Urinary lithogen risk test: usefulness in the evaluation of renal lithiasis treatment using crystallization inhibitors (citrate and phytate).

OBJECTIVES: This paper presents the results of a test to globally determine the urinary risk factor of calcium stone formation in the evaluation of treatments using crystallization inhibitors, such as citrate and phytate.
METHODS: Three groups of active calcium oxalate stone-formers have been selected. The lithogen urinary risk was determined using a specially designed disposable test before any medical treatment. After evaluation group I did not receive any treatment, group II was treated with potassium citrate and group III with a phytate-rich dietary complement. When 15 days had elapsed, the test to evaluate the risk of urinary calcium stone formation was applied again to the three groups. The main lithogenic biochemical parameters of each tested urine were also determined before and after treatment.
RESULTS: An important number of calcium oxalate stone-formers with high urinary risk factor (positive test) became negative after medical treatment (52% of the citrate-treated patients and 50% of the phytate-treated patients), but only 7% of the untreated patients (1 patient) showed a decrease in their urinary risk factor for calcium stones (negative test) after 15 days had elapsed. When the treatment was not effective, in an important number of cases, the urine contained high levels of calcium or showed pH values greater than 6.5.
CONCLUSION: From the obtained results it can be concluded that the test is useful to evaluate the efficacy of a given renal lithiasis medical treatment, and also the efficacy of the treatment of calcium oxalate renal lithiasis using crystallization inhibitors, such as citrate and phytate, in an important number of cases.