Evolution of Thalassaemia Management Four Decades in Thalassaemia Care – Our Achievements and Challenges

Advances in bone marrow transplantation

Initially, only HLA-identical sibling was used as the donor. Bone marrow or cord blood can be sued for transplant purposes. With the establishment of Hong Kong Marrow Match Foundation and lately Hong Kong Bone Marrow Donor Registry in 1991, clinicians started to use human leukocyte antigen (HLA) matched unrelated donor for transplantation. Severe graft-versus-host disease (GVHD) was a major complication in the early era when the HLA matching was crude at antigen level. Throughout the past decades, transplant outcomes continue to improve with advancement in molecular HLA typing techniques, development of potent immunosuppressants, refinement of transplant conditioning and supportive care, as well as diagnostics and therapeutics of infective and other complications. Apart from HLA-matched related and unrelated donors, we also increasingly utilize unrelated cord blood units as stem cell source, in parallel with expansion of public cord blood banks. Cord blood transplant has significant advantages of fast availability, absence of donor risk, and less stringent requirement for HLA matching. Nowadays, outcomes of standard HSCT in Hong Kong are on a par with most developed countries.

A donor source is becoming more and more used is called haplo-identical donor usually a parent who is half matched for HLA. Attempts have been made to overcome rejection by high dose of donor stem cells and more intensive pre-transplant immunosuppression; and various in vitro and in vivo methods have been employed to remove donor T cells which are responsible for GvHD. These approaches have gradually improved outcomes of haploidentical family donor HSCT and broadened the donor choices so that virtually all patients would have at least one readily available donor for HSCT. We have adopted such approach for haploidentical donor transplant in Hong Kong since 2014. Fig. 16