Abstract Book - 26th ESPU Congress, Joint Meeting with ICCS + SPU + AAP/SOU + AAPU + SFU

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S22-16 (P)
HIGHLY ELEVATED CYSTATIN C GFR IN PEDIATRIC MYELOMENINGOCELE
PATIENTS: DOES IT INDICATE NEPHROPATHY?
Zachary LISS1, Brian VANDERBRINK2, Pramod REDDY2, Eugene MINEVICH 2, Elizabeth JACKSON2, Curtis SHELDON2,
Marion SCHULTE2 and William DEFOOR2
1) Cincinnati Children's Hospital, Pediatric Urology, Cincinnati, USA - 2) Cincinnati Children's Hospital Medical Center,
Pediatric Urology, Cincinnati, USA
PURPOSE
Serum Cystatin C is becoming widely used to estimate Glomerular Filtration Rate (GFR) in complex pediatric urology
patients with neurogenic bladder. A highly elevated GFR has been suggested to indicate hyperfiltration injury to the
kidneys. It has been our practice to assess for proteinuria in this patient population. The purpose of this study is to
review the results of this practice to see if nephropathy is a concern with an elevated Cystatin C GFR.
MATERIAL AND METHODS
A retrospective cohort study was conducted of all MM patients with an available Cystatin C GFR at a single pediatric
institution between the ages of 2 and 12 years. Data abstracted included patient demographics, Cystatin C GFR, urine
protein data, and urine specific gravity. High GFR was defined as greater than 150 ml/min. Proteinuria was defined as
presence of greater than trace protein on urine dipstick or a quantitative urine protein to creatinine ratio exceeding
0.21. Patients were excluded if the urinalysis had a low specific gravity that could possibly cause a false negative for
proteinuria.
RESULTS
A total of 261 patients with MM were identified. Median age was 7 years. 54 patients (21%) had a Cystatin C GFR
greater than 150 ml/min. 18 had a specific gravity less than 1.010. Thus, 36 patients were included in the study
group. Of these patients, 30 (83%) had a negative urinalysis for protein and/or a negative quantitative protein to
creatinine ratio. Only 6 patients (17%) had evidence of proteinuria.
CONCLUSIONS
An elevated Cystatin C GFR (CGFR) is not uncommon in the myelomeningocele population. Our preliminary data shows
that the vast majority do not show evidence of proteinuria or hyperfiltration injury. Further evaluation is necessary to
assess if those patients with proteinuria or a dilute urinalysis have evidence for hypertension, upper tract deterioration,
and/or worsening bladder dynamics.