Cystine Stones: A Single Tertiary Center Experience.

[cystinuria]

Abstract Objective : To analyze the epidemiological and clinical characteristics and therapeutic outcomes of patients with cystine stones and to compare them with the characteristics of patients with calcium oxalate stones . Patients and Methods : We identified 30 patients with cystine stones who were consulted in our department from January 1972 until December 2013 . These patients were matched and paired , based on age and gender , to 30 calcium oxalate stone formers who were diagnosed and treated in our department from January 2011 until December 2013 . Results : Cystine stones were significantly large in size (p <0 .001 ) and most of them were found in the kidney (p =0 .002 ). Patients with cystinuria had their first stone episode at an early age (p <0 .001 ) compared with patients with calcium oxalate stones . No significant differences were observed regarding the frequency and the severity of symptoms . Both groups had similar visits per year in outpatient clinics , emergency room admissions , and episodes of febrile urinary tract infections . Cystine stone formers had undergone significantly higher number of procedures for stone removal (p <0 .001 ). No statistical differences were found in the compliance rates between the groups . Patients with cystine stones had significantly higher serum creatinine levels (p =0 .005 ). Conclusions : Cystine stones present in an earlier age and have the likelihood to be large in size . Patients with cystine stones undergo a greater number of procedures , and they have a greater risk to develop chronic renal impairment .