A semiautomated procedure for urinary D-glucaric acid using a centrifugal analyzer

Area of Science:

• Biochemistry
• Clinical Chemistry
• Analytical Chemistry

Background:

• D-glucaric acid is a biomarker for metabolic processes.
• The enzyme inhibition method is standard for its quantification.
• This method is a two-step procedure involving beta-glucuronidase inhibition.

Purpose of the Study:

• To adapt the enzyme inhibition method for D-glucaric acid quantification to a Cobas-Bio centrifugal analyzer.
• To evaluate the performance of the semiautomated method compared to the manual method.

Main Methods:

• Urine was boiled at acidic pH to form 1,4-glucarolactone, inhibiting beta-glucuronidase.
• Beta-glucuronidase inhibition was measured as an indirect indicator of D-glucaric acid.
• The second step was adapted for a Cobas-Bio centrifugal analyzer.

Main Results:

• The semiautomated method showed high correlation with the manual method (r = 0.976).
• Precision was comparable between the manual and semiautomated methods.
• Sample throughput increased from 8 to 20 samples per day.

Conclusions:

• The semiautomated enzyme inhibition method is a reliable and more efficient alternative for quantifying D-glucaric acid.
• This adaptation enhances the practicality of measuring D-glucaric acid in clinical settings.