New Technique Prevents Kidney Rejection
April 30, 2002, -- Thousands of Americans die each year of end-stage renal disease, or permanent kidney failure, while waiting in vain for a kidney transplant. But a relatively simple technique revealed this week might mean the difference between life and death for many of them.
Researchers at Baltimore's Johns Hopkins Medical Institutions report that a process in which natural antibodies are filtered from the blood of kidney patients effectively prevents rejection of live-donor organs when blood or tissue incompatibility is an issue. The procedure may also help reduce rejection in heart, pancreas, and lung transplant patients.
Of the roughly 12,000 kidneys transplanted in the U.S. annually, approximately 5,000 are from live donors. But one-third of patients with available live donors find that those donors are not good matches, either because their blood types are incompatible or because they have developed antibodies against donor tissue during previous transplants, blood transfusions, or pregnancies.
The Johns Hopkins research team was able to overcome these incompatibilities by filtering donor-specific antibodies from the patients' blood through a process called plasmapheresis. Patients were also given a protein to keep the antibodies from returning and to lower the risk of infection.
In a presentation Tuesday to the American Transplant Congress meeting in Washington, D.C., transplant surgeon Robert A. Montgomery, MD, reported on the outcome of 29 kidney transplant recipients who had the procedure. Five of the patients had blood types that were incompatible with their donors, and 24 had incompatible tissue proteins.
Each patient had an average of three or four plasmapheresis treatments every other day starting a week to 10 days before transplantation, with three additional treatments given the week after. At an average of 17 months following surgery, 27 of the patients had normally functioning kidneys.
Montgomery tells WebMD that 20 additional patients who developed kidney threatening-antibodies following transplantation also responded favorably when treated with the protocol.
"This could make a tremendous difference for people with live donors who aren't good matches and who might otherwise have to wait three or even five years for a transplant," he says. "There is nothing standing in the way if a patient is medically eligible for surgery and has a live donor who is medically eligible. That is a big change."
About 52,000 people in the United States are on waiting lists for kidney transplants, and about 60,000 Americans die each year from end-stage renal disease. Though the number of cadavers available for transplants has remained steady over the past decade, the number of live donors has increased dramatically. In 2000, slightly more than 5,200 live donor kidney transplants were performed, compared with 1,800 in 1988.
The plasmapheresis technique may also be useful in patients undergoing heart, lung, and pancreas transplants, Montgomery says. Early studies in these areas appear promising.