Typing for Transplants

Though the payoffs in transplant sur gery are still distressingly few, hopes remain high; both the number and vari ety of transplant operations are increasing. Trouble is, the human body has a habit of trying to reject any tissue or organism that is foreign to its own chemistry. Only with transplants between identical twins is there reasonable hope of long-term success. Among other people, the rejection reaction is always present, though it varies in intensity.* To some Manhattan researchers, this very variation offered new hope for transplant success. In Science, the in vestigators report a new technique for predicting the strength of a patient's re sistance to a transplanted organ -- and thus for selecting donors whose organs will have the best chance of survival.

Add & Multiply. The spleen, lymph nodes and bone marrow manufacture white blood cells of a type known as lymphocytes, which are loaded with antibody ammunition to battle any invader. They attack a transplant much as they would fight an army of diseasecausing virus particles. But transplant patients' lymphocytes show more hostility to cells from some donors than from others. Dr. Kurt Hirschhorn and Dr. Fritz Bach of New York University School of Medicine noted that when lymphocytes from two people of widely different ethnic groups were put together in a test tube, the cells became overactive; they enlarged and multiplied. By contrast, when lymphocytes from identical twins were combined, there was no reaction at all. This suggested that typing of donors for transplants might be developed along lines similar to blood typing.

At New York Hospital-Cornell Medical Center, doctors were trying a similar cell-matching technique in an effort to measure the body's buildup of antibody against a transplant. This was so that they could prescribe anti-rejection drugs not only in the right amount but at the right time. Such timing is vitally important. It is dangerous to suppress the rejection mechanism completely, even after a transplant, because to do so leaves the patient defenseless against many potentially fatal infections.

Drugs in Time. The cell-typing system has already been tried on patients. At New York Hospital, one girl got a kidney transplant from her mother, whose cells showed little antagonism to her own. When cell tests showed that rejection activity was building up, the doctors were able to give rejection-suppressing drugs in good time. After careful cell matching, another girl received a kidney from her father. Some five months after transplantation, the kidneys are still working well.

* Last week Ecuadorian Sailor Julio Luna, whose grenade-smashed right hand had been replaced by a transplant from a recently dead donor (TIME, March 6), was flown to Boston's Peter Bent Brigham Hospital. There doctors concluded, "The natural rejection mechanism of the patient had progressed to the point that prolongation of the transplant would jeopardize the health of the patient's whole arm," reluctantly amputated Luna's new hand.

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