New Delhi, Aug. 6: The All-India Institute of Medical Sciences here has announced plans for a nationwide campaign to expand its register of potential bone marrow donors to help patients with blood cancer and other disorders to find suitable donors.
The Asian Indian Donor Marrow Registry, launched by the AIIMS immunogenetics department two decades ago, plans to increase the number of people registered as potential blood donors from about 3,300 to over 500,000 within the next five years.
Doctors say the greater the number of people registered as potential bone marrow donors, the easier it is to find matching donors for leukaemia, lymphoma and other blood disorders such as aplastic anaemia or thalassemia.
“About 70 per cent of patients with such disorders don’t get the right donor within the family,” said Narinder Mehra, head of the department of transplant immunology and immunogenetics at the AIIMS, who had launched the registry in the mid-1990s.
Unlike the relatively simple blood group matching before blood transfusions, bone marrow transplants require matching a patient’s so-called human leucocyte antigen (HLA) profile with those of potential donors to determine the most suitable match.
Family members, particularly brothers and sisters, have a one-in-four chance of making the best HLA match. But the chance of finding a match in the HLA profile of patients and unrelated donors will range from one-in-500 to one-in-a-billion.
“The more we have on our registry, the easier to find a match — this is why we need to dramatically scale up the registry,” Mehra told The Telegraph on the sidelines of a donor-recruitment drive at AIIMS today where over 60 people signed on as potential donors.
Until now the registry, which has received funding from the department of biotechnology, has primarily signed on siblings and relatives of patients seeking treatment at AIIMS. Mehra expects medical institutions from across the country to join the campaign to scale up the registry.
The registry hopes to seek out partnerships with medical institutions in the north, south, east, west and the Northeast to add potential donors. “We need representatives of all ethnic groups in India,” he said.
Bone marrow, located in the cavities of bones, contains certain types of stem cells that can serve as precursors for red and white blood cells and other types of blood cells. Bone marrow transplants are often required by patients with blood cancers, thalassemia, and aplastic anaemia, among other blood disorders, whose bone marrow has stopped producing the right levels of various blood cells.
An individual may register as a bone marrow donor by giving a small sample of blood. The registry technicians will analyse the HLA profile and store the data in a database. A patient’s HLA profile is compared with those in the database to look for suitable donors.
The bone marrow itself is harvested from the back of the pelvic bone through a needle in a procedure that takes about an hour with the donor under general anaesthesia. The amount of bone marrow harvested is less than 5 per cent of the marrow reservoir and naturally regenerates within a few weeks.
An international donor bone marrow registry has signed up over 22 million potential donors but, Mehra said, that registry is dominated by Caucasian donors. Immunogenetic studies in the past have revealed some unique HLA profiles in India not observed in other populations.