Who Is Gonna Lose a Kidney

Kidney transplant rejection better predicted using lower urine albumin-to-creatinine ratio

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Getting a kidney transplant can be the difference between life and death for many patients. Yet even when patients finally get a much needed kidney, their body may reject the new organ.

In a recent study, researchers set out to see if certain markers used to predict the loss of a kidney transplant were accurate.

Microalbuminuria - a condition when the kidney leaks the protein albumin into the urine - is used to see if a kidney transplant will stick. Researchers found that the albumin levels currently used to predict transplant loss are too high.

"Kidney transplant loss could be predicted."

Doctors use something called the urinary albumin-to-creatinine ratio (UACR) to spot microalbuminuria. This measurement is the amount of albumin (a protein that helps control where body fluids go) compared to the amount of creatinine (a waste molecule) in a person's urine.

Currently, the cutoff point for microalbuminuria is a UACR of 30 mg/g. However, Arie Erman and colleagues from Rabin Medical Center in Israel found that this cutoff may need to be set lower in order to better single out those kidney transplant patients who may lose their new organ.

For their study, Erman and colleagues tested the urine of kidney transplant patients to see which UACR cutoff points most accurately spotted microalbuminuria. For men, they tested the cutoff points of 30, 21, and 17 mg/g. For women, they tested the points of 30, 25, and 24 mg/g.

They found that the best cutoff point for men was 21 mg/g. For women, the best cutoff point was 24 mg/g.

In women, the 24 mg/g cutoff point was 100 percent accurate in spotting microalbuminuria. The 21 mg/g cutoff point was 87 percent accurate in spotting microalbuminuria in men.

According to the study's authors, these findings show that the cutoff for spotting microalbuminuria, and thus kidney transplant loss, should be lower than the currently used 30 mg/g cutoff.

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Review Date: 
June 10, 2011
Last Updated:
June 11, 2011