January 31, 1997

Pediatric Urology, Nephrology link to benefit patients

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Dr. John Brock III and his division, Pediatric Urology, are combining research and clinical efforts with the division of Pediatric Nephrology to benefit patients like six-year-old Kristen Pedigo

Pediatric Urology, Nephrology link to benefit patients

It's a marriage between two "unselfish" divisions.

The divisions of Pediatric Urology and Pediatric Nephrology at Vanderbilt University Medical Center have joined together to collaborate on research and clinical work. It is a collaboration that is unprecedented at other institutions, said Dr. John W. Brock III, associate professor of Urology and director of Pediatric Urology.

"What's so wonderful about our working together is that we're using our special expertises and adding them together to make something that's better than the individual parts."

The collaboration resulted in Brock's recent receipt of the Clinical Research Award in Pediatric Urology from the American Academy of Pediatrics.

"Our award was the result of the wonderful basic science work Pediatric Nephrology has done that we have taken to the clinical arena as a team to look at children with all types of congenital urologic problems," Brock said.

"The award was a result of the collaboration between Pediatric Nephrology and Pediatric Urology, specifically the work of Drs. Iekuni Ichikawa, professor of Pediatrics and director of Pediatric Nephrology, Valentina Kon, associate professor of Pediatrics, Tracy Hunley, fellow in Pediatric Nephrology, Mark C. Adams, associate professor of Urologic Surgery, and myself."

Also contributing to the study was Lisa A. Trusler, RN, clinical nurse specialist in Pediatric Urology.

"This is something that is new and different for here and for the Pediatric Urology world," Brock said.

The study leading to the award dealt with the importance of the Renal Angiotensin System (RAS) in progressive deterioration of renal function. The study, which involved 85 pediatric patients with various congenital urologic abnormalities, looked specifically at the Angiotensin Converting Enzyme (ACE) gene and how the deletion of this particular gene has been associated with myocardial infarction and cardiac hypertrophy.

The investigators looked at how the genetic variant is associated with prognosis in renal disorders, in particular children with congenital urologic abnormalities. A substantial number of these children go on to progressive renal deterioration, even when there is early corrective intervention.

The study found that the child's genotype, independent of other factors, modifies the likelihood of developing renal deterioration.

"This theory has been examined in patients with medical diseases in the kidneys such as diabetes and nephropathy," Brock said. "What had never been done before was to look at congenital urologic problems to see if there was a difference in the way those children genotyped; to see if there was a correlation between their prognosis and the specific genotype."

Brock said that ultimately the research might lead to identifying children with a poor genotype, then testing to see if ACE inhibitors might be utilized to improve these childrens' prognoses.

"We don't have enough information for that yet, but that would be our Holy Grail, if you will," Brock said. "It would be some way to predict if a child with posturethral valves or reflux is going to respond more poorly because they have a specific genotype.

"If we could take those patients and treat them with Angiotensin Converting Enzyme, we could perhaps modulate their response to obstruction and therefore improve their long-term prognosis. That's been shown to happen in adults with diabetic nephropathy, kidney disease and secondary diabetes," he said.

Brock said the research is only "the tip of the iceberg, the beginning of collaboration that has certainly never been done here or anywhere before.

"I'm not a molecular biologist of the sort that Drs. Kon and Ichikawa are," Brock said. "What I am is a clinician with an incredible patient population in which to look at things."

Approximately 4,500 children with a variety of urologic problems are seen in Brock's clinic each year.

Joining the faculty this summer will be Dr. John Pope, a graduate of Vanderbilt University School of Medicine and a former resident. Pope, who will have a joint appointment in pediatric urology and nephrology, is currently completing a pediatric urology fellowship at the University of Indiana and will return to VUMC this summer. He will spend three days a week in Ichikawa's lab and practice clinical medicine with Brock the remainder of the time.

"What's particularly interesting about this is that I don't know of any pediatric urologist who is going to have this type of opportunity. We're building on the collaboration we already have begun."

In addition, Brock's residents are rotating in Ichikawa's lab.

"I believe there will be some outstanding research coming out of this collaboration, and I am very excited about the future," Brock said.