[Cystine-lysinuric lithiasis].

Cistin-lisinuria is not a unfrequent etiology of lithiasis in children. Six patients have been studied as well as their families, being a total of 45 patients. Lithiasis was present in ten of our patients, and hyperaminoaciduria, without lithiasis in ten, affecting in both cases (with or without litiasis) either all the four amynoacide (cystine, lysine, arginine and ornithine) or only one or two of them. Authors have not found any correlation between clearance of cystine and the presence or absence of lithiasis; on the other hand the best index to correlate the presence of lithiasis is to reach a value, equal or superior to 300 mgr of cystine excreted in the urine per 1 gr of creatinine excreted in urine. The correct treatment in cystinuric patients with lithiasis is to alcalize the urine maintaining a constant urinary pH between 7-8, giving a sufficient dose of sodium bicarbonate per os. In case of resistance to this treatment or if a great calculi is present, D-penicillamine would be an efficient treatment to disolve the calculi. These treatment when carried out under analytical control presents no problems or complications in their experience.