A research team from Johns Hopkins Children’s Center and other hospitals has devised a fast, cheap and easy way to accurately gauge a child’s kidney function that can be used to routinely monitor kidney function in children. The new approach also can be used to track kidney function in children with chronic kidney disease when they take medications or undergo treatments that can damage their kidneys.
A report on the study appears in the March 2009 issue of the Journal of the American Society of Nephrology.
Currently, the gold standard for measuring kidney function is gromerular filtration rate (GFR), which measures the rate at which kidneys filter waste. It is the best indicator of kidney capacity and health, but the determination of true GFR is time-consuming and costly to perform in day-to-day clinical practice. However, the new equation that uses tests results collected at routine office visits can effectively accomplish this, the researchers say. The new formula could be helpful in measuring kidney function when in children who receive antibiotics, chemotherapy or other drugs that could harm the kidneys or it could be used to track kidney disease progression in children with chronic kidney disease.
The new formula to estimate GFR uses demographic data, such as sex and height, and biochemical markers of kidney function such as creatinine, a waste product filtered by the kidneys, the protein cystatin C, which is removed by from the blood by the kidneys, and blood urea nitrogen, another waste product cleared from the blood by the kidneys, all of which can be easily measured in the clinic.
In a group of 168 children with chronic kidney disease, the new formula rendered results nearly as accurate as the more complicated and time-consuming standard tests to measure GFR, researchers report. The formula could be a valuable tool for pediatricians who care for children with chronic kidney disease.
“This new precise tool should help pediatricians accurately and easily gauge their patients’ kidney function and predict a patient’s ability to sustain any potentially dangerous treatments that could harm the kidneys,” says study investigator Susan Furth, M.D., Ph.D., a kidney specialist at Hopkins Children’s.
Lead author on the study: George Schwartz, M.D., University of Rochester Medical Center in Rochester, NY. Other investigators in the study: Alvaro Munoz, Ph.D., and Michale Schneider, M.S., of the Johns Hopkins Bloomberg School of Public Health; Robert Mak, M.D., Children’s Hospital of San Diego; Frederick Kaskel, M.D. Ph.D., Albert Einstein College of Medicine, Bronx, NY; Bradley Warady, M.D., Children’s Mercy Hospital, Kansas City, MO.