WEDNESDAY, Sept. 3, 2003 (HealthDayNews) -- Kidney failure is a disturbingly high risk for all transplant patients, says the largest survey ever done.
Ironically, the major cause of those kidney failures is an unavoidable side effect of the rejection-suppressing drugs that made transplantation possible, experts say.
"The five-year risk of chronic renal [kidney] failure after transplantation of a non-renal organ ranges from 7 to 21 percent, depending on the type of organ transplanted," says a report in the Sept. 4 issue of the New England Journal of Medicine by transplant specialists at the University of Michigan.
Kidney failure in those patients more than quadruples the risk of death, the researchers say.
"The magnitude of the problem is much higher than what one would expect based on what we see day-to-day in the clinic," says study leader Dr. Akinlolu O. Ojo, an associate professor of medicine at Michigan. "A number of 20 percent is higher than one would come up with if one had to make a guess."
The numbers come from a study of nearly 70,000 persons who received other-than-kidney transplants (liver, heart, lung, heart-lung or intestine) in the United States in the 1990s. Overall, 11,426 of those patients suffered kidney failure in the first three years after surgery, an incidence of 16.5 percent.
"While this report does not specifically say so, previous work would suggest that the main cause of kidney disease that arises after transplantation are these drugs," says Dr. Colin C. Magee, a staff physician in the renal division of Brigham and Women's Hospital, the teaching hospital of Harvard Medical School.
Two drugs are the mainstays of efforts to prevent the immune attack that kills transplanted tissues -- cyclosporine, whose appearance in the early 1980s revolutionized transplantation, and tacrolimus, which was introduced later.
"It is important to remember that these are drugs are lifesaving drugs," Magee says. "Without these drugs, transplantation would not be possible."
But the high incidence of kidney failure after transplantation not only worsens the quality of life but also can translate into a requirement for artificial kidney treatment or kidney transplants for many thousands of patients, which can strain medical resources, Magee says. While fewer than 1 percent of Medicare patients have kidney failure, they account for almost 6 percent of the Medicare budget, the editorial says.
There are ways to lessen the problem, Ojo and Magee say. It might be possible to use lower doses of cyclosporine and tacrolimus in selected patients, and to use newer rejection-preventing drugs in those patients, Magee says. But doctors will be cautious about changing the existing regimens, because any new dosage schedules might not be as effective, he says.
Ojo proposes a strategy based on other findings of the survey -- that a number of factors other than drug therapy contribute to the risk of kidney failure. Those factors include older age, being a woman, having hepatitis C infection, high blood pressure and diabetes, the survey shows. Those factors can be combined in a formula to determine a patient's overall risk, he says.
"We need a way to stratify people before they get transplants so that we could reduce the amount of drugs we use or use the newer drugs in these patients to avoid toxicity," Ojo says. But he advises caution in use of the newer drugs, because they may not be as effective in preventing rejection as the two older medications.
Transplant centers, including the one at Michigan, are not now using the risk-stratifying strategy because the risk factors have not been laid out clearly, Ojo says. The surgery results may help promote the strategy, he says.
More information
Read more about organ transplantation at the United Network for Organ Sharing", and you can learn about kidney disease from the National Institute of Diabetes and Digestive and Kidney Diseases.
