URINARY N-ACETYL-^|^beta;-D-GLUCOSAMINIDASE ACTIVITY IN ACUTE PYELONEPHRITIS PATIENTS WITH SPINAL CORD INJURIES

Abstract

The urinary N-acetyl-beta-D-glucosaminidase (NAG) activities were determined in acute pyelonephritis patients with spinal cord injuries. The urinary NAG activity was significantly elevated in 23 of 31 cases (74%) compared with normal controls. Out of 7 acute pyelonephritis patients without spinal cord injuries, 4 patients (57%) showed significantly elevated urinary NAG activities. The urinary NAG activities were within normal range in 20 patients with acute simple cystitis and 11 patients with chronic complicated cystitis. Out of 6 patients with urethritis, only one case (17%) showed a significantly higher level of urinary NAG activity. Significantly higher levels in urinary NAG activities were observed in 6 of 9 patients (67%) with acute prostatitis and 5 of 9 patients (56%) with acute epididymitis. In patients with spinal cord injuries, having frequent urinary tract infections and complicated pathophysiological conditions, urinary NAG is one of the helpful laboratory findings for the diagnosis of acute pyelonephritis.

Diagnosis and localization of a complicated urinary tract infection in neurogenic bladder disease by tubular proteinuria and serum prostate specific antigen

“…9 ± 11,13 Using urinary enzymes have not been found to be useful in the diagnosis of upper tract infection in spinal cord injury patients. 12 In our patient group with neurogenic bladder disease, we found the urinary a1Mg to be a highly sensitive (96%) and speci®c (93%) marker of upper tract infection. Positive results can also be generated by other causes of tubular damage 9 ± 11,13 like renal failure, diabetes, nephrotoxic drugs (aminoglycosides, chemotherapy, contrast media), heavy metal intoxication, myeloproliferative diseases, and AIDS.…”

“…Renal enzymes (b-N-acetyl glucosaminidase) have not proven to be useful in the localization of a urinary tract infection in spinal cord injury patients. 12 We have been unable to ®nd any studies of tubular proteins in neurogenic bladder disease patients. Serum proteins with a molecular mass of less than 40 000 Da easily cross the glomerular membrane and are subsequently reabsorbed by the renal tubule so that only extreme low quantities are found in normal urine.…”

“…Acute pyelonephritis damages the proximal renal tubules, which causes leakage of tubular proteins 9 ± 11 and renal enzymes 12,13 into the urine. Renal enzymes (b-N-acetyl glucosaminidase) have not proven to be useful in the localization of a urinary tract infection in spinal cord injury patients.…”

Combined Use of Urinary α₁-Microglobulin and ^99mTc DMSA Scintigraphy in the Diagnosis and Follow-Up of Acute Pyelonephritis and Cystitis in Children

“…Urinary N-acetyl-β- D -glucosaminidase activity has been found useful in the diagnosis of APN in children but not in spinal cord injury patients [16, 17]. In contrast, urinary α 1 -MG had a high sensitivity and specificity in a prospective study in spinal cord-injured patients, which suggests a higher sensitivity of urinary α 1 -MG in comparison with urinary N-acetyl-β- D -glucosaminidase activity [18].…”

“…Abnormalities in concentrating capacity [12]and sodium potassium exchange (pseudohypoaldosteronism) [13]have been described but are not sensitive enough in focal interstitial lesions because other parts of the kidney may compensate. Markers of proximal tubular dysfunction may also be useful in the diagnosis of APN, which causes leakage of tubular proteins [14, 15]and renal enzymes [15, 16, 17]into the urine. Serum proteins with a molecular mass of <40,000 Da easily cross the glomerular membrane and are subsequently reabsorbed by the renal tubule so that only extremely low quantities are found in normal urine.…”