PROTEINURIA AND RENAL TUBULAR DAMAGE - URINARY N-ACETYL-BETA-D-GLUCOSAMINIDASE AND ISOENZYMES IN DISSIMILAR RENAL-DISEASE

Markers of renal tubular injury are difficult to interpret in patients with proteinura. The 24-hour urinary N-acetyl-beta-D-glucosaminidase (NAG) concentration was measured in 167 patients with dissimilar renal disease, function, and proteinuria. NAG isoenzymes were also separate d in 69 patients, using a modified fast protein liquid chromatography technique. The 'A2' isoenzyme predominated at all levels of renal func tion and in all diagnostic groups. Urinary NAG and proteinuria were we ll correlated at all levels of renal function, as was NAG 'A2' isoenzy me. Proteinuria and urinary NAG were similarly correlated in patients with different glomerulonephritides, hypertensive nephrosclerosis, and chronic pyelonephritis, but not in those with diabetic nephropathy.