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Volume 13 | Issue 2 | Year 2026 | Article Id. IJMS-V13I2P101 | DOI : https://doi.org/10.14445/23939117/IJMS-V13I2P101

Revisiting Immune Tolerance: The Role of Hematopoietic Stem Cells in Organ Transplantation

Syed Zain Imam

Received Revised Accepted Published
20 Feb 2026 22 Mar 2026 11 Apr 2026 27 Apr 2026

Citation :

Syed Zain Imam, "Revisiting Immune Tolerance: The Role of Hematopoietic Stem Cells in Organ Transplantation," International Journal of Medical Science, vol. 13, no. 2, pp. 1-6, 2026. Crossref, https://doi.org/10.14445/23939117/IJMS-V13I2P101

Abstract

Transplantation of the organ is the conclusive mode of treatment for end-stage organ failure, but the graft survival is not long-term due to immune-mediated rejection and complications of lifelong immunosuppressive therapy. Recent progress in transplantation immunology has brought the possibility of Hematopoietic Stem Cells (HSCs) into the limelight to ensure immune tolerance and increased graft survival. HSCs have a distinct biological property, such as self-renewal and multilineage differentiation, and they can be used to reconstitute hematopoietic and immune systems. Transplanting donor-derived HSCs into recipients can result in the development of mixed hematopoietic chimerism, i.e., the co-existence of donor and recipient immune cells. This immunological condition is favorable to donor antigen tolerance in both central and peripheral ways, including the deletion of alloreactive T cells, generating regulatory T cells, and altering the operation of antigen-presenting cells. The preclinical and clinical experiments showed that combined organ and hematopoietic stem cell transplantation could make it possible to have a stable graft survival without or with a minimal amount of immunosuppressive treatment. Although these results are encouraging, challenges such as graft-versus-host disease, toxicity of conditioning regimen, and the inconsistency of chimerism stability are still notable obstacles. This review will discuss the biological properties of HSCs, the immunology of transplant rejection, and how HSCs facilitate immune tolerance. Also, the present therapeutic approaches, clinical evidence, and future of the therapy of stem cell-based tolerance in organ transplantation are discussed.

Keywords

Hematopoietic Stem Cells; Immune Tolerance; Mixed Chimerism; Organ Transplantation; Transplant Immunology.

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