CALCIUM-OXALATE NEPHROLITHIASIS - AN EASY WAY TO DETECT AN IMBALANCE BETWEEN PROMOTING AND INHIBITING FACTORS

Calcium oxalate stone formation depends on both urine oversaturation with calcium oxalate, which in turn depends mainly on oxalate excretion, and the excretion of inhibitors; the possibility that a ratio of these variables might differentiate [human] stone-formers from stone-free subjects was explored. From 20 control subjects and 53 idiopathic calcium oxalate stone-formers receiving a standard diet, the 24 h urine was studied. A further group of 2-h urine samples (from 0700-0900), collected after an overnight fast from 16 non-stone and 24 stone-forming persons on a normal diet, were examined. The ratio oxalate/citrate .times. acid mucopolysaccharides (Ox/Cit .times. AMP) seems capable of differentiating > 80% of stone-formers from non-stone-formers using both 24-h and 2-h urine collection.