When considering pyruvic acid testing, this is the preferred test. This test reports concentrations for lactate, pyruvate, and the L:P ratio on the same specimen.
This test is New York DOH approved.
- Patient Preparation
- Patient should be fasting and at complete rest. Patient should avoid any exercise of the arm or hand before or during collection. Draw the specimen without the use of a tourniquet or within three minutes of applying the tourniquet, but before releasing the tourniquet.
- Whole blood using either a syringe or green (sodium or lithium heparin), lavender (EDTA), or pink (K2EDTA).
- Specimen Preparation
- 1) Immediately after blood is drawn, add exactly 1 mL whole blood to a chilled pyruvate collection tube containing 2 mL 8 percent (w/v) perchloric acid (ARUP supply #16567) available online through eSupply using ARUP Connect™ or contact Client Services at (800) 522-2787.
2) Mix well for 30 seconds then place in an ice bath for 10 minutes.
3) Centrifuge for 10 minutes at 1500 x g.
4) Decant 2 mL supernatant to an ARUP Standard Transport Tube and freeze. (Min: 1 mL)
- Storage/Transport Temperature
- Unacceptable Conditions
- If less than 1 mL of blood is added to collection tube, pH of the supernatant will be too low for testing.
- Ambient: 8 hours; Refrigerated: 3 weeks; Frozen: 1 month
The blood lactate to pyruvate (L:P) ratio is used to distinguish between pyruvate dehydrogenase deficiency and other causes of congenital lactic acidosis. In conjunction with an elevated lactate, an L:P ratio greater than 30 suggests inherited disorders of the respiratory chain complex or tricarboxylic acid cycle disorders. In conjunction with an elevated lactate, an L:P ratio less than 25 suggests a defect in pyruvate metabolism. An artifactually high L:P ratio can be observed in acutely ill individuals. Abnormal concentrations of lactate, pyruvate, and the L:P ratio are not diagnostic for any single disorder and must be interpreted in the context of the individual's clinical presentation and other laboratory studies.
See Compliance Statement B: www.aruplab.com/CS
If addition to perchloric acid is delayed, lactate concentration of whole blood increases by approximately 30 percent after 30 minutes, 50 percent after 1 hour, and 75 percent after 2 hours at room temperature.
|Component Test Code*||Component Chart Name|
|2007938||Lactate to Pyruvate Ratio|
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
- Lactate Pyruvate Ratio
- LP Ratio
- Pyruvate (Pyruvic Acid)