Hematopoietic Stem Cell (HSC) Transplantation for Blood & Immune Reconstitution — Regenerative Therapies

FDA-approved stem cell transplant using bone marrow or peripheral blood stem cells to reconstitute the hematopoietic system.

Overview

Hematopoietic Stem Cell Transplantation (HSCT) is the original and most established form of stem cell therapy, with over 50,000 transplants performed annually worldwide. HSCs reside in bone marrow and give rise to all blood cell lineages. HSCT involves ablating a patient's diseased or defective hematopoietic system with high-dose chemotherapy and/or radiation (myeloablative conditioning), then infusing donor (allogeneic) or patient-derived (autologous) HSCs to reconstitute the blood and immune system. First performed successfully by E. Donnall Thomas in 1957 (Nobel Prize 1990), HSCT is now standard-of-care for leukemias, lymphomas, severe aplastic anemia, sickle cell disease, thalassemia, and severe combined immunodeficiency (SCID). Sources include bone marrow, mobilized peripheral blood (G-CSF), and umbilical cord blood.

Indications

  • Acute myeloid leukemia (AML)
  • Acute lymphoblastic leukemia (ALL)
  • Chronic myeloid leukemia (CML)
  • Non-Hodgkin and Hodgkin lymphoma
  • Multiple myeloma
  • Severe aplastic anemia
  • Sickle cell disease (curative)
  • Thalassemia major (curative)
  • Severe combined immunodeficiency (SCID)
  • Myelodysplastic syndromes (MDS)

Mechanism of Action

Myeloablative (high-dose chemo +/- TBI) or reduced-intensity conditioning to destroy diseased marrow and create space for donor cells

Dosing

CompoundDoseFrequencyNotes
Mobilized Peripheral Blood Stem Cells2-5 x 10^6 CD34+ cells/kgSingle infusion after conditioningStandard dose for allogeneic peripheral blood stem cell transplant
Bone Marrow Aspirate2-3 x 10^8 nucleated cells/kgSingle infusion after conditioningStandard bone marrow transplant dose
Umbilical Cord Blood>2.5 x 10^7 nucleated cells/kgSingle infusion after conditioningCord blood unit(s); may require double cord blood transplant

Evidence Grade

GRADE C

Safety & Contraindications

  • Major medical procedure with significant morbidity and mortality
  • Transplant-related mortality: 10-30% depending on conditioning and disease
  • Graft-versus-host disease (GVHD): acute and chronic forms affect 30-70% of allogeneic recipients
  • Prolonged immunosuppression: high infection risk for months to years
  • Myeloablative conditioning causes pancytopenia, mucositis, organ toxicity
  • Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) risk
  • Secondary malignancies (MDS, AML) may develop years later
  • Infertility from conditioning regimens - fertility preservation counseling essential
  • Requires specialized transplant centers with intensive care capabilities
  • Engraftment failure occurs in 5-10% of cases