Abbreviations:

Graft versus host disease (GVHD) 

Human leukocyte antigens (HLA)

Blood and Marrow Transplantation (BMT)

Description:

The advantages of peripheral blood stem cells transplant (PBSCTs) include more rapid engraftment rate compared to bone marrow where it takes about 2 weeks of recovery in the former and is delayed for 5 days more in the latter, but the use of post-transplant immunosuppressive regimen to prevent GVHD can prolong the increase in bone marrow products. Moreover, the rate of acute GVHD appears to be similar when compared with bone marrow transplantation in HLA- identical matched related donors. However, chronic GVHD appears to be encountered more after peripheral blood stem cell transplant which could lead to more complications. In the study by Anasetti et al., the primary endpoint was the difference in the 2-year overall survival seemed to be non-significant in the two groups. However, secondary end points showed more stable grafts with decreased graft failure in the group which received peripheral blood stem cell transplant but also this group had a higher incidence of chronic GVHD. Other similar studies comparing both bone marrow transplant and peripheral blood SCTs concluded that the psychological burden due to chronic GVHD and the 5-year ability to restore normal activities including going back to work were better in the bone marrow transplanted group.

The advantages of cord blood transplant include the rapid collection and administration which serves in treating urgent conditions, less frequency of infections, lower rates of GVHD with the same rate of GVT, less need for a stringent identical HLA. The disadvantages include delayed engraftment with a higher possibility of graft rejection and higher rates of disease relapses. The cord blood transplant is most used in patients without matched related or unrelated donors. A major study by Locatelli et al. demonstrated the utility of cord blood transplant in patients with thalassemia major and sickle cell anemia and showed similar 6-year overall survival in the CBT and BMT groups. The most important factors that affect the outcome of CBT are the total nucleated cell dose and HLA matching with a recommended minimum dose of total nucleated cells of 2 x 10*7 cells/kg for successful engraftment. Theoretically, strict HLA matching is not required in the case of cord blood transplant given it is devoid of mature T cells but studies have shown better outcomes when matching recipients at HLA-A, HLA-B, HLA-C, and HLA-DRB1. Given that a single blood cord unit might not contain the required amount of nucleated cells an approach using double cord transplant is used to overcome this problem. However, only one cord blood transplant product will predominate within 3 months of infusion. Further, randomized controlled trials failed to show a significant difference in terms of outcome benefits or risks between double cord blood and a single cord blood transplant.

Haplo-identical stem cell transplantation refers to the administration of bone marrow products from a first degree related haplotype-mismatched donor. This helps in non-white patients like African American, Hispanics, and patients from countries where there is no wide access to resources as they have fewer chances of having a matched unrelated donor. The advantages include lower cost and rapid availability of the hematopoietic cell products.

However, the disadvantages include hyper acute GVHD which increases mortality and graft rejection. This has been overcome by depletion of T cells responsible for the reaction mentioned above, but this also leads to delayed immune recovery and decreased graft versus tumor effect. Recently strategies including selective depletion of subsets of T cells including alpha-beta have shown improved outcomes when compared to conventional ex vivo depletion of large T-cell populations.

Insights in stem cells is an international open access, peer-reviewed academic journal. The journal is dedicated to publish quality articles with an emphasis on basic, translational and clinical research on stem cell. Insights in stem cell publishes articles that cover all aspects of Stem cell therapy, Stem cell transplant, Stem cell biology, Cancer stem cell, Therapeutic cloning, Neural stem cells, Somatic stem cell, regenerative medicine.

Submissions online at: https://www.imedpub.com/submissions/insights-stem-cells.html

Regards,                                                                         

Alina Grace,

Associate Managing Editor,

Insights in Stem Cells