|Year : 2019 | Volume
| Issue : 2 | Page : 129-131
Transfusion Medicine has Emerged: Redefining the Role of the Transfusion Specialists in the Changing Scenario
Consultant and Head-Transfusion Medicine, Manipal Hospitals, Bengaluru, Karnataka, India
|Date of Submission||26-Sep-2019|
|Date of Acceptance||26-Sep-2019|
|Date of Web Publication||17-Oct-2019|
Consultant and Head-Transfusion Medicine, Manipal Hospitals, Bengaluru, Karnataka
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Chandrashekar S. Transfusion Medicine has Emerged: Redefining the Role of the Transfusion Specialists in the Changing Scenario. Glob J Transfus Med 2019;4:129-31
|How to cite this URL:|
Chandrashekar S. Transfusion Medicine has Emerged: Redefining the Role of the Transfusion Specialists in the Changing Scenario. Glob J Transfus Med [serial online] 2019 [cited 2019 Nov 12];4:129-31. Available from: http://www.gjtmonline.com/text.asp?2019/4/2/129/269401
| Evolution of Transfusion Medicine|| |
Transfusion medicine has evolved from being the art of blood banking to a science dealing with various facets of clinical medicine. No longer are blood bankers content with providing blood components, collected from a safe donor, and ensuring its safe transfusion. Further, with the passing of time, blood donors as source of blood are on the decline. Researchers have shown that population aging in westernized countries will likely lead to a reduction in the number of blood donors and an increase of blood recipients. This will further compound the problem of blood shortage and force us to look for alternatives.
We do understand that red blood cells (RBCs) and platelets are indispensable for oxygen delivery and hemostasis. Derivation of these blood elements from induced pluripotent stem (iPS) cells has the potential to develop blood donor-independent manipulated products to complement or replace current transfusion banking.
Lu et al. reported differentiation of human embryonic stem cells into functional oxygen-carrying erythrocytes on a large scale.
Nevertheless, embryonic stem cells are associated with ethical concerns, and therefore, iPS cells are the preferred source for blood cells.
The derivation of RBCs and megakaryocytes from pluripotent cells is very similar to normal hemopoiesis. In both cases, they are derived from a common megakaryocyte–erythrocyte precursor.
Induced pluripotent stem cell-derived blood that will be free from pathogens and will be usable universally by all recipients carries the potential to mitigate or eliminate allogenic blood shortages.
| Testing and Processing Technologies Are Passé: Cultured Blood Components are in|| |
Emerging infections and efforts at improving blood safety such as nucleic acid testing (NAT), bacterial detection, leukoreduction, and pathogen reduction have all greatly added to the cost of blood. In future, the focus will be to provide blood independent of blood donors, at least not in the scale that we need today.
As solid organ and stem cell transplants rise, there will be an increased demand for blood components. The world needs more than 117 million units of blood annually. Despite years and years of effort, there is no uniformity in availability or quality of blood worldwide. Yet, transfusion specialists are engaging in more and more therapeutic procedures, and transfusion service has moved on from being a support service to an active clinical service. If transfusion specialists are not doing more, it is only because of our archaic laws and training curriculum. Take the case of hematopoietic stem cell transplant. Except for mobilization of stem cells, most other steps such as human leukocyte antigen (HLA) typing, stem cell collection by aphaeresis, cryopreservation, and infusion are done by the blood bank. Yet, it is the clinical hematologist or the medical oncologist who is credited with the success or failure of the stem cell transplant. This is simply because transfusion medicine (TM) training curriculum did not include clinical aspects of transplantation and did not treat TM specialists as clinicians. We know that there is a severe dearth of specialists in most developing countries, let alone superspecialists such as clinical hematology and medical oncologists. The advent of stem cell apheresis and other therapeutic apheresis procedures while being good for the community is hampered by the lack of superspecialists in most hospitals.
| What's Driving This Revolution in Transfusion Medicine?|| |
The search for blood substitutes is not new. We already have factor concentrates to replace fresh-frozen plasma. Although we do have oxygen carriers in the form or perfluorocarbons, they have not been successful on a wider scale. Hence, cultured RBCs and platelets remain our only hope for replacing allogeneic platelets and red cells. Today, there is a proof of concept that red cells can be generated from stem cells.In vitro generation of RBCs which we may call cultured RBCs (cRBCs) from pluripotent stem cells is a distinct possibility. As and when this happens, the concepts of voluntary blood donation, testing for blood by NAT, and use of pathogen inactivation by every blood center will all become redundant. Just as e-mails wiped out written letters, stem cell-derived red cells will all of a sudden make blood banking as it exists today redundant. There will be no grouping, no cross matching, and no testing.
| Revamping the Blood Supply Model|| |
Thein vitro generation of RBCs is now distinctly possible. The concept of cRBCs has emerged. The aim of the current research is to genetically modify human stem cells so that they proliferate indefinitely in the undifferentiated state and can, on demand, be induced to differentiate into RBCs. It is presumed that the homogeneous nature of a young cRBC is going to confer on it a longer lifespan compared to a heterogeneous population of native RBCs in blood that are at various stages of development or maturation. This enhanced lifespan can be expected to reduce the number of transfusions and thereby lower the cost of transfusion as well. Hence, technologies that are today regarded as cost prohibitive could be affordable with time.
The day is not far off when all our red cells will be ordered and delivered, not from regional blood centers but from large industrialized stem cell centers.
| What Should Transfusion Specialists Do in Such a Scenario?|| |
If all blood becomes universal and is ordered by clinicians from the pharmacy/similar institution, what role will the blood bankers have? As on date, India has 3000+ blood centers and our country can be expected to have a surplus of transfusion specialists in the coming years. If so, how should we redesign our curriculum, so that we remain relevant with time. Even on date, transfusion specialists do not like to do mundane things like going to blood donation drives, instead they would like to engage in more and more therapeutic procedures. We, thus, need to divert our focus from NAT testing, pathogen reduction, and immunohematology, which we cherish so dearly to more and more therapeutic aphaeresis procedures, for that's the future. Surely, no one understands aphaeresis better than us. Simply knowing the subject is however not enough. We need license to do these procedures on par with medical oncologists and clinical hematologists, who are in short supply. In the changing scenario, not many in future will choose transfusion medicine as a specialty if we do not revamp our postgraduate transfusion medicine curriculum. The need of the hour is to expand the scope of our subject in two ways. MD in transfusion medicine can be clubbed with hematology to have dual specialization in “MD in hematology and transfusion medicine” or alternately the people pursuing MD in transfusion medicine could be given the option of doing a course in “MD in transfusion and transplantation medicine” with special focus on hematological malignancies. The curriculum needs to include transfusion medicine, transplantation medicine (cell therapy), and clinical hematology, relevant medical oncology, molecular biology, HLA, and other allied subjects. Half of the time should be spent in the clinics and half in the laboratory/transfusion service. As undergraduates, we are already exposed to immunobiology of cancers and immunology of transplants in microbiology and medicine. We only need to build on this. This way transfusion medicine will grow and benefit millions of cancer patients worldwide. If people with MD pathology are allowed to do DNB in clinical hematology which is a waste of pathology, surely transfusion medicine specialists can do a more dedicated job if trained in clinics from day 1. It is for the transfusion fraternity to think it over. However, all is not lost right now, it will be another decade or two before my prophecy comes true.
We have time to think, deliberate, contradict, and revamp!
| References|| |
Ali A, Auvinen MK, Rautonen J. The aging population poses a global challenge for blood services. Transfusion 2010;50:584-8.
Focosi D, Amabile G. Induced pluripotent stem cell-derived red blood cells and platelet concentrates: From bench to bedside. Cells 2017;7. pii: E2.
Lu SJ, Feng Q, Park JS, Vida L, Lee BS, Strausbauch M. Biologic properties and enucleation of red blood cells from human embryonic stem cells. Blood 2008;112:4475-84.
Klimchenko O, Mori M, Distefano A, Langlois T, Larbret F, Lecluse Y, et al.
Acommon bipotent progenitor generates the erythroid and megakaryocyte lineages in embryonic stem cell-derived primitive hematopoiesis. Blood 2009;114:1506-17.
Focosi D, Pistello M. Effect of induced pluripotent stem cell technology in blood banking. Stem Cells Transl Med 2016;5:269-74.
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