Evolution of the role of haploidentical stem cell transplantation: past, present, and future

ABSTRACT

Introduction

The accessibility to haplo-donors has led to an increase in the number of haplo-HSCT worldwide. A systematic search of the PubMed database between 2000 to present was performed.

Areas covered

In this review, the authors discussed the most used approaches to perform haplo-HSCT and its results: T-cell depletion (TCD, including Perugia platform and its modifications) and T-cell repleted haplo (TCR, including the high-dose post-transplant cyclophosphamide strategy (Baltimore protocol) and the Beijing protocol). The improvements and modifications made to the different strategies have increased the indications of haplo-HSCT, including both malignant and nonmalignant disorders. Focusing on the Baltimore protocol, the authors review the results of the retrospective studies that have compared it to other donor transplants. The limitations of this strategy in terms of toxicity, graft complications, and GVHD are also discussed in detail. Finally, possible approaches to improve the outcomes of TCR haplo-HSCT are presented.

Expert opinion

The recent advances in the field of haplo-HSCT have allowed a large number of patients with incurable diseases to benefit from this procedure despite not having a matched donor. With all available strategies, virtually no patient who needs an allogeneic transplant should be excluded by the absence of a donor.

KEYWORDS:

• Haploidentical stem cell transplantation
• T-cell depleted
• T-cell repleted

Article highlights

• Three main approaches are the most used to perform haplo-HSCT: TCD (Perugia) and TCR (Baltimore and Beijing). Several retrospective studies have shown comparable results of these HSCT to those obtained with matched related and unrelated donors. However, prospective comparative studies are needed to confirm these results.

• The improvements and modifications made to the different strategies have increased the indications of haplo-HSCT, including non-malignant disorders.

• Despite haplo-HSCT is a valid option, there are several limitations that should be improved in terms of toxicity, graft complications, and GVHD.

• New combinations of immunosuppressive drugs, cellular adoptive therapy and a better understanding of mechanisms of relapse could improve the results of haplo-HSCT.

Acknowledgments

Authors thank the staff and nurses of all the hematology and transplant units for their care and contributions to making this work possible.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This manuscript was not funded.