Preserving the Cord of Life

The concept of banking umbilical cord stem cells was already creating a significant buzz in medical circles within the country. The emergence of private and public cord blood banks in India has added resonance to the issue. Divya Nair looks at this area of medical science which is promising but still under scrutiny.

It sounds straight out of a Hollywood sci-fi movie—that a waste by-product of pregnancy and delivery could possibly fix a fatal genetic problem. Fortunately for all of us, we are talking neither about fiction or wild imagination, but about a process with a record of offering treatment to more than 45 disorders around the world. The technique is called ‘Umbilical Cord Stem Cell Banking’ (UCSCB).

Till recently, the umbilical cord along with the placenta was discarded following the birth of a baby. It’s however now known that blood retrieved from the umbilical cord can be a rich source of stem cells. This is because the concentration of haemoglobin of the foetal type and stem cells is much greater at infancy, and is gradually replaced only during the first year, with the adult blood type.

These unspecialised blood cells (stem cells) also continually replicate to produce all other blood cells including the blood-clotting platelets and the red (oxygen-carrying) and white blood cells. It is also the same stem cells that help enhance a person’s blood-producing capability and immune system, when it might be damaged or destroyed by cancer treatments or impaired through an inherited genetic defect.

Hence banking stem cells from umbilical cord blood is being considered as an answer to various genetic disorders that affect the blood and immune system. What’s more, stem cells derived from this source can be transplanted not only into the donor, but also to a family member or an unrelated recipient.

Why UCSCB?

“Till recently, it was bone marrow that was considered to be the most common source of stem cells,” explains Dr Maheboob Basade, who is a consultant haemato-oncologist and medical oncologist for Breach Candy Hospital and the Jaslok Hospital and Research Centre, in Mumbai. “A bone marrow transplant however, demands a nearly perfect match of certain tissue proteins (Human Leukocyte Antigen) between the donor and the recipient for the process to succeed. In contrast, the donor stem cells from cord blood appear more likely to engraft, even when the tissue matches are not 100 per cent absolute. Transplants can be done with umbilical cord blood stem cells even when only three of the six antigens between the donor and the recipient match.”

A potentially fatal complication called graft versus host disease (GVHD), in which donor cells can attack the recipient’s tissues also appears to occur less frequently with cord blood than with bone marrow. This is because the cells are naïve and although usually active in an immune reaction, have not yet been educated to attack the recipient.

Shortage of donors owing to the painful mode of collection is another obstacle that plagues bone marrow transplants. Harvesting stem cells from bone marrow entails a surgical procedure that is usually carried out under general anaesthesia. This involves and also post-operative pain to the donor. Stem cells from cord blood are relatively much easier to get because they are readily obtained from the placenta at the time of delivery.

The method

“The process takes less than two minutes and is absolutely safe and simple,” according to Dr Saranya Nandakumar, medical director, LifeCell. “There is no harm done either to the mother or the child and the collection is done only after the baby is taken away,” she explains. LifeCell was launched recently by Chennai-based Asia Cryo-Cell Ltd to serve as a private cord blood banking service within India.

Collecting cord blood

The collection is based on the principle of gravity. After the umbilical cord is clamped and the baby is taken away, the needle of the blood bag is inserted into the vein and the bag is held down at a lower level, to allow the blood to drain into the bag by way of gravity. Once the leftover blood in the umbilical cord is drained out, the cord collapses. “We collect all the blood in the cord, because the quantity of blood collected is directly proportional to the number of stem cells,” explains Dr Nandakumar.

The quantity of blood in the cord depends on factors like the baby’s weight, mother’s health and her nutritional status. “We insist on collecting at least 60 ml of cord blood,” reveals a spokesperson of Reliance Life Sciences (RLS). RLS is the first private stem cell enriched repository that has received the Indian FDA licence.

The collection can be done by an obstetrician or a trained paramedic or a nurse. Nevertheless it is imperative to carry out the procedure under strictly hygienic conditions. RLS receives its biological material from a few nursing homes in and around Mumbai, which have been certified and audited by them for quality parameters, and sends its volunteers to train doctors and staff nurses at these places to collect the cord blood within the specified short span of time.

“We have any number of people who are willing to donate their cord blood. It is however difficult for us to be present everywhere,” explains the RLS spokesperson. “We therefore conduct training programs at nursing homes to educate the hospital staff about pre-delivery counselling, documentation of records, collection and transportation of the cord blood. We also conduct regular audits, to ensure that our stringent quality practices are being met by the nursing homes.”

Transportation

After collection, the cord blood is maintained at a temperature between five and 25 degree Celsius, using gel packs inside the collection kit. While RLS insists on transportation within 30 hours, LifeCell allows for 48 hours. “As per our agreement with the courier services, the sample must reach us within 36 hours giving us a buffer time of 12 hours,” clarifies Nandakumar. “The blood bank has till date received about 250 samples from within and outside the country, with all the samples having reached the lab within the stipulated time,” she says.

“Two weeks back, one of our samples from Ahmedabad reached Mumbai when the city was hit with torrential rains. As soon as we realised the gravity of the problem, we got the sample shipped back to Ahmedabad, from where we flew it to Delhi and then to Chennai to ensure that the sample reached us on time,” explains Prasad Mangipudi, vice president, marketing, LifeCell.

After bringing the cord blood to the centre, several tests are conducted on it. “We test the collected cord blood for RH grouping or typing, blood cultures and the CD-34 counts,” details Dr Nandakumar. “Eight different tests are also conducted on the mother’s blood at the time of cord blood collection. We test it for the HIV Antigen & Antibody, Syphilis, Hepatitis B&C, Alanine Amino Transferase (ALT), Malaria, Leptospirosis, Human T Lymphoma Virus (HTLV) 1&2, and Cytomegalo Virus (CMV). This is to ensure that the cord blood is not infected.”

Harvesting stem cells

The Umbilical Cord blood is not stored as such, but instead processed to harvest the stem cells enriched fraction from it. These stem cells are then stored in cryo-vials at -196 degrees Celsius in liquid nitrogen. Theoretically the cells can be stored forever at -196 degree Celsius, as a suspended emulsion. The record however is of 16 years for the storage of umbilical cord blood stem cells and 35 years for bone marrow stem cells. “In all likelihood the stem cells outlive the person from whom it has been taken,” informs Dr Nandakumar.

Molecular tests are conducted on the stem cells before freezing them, for tissue (HLA type) matching. A recipient can go ahead with the transplant, if his or her HLA type matches that of the donor.

Blood banks with a difference

While LifeCell has been spreading the message to preserve cord blood stem cells for the family’s own use, RLS lays more emphasis on providing this biological material to any appropriately matched individual needing a transplant. “We train the nursing homes to provide counselling to pregnant women, who if convinced choose to donate cord blood for absolutely altruistic reasons,” says the spokesperson from RLS.

This service provided by RLS is called Relicord A (A for Allogenic), and through this project, the company assumes responsibility for transportation, processing, storage, and documentation of reports for the donor stem cell samples. Transplantation centres which need the biological material contact RLS and compare their requirements with the donor samples, to decide whether or not to carry out a transplant.

LifeCell, on the other hand, provides a service where clients pay and bank for their own use. The client therefore receives a copy of the stem cell report that is maintained by the bank. “The stem cells belong to the baby, and the parents are the custodians till the baby reaches adulthood. After collecting the cord blood during delivery, we fill in an enrolment form. So in the unfortunate event of the parents’ death, the baby can still gain access to his stem cells by writing to us, with an enclosed copy of the enrolment form, the agreement copy and the stem cell report,” explains Dr Nandakumar.

Ignorance is not always bliss

“The use of umbilical cord blood stem cells for transplantation treatment is promising, but one needs to be well informed before considering this option because the process has its own flipsides,” warns Basade. It is highly imperative that families receive complete information and counselling from health care providers, including genetic counsellors before they choose this option. “One also needs to consider the safety issues when it comes to the method of cord blood collection, to avoid contamination.”

While the chances of finding a match amongst siblings, according to Dr Basade, is only 25 percent, the chances of finding one in an unrelated recipient is as small as one in one lakh. The likelihood of a child requiring a stem cell transplant in his own lifetime, he says, is also quite small.

“A transplant will be effective mostly for diseases that the child will develop later in life as there is no proof to guarantee that the child’s own stem cells will not carry his birth defects or will not be cancerous at the time of his birth,” he cautions.

Since most families have no risk factors, and very little possibility of needing stem cell transplants, it is mostly advisable that only expectant parents with a family history of certain genetic diseases consider the family benefit of storing cord blood. “It is not ethical of parents to bear a second child only to find an HLA match for the first baby,” warns Dr Basade.

He also reiterates the fact that is important to have sound advice, medical evidence and informed consent, before making a decision.