March 14, 2001 BOSTON (AP) - It was Valentine's Day 1996. Dr. Lori West's own heart pounded as she transplanted a new one into the chest of a 2-week-old boy.
The donor had a different blood type. Though medical wisdom dictated that blood types should match, West's logic told her that the immature immune systems of babies should tolerate hearts from incompatible donors.
Still, medical literature testified to the result of mistakes in adults: quick death as the new heart clotted over and seized within minutes.
``I will never, ever forget that first one we did. It's very scary because you're doing something that's never been done,'' West said this week.
Ten transplants and five years later, she and her colleagues at the Hospital for Sick Children, in Toronto, are reporting a survival rate of 80 percent - as good as the rate with compatible donors. Their findings were being published Thursday in The New England Journal of Medicine.
``That's impressive,'' said Dr. Robert Morrow, who performs infant heart transplants at Arkansas Children's Hospital in Little Rock. ``I think it'll stir a lot of debate.''
If confirmed by larger and longer studies, the findings could help ease the shortage of donor hearts for thousands of desperately ill babies, doctors said.
The Canadian doctors transplanted hearts of incompatible blood type into 10 infants with failing hearts. The children, who were as old as 14 months, were almost all of type O blood. In most of them, the immune systems did not yet produce antibodies against incompatible blood types.
About one in every 5,000 newborns suffers from congenital heart disease and can potentially be a candidate for a heart transplant. But many children, especially with type O blood, die waiting for a compatible heart. Type O recipients are compatible only with type O donors, while recipients with A, B and AB blood can be matched with at least two other types.
Eight of the 10 patients survived the Canadian study, which followed them for up to five years. Two died, but the causes appeared unrelated to blood compatibility, according to the researchers.
``I think there is enough evidence to say this is safe to do in babies, providing that they don't have the antibodies,'' West said. Babies typically develop antibodies to incompatible blood at 6 to 14 months of age.
However, University of Colorado doctor Mark Boucek, who wrote an accompanying editorial, said such experiments should be duplicated elsewhere and expanded before the practice is accepted as standard.
In the Canadian study, even when infants began to make the blood antibodies, they did not attack the heart.
Doctors said this finding strengthens hope that the body's general rejection of transplants can eventually be eliminated altogether. Immune-suppressing drugs now in use make a patient susceptible to other diseases.
Copyright 2001 The Associated Press. All rights reserved.
