Researchers at the University of Chicago have discovered that an anti-inflammatory protein called calgranulin, previously detected only in white blood cells, may play a key role in the prevention of kidney stones.

Sokalingum Pillay, Ph.D., Research Associate and assistant professor of medicine at the University found that calgranulin is present in the kidney and human urine and can, even in minute amounts, stop the growth of calcium oxalate crystals--the major component of kidney stones.

His findings will be published in the August issue of the American Journal of Physiology Renal with co-authors Fredric Coe, MD, Section Chief of Nephrology, and John Asplin, MD, assistant professor of medicine.

"Measuring calgranulin in urine could become a new diagnostic tool for determining if a patient is at high risk for forming kidney stones, and preventive measures could be taken," says Pillay.

He found that calgranulin, which is made up of two distinct subunits, is often defective in stone-formers. "In many people with kidney stones, the subunits don't come together to form the bigger, active protein calgranulin. We suspect this is a factor in their tendency to form stones," says Pillay.

According to the basic laws of chemistry, our kidneys should be chock-full of kidney stones. Although the kidney is supersaturated with calcium and oxalate, the basic components of kidney stones, only three to five percent of people in the Western Hemisphere form them. Most people pass microscopic calcium oxalate crystals with their urine before they can grow into dangerous masses. "It is the natural fate of supersaturated solutions to grow crystals," says Asplin. "Something must be working to prevent this in the kidneys."

Over the past ten years, several proteins have been found that have some e
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Contact: Sharon Parmet
sparmet@mcis.bsd.uchicago.edu
(773) 702-6241
University of Chicago Medical Center
29-Jul-1998