Hemopoietic stem cell transplantation (HSCT) was developed in the early 1970s and was recognised as a potential treatment for a number of benign and malignant haematological diseases. Since then, the field has grown into a full specialty. Keeping pace with technological advances, this area has also seen evolution as regards to indications, availability of donor in family (an HLA identical sibling) or outside HLA matched unrelated donor (with the help of bone marrow donor registries) or haploidentical donor from parent or sibling.
In India, this treatment was started in 1983. The progress was slow initially, but has picked up in the last two decades. Currently, more than 110 centres are doing transplant. As per the Indian Society of Blood and Marrow Transplantation Registry, 23,843 patients underwent HSCT till 2021. Of these, 13,962 underwent allogenic HSCT (using stem cells from a donor), and 9,881 autologous HSCT (using patient’s own stem cells). Multiple myeloma and lymphomas (Hodgkin’s and Non Hodgkin’s) are major indications for autologous HSCT, while acute myeloblastic leukemia (AML), β-Thalassemia, severe aplastic anaemia and acute lymphoblastic leukemia are major indications for allogeneic HSCT.
However, the number of transplant centres is still inadequate for a country with a population of 1.42 billion. Roughly, only 30 per cent of the needy patients are able to undergo transplant. Some of the reasons for this low number are: almost all transplant centres are located in major cities (patients have to travel long distance for treatment and stay there for two to three months post transplant), lack of trained manpower (transplant physicians, nurses and technical staff) and inadequate transfusion services and financial constraints. In a study from our centre, reasons cited for delayed transplant for myeloma were logistical―patients had to make arrangements for stay as most of them came from far away or had family commitments like marriage or exams of children. Some cited financial reasons as well.
With the change in social structure, as families become smaller, getting an HLA matched donor within the family is a problem for nearly 70 per cent of patients. There is a need to increase the donor pool to find a suitable voluntary donor outside the family. Currently, there are six bone marrow donor registries namely DATRI (blood stem cell donors registry) in Chennai, Jeevan Blood Bank in Chennai, MDRI (Marrow Donor Registry India) in Mumbai, Gene Bandhu (Bharat Stem Cells) in New Delhi, SCRI-BMST in Bengaluru and BMCDT-BMR in Bengaluru. Among these, DATRI has 3.75 lakh donors registered, others have small numbers.
Timely referral of patients to a transplant centre is crucial for good outcome, specifically for patients with severe aplastic anemia and β-Thalassemia. This needs education of not only patients and their families but also of treating physicians.
Recent advances in the field with better understanding of disease biology or genomics, drug development (targeted therapy, small molecules and biologicals), monoclonal antibodies, engineered cellular products like CAR T-cell therapy and disease monitoring- measurable residual disease (in myeloma, acute myeloid leukemia and acute lymphoblastic leukemia) have moved the stem cell transplant field forward, but have also escalated cost. This has also led to discussion over how to deliver cost-effective, quality transplant care. The cost of HSCT is lower in India, compared with the costs in north America and western Europe. Currently, for an autologous HSCT, the estimated cost is about Rs7 lakh, and for an allogeneic sibling transplant, it is about Rs15 lakh. For an haploidentical transplant, it is about Rs25 lakh. The cost is lower in India possibly because of cheaper (generic) chemotherapeutic drugs, hospitalisation, physician and nursing care.
In low- and mid-income countries, more dedicated centres for stem cell transplant programmes with multi-pronged approach―from case selection, protocol-based approach, identification of high-risk patients to a rigorous followup―are key for further improvement.
Kumar is chairperson, oncology & bone marrow transplant, Artemis Hospitals.