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STONE COMPOSITION IN PEDIATRIC UROLITHIASIS: A PEDIATRIC STONE
CONSORTIUM ANALYSIS
Larisa KOVACEVIC
1
, Gina CAMBARERI
2
, Aaron P BAYNE
3
, Sean CORBETT
4
, George CHIANG
5
, Dana GIEL
6
, Hong LU
1
,
Cortney WOLFE-CHRISTENSEN
1
and Yegappan LAKSHMANAN
1
1) Children's Hospital of Michigan, Pediatric Urology, Detroit, USA - 2) Rady Children's Hospital, Pediatric Urology, San
Diego, USA - 3) Children's Hospital, Pediatric Urology, Portland, USA - 4) University of Virginia, Pediatric Urology,
Charlottesville, USA - 5) Rady's Children's Hospital, Pediatric Urology, San Diego, USA - 6) Le Bonheur Children's
Hospital, Pediatric Urology, Memphis, USA
PURPOSE
Scant data exists regarding stone composition in pediatric urolithiasis. We studied (1) the variation of stone composition
by age and gender, and (2) gender-related differences in urinary risk factors in relationship to stone composition.
MATERIAL AND METHODS
A retrospective multicenter review of 122 children with upper urinary tract calculi was performed, analyzing both stone
composition and urinary metabolic data.
RESULTS
The mean age was 12.87± 3.93 years, and 48.3% were males. Most stones were either pure calcium oxalate (CaOx)
(44%) or CaOx mixed (44%), without significant differences in age and gender for either stone type. Calcium phosphate
(CaP) was present in 85% of the CaOx mixed group. Among children with pure CaOx, there were significant differences
in urinary risk factors between males and females (Table). No significant differences were seen in the CaOx mixed
group. Abnormal urinary calcium excretion was found in 26% of children with pure CaOx and in 31% of CaOx mixed.
Urine Component Males (n=27) Females (n=27) p-value
Oxalate
(mg/1.73 m²/day) 37.81 ± 10.57 31.74 ± 11.90 0.05
Sodium
(mmol/kg/day) 3.41 ± 1.48 2.63 ± 1.00 0.02
Magnesium
(mg/kg/day) 2.09 ± 0.86 1.67 ± 0.79 0.06
Citrate
(mg/gm creatinine) 398.44 ± 286.24 547.46 ± 292.48 0.06
CONCLUSIONS
CaOx, alone or in combination with CaP, was the predominant component of pediatric stones across all ages, and both
genders. Approximately one third had hypercalciuria. In males with pure CaOx stones, higher urinary oxalate and
sodium and hypocitraturia indicate the need for dietary evaluation/modification.