Checking kids and kidneys

            BALTIMORE - Early progression of chronic kidney disease in kids and teens is poorly understood, Newswise disclosed, but a research team led by Johns Hopkins University scientists has begun the largest ever study to learn more about this often stealthy killer. “There has never, to our knowledge, been a study designed to assess systematically changes in kidney function over time in with early kidney disease and to determine how these changes affect behavior, learning, heart disease risk, and growth,” says Dr. Susan Furth, nephrologist at the Johns Hopkins Children’s Center (JHCC), one of three principal investigators and lead author of a report in the Clinical Journal of the American Society of Nephrology. This National Institutes of Health-funded, 57 center study hopes to follow over four years 540 children 1-16 with mild to moderate kidney disease. JHCC is one of two coordinating sites, with the Children’s Hospital at the University of Missouri/Kansas City. Johns Hopkins Bloomberg School of Public Health is the data coordinating center.

Scientists will collect blood, urine, fingernail, and hair samples and monitor kidney function, height, weight, blood pressure, and heart disease by the use of echocardiograms. Periodic surveys are planned to track everything from quality of life and social and cognitive development to sexual maturation in puberty, which is often delayed in teens with kidney disease. Patients will fill out questionnaires detailing everything from symptoms, to use of medications and dietary supplements, to lifestyle and exercise. Researchers will harvest cell lines to study the genetic elements of kidney disease. Results will be reported incrementally, but some preliminary findings are in. For example, using data from the pilot study, researchers refined an existing method - used mostly in Europe - that measures glomerular filtration rate ( GFR ). GFR , which measures the kidneys’ filtering capacity, is the most precise indicator of kidney function and status. The new, improved method, which measures how fast the kidneys clear an injected contrast agent from the blood, promises to become the new gold standard for kidney function estimates in clinical trials and will help researchers refine existing GFR estimate formulas doctors use for children. The current methods for estimating GFR yield faulty results in children 25% of the time. Kidney disease in children tends to start and evolve silently. More than 37% of kidney transplant patients in 2001 were 20-44, and the majority of them likely developed the disease in childhood, researchers say. They estimate 650,000 Americans will develop end-stage renal disease by 2010, costing the health care system $28 billion a year.