No Other Cross-Species Heart Transplants on Horizon : 1 Year After Baby Fae: a Basic Problem

One year after the historic transplant of a baboon heart into the chest of an infant girl, the hospital where the operation was performed seems no closer to a second cross-species operation than it did the day Baby Fae died.

Ten infants, all suffering from the same fatal heart disorder as the little girl who tugged at the nation’s heartstrings with her valiant fight to survive, have since been referred to Loma Linda Medical Center.

All 10 were rejected for animal transplants, and all have since died.

Baby Fae, a victim of hypoplastic left heart syndrome, a fatal underdevelopment of the organ’s left side, died 21 days after receiving the heart of a 7-month-old baboon.

Hospital officials said none of the other infants has been offered a baboon heart because “thorough investigations of Baby Fae’s experience have not been completed.”

Dr. Leonard L. Bailey, who made the bold and maverick decision for a cross-species transplant, has shunned the media in the last year, even refusing to comment on his remarks at a recent medical conference that Baby Fae died because of a “catastrophic” medical decision.

‘Tactical Error’

Bailey told the annual meeting of the California Perinatal Assn. in Monterey, Calif., that failure to match blood types between Baby Fae and the baboon was “a tactical error that came back to haunt us.”

Baby Fae had type O blood. The baboon used in the experiment had type AB blood.

“If Baby Fae had the AB blood group she would still be alive today,” Bailey insisted in his talk to medical colleagues.

He explained that the blood mismatch apparently led Baby Fae to develop antibodies to her own red blood cells, causing her blood to clot and forcing her kidneys to shut down.

The infant, who was born Oct. 14, 1984, received the baboon heart 12 days later in an operation preceded only by those on four adults who were given hearts of other lower primates in the 1960s. The adults all died shortly after their operations.

Dr. Randall Morris, a transplant immunologist at the Stanford University Cardiovascular Research Department, said there have been no “conceptual or practical breakthroughs” in the area of cross-species transplantation since the Baby Fae experiment.

“Doctors rarely try to perform human-to-human heart transplants without an appropriate match for blood types,” Morris added.

“Universally, surgeons always try to match donors for red blood types. Red blood cells are a litmus test for the narrow spectrum of proteins on the blood vessel lining. When an uncrossed match is put into a recipient, damage can occur within hours.

Incompatible Blood Match

“Researchers as far back as 20 years ago had found that the majority of lower primates possess type AB blood, an incompatible match for humans with type O.”

Because of that difficulty, Morris said, cross-species heart transplantation “is not an area under intensive investigation by a large number of scientists” around the country.

Blood types are determined by antigens, or proteins, on an individual’s blood cell surface. Because the surfaces vary from person to person, transplants and blood transfusions usually are limited to people with compatible blood types.

Last year, physicians and bioethicists lambasted Bailey for not conducting a thorough search for a human heart to transplant into the infant. The doctor has since called that an “oversight.”

However, he has defended his continuing research in cross-species transplantation by noting that current methods of treatment for hypoplastic left heart syndrome do not alleviate the problem.

Clearer information to be gleaned from the Baby Fae case probably will not be revealed until publication of Bailey’s research in the Journal of the American Medical Assn., expected in a few months.

Bailey, meanwhile, indicated in a statement released by the Loma Linda Medical Center that while he is working toward a second cross-species transplant, he does not plan to proceed until he thinks the situation is right.

“We are under no arbitrary time constraints,” he said. “Rather, we are more concerned that the scientific, humanitarian and bioethical aspects of this research be appropriate.”