Immune reconstitution following hematopoietic stem cell transplantation using different stem cell sources

ABSTRACT

Introduction: Adequate immune reconstitution post-HSCT is crucial for the success of transplantation, and can be affected by both patient- and transplant-related factors.

Areas covered: A systematic literature search in PubMed, Scopus, and abstracts of international congresses is performed to investigate immune recovery posttransplant. In this review, we discuss the pattern of immune recovery in the post-transplant period focusing on the impact of stem cell source (bone marrow, peripheral blood stem cells, and cord blood) on immune recovery and HSCT outcome. We examine the impact of serotherapy on immune reconstitution and the need to tailor dosing of serotherapy agents when using different stem cell sources. We discuss new techniques being used particularly with cord blood and haploidentical grafts to improve immune recovery in each scenario.

Expert opinion: Cord blood T cells provide a unique CD4+ biased immune reconstitution. Initial studies using targeted serotherapy with cord grafts showed improved immune recovery with limited alloreactivity. Two competing haploidentical approaches have developed in recent years including TCRαβ/CD19 depleted grafts and post-cyclophosphamide haplo-HSCT. Both approaches have comparable survival rates with limited alloreactivity. However, delayed immune reconstitution is still an ongoing problem and could be improved by modified donor lymphocyte infusions from the same haploidentical donor.

KEYWORDS:

• Immune recovery
• cord blood
• haploidentical
• stem cell source
• TCRαβ/CD19 depleted grafts
• serotherapy
• rATG

Article Highlights

• Good immune reconstitution is vital to the success of HSCT.

• Poor immune reconstitution increases the risk of infection and disease relapse.

• Different stem cell sources give rise to varying patterns of immune reconstitution.

• The use of serotherapy in conditioning needs to be tailored to the disease, donor type, and stem cell source. Particular attention is required with cord blood.

• Cord blood T cells provide a unique CD4+ biased immune reconstitution.

• Modern approaches are improving immune reconstitution and hence the outcome of mismatched HSCT.

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. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

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

Additional information

Funding

This paper was not funded.