1. ESTIMATION OF SELECTED MACROMOLECULES IN URINE OF CHILDREN WITH IDIOPATHIC HYPERCALCIURIA
Katarzyna Jobs, Anna Jung
Military Institute of Medicine, Pediatric Nephrology Department
Warsaw, Poland

2. Idiopathic hypercalciuria is the most frequent metabolic disorder leading to stones formation in urinary tract both in adults and children . But to form a stone specific imbalance between crystallization promoters and inhibitors is necessary.
Kidney stones are biominerals. Some macromolecules may play crucial role in the process.
The aim of the study was estimation of the level of osteopontin, calgranulin, bikunin and uromodulin in urine of patients with idiopathic hypercalciuria and in healthy control group. We tried to compare the activity of stone forming with macromolecules level.
Material: 57 children with idiopathic hypercalciuria aged 1-18 y. and 33 age matched control group
Methods: ELISA estimation of osteopontin, calgranulin, bikunin and uromodulin in fresh morning urine of examined children.

3. Statistical significance-p
Pts with hypercalciuria- mean value
Control group- mean value
Statistical significance-p
Osteopontnin
2058,660
3590,200
0,0005
Calgranulin
268,802
120,145
0,0651
Uromodulin
13,516
12,190
0,3869
Bikunin
23,106
16,478
0,0128
Results: we found significant difference in osteopontin level between hypercalciuric children and control group (2058,66 vs 3590,2 ng/ml, p<0,05) and in bikunin level (23,106 vs 16,47 ng/ml, p<0,05); no statistically significant difference between groups as regards calgranulin (however there is a trend : 268,8 vs 120,14 pg/ml, p=0,065) and uromodulin were found.
We found also statistically significant correlation between disease activity and osteopontin level (p 0,046)
Conclusion: it is possible that children with idiopathic hypercalciuria have lower level of osteopontin and higher level of bikunin in urine in comparison to healthy children and that osteopontin level distinguishes subgroup of children with idiopathic hypercalciuria with potential greater ability of stones formation. The result needs further investigations.