Granulocyte-mobilized bone marrow

Area of Science:

• Hematopoietic Stem Cell Transplantation
• Immunology
• Cellular Therapy

Background:

• Mobilized peripheral blood is now preferred over bone marrow for stem cell grafts, but leads to higher rates of chronic graft-versus-host disease and transplant-related mortality.
• Outcomes for mobilized peripheral blood and bone marrow grafts are generally similar in the long term.
• Granulocyte colony-stimulating factor (G-CSF) priming of bone marrow is a recent development in transplantation.

Purpose of the Study:

• To review the biological mechanisms and clinical outcomes of using G-CSF-primed bone marrow for allogeneic stem cell transplantation.
• To evaluate G-CSF-primed bone marrow as a graft source, particularly for HLA-haploidentical transplants.

Main Methods:

• Review of biological data and clinical results concerning G-CSF-primed bone marrow.
• Analysis of G-CSF's effects on hematopoietic stem cell (HSC) mobilization and T-cell immunomodulation.
• Evaluation of clinical outcomes in HLA-haploidentical transplants using G-CSF-primed unmanipulated bone marrow.

Main Results:

• G-CSF enhances the HSC compartment and shifts T-cell responses from Th1 to Th2, increasing anti-inflammatory cytokine production.
• G-CSF-primed unmanipulated bone marrow has shown encouraging results in HLA-haploidentical donor transplants.
• This approach mitigates some of the risks associated with traditional graft sources.

Conclusions:

• G-CSF-primed unmanipulated bone marrow from a haploidentical donor, combined with immunosuppression, is a valid alternative for patients without an HLA-identical sibling.
• Outcomes are comparable to umbilical cord blood, HLA-matched unrelated grafts, or T-cell-depleted haploidentical transplants.
• This strategy improves the feasibility and success of allogeneic stem cell transplantation from alternative donors.