Life-Saving Mission of SCBB: An Interview with Dr. William Hwang
Singapore Cord Blood Bank (SCBB), Singapore’s non-profit public cord blood bank, was officially opened in September 2005 in response to the growing demand for unrelated donor umbilical cord blood transplantation. Haematologists and paediatricians in Singapore identified this need as their patients were unable to find matching stem cell units they needed for blood stem cell transplants.
SCBB strives to provide safe and high quality cord blood units to support transplantation and related research, through the practice of internationally accredited collection techniques processing, banking and distribution of these donated cord blood units. Earning itself the international reputation of a national public cord blood bank with the highest standards, SCBB holds all international accreditations including accreditation by AABB (formerly known as American Association of Blood Banks), College of American Pathologist (CAP) and Foundation for the Accreditation of Cellular Therapy (FACT).
SCBB has facilitated over 180 cord blood transplants for patients in Singapore and 15 other countries. Without this stem cell resource, many of these patients would otherwise succumb to their diseases.
Advantages of Cord Blood
Cord blood is rich in haematopoietic stem cells (HSCs), which are also found in bone marrow and peripheral blood. Compared to those in bone marrow and peripheral blood, stem cells in cord blood are more ‘naïve’ and can more easily adapt in the patient’s body, lowering the chances of transplant complications for the patient. Hence, the stem cells in cord blood do not require a perfect match between a donor and patient.
Supporting Unrelated Stem Cell Needs of Asian Patients
70% of patients worldwide are unable to find a match within their family.  They have to turn to public stem cell registries such as public cord blood banks for suitable matches.
Ethnicity plays an important role when finding a match for patients. With majority of public stem cell registries in the world of Caucasian origin, it is crucial for Asian and multi-ethnic populations such as Singapore to establish public stem cell registries to serve its community.
The profile of SCBB’s public cord blood inventory is reflective of Singapore’s multi-ethnic community. Today, SCBB contributes approximately 35 percent of the Asian Cord Blood Units listed in the National Marrow Donor Program (NMDP), the world’s largest and most diverse stem cell registry based in America.
1. Under which circumstances is a haematopoietic stem cell transplant not recommended, even when a matched cord blood unit is available?
There are several factors that a transplant physician looks at before recommending a haematopoietic stem cell transplant; whether it is using stem cells from bone marrow, peripheral blood or cord blood. Transplant is not recommended when the transplant physician deems the patient’s body as unsuitable to undergo transplant; e.g. if an organ of the patient is damaged or if the patient is suffering from recurring infections. This increases the risk factor for the patient and puts him/her at a higher risk for transplant complications.
2. Please comment on the changes in transplant protocols and procedures that have helped to improve cord blood transplant outcomes.
The haematopoietic stem cell transplant procedure is similar regardless of the source of stem cell (i.e. bone marrow, cord blood or mobilized peripheral blood) that the patient will be receiving. Once a suitable match is found for the patient, the Transplant Physician will first assess the patient’s health to ensure he/she can go through a transplant. The patient will then undergo a conditioning regimen – chemotherapy and/or radiation – to destroy the patient’s unhealthy cells and prepare the patient’s body to receive the new healthy blood stem cells.
The patient’s immune cells will also be destroyed in this process. Thus, the immune-compromised patient will be isolated in a special Bone Marrow Transplant (BMT) room where the environment is controlled.
This will be followed by the transplant. The new healthy stem cells in a blood bag are infused through an intravenous (IV) line, usually through the patient’s Central Venous Catheter (CVC), or central line, into the patient’s body.
The first sign of a successful transplant is when the new stem cells move through the patient’s bloodstream to reach the bone marrow and begin to produce new red blood cells, white blood cells and platelets.
3. What are the possible developments that you would like to see in the next five years in the field of cord blood transplant & research?
I would like to see the advancement in ex-vivo expansion of haematopoietic stem cells (HSCs) so that cord blood units with low cell dose can be used for patients’ transplantation. In addition, I hope to see the development in HSC homing that will provide better ways to improve homing and engraftment of cord blood stem cells in patient’s body; e.g. utilizing intra-bone marrow cord blood injections (intraosseous infusion (IO) instead of the traditional intravenous route)
About the Authors
Dr. William Hwang is the Medical Director of Singapore Cord Blood Bank (SCBB), since March 2004. Concurrently, Dr. Hwang is the Head and Senior Consultant, Department of Haematology at Singapore General Hospital (SGH) as well as the SingHealth Duke-NUS Blood Cancer Centre. He is Associate Professor in the Cancer and Stem Cell Biology Program in Duke-NUS Graduate Medical School where he is the Principal Investigator of Haematopoietic Stem Cell Laboratory. He also serves as the Director of SingHealth Transplant and President of the Singapore Society of Haematology.
His major research interest is in Haematopoietic Stem Cells, for which he has published numerous scientific and clinical research papers. His recent interests include the use of mesenchymal stromal cells, NK cells and other derivatives to modulate immune responses and tissue repair.