Hyperuricosuric calcium oxalate nephrolithiasis

Abstract

Calcium stone formers with uric acid disorders may represent a significant metabolic subgroup of calcium stone disease. Study of patients has provided four kinds of evidence linking their hyperuricosuria to calcium stone formation and setting them apart from other calcium stone formers. The evidence includes an atypical natural history of stone disease, in vitro evidence for heterogeneous nucleation of calcium oxalate crystallization by seed crystals of sodium hydrogen urate or uric acid, a reduction by urate or uric acid of the inhibiting effect which urine normally has upon the aggregation of calcium oxalate crystals, and an apparently dramatic effect of allopurinol to reduce new stone formations. Taken altogether, the weight of evidence supports the existence of a distinct syndrome of hyperuricosuric calcium oxalate nephrolithiasis.