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Baboon Cells Fail to Grow in AIDS Patient, Doctors Say

February 08, 1996|THOMAS H. MAUGH II | TIMES MEDICAL WRITER

An experimental baboon bone marrow transplant performed in December in an effort to prolong the life of a San Francisco AIDS activist has apparently failed, but the patient nevertheless remains in remarkably good health, physicians said Wednesday.

The results have convinced researchers to be "more aggressive" with the next transplant they undertake, said Dr. Steven Deeks, the UC San Francisco physician who performed the Dec. 14 procedure.

A series of blood tests performed on Jeff Getty, 38, over the past few weeks have failed to show the presence of baboon cells, a strong indication that the transplant did not take, said Deeks.

"The tests [for the baboon cells] are experimental and difficult to do," Deeks said, "but clearly, if there were any significant amount present, we would know by now."

Nonetheless, Deeks added, "Jeff is doing extremely well. Clinically, his health is as good as it has been in a couple of years."

Deeks and his colleagues are not certain why Getty's health has improved, but they suspect that it may have been the result of radiation therapy used in preparing him for the transplant.

In a statement released by Project Inform, Getty said, "I am very pleased with the results of the experiment. I feel great. . . . My immunological health hasn't looked this good since 1989."

Deeks also emphasized that the experiment had reached one other goal: to demonstrate that it was safe, both for Getty and for the public health. Critics had feared that transplanting baboon organs into a human would lead to the transmission of potentially deadly animal viruses into the general population. That has apparently not happened.

Although the Centers for Disease Control and Prevention are still conducting some testing, Deeks said, "We have not seen any baboon viruses in Jeff."

The experimental transplant, using techniques devised by Dr. Suzanne Ildstad of the University of Pittsburgh Medical Center, was attempted because baboons normally cannot be infected with the AIDS virus. The hope was that the baboon bone marrow would establish itself in Getty's body and provide him with a parallel immune system that would help him fight off infections.

But they found no trace of baboon white cells in Getty's marrow. Nevertheless, Deeks said he does not consider the transplant to be a failure. "Our plan initially was to err on the conservative side," he said. "We gave him very low doses of chemotherapy and radiation therapy with the goal of doing no harm." The radiation and drugs were designed to kill off some of Getty's own bone marrow and thereby make room for the baboon marrow.

Apparently, Deeks speculated, they did not kill off enough of Getty's marrow cells. If another patient receives the therapy--a decision that will be made in four to six months--"we'll use a more aggressive therapy up front and will have a better chance of getting the cells to take."

On the day of the transplant, Getty received low doses of radiation directed at circulating bone marrow cells in his lymph nodes. Those nodes are where most T cells--the white blood cells attacked by HIV--accumulate in the body and are the primary sites of HIV replication.

"By turning off the T cells, we could be turning off viral replication, which could theoretically provide some of the benefit we are seeing now with Jeff," Deeks said.

As soon as possible, he added, they will try using radiation to treat primates infected with HIV to determine if that is really what happened.

Deeks noted that the team is making the results public before a formal publication because Getty is such a well-known figure in San Francisco. "People were getting the false hope that he has been cured," he said, "and we need to put those false hopes and false optimism to rest."

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