In the anguishing wait for a new kidney, tens of thousands of patients on waiting lists may never find a match because their immune systems will reject almost any transplanted organ.
In the anguishing wait for a new kidney, tens of thousands of patients on waiting lists may never find a match because their immune systems will reject almost any transplanted organ. Now, in a large national study that experts are calling revolutionary, researchers have found a way to get them the desperately needed procedure.
In the new study, published last Wednesday in The New England Journal of Medicine, doctors successfully altered patients’ immune systems to allow them to accept kidneys from incompatible donors. Significantly more of those patients were still alive after eight years than patients who had remained on waiting lists or received a kidney transplanted from a deceased donor.
The method, known as desensitisation, “has the potential to save many lives,” said Dr Jeffery Berns, a kidney specialist at the University of Pennsylvania’s Perelman School of Medicine and the president of the National Kidney Foundation. It could slash the wait times for thousands of people and for some, like Clint Smith, a 56-year-old lawyer in New Orleans, mean the difference between receiving a transplant and spending the rest of their lives on dialysis. The procedure, Smith said, “changed my life.”
Researchers estimate about half of the 100,000 people in the United States on waiting lists for a kidney transplant have antibodies that will attack a transplanted organ, and about 20 percent are so sensitive that finding a compatible organ is all but impossible.
In addition, said Dr Dorry Segev, the lead author of the new study and a transplant surgeon at the Johns Hopkins University School of Medicine, an unknown number of people with kidney failure simply give up on the waiting lists after learning that their bodies would reject just about any organ. Instead, they resign themselves to dialysis, a difficult and draining procedure that can pretty much take over a person’s life.
Desensitisation involves first filtering the antibodies out of a patient’s blood. The patient is then given an infusion of other antibodies to provide some protection while the immune system regenerates its own antibodies. For some reason — exactly why is not known — the person’s regenerated antibodies are less likely to attack the new organ, Dr Segev said. But if the person’s regenerated natural antibodies are still a concern, the patient is treated with drugs that destroy any white blood cells that might make antibodies that would attack the new kidney. The process is expensive, costing $30,000, and uses drugs not approved for this purpose. The transplant costs about $100,000. But kidney specialists argue that desensitisation is cheaper in the long run than dialysis, which costs $70,000 a year for life.
Although by far the biggest use of desensitisation would be for kidney transplants, the process might be suitable for living-donor transplants of livers and lungs, researchers said. The liver is less sensitive to antibodies so there is less need for desensitisation, “but it’s possible if there are known incompatibilities,” Dr Segev said.