What are stem cells?

Stem cells are very early stage cells that have the ability to turn into other specialised types of cells, in the right environment. For example a stem cell can turn into liver cells, skin cells, nerve cells, etc.

There are three important types of stem cells. Namely;

• Embryonic stem cells
• Adult stem cells
• Umbilical cord stem cells

A very small amount of stem cells are found in adult blood.

What is cord blood?

The blood that circulates from the foetus to the placenta for oxygenation is called cord blood. This cord blood is functional till the baby is born.

After birth, usually the cord is cut and the blood that remains in it (placental end) as well as the placenta is discarded as waste.

Why is cord blood used in stem cell transplants?

The advantage of cord blood is that it is rich in haematopoietic (related to blood) stem cells and has very naive immune cells (lymphocytes). So, it has the potential to be used for the reconstitution of the haematopoietic process in recipients.

Since the naive immune cells are not exposed to substances or infections (i.e. are immunologically naive), they won't set off a reaction in the recipient. So the risk of transplant versus host disease is significantly less.

This means that cord blood stem cells can be used for haematopoietic (blood-related) transplantation even when the genes don't match a 100 %. This is not possible with adult haematopoietic stem cells.

What is the procedure and cost?

The procedure for collection of stem cells from umbilical cord was pioneered in India by Tata Memorial Hospital.

After the baby is delivered and the placenta is clamped, using a sterile collection system, the placental end of the cord is cannulized. The cord blood is then collected in a bag that is placed two to three feet below the table on which the placenta is lying.

Usually about 40ml-200 ml of cord blood is collected in this manner. The collected cells are then concentrated, harvested and cryopreserved (frozen) for long-term storage at a temperature of -180°C.

The cord blood is thawed for use whenever required.

The approximate cost of collecting cord blood is between Rs.50, 000 to Rs.1, 00,000. Preservation costs vary between commercial labs like Reliance Life Sciences.

Which ailments can be treated with cord blood transplantation? What is the success rate?

The number of ailments that can be potentially treated with cord blood transplantation is increasing every year. Today there are about 20 such indications including haematological disorders (blood related), genetic diseases and some cancers.

The success rate depends on the individual, the disease and the stage of the disease.

Where in India is this treatment done?

The procedure of cord blood transplantation has already been done by these five centres in India;

• Department of Medical Oncology of Tata Memorial Hospital
• Department of Oncology of Apollo Hospital, Chennai
• Army Hospital (R&R), New Delhi
• Command Hospital, Pune
• CMC, Vellore
• AIIMS, New Delhi

It is also available at any of the 20 centres offering bone marrow and peripheral blood stem cell transplant in India.