N-acetyl-beta-D-glucosaminidase in the localisation of urinary tract infection in patients with spinal cord injury

Urinary N-acetyl-beta-D-glucosaminidase concentration in patients with spinal cord injury: relationship with urodynamic parameters

OBJECTIVES

To investigate the relationships between urinary N-acetyl-beta-D-glucosaminidase (NAG) concentrations and urodynamic parameters in patients with spinal cord injury (SCI). NAG has been proposed as a marker of renal damage.

METHODS

Twenty-three patients with SCI were evaluated with urodynamic studies. Urine samples were collected from the 23 patients and 10 healthy volunteers, the NAG levels were evaluated, and the urodynamic parameters were compared with the urinary NAG levels. The patients were divided into two groups according to the amplitude of the hyperreflexic detrusor contractions (HDCs): group A, patients with an HDC amplitude of 40 cm H(2)O or greater, and group B, patients with an HDC amplitude of less than 40 cm H(2)O; group C was composed of healthy volunteers. The urinary NAG concentrations in the three groups were compared.

RESULTS

A positive correlation was found between the urinary NAG levels and the HDC amplitude and detrusor leak point pressure (P = 0.015 and 0.007, respectively). The urinary NAG concentration was 3.38 U/g in group A, 2.14 U/g in group B, and 2.12 U/g in group C. The differences in the urinary NAG concentrations between groups A and B and between groups A and C were statistically significant (P = 0.03 and P <0.001, respectively). The concentrations between groups B and C were comparable.

CONCLUSIONS

In our experience, the only urodynamic parameters that clearly and positively correlated with the urinary NAG levels were those expressing the amplitude of intravesical pressure. This result stresses the importance of reducing the intravesical pressure in patients with SCI using alternative treatments or surgical procedures if the usual conservative therapies are not effective.

Analytical biochemistry and clinical significance of N-acetyl-beta-D-glucosaminidase and related enzymes

Human N-acetyl-beta-D-glucosaminidase, N-acetyl-alpha-D-glucosaminidase, endo-beta-N-acetylglucosaminidase, hexosaminidase, beta-N-acetylgalactosaminidase and glucocerebrosidase have not been so widely studied as the beta-N-acetylhexosaminidases in bacteria, fungi and arthropods. Their biochemical role has been elucidated, however, and their urinary and plasma determination is being adopted for the early detection of diseases before clinical manifestation, in particular for hypertension, renal injuries and disorders, depression and lysosomal storage diseases. The spectrophotometric determinations of N-acetyl-beta-D-glucosaminidase, most often done with 3-cresolsulphone phthaleinyl N-acetyl-beta-D-glucosaminide, have been recently simplified and adapted to automatic instruments.

Relapsing significant bacteriuria: effect on urinary tract infection in patients with spinal cord injury

OBJECTIVE

To evaluate whether there is a relation between relapsing significant asymptomatic bacteriuria (ASB) and symptomatic urinary tract infection (UTI), and to determine the frequency rate of UTI in patients with spinal cord injury (SCI) using indwelling catheters (IC).

DESIGN

Cohort study. Patients were followed up for 24 to 270 days (mean, 66.3 +/- 42.2).

SETTING

A department of physical therapy and rehabilitation in a research hospital of a university referral center.

PATIENTS

Fifty patients with SCI using IC. Patients with severe concurrent illness, known vesicouretheral reflux, urinary calculi, and severely disturbed renal function were excluded.

MAIN OUTCOME MEASURE

Symptomatic UTI, relapsing ASB, and recurrent significant ASB.

RESULTS

There was significant difference between relapsing ASB and recurrent ASB with regard to occurring symptomatic UTI (chi 2, 4.92; p < .03). Symptomatic UTI was observed at a rate of 9.35, relapsing ASB 35.59, and recurrent ASB 55.80 per 1,000 patient-days.

CONCLUSION

Relapsing ASB is an important factor in the development of symptomatic UTI.