How should blood be treated for a patient with pyruvate kinase (PK) deficiency requiring a blood transfusion?

Blood Transfusion Requirements for Patients with Pyruvate Kinase Deficiency

For patients with pyruvate kinase deficiency requiring blood transfusion, blood components must be irradiated to prevent transfusion-associated graft-versus-host disease. 1

Rationale for Irradiation of Blood Components

• Patients with pyruvate kinase deficiency (PKD) fall into the category of patients requiring irradiated blood components due to their hematological condition 1
• The American Association of Blood Banks (AABB) guidelines specifically identify that patients with certain hematological conditions require irradiated blood to prevent transfusion-associated graft-versus-host disease (TA-GVHD) 1
• TA-GVHD is a rare but usually fatal complication that can occur in certain patient populations receiving cellular blood components 2

Specific Blood Treatment Requirements

• Blood components must be irradiated with a dose of 2500 cGy (25 Gy) to completely inactivate T cells 2
• Only cellular components require irradiation, including:
  • Whole blood
  • Red blood cells
  • Platelets
  • Granulocytes 1, 2

Timing Considerations for Blood Testing and Transfusion

• Blood testing for PK enzyme activity should be delayed as long as possible after previous transfusions 1
• Ideally, testing should be performed at least 50 days after the last transfusion to minimize the effect of donor red blood cells on enzyme activity measurements 1
• In transfusion-dependent patients, this waiting period may not be possible, and results should be interpreted with caution 1

Transfusion Approach in PKD

• Transfusions should be symptom-directed rather than based on a fixed hemoglobin threshold 3
• Patients with PKD may tolerate anemia better than expected due to increased red cell 2,3-DPG content, which causes a rightward shift in the oxygen dissociation curve 1
• The decision to transfuse should be individualized based on symptoms, growth (in children), and quality of life rather than hemoglobin level alone 4

Special Considerations

• Patients with PKD may develop iron overload even when transfusion-independent, likely due to ineffective erythropoiesis and inappropriately low hepcidin levels 1
• Monitor for complications of chronic transfusion including iron overload, which requires appropriate chelation therapy 5
• Be aware that transfused blood will affect diagnostic testing for PKD:
  • Donor contamination can lead to falsely normal PK enzyme activity levels 1
  • The contribution of normal donor red cells can mask the enzyme deficiency for up to 120 days after transfusion 1

Practical Management Points

• Check patient details against those on the blood bag before administration 1
• Once irradiated, red cell units have a shorter storage time due to membrane damage from irradiation 2
• Irradiated blood components should be used within their specific storage and expiry times to avoid wastage 1
• White cell-reduction filters do not prevent TA-GVHD and are not a substitute for irradiation 2

By following these guidelines for blood treatment in PKD patients, clinicians can minimize the risk of transfusion complications while providing appropriate supportive care for these patients.