Crystalluria in normal subjects and in stone formers with and without thiazide and cellulose phosphate treatment.

Quantitative and qualitative studies have been made of the urinary crystals from a series of normal subjects and from stone formers with idiopathic hypercalciuria with and without treatment with thiazide diuretics and/or cellulose phosphate. The results obtained from mid-morning unprepared subjects seemed more helpful than those obtained following overnight collections or after a dry breakfast. Crystalluria was more common in stone formers than in normal subjects, but was seen in both groups. The most striking difference between these 2 groups was the almost complete absence of aggregation of oxalate crystals in the normal subjects. Cellulose phosphate greatly reduced phosphate crystals but resulted in a large increase in small oxalate crystals but without change in the incidence of aggregation of oxalate crystals. Thiazides also reduced occurrence of phosphate crystals but only gave a very small increase in oxalate crystals and also without change in aggregation of oxalate crystals.