[Medical treatment of cystinuria: evaluation of long-term results in 30 patients].
OBJECTIVE
Because urinary hyper-excretion of cystine is permanent in homozygous cystinuric patients, stone recurrence is frequent and may alter renal function. Identification of factors predictive of success of medical treatment (no further urological procedure required) is therefore needed to improve patient management.


METHODS
Thirty adult patients with homozygous cystinuria and urolithiasis were referred to the nephrology department of the Necker Hospital from 1963 to 1999, with a mean follow-up of medical therapy of 10.5 +/- 8.4 years. The basal treatment schedule was hyperdiuresis and alkalinization with thiol derivative (D-penicillamine or tiopronine) added when needed.


RESULTS
Overall incidence of urological procedures decreased from 0.33/pt-year in the pretherapeutic period to 0.15 on treatment (p < 0.01), a 55% reduction. Sixteen patients (53%) did not require any urological procedure during follow-up. The only significant difference between those patients and the other 14 in whom medical therapy failed was the daily urine volume (3.2 l/day in the former compared with 2.4 l/day in the latter, p < 0.001).


CONCLUSIONS
Regular medical therapy was able to stop stone disease activity in the long term in more than half of the patients. Sustained hyperdiuresis, with a daily urine volume > 3 liters, appears as a major factor of therapeutic success, even in patients treated with thiols.
Barbey
F
F
Département de Néphrologie, Hôpital Necker, Paris.
Joly
D
D
Rieu
P
P
N'Guessau
K
K
Daudon
M
M
Jungers
P
P
D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000704:Analysis of Variance; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D003555:Cystinuria / Q000150:complications / Q000503:physiopathology / Q000628:therapy*; D004231:Diuresis; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007669:Kidney Calculi / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010396:Penicillamine / Q000627:therapeutic use; D013439:Sulfhydryl Reagents / Q000627:therapeutic use
D015415:Biomarkers; D013439:Sulfhydryl Reagents; D003404:Creatinine; D010396:Penicillamine