Phytate and L-methionine for preventing recurrence of infection renal stones

BACKGROUND: Urine acidification and inhibition of crystallization are strategies that can be employed to prevent recurrent infection stones and calcium phosphate stones. METHODS: A series of cases demonstrating the beneficial effects of treatment with phytate and L-methionine in preventing recurrent stones associated with urinary tract infections and brushite stones is presented. RESULTS: The treatment proved effective in the prevention of stones associated with various clinical conditions. We describe three cases of staghorn infection renal stone, three cases of recurrent renal infection stones, one case with recurrent brushite stones and one case of dystrophic tissue calcification. In this group, ages ranged from 26 to 77 years, and the M/F ratio was 4:4. In most cases the initial urinary pH was approximately 8-8.2. Stone composition was magnesium ammonium phosphate (struvite) in 4 cases, a mixture of struvite and apatite in other 2 cases, and brushite in 2 cases. Pathogens isolated in the urine cultures of patients with struvite containing stones included Proteus spp. in 3 cases, Escherichia coli in 2 cases, and Klebsiella pneumoniae in one case. A combination of phytate and L-methionine was administered in all cases. Urinary pH was monitored using a portable medical device. In the six cases with infection stones, treatment prevented stone recurrence or regrowth following surgical treatment. Recurrence of infection was also prevented and renal function stabilized or improved. Administration of phytate and L-methionine with frequent urinary pH monitoring was also effective in the case of recurrent brushite stone formation and in the prevention of extensive dystrophic calcifications of the prostatic bed following HoLEP for benign prostatic hyperplasia treatment. CONCLUSIONS: The findings of these case reports demonstrate that urinary acidification can be effectively achieved by oral administration of L-methionine in association with phytate in patients with chronic urinary tract infections who form urinary stones with the goal of preventing stone and infection recurrence and preserving renal function.