Consultancy Corner: Significance of stem cell donation in India’s fight against Thalassemia

Known as haemoglobinopathies in medical terminology, these genetic blood disorders are majorly of the following kinds-Thalassemia Minor, Thalassemia Major, Thalassemia Intermedia, Sickle Cell Disease (SCD) and Haemoglobin E (HbE), occurring singly or in combinations.

With about 150,000cases, India has the largest number of children with Thalassemia Major in the world, while there are almost 42 million carriers of the Thalassemia Minor trait. An estimated 10,000-15,000 babies with Thalassemia Major are born every year[i].An average prevalence rate of 3-4 per cent exists across the country, but a higher frequency has been observed in certain communities like Sindhis, Punjabis, Gujaratis and Bengalis[ii]. Significantly lesscompared to Thalassemia Major, SCD prevalence is high in many tribal communities. The carrier frequency goes up to 35 percent in certain regions of Chhattisgarh, Madhya Pradesh, Andhra Pradesh and Odisha.

Unlike in a healthy person where haemoglobin is smooth and flexible, in SCD patients, the red blood cells resemble a sickle and are rigid. The odd-shaped cells block blood flow causing severe pain in finger joints and obstruct the flow of blood to lungs leading to low oxygen levels and fatigue. Haemoglobin E causes mild anaemia but none of the other symptoms that occur in SCD, such as fatigue, weakness, pale or yellowish skin, facial bone deformities, slow growth, abdominal swelling and dark urine.

Thalassemia requires lifelong blood transfusions-about 12 to 30 annually, and iron chelation treatment (removal of excessive iron from the body), besides monitoring and management of disease complications. SCD also requires lifelong supportive care that includes pain management, blood transfusions and antibiotic prophylaxis (the prevention of infection complications using antibiotics).

Peripheral Blood Stem Cell Transplantor bone marrow transplantation (BMT) from a suitable Human Leukocyte Antigen (HLA) matched donor is the only cure available for Thalassemia Major and SCD. HLA is a test done to match blood types of the donor and patient. For thousands of patients, suffering from genetic blood disorders, the only hope is a BMT.

BMT is the procedure of replacing damaged stem cells with healthy cells enabling the body to make enough white blood cells, platelets, or red blood cells. Stem cells are collected either from the bloodstream called peripheral blood stem cell (PBSC) collection or from the bone marrow called BM harvest.

BM harvest requires surgical procedure under which a needle is inserted into the pelvic bone to extract the marrow. However, no surgical incision is involved.

The risks of stem cell donation are minimal especially in Peripheral blood stem cell (PBSC) donation, which requires barely 2-3 hours. Besides sensitizing the existing pool of regular blood donors, families of stem cell recipients can also be encouraged to register themselves as donors. PBSC donation is a nonsurgical procedure, also known as Apheresis and the process can take place at an experienced blood bank or a hospital.

For 5 days till the procedure, the patient is given injections to increase the number of blood-forming cells in the bloodstream. On the specific day, blood is removed through a needle in one arm and passed through a machine that will collect only the blood-forming cells. The remaining blood is returned to the patient through a needle in the other arm. This process is similar to that used when donating blood platelets.

While globally stem cell transplantation and donation has grown rapidly, India lags in both the aspects. Only about 1000-1200 transplants take place annually in India when ideally, it should besomewhere around 15,000 - 20,000. Of the 1000 odd transplants, around 50- 60% are for non-malignant disorders. With a population more than 1.3 billion, only a few lakhs are registered as stem cell donors in India as against the global figure of over 30 million.

As Stem Cell Transplantation becomes a widely employed approach globally to treat diseases and cancers of the blood, India too is catching up. Several stem cells donation registries have come up across the country.  

There are some of stem cell donation registries which have a fair number of donors registered with them. The Ministry of Health and Family Welfare is also mulling setting up a National Stem Cell Registry. The need is to mobilise regular blood donors towards stem cell donation.