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Mayo Test ID DOXA1 Oxalate Analysis, Hemodialysate


Specimen Required


Specimen Type: Dialysate fluid

Patient Preparation: Patient should avoid taking vitamin C supplements for 24 hours prior to dialysis

Supplies: Urine Tubes, 10 mL (T068)

Container/Tube: Plastic, 10-mL urine tube or a clean, plastic aliquot container with no metal cap or glued insert

Specimen Volume: 5 mL

Collection Instructions: Adjust the pH of the specimen to 2.5 to 3.0 with 6M Hydrochloric Acid

Additional Information: Nonacidified frozen hemodialysate delivered to the laboratory within 3 days from collection will be accepted and the following comment will be added to the result: In nonacidified hemodialysate stored frozen, oxalate values may increase spontaneously.


Useful For

Determining the amount of oxalate removed during a dialysis session

 

Individualizing the dialysis prescription of hyperoxaluric patients

Method Name

Enzymatic

Reporting Name

Oxalate, Dialysate Fluid

Specimen Type

Dialysate Fluid

Specimen Minimum Volume

2 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Dialysate Fluid Frozen 14 days

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Clinical Information

Oxalate is a dicarboxylic acid, an end product of glyoxalate and glycerate metabolism that is excreted in the urine where it is a common component of kidney stones (up to 85%). Hyperoxaluria can be either genetic (eg, primary hyperoxaluria) or acquired/secondary (eg, enteric hyperoxaluria), and can lead to nephrocalcinosis and renal failure. Monitoring the adequacy of oxalate removal during hemodialysis can be useful in the management of patients with hyperoxaluria and renal failure, particularly following transplantation.

Reference Values

Not applicable

Interpretation

An exponential decrease in oxalate signal is expected through dialysis procedure.

 

Signals below 2 mcM at any point during dialysis suggest that the plasma has been effectively cleared, although there can be rebound after dialysis ceases.

 

Total oxalate removed during a dialysis session can be estimated by multiplying the concentration of oxalate in the dialysate by the oxalate flow rate for each time period that the oxalate is measured.

Clinical Reference

1. Perinpam M, Enders FT, Mara KC, et al: Plasma oxalate in relation to eGFR in patients with primary hyperoxaluria, enteric hyperoxaluria and urinary stone disease. Clin Biochem 2017;50(18):1014-1019

2. Tang X, Voskoboev NV, Wannarka SL, et al: Oxalate quantification in hemodialysate to assess dialysis adequacy for primary hyperoxaluria. Am J Nephrol 2014;39(5):376-382

3. Marangella M, Petrarulo M, Mandolfo S, et al: Plasma profiles and dialysis kinetics of oxalate in patients receiving hemodialysis. Nephron 1992;60(1):74-80

4. Marangella M, Vitale C, Petrarulo M, et al: Bony content of oxalate in patients with primary hyperoxaluria or oxalosis-unrelated renal failure. Kidney Int 1995;48(1):182-187

Method Description

This is an enzymatic method based on the reduction of oxalate by oxalate oxidase. The reaction releases hydrogen peroxide, which in the presence of peroxidase reacts with a dye to give a colored end point that is measured using a BioTek EPOCH plate spectrophotometer at 590 nm.(Package insert: Trinity Biotech, Oxalate Kit, Jamestown, NY, V. 07/2016)

Day(s) Performed

Monday through Friday

Report Available

3 to 7 days

Specimen Retention Time

14 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Test Classification

This test has been modified from the manufacturer's instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the US Food and Drug Administration.

CPT Code Information

83945

LOINC Code Information

Test ID Test Order Name Order LOINC Value
DOXA1 Oxalate, Dialysate Fluid 47715-8

 

Result ID Test Result Name Result LOINC Value
DOXA1 Oxalate, Dialysate Fluid 47715-8