[Serum cystatin C concentration in children with urinary stones].
Stone formation precedes long period, when the crystals are accumulated in basement membranes of renal tubules and intestinal tissue. Accumulated, inside of renal tubules crystals and stones in urinary tract cause urinary tract obstruction, what may lead to impairment of renal function. The aim of work was the assessment of serum cystatin C (cys C) concentration in children with urolithiasis, confirmed by the presence of renal stones in renal pelvis in comparison to serum creatinine concentration and creatinine clearance (Cr cl).


METHODS
Examined group (B) consisted of 30 children aged (13.08 +/- 4.14 years) with urolithiasis, which was divided into 3 subgroups (I, II, Ill) in dependence on stones' diameter (0.35-1.6cm). Control group (C) consisted of 26 healthy children at the same age. Nephelometric method was used to determine serum cystatin C level, Jaffe method to assess serum creatinine and the Schwartz formula to estimate glomerular filtration rate.


RESULTS
In control group (C) serum cys C did not exceed 0.95 mg/l. In group B serum cystatin C and serum creatinine concentration and Cr cl was similar to the results of control group (p > 0.05). However in 16% of children with urolithiasis, in whom the stones of 0.8-1.6cm diameter were found in both renal pelvis, the concentration of serum cys C exceed 1.2 mg/l, and the value differed significantly from the results of control group (p < 0.05). A weak positive correlation between cys C and creatinine concentration and also between cys C and Cr cl was found. The serum cys C concentration in children with single stones of 0.35-0.8 diameter was normal.


CONCLUSIONS
Serum cystatin C increases with increased degrees of urolithiasis assessed by stone size and their number in kidney.
Zoch-Zwierz
Walentyna
W
Akademia Medyczna w Białymstoku, I Klinika Chorób Dzieci SP DSK. iklinped@amb.edu.pl
Hackiewicz
Lech
L
Porowski
Tadeusz
T
Wasilewska
Anna
A
Jadeszko
Iwona
I
D000293:Adolescent; D055316:Cystatin C; D015891:Cystatins / Q000097:blood*; D005260:Female; D006801:Humans; D008297:Male; D012720:Severity of Illness Index; D014545:Urinary Calculi / Q000097:blood* / Q000503:physiopathology
C525030:CST3 protein, human; D055316:Cystatin C; D015891:Cystatins