FIRST BLOOD
Blood from the umbilicus-the physiological connection between mother and child-is a source of stem cells may be used for treatment of diseases in the future
By Dong de los reyes, Contributing Editor
Some coins to ensure wealth, the stub of a pencil for wisdom, a nail for iron will, and a wee piece of silk or linen cloth for an easy life-these used to be put together in a nondescript bag with the afterbirth, clots of cord blood, and a length of the cut umbilicus, then buried at the foot of the stairs in the household where the child first saw the light of day. Maybe that's two-bit superstition. Likely an ancient tradition to wish life's best for the newborn.
Forward-looking parents have it done differently these days not out of superstition or keeping a cherished tradition alive. About five ml of the cord blood is collected, reposed in a plastic bag, cell count and tests for viability and infectious diseases done, then sent off by plane within 24 hours to a special facility in Singapore for cryogenic storage in liquid-nitrogen tanks up to 20 years or until a life-or-death occasion arises in which the cord blood sample is to be used:
First blood can be that precious and life saving. Blood from the umbilicus-the physiological connection between mother and child-is a source of stem cells, the sort capable of self-renewal and can grow into specialized cells. In vitro, certain substances can be added to the stem-cell sample and nudge their growth into a type you like them to turn up. Stem cells provide the start-up material, building blocks for cloning-the outright duplication of an individual.
"Now, clinically stem-cell transplantation is used to replace diseased (bone) marrow. This has been the most widely used application-to repopulate the marrow that is destroyed by chemotherapy or radiation given for a variety of malignant disorders. More lately, [stem-cell transplantation] is used to correct defective genes-cells can be manipulated in order that they will contain the defective gene and is given to the patient."
So explained Dr. Arvin Faundo, a consultant in bone-marrow-stem-cell transplantation at the Asian Hospital and St. Luke's Medical Center. He is also a consultant/director of The Medical City's immunology department.
Since the 1960s, the most commonly tapped source for stem cells has been the bone marrow, which, compared to cord blood, is a richer reserve as it continuously churns out blood elements. In the 1990s, peripheral blood provided the alternative harvest in stem cells-certain drugs are administered to the donor to mobilize the bone-marrow stem cells into the peripheral blood, and then collected by apheresis.
But then a bone-marrow-stem-cell donor can be stymied at the discomforts, even pains he has to go through. He has to be in an operating room, under sedation; several punctures are done on the harvest area, the posterior iliac crest or the butt's top portion: "You could imagine why a lot of people are shying away from bone-marrow donation," said Faundo.
Peripheral-blood donation is relatively less discomfiting. Bone-marrow stem cells are coaxed out via injections on the donor; the cells are then collected by apheresis machine-less painful, less invasive on the donor.
No such hassles for the donor of cord-blood-derived stem cells.
"It is collected after delivery. It is stored right away such that when needed, it will be, it can be used for transplantation in a much shorter period compared to that sourced from bone marrow or peripheral blood," noted Faundo.
As with the afterbirth or placenta-some enterprising individuals in maternity hospitals are collecting them to go into manufacture of skin-care products-cord blood is considered a throwaway by-product after delivery.
Elaborated Faundo: "The placenta could still be attached to the uterus or it could have been delivered after. The umbilical vein is punctured and stem cells collected from the umbilical vein, umbilical cord. Basically painless and there's no harm to the mother or child. There is no risk for the cord blood donor."
He continued: "Stem-cell dose in cord blood is lower as there's lesser volume. But the cost is much cheaper. And cord blood is widely available in a shorter period of time for patients in dire need, who could die, become higher risk, or ineligible for transplant."
Despite the cord blood's low stem-cell content, there are strategies in use, one is ex vivo expansion of stem cells or something similar to culturing the stem cells to have more of them.
Even stored cord blood can be taken out just like getting an item off a kitchen shelf and used at once without much preamble.
Also, there is lower risk of rejection: "For transplantation you would usually need six antigen match between patient and donor. If you are using cord blood, two antigen mismatch can still be tolerated-four out of six matches would be good."
There was one antigen mismatch in the first cord-blood transplant done in the Philippines in 2004 on a nine-year old girl who had acute myelogenous leukemia. And since there isn't an existing storage facility for cord blood in the country, a global registry of cord-blood donors in the world's continents had to be checked out; overseas sources had to be tapped. Luckily a donor unrelated to the girl was found in a Japanese cord-blood bank. The patient tolerated the mismatch-there was delayed engraftment but there was no graft-versus-host disease. She is now on her 27th month posttransplant.
"Most of the uses [for cord blood] would be on hematologic disorders-namely leukemias, lymphomas-and (as recent studies have it) myeloplastic syndromes and thalassemia, all these are fatal or chronically debilitating diseases," he related.
In perinatal medicine, cord blood has been used for inborn errors of metabolism, disorders like adrenoluekodystrophy and Herder's disease that result in very debilitated children-"cord blood has to be given early before symptoms develop or the result would not be very, very good," Faundo added.
Other potential applications cited were on primary immunodeficiency and injury at birth that would affect the lungs, the brain-pulmonary diseases and perinatal brain injury. These applications are still being tested on animals but evidence shows that transplanted stem cells could transdifferentiate, i.e. cells go to the injury site and provide replacement.
Stem-cell use for regenerative medicine is showing promise. It was accepted then that the heart and the brain are not able to repair themselves after injury-now that is being challenged nowadays.
"Researchers would like to believe that stem cells in the myocardium or even in the brain itself could repair damaged tissues. It is also postulated that administration of stem cells might help in the repair and recovery of these organs. There's a problem in getting organs for transplants so what is being tried is to make organs out of stem cells-bioartificial tissues or stem cells as a suspension administered to the patient and these cells find their way into the damaged organ," said Faundo.
He cited a landmark study in 2004 that pointed to plasticity of stem cells-the cells are able to become different beyond the tissue they normally reside.
Most of the animal studies being carried out focus on Parkinson's disease and spinal-cord injury. Work on diabetes is in the pipeline, while myocardial-infarction applications are now into clinical trials.
A long line of ailments and disorders may most likely be remedied in one fell swoop in the not-so-distant future. An eminent specialist in cord-blood biology expressed the hopes of many: "We all look forward in anticipation to the future role that cord-blood transplantation will play in the cure of numerous malignant and life-threatening nonmalignant disorders that continue to plague so many."
And just maybe, 'twas the Almighty who pointed eons back toward the current avenues of medical research through the opening lines of the Holy Qur'an: "Recite, thou in the name of thy Lord who created-created man from clots of blood."
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