Extraction of bone marrow was the first technique to collect HSCs and continues to be famous for allogeneic and autologous transplants. The method requires general or spinal anesthesia and consists of bone marrow aspirations by multiple punctures from the anterior and posterior iliac crest regions, resulting in a total volume of 800 to 1200 mL. As the bone marrow is extracted, it is collected in an anticoagulant. Once the collection has been completed, the marrow is filtered to remove fatty lumps and bone chips. Further separation of plasma and red cells will reduce the total volume of the transplant product.
If the donor and patient are ABO incompatible, the plasma and/or red cells can be removed to prevent a transfusion reaction that could affect the transplant outcome. A major incompatibility can occur when antibodies in the patient’s plasma react to red cell antigens in the transplant. A minor incompatibility can occur when antibodies in the transplant react with red cell antigens in the patient. Severe hemolysis can be prevented by administering an immunosuppressant, such as methotrexate.
After filtration, the final product is ready and is usually transfused within a few hours. Confirmatory testing of the allogeneic donor for HLA type and infectious and genetic diseases is necessary before the extraction procedure is scheduled.
Bone marrow extraction for an allogeneic transplant.
