New Test Gives Early Warning of Kidney Failure

Finding could lead to quicker use of life-saving treatment

FRIDAY April 1, 2005 (HealthDay News) -- Doctors may soon have a much quicker, accurate means of spotting imminent kidney failure, allowing them to provide life-saving treatment to patients when they need it most.

The test measures blood or urine levels of a protein marker of severe kidney damage called neutrophil gelatinase-associated lipocalin (NGAL). According to a study in the April 2 issue of The Lancet, the test correctly spotted the possibility of kidney failure in 71 children undergoing heart bypass surgery.

The screen might ultimately be used "for all patients who we think are susceptible to kidney injury, and right now that is a wide spectrum," said lead researcher Dr. Prasad Devarajan, director of the division of nephrology and hypertension at Cincinnati Children's Hospital Medical Center.

Markedly high levels of NGAL were found in the 20 young patients who developed kidney failure one to three days after their heart surgeries, the doctors reported.

Most important, the NGAL test results were available in a matter of hours, compared to the two to three days now required for the standard kidney function test, which measures a protein called creatinine.

Statistics show that 5 percent of all hospital patients and more than 30 percent of those in intensive care units will have kidney failure, Devarajan said, and more than half of these patients will die. Quick identification of those at risk can not only save lives but also save money by eliminating the need for artificial kidney treatment, he said.

Devarajan believes the test would be useful in treating a wide range of patients, including "patients who undergo cardiac surgery or abdominal surgery, patients who have trauma and bleeding and, in addition, patients who have sepsis [infection] and those who get medications known to affect the kidneys, such as some antibiotics and chemotherapeutic agents."

The Cincinnati researchers are now working with biotechnology companies to develop two commercial versions of the test, Davarajan said.

"One would be very similar to the pregnancy test we now do, a urine test," he said. "The other would be a blood test. One would give an answer in a matter of minutes. Also there would be a more sophisticated version that would take 30 minutes and would be more quantitative and more accurate."

The projected per-use price for a commercial test would be $40 to $50, Davarajan estimated. "That's a small price to pay, given the enormous financial burden that kidney failure will create."

Working out details of a marketable test and getting approval for its use from the U.S. Food and Drug Administration will take two to three years, he added.

"Right now it is a research tool, but it can be set up by anyone who wants to set it up," he said. "It is a noninvasive test, requiring just a drop of urine or a drop of blood. But if I were a hospital, I would wait until a commercial test is available and validated."

The Cincinnati work on NGAL as a diagnostic tool has been verified by a group led by Dr. Jonathan M. Barasch, associate professor of medicine at Columbia University College of Physicians and Surgeons in New York City.

The two groups have been collaborating closely since the vital role of NGAL in kidney function became clear several years ago, Barasch said.

"The story began a few years ago when we purified the molecule from embryonic kidney and showed that it could activate kidney formation," he said. Almost immediately, the Cincinnati and New York groups began a collaboration that continues to this day, Barasch said.

"Both groups have demonstrated that in mice it can have a therapeutic effect," he said, so it is possible that elevated levels of NGAL seen in kidney damage indicate the body is trying to repair that damage. Both groups are now developing animal models to extend their research efforts, Barasch said.

More information

You can learn more about kidney failure from the National Library of Medicine.

SOURCES: Prasad Devarajan, M.D., director, division of nephrology and hypertension, Cincinnati Children's Hospital Medical Center, Cincinnati; Jonathan M. Barasch, M.D., Ph.D, associate professor of medicine, Columbia University College of Physicians and Surgeons, New York City; April 2, 2005, The Lancet
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