[Metabolic etiology of urinary calculi in children].

The analysed material includes 100 children with urolithiasis treated in the Pediatric Clinic of the National Research Institute of Mother and Child in Warsaw between 1976 and 1978. Patients' age was from 3 months to 18 years. The analysed group included 51 boys and 49 girls. Urinary tract infection was found in 54 cases, i.e. 57,4% of the analysed material. The most common bacterial strains were those producing urease. They were detected in 48 children i.e. 88,9% of cases with urinary tract infection. Mostly these were bacteria of Proteus group--sporadically Pseudomonas aeruginosa and Staphylococcus albus. In the analysed patients urinary tract obstruction was observed in 36 children, i.e. 36% of cases. In 77% of the analysed material, localization of concrements was in upper urinary tract in 19% in the ureters and in 4% in the lover urinary tract. While in adult patients the most common compound of urinary stones was calcium oxalate, in children the most common stone compounds were phosphates (found in 38 cases i.e. 58,4% of the analysed material). The second frequent compound was oxalate found in 20 cases (30,7%). Less frequent compounds were uric acid and cystine. Performed study allowed to establish the cause of urolithiasis in 93 out of 100 examined children. Metabolic reasons of urolithiasis were found in 26 cases, i.e. 26% of the analysed material. They were as follows: idiopathic hypercalciuria--12 cases, uric acid urolithiasis--8 cases, primary hyperoxaluria--3 cases, cystinuria--2 cases, and incomplete acidosis of distal renal tubuli--1 case. Urolithiasis of probably metabolic origin was detected in 13 children (13%). Other reasons of urolithiasis in children were: infection (31%), idiopathic urolithiasis (17%) and others (6%). In 7 cases the reason of urolithiasis was not established.