The importance of urinary enzymes in diagnostic of tubular damage caused by proteinuria

Proteinuria causes damage to proximal tubular cells. To investigate the influence of different levels of glomerular proteinuria, we examined 50 patients (24 male and 26 female). Their creatinine clearance (Ccr) was higher than 50 mL/min (87,29"31,17 mL/min). According to the proteinuria range level patients were separated in three groups. The first group, with proteinuria less than 0,3 g/24h, included 19 persons (7 man and 12 woman), mean age 45,12"13,28 years and mean Ccr 94,27"34,70 mL/min. Proteinuria 0,3’3,0 g/24h is the second group characteristic. This group included 18 patients (8 male and 10 female) mean age 45,39"12,64 years, with mean 90,07"31,89 mL/min. Patients with proteinuria higher than 3,0 g/24h were members of third group. Mean age 50,08"13,73 years and mean Ccr 73,25"20,44 mL/min are caracteristics of 13 members (9 male and 4 female) of the third group. Enzymes alkaline phosphatase (AP), g-glutamil transpherase (gGT) and Nacetyl- b-D-glucosaminidase (b-NAG) were used as parameters of tubular damage. Gama-glutamil transpherase is more sensitive parameter of tubular damage then alkaline phosphatase. N-acetyl-b-D-glucosaminidase is the most sensitive parameter of tubular damage due to proteinuria.