Wider Use Of Stem Cells Is Forecast

      Stem cells, sometimes called the building blocks of life, have proven effective in helping a child born with an inherited disease. Researchers now believe they may be used more frequently in the future to help ailing children and adults.

      In recent years, researchers have found that stem cells from human embryos can transform themselves into different types of tissue. These cells are different from the more mature human stem cells that produce specific tissues for a single organ.

      When babies are born, their umbilical cords contain blood rich in post-embryonic stem cells that can provide a new blood supply and immune system to the recipient, usually a desperately ill sibling.

      Scientists have applauded a recent case in which embryonic cells were tailored to produce blood free of inherited genetic disorders in a newborn for the benefit of a sibling suffering from a rare disease. But the case has also raised concerns that the process might enable parents to go beyond health and safety issues to choosing physical traits of their children.

      ``We are seeing amazing possibilities coming from early progenitor cells where we can not only dramatically improve the health of newborns but also begin to reconstruct tissues damaged by disease,'' said Dr. Harvey G. Klein, chief of the Department of Transfusion Medicine at the National Institutes of Health.

      His comments follow a closely watched stem cell transplant on Sept. 29 to save Molly Nash, an 8-year-old girl from California. She was suffering from Fanconi anemia, a rare inherited disorder that causes a breakdown of bone marrow cell production and is almost always fatal.

      The stem cells she received were from her baby brother Adam. But unlike similar stem cell transplants from one sibling to another, where there remains a one-in-four chance that the newborn will also carry the defective gene and become ill, Adam''s umbilical cord blood contained no sign of the disease.

      To eliminate the risk, the parents, Jack and Linda Nash, turned to a new technique called preimplantation genetic diagnosis to screen their embryos for genetic diseases and tissue compatibility before Linda Nash became pregnant.

      The procedure required Nash to take drugs to stimulate the simultaneous production of multiple eggs, which were fertilized by her husband''s sperm in a petri dish. Six embryos were selected, each extensively tested to make sure it was free of Fanconi anemia. Five embryos were implanted before a pregnancy resulted with the sixth embryo last Christmas Eve.

      In late August, Linda Nash gave birth to Adam, a healthy son. His stem cells were immediately harvested from his umbilical cord in a painless procedure. The cells were stored until late last month when Molly received them in an operation at Fairview-University Hospital in Minneapolis, which specializes in bone marrow replacements for children with Fanconi anemia.

      The hospital reported that Molly is doing well and that her chance for survival is now 85 percent compared to the 31 percent it would be if the donor were not her baby brother. Already, 10 other families are preparing to use preimplantation genetic screening to ensure their babies are free of any genetic disease and that the umbilical cord blood can help a sibling.

      ``For those rare applications of inherited disorders like sickle cell anemia, thalassemia and blood disorders where we can make sure that the embryonic cells don''t have the diseases, this will be widely used,'' predicted Dr. George Q. Daley, an assistant professor of medicine at the Harvard Medical School and a Whitehead fellow at the Whitehead Institute of Biomedical Research.

      Daley said such uses carry little threat to society. ``This is not the conveyor belt of choosing biological traits that we expect from a Brave New World, but a careful use of technology to treat and cure rare diseases,'' he said.

      Still, the use of human embryonic stem cells remains controversial to abortion opponents because many embryos are killed. In August, the Roman Catholic Church condemned the use of these cells after the National Institutes of Health said it would selectively fund research using stem cells.

      Beyond the use of stem cells to treat children, scientists are also making strides in the use of adult stem cells and in cell experiments with animals.

      Last month, researchers at the Robert Wood Johnson Medical School in Piscataway, N.J., reported converting adult stem cells taken from bone marrow into nerve cells, giving hope for new treatments to repair spinal injuries, stroke, Alzheimer''s, and Parkinson''s.

      Diacrin Inc. of Boston is developing transplantable cells for the treatment of Parkinson''s disease and Huntington''s disease in a joint venture with Genzyme Corp. and is using spinal cord cells from pigs for human spinal cord injuries.

      On the West Coast, StemCells Inc., formerly CytoTherapeutics Inc., is researching the use of stem cells to treat diseases of the central nervous system and liver, while Geron Inc. is examining the use of stem cells to treat brain cells damaged by stroke and Parkinson''s disease.

      On the horizon are plans to use infant stem cells to treat parents with certain cancers and blood diseases such as leukemia, said Cynthia Fisher, president of ViaCord Inc.

      Her seven-year-old, Boston-based company provides ``biological insurance'' for families. It has collected more than 6,000 umbilical cords with stem cells for families at an average cost of $1,500 plus $95 a year for cold storage.

      Fisher said ViaCord''s sister company ViaCell has developed a manufacturing process to significantly increase the quantity of newborn stem cells needed to accommodate adult medical needs.

      (The Boston Globe Web site is at http://www.boston.com/globe/)

     

c.2000 The Boston Globe