A simple urine test used widely to screen for kidney problems also appears to be a handy gauge of kidney function and disease progression in children with chronic kidney disease, according to results of research at the Johns Hopkins Children’s Center and several other institutions.
Researchers studied 92 children with mild to moderate kidney disease and found that increases in the amount of protein in the urine (proteinuria) corresponded directly to loss of kidney function. The relationship between proteinuria and loss of kidney function is well-established in adults, but had not been studied in children, particularly in those born with kidney disease.
“These results are quite encouraging because this test is fast, cheap and simple and is a really handy tool to help us track disease progression in children with kidney disease,” says Susan Furth, M.D., Ph.D., of the Johns Hopkins Children’s Center.
The current standard for tracking kidney function is GFR (glomerular filtration rate), a test conducted by injecting a contrast agent into the bloodstream and measuring how fast the kidneys remove it. By using both GFR and the urine tests, Furth and colleagues showed that, as proteinuria increased, GFR proportionately decreased.
“Now that we know that the urine tests accurately parallel what’s going on with kidney function, we’ll take the next step, which is to learn just how good the test is,” Furth says. “The hope is that eventually, we will be able to say with precision that ‘X’ amount of protein in the urine corresponds to a risk of ‘Y’ amount of kidney function loss.”
