From the Guidelines
Blood transfusions for patients with Sickle Cell Disease (SCD) should aim to reduce the percentage of sickle hemoglobin (HbS) to below 30% while increasing the total hemoglobin to 9-10 g/dL, as recommended by the American Heart Association/American Stroke Association 1.
Key Considerations
- Patients typically receive packed red blood cells (PRBCs) that are phenotypically matched, leukocyte-reduced, and negative for hemoglobin S.
- The standard transfusion volume is 10-15 mL/kg of PRBCs, administered at a rate not exceeding 5 mL/kg/hour to prevent volume overload.
- Two main transfusion approaches are used: simple transfusions for acute complications and exchange transfusions for severe complications like acute chest syndrome or stroke.
- For chronic transfusion therapy, patients typically receive transfusions every 3-4 weeks to maintain HbS levels below 30%.
- Iron chelation therapy with medications like deferasirox (Jadenu/Exjade) or deferiprone (Ferriprox) is essential for patients on chronic transfusion regimens to prevent iron overload, as supported by the American Society of Hematology 2020 guidelines for SCD: transfusion support 1.
Transfusion Support
- The American Society of Hematology guideline panel addressed specific questions related to the extent of red cell antigen typing and matching, transfusion indications, and mode of administration 1.
- Automated red cell exchange (RCE) and manual RCE are two primary methods used for transfusion support, with simple transfusion being the third option 1.
- Pre-transfusion testing should include extended blood typing for antigens C, E, K, Fya, Fyb, Jka, and Jkb to minimize alloimmunization risk.
Outcome
- These guidelines help prevent sickle cell crises, reduce organ damage, and improve quality of life by maintaining adequate oxygenation and reducing the proportion of sickled cells in circulation.
- The goal of transfusion therapy is to reduce the risk of stroke and other complications associated with SCD, as supported by the 2021 guideline for the prevention of stroke in patients with stroke and transient ischemic attack 1.
From the Research
Guidelines for Blood Transfusion in Sickle Cell Disease
- Blood transfusion is used to improve blood flow, reduce hemolysis, and increase blood oxygen carrying capacity in patients with Sickle Cell Disease (SCD) 2.
- Transfusion is indicated for prophylaxis (stroke) and as therapy (acute chest syndrome and stroke) for major complications of SCD 2, 3.
- Other indications for blood transfusion in SCD include:
- Exchange blood transfusion is used in some complications of the disease, such as acute chest syndrome (ACS), priapism, or perioperatively 3, 4.
- The transfused blood should be Hb S negative, Rh and Kell antigen matched to reduce the risk of alloimmunization 3, 5, 6.
- Transfusion therapy should be aimed at increasing tissue delivery of oxygen, and simple transfusions may be effective in many ACS cases 3, 4.
Complications of Blood Transfusion in SCD
- Iron overload is a major and unavoidable complication of transfusions in SCD 2, 5.
- Alloimmunization and delayed hemolytic transfusion reactions are also significant risks associated with blood transfusion in SCD 5, 6.
- Recent studies demonstrate that RH genetic diversity in patients with SCD contributes to Rh alloimmunization, suggesting that more refined RBC matching strategies are needed 5.
Management of Blood Transfusion in SCD
- Transfusional iron overload management includes automated RBC exchange, noninvasive imaging to monitor iron burden, and iron chelation with parenteral or oral agents 5.
- Phenotypically matching transfused blood has been shown to decrease alloimmunization, and genotyping for antigen matching may help match donors to patients in the future 6.
- Standardized transfusion guidelines and enhanced patient education are necessary to optimize transfusion management in SCD patients 4.