The use of haploidentical stem cell transplant as an alternative donor source in patients with decreased access to matched unrelated donors

ABSTRACT

Introduction

The likelihood of finding HLA-matched unrelated donors for rare HLA types and non-white European ancestry continues to be a challenge with less than a 70% chance of finding a full match. Mismatched transplants continue to have high rates of transplant-related mortality. With the near-universal ability to find a haploidentical donor in families, haploidentical transplants have become of more critical importance in ethnic minority groups and patients with rare HLA types.

Methods

Data was collected through clinical trials, review articles, and case reports published in the National Library of Medicine.

Results

The use of improved lymphodepleting conditioning regimens, graft versus host disease (GVHD) prophylaxis using regimens such as post-transplant cyclophosphamide, mycophenolate, and tacrolimus have improved engraftment to nearly 100 percent and reduced transplant-related mortality to less than 20 percent. Attention to donor-specific antibodies (DSAs) with interventions using bortezomib, rituximab, and plasmapheresis has decreased graft failure rates.

Conclusion

With improved prevention of GVHD with interventions such as post-transplant cyclophosphamide and management of DSAs, haploidentical transplants continue to improve transplant-related mortality (TRM) compared to patients who received matched-related donor transplants. While TRM continues to improve, ongoing research with haploidentical transplants will focus on improving graft and donor immunosuppression and identifying the best regimens to improve TRM without compromising relapse-free survival.

KEYWORDS:

• Haploidentical transplant
• post-transplant cyclophosphamide
• donor specific antibodies
• HSCT transplant access
• T-cell depleted allograft
• T-cell replete allograft
• umbilical cord blood
• HLA match

Acknowledgements

No additional acknowledgements.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Data supporting this article can be found published through the National Library of Medicine. No new data was generated in this article.

Authorship contributions

Christopher Graham: responsible for writing, conceptualizing article. Mark Litzow: responsible for conceptualization of article, editing and writing the article.

Additional information

Notes on contributors

Christopher Graham

Christopher Graham: Dr. Graham is a Blood and Marrow Transplant Fellow at Mayo Clinic. His research focuses on increasing access of allogeneic stem cell transplant to patients.

Mark Litzow

Mark Litzow: Dr. Litzow is Professor of Medicine in the Division of Hematology at Mayo Clinic. He was the Director of the BMT Program at Mayo from 1992 to 2008 and continues to remain active in the BMT program. He was the Director of the Myeloid Disease Oriented Group in the Division of Hematology from 2002 to 2016. He was appointed chair of the Leukemia Committee of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network (ECOG-ACRIN) in September 2013 after having served as co-chair of the committee since 2001.