fever, jaundice, and renal insufficiency 2
- Delayed serologic transfusion reactions (DSTRs) are characterized by serologic findings consistent with DHTRs but no clinical evidence of hemolysis 2, 3
Incidence and Risk Factors
- The incidence of DSTRs is estimated to be 1 (0.66%) of 151 recipients with posttransfusion samples available for testing, while the incidence of DHTRs is only 1 (0.12%) of 854 patients tested 3
- Risk factors for DHTRs include high alloantibody evanescence rates among both general patient groups and those with sickle cell disease (SCD) 4
- Transfusion record fragmentation can also hamper antibody detection and contribute to the risk of DHTRs 4
Treatment and Prevention
- Automated red blood cell exchange (ARE) can be used to limit hemolysis associated with an emerging DHTR 5
- Novel immunosuppressive agents may be used to prevent or treat hyperhaemolytic DHTRs, particularly in patients with SCD 4
- Implementing practical preventive strategies, such as enhancing antibody detection and improving transfusion record management, is a priority for reducing the risk of delayed transfusion reactions 4
Pathophysiology and Clinical Significance
- DHTRs are mediated by blood group antibodies that undergo anamnestic increases following antigen reexposure 2, 5
- The persistence of a positive direct antiglobulin test (DAT) after DSTR or DHTR may involve several immunologic mechanisms, including the development of posttransfusion autoantibodies 3
- Delayed serologic and haemolytic reactions remain important and highly relevant transfusion-associated adverse events, and further research is needed to understand their basic mechanisms and develop evidence-based approaches for treatment and prevention 4