[Determination of enzyme activities in urine of patients with calcium oxalate calculi].

The catalytic activity of lactate dehydrogenase, gamma-glutamyltransferase, alkaline phosphatase, alanine aminopeptidase and N-acetyl-beta-D-glucosaminidase has been measured in 24 h urines of patients with a calcium oxalate calculus (9 men, 11 women) and has been compared with those of a reference collective (11 men, 10 women). The diagnostic sensitivity and the diagnostic specificity have been calculated according to four different discrimination methods in which the diagnostic sensitivity lies between 65% and 100%, the diagnostic specificity between 72% and 100%. Within the reference group there was a correlation between the excretion of the three brush-border enzymes, whereas within the group of patients only a correlation between gamma-glutamyltransferase and N-acetyl-beta-D-glucosaminidase was observed. From this pathophysiological conclusions can be drawn.