Does hyperuricosuria play a role in calcium oxalate lithiasis?

This review evaluates the epidemiologic, clinical and experimental evidence for an etiological link between urinary uric acid and the propensity to develop calcium oxalate calculi. While epidemiologic and laboratory studies provide only equivocal support for a synergistic relationship, several clinical trials with allopurinol have demonstrated a reduction in calculus recurrence. These beneficial effects are observed only when allopurinol is given to subjects with calcium oxalate calculi who have isolated hyperuricosuria. The specificity of this effect suggests that there is an important interaction between uric acid and calcium oxalate but the mechanism(s) remain to be elucidated.