As a newly minted zoo clinician in the early 1990s, Dr. Kathryn Gamble twice faced the possibility of transfusing gorillas.
Fortunately, the procedure wasn't necessary in either instance, but Dr. Gamble was surprised by how lean the scientific literature on great ape hematology was. Then, in 2005, while Dr. Gamble was director of Veterinary Services at Lincoln Park Zoo in Chicago, her patient Mumbali, a young, severely anemic female gorilla, was facing both a blood transfusion and dialysis.
Dr. Gamble soon learned that the hematology literature had not advanced at all in a decade.
While veterinary medicine knows much about the blood types of domestic dogs, cats, horses, and even llamas and ferrets, until recently, the same couldn't be said for the great apes: gorillas, orangutans, common chimpanzees, and bonobos. Dr. Gamble was taken aback by this revelation, especially in the case of chimpanzees, which have been used for decades as models in human health studies.
"I had had enough," she recalled.
Jill Moyse, assistant lead keeper at Lincoln Park Zoo in Chicago,
trains Kwan, a male silverback gorilla, to insert his arm into a sleeve
so that, eventually, blood can be drawn without sedation.
With little time to waste, Dr. Gamble anesthetized Kwan, an unrelated male silverback also in the LPZ collection. She performed a major-minor cross match—a standard procedure with animal species for which little blood type data exist—in which red blood cells and plasma are screened to determine whether a potential donor and recipient are a match.
Although the test showed Kwan to be a suitable donor, and the transfusion did take place, Mumbali died as a result of her illness.
"There was a lot of grieving. This was a young animal in the prime of her life," Dr. Gamble said, and staff struggled to find meaning in the ape's death, especially Mumbali's trainer, Jill Moyse. "My answer to Jill was, 'Help me do what needs to be done.'"
That conversation started Dr. Gamble and Moyse down the road to identifying and cataloging the blood group phenotypes for great apes housed in North American and European zoos as well as some in situ ape populations managed in Africa and Asia.
Using human monoclonal antibody technology and in collaboration with the University of Chicago Department of Human Genetics, they assigned human ABO blood groups to whole blood samples from nearly 700 great apes, creating a "virtual blood registry" maintained by Dr. Gamble and her staff.
Hundreds of small, chemically coated cards donated by a Danish company were sent to participating institutions. Drops of blood revealed the donor's group, and the card was either sent or e-mailed to Chicago as a digital image. It took four years to gather the samples because they were collected during regularly scheduled procedures, which can be more than two years apart, Dr. Gamble explained, adding that it took Lincoln Park Zoo nearly two-and-a-half years to get through its 27 apes.
This registry is intended to facilitate quality transfusion medicine by taking the guesswork out of locating suitable blood donors. "Blood loss is a major concern. You may not need blood during a procedure, but you're more confident if it's available," Dr. Gamble said. "Now if someone is faced with (doing) a blood transfusion, and there is no good match on-site, they can contact Lincoln Park Zoo to learn which institutions a short distance away have appropriate potential donors."
Dr. Thomas Meehan, head of the veterinary advisory group to the Gorilla Species Survival Plan for the Association of Zoos and Aquariums, said the registry gives veterinarians the assurance to perform advanced surgeries on apes in which blood loss could be a problem. "Such procedures are relatively rare for great ape species," Dr. Meehan explained, "but it's nice to know extra blood's available, should it be needed."
Dr. Gamble and the research team found orangutans in the Bornean genus have all four human blood group phenotypes—A, B, AB, and O—which has not been previously documented. They also learned common chimpanzees and bonobos are predominantly group A, but chimpanzees with wild origins are more likely to be group O.
Ironically, the blood group of the gorilla—the very species that inspired the project—is still indeterminate. "Gorillas appear to be O, but our collaborators at University of Chicago say it's not all the same O, and it's not responding in a way consistent with O in humans," Dr. Gamble said. "We don't know right now how we're going to be able to determine them except through major-minor cross match."
Dr. Gamble has received two phone calls, including one from an international contact, for donor information since the results of the project were published in the November/December 2010 issue of the journal Zoo Biology.
Jill Moyse, the gorilla trainer, is currently working with Kwan so that blood can be drawn from him without sedation.
"We feel like we can now do better transfusion medicine," Dr. Gamble said. "Is it ideal? No, but we're so much in a better position than we were."