| Laboratory: | Clinical Biochemistry (SENDOUTS) |
| Test Name: |
PYRUVATE - (B)
Test Code:
PYR
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| Clinical Information: |
Part of Lactate/Pyruvate Ratio
Description: Pyruvic acid is an intermediate metabolite that plays an important role in linking carbohydrate and amino acid metabolism to the tricarboxylic acid cycle, the fatty acid beta-oxidation pathway, and the mitochondrial respiratory chain complex. This test does not calculate the lactate:pyruvate ratio. To obtain this information Lactate, Plasma must be ordered. The ratio can be calculated from the results obtained from these tests. A separate specimen must be obtained for lactate testing. Test Indications: Though isolated elevated pyruvate is not diagnostic of any inborn error of metabolism, analysis with lactate may suggest an inborn error of metabolism as some present with lactic acidosis and/or a high lactate-to-pyruvate (LP) ratio. The LP ratio is elevated in several, but not all, mitochondrial respiratory chain disorders. Determination of lactate, pyruvate, and LP ratio in cerebrospinal fluid is helpful in directing attention toward a possible mitochondrial disorder in cases with predominantly neurological dysfunction and normal blood lactate levels, though further confirmatory testing will be required to establish a diagnosis. An elevated LP ratio may indicate inherited disorders of the respiratory chain complex, tricarboxylic acid cycle disorders and pyruvate carboxylase deficiency. Respiratory chain defects usually result in LP ratios >20. A low LP ratio (disproportionately elevated pyruvic acid) may indicate an inherited disorder of pyruvate metabolism. Defects of the pyruvate dehydrogenase complex result in LP ratios <10. The LP ratio is characteristically normal in other patients. An artifactual high ratio can be found if the patient is acutely ill. Cerebrospinal fluid (CSF) LP ratio may assist in evaluation of patients with neurological dysfunction and normal blood LP ratios. Blood and CSF specimens should be collected at the same time Patient preparation instructions: Patient must be fasting at least 4 hours |
| Collection Devices: |
Preferred Device: Syringe
Device Comment: Special collection tube containing 2.5 mL of 6% perchloric acid (Supply T012 from Mayo Laboratory) available at HSC Laboratory MS5.
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| Specimen Required: |
Blood: 1.0 mL
Pediatric Blood: 1.0 mL
Collection Information: Prior arrangement must be made with HSC Clinical Chemistry MS5. Not routinely available. Contact Metabolic Laboratory at 787-1534 to make arrangements. · Chill special collection tube on ice. · Draw enough blood directly into syringe to add 1 mL of blood to the special collection tube (pre-chilled). Use of any anticoagulant is not acceptable. · (Note: Plasma lactate should also be drawn at the same time for in-house analysis so that a lactate/pyruvate ratio can later be determined.) · Immediately transfer EXACTLY 1 mL blood to the pre-chilled special collection tube and shake vigorously to mix. · Immediately transfer to HSC laboratory. Specimen Stability: Ambient: not acceptable Refrigerated: 15 days Frozen: not acceptable |
| Referral: |
Whole Blood: 1.0 mL
Pediatric Whole Blood: 1.0 mL
Shipping & Storage: Store and ship refrigerated temperature to Mayo Medical Laboratories. Ambient or frozen temperature NOT acceptable.
Testing Laboratory (MB): Mayo Clinic Laboratories Other comments: HSC lab to Call 800-533-1710 or 507-266-5700 to order special collection tube. |
| Requisition: | |
| Reference Values: |
See Mayo Clinic Laboratory for reference intervals (Test Code: PYR).
Method of Analysis: See Mayo Clinic Laboratory for the methodology. |
| Availability: |
Within 10 Days
Not routinely available. Contact Metabolic Laboratory at 787-1534 to make arrangements. Specimen will be collected by the laboratory.
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| See Also: | |
| More Information: |
*Prior arrangement must be made with HSC Clinical Chemistry MS5. Special collection tube containing perchloric acid must be obtained from Mayo Medical Laboratories. Store and ship refrigerated temperature to Mayo Medical Laboratories (UNIT CODE 8657). Ambient or frozen temperature NOT acceptable.
Additional information: http://www.mayomedicallaboratories.com/test-catalog/Overview/8657 |