Bestimmung von Enzymaktivitäten in Urinen von Calciumoxalatstein-Patienten

Abstract

Zusammenfassung: Die katalytischen Aktivitäten von Lactatdehydrogenase, -Glutamyltransferase, alkalischer Phosphatase, Alaninaminopeptidase und N-Acetyl-ß-/)-glucosaminidase wurden im 24-Stunden-Urin von Calciumoxalatstein-Patienten (9 Männer, 11 Frauen) gemessen und mit denen von einem Normalkollektiv (11 Männer, 10 Frauen) verglichen. Die diagnostische Sensitivität und die diagnostische Spezifität wurden nach vier verschiedenen Diskriminationsverfahren berechnet, wobei die Sensitivität zwischen 65%-l 00% lag, die Spezifität zwischen 72%-l00%.Beim Normalkollektiv war eine deutliche Korrelation in der Ausscheidung der drei Bürstensaumenzyme vorhanden, während bei den Calciumoxalatstein-Patienten nur eine Korrelation zwischen -Glutamyltransferase-und N-Acetyl-ß-/)-glucosaminidase-Exkretion nachzuweisen war. Hieraus lassen sich pathologische Schlüsse ziehen. Determination of catalytic activities in urines ofpatients with calcium urolithiasis Summary:The catalytic activity of lactate dehydrogenase, -glutamyltransferase, alkaline phosphatase, alanine aminopeptidäse and N-acetyl-ß-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 -glutamyltransferase and N-acetyl-ß-Dglucosanünidase was observed. From this pathophysiological conclusions can be drawn.

Urinary NAG in children with urolithiasis, nephrocalcinosis, or risk of urolithiasis

“…There is more information on tubular enzymuria in adults with urinary stone disease [16,17,18,19,20]. All of these reports showed an elevated activity of NAG or other tubular enzymes in active stone formers, which is in accordance with our results.…”

“…All of these reports showed an elevated activity of NAG or other tubular enzymes in active stone formers, which is in accordance with our results. Such elevated excretions were hypothesized to be a sign of a primary tubular defect or a secondary phenomenon [16,17]. In contrast, Jaeger et al [18] concluded that tubulopathy in UL is rather a consequence than a cause of the disease, because tubular defects in their studies were not specific with regard to the type of stones or the coexisting metabolic disturbances.…”