Sign in →

Test Code LAB2111 Pyruvic Acid, Blood

Additional Codes

PYR

PYRUVATE

Useful For

Screening for possible disorders of mitochondrial metabolism, when used in conjunction with blood lactate collected at the same time, to determine the lactate-to-pyruvate ratio

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Specimen Type

Whole blood


Additional Testing Requirements


This test does not calculate the lactate:pyruvate ratio. To obtain this information, both this test and LACS1 / 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, see LACS1 / Lactate, Plasma.



Specimen Required


Call 800-533-1710 or 507-266-5700 to order special collection tube.

 

Patient Preparation: Fasting (at least 4 hours)

Supplies: Perchloric Acid-Pyruvate Tube (T012)

Container/Tube: Special collection tube containing 2.5 mL of 6% perchloric acid

Specimen Volume: Exactly 1 mL

Collection Instructions:

1. Special collection tube must be prechilled prior to collection.

2. Draw enough blood directly into syringe to add exactly 1 mL of blood to the prechilled special collection tube.

3. Taking care to not spill any of the preservative, cautiously remove the cap from the tube.

4. Immediately transfer blood, once drawn, to the prechilled, special collection tube, recap, and shake vigorously to mix.

Additional Information:

1. Check expiration date before using. Supplied collection tube expires 14 months after preparation.

2. If perchloric acid (preservative) spills, obtain a new, prechilled tube.


Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Whole blood Refrigerated 15 days PYRUVATE

Reference Values

0.08-0.16 mmol/L

 

NIH Unit

0.7-1.4 mg/dL

Day(s) Performed

Monday, Wednesday

CPT Code Information

84210

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PYR Pyruvic Acid, B 14121-8

 

Result ID Test Result Name Result LOINC Value
8657 Pyruvic Acid, B 14121-8
7729 Pyruvic Acid, B 2905-8

Interpretation

An elevated lactate-to-pyruvate (L:P) ratio may indicate inherited disorders of the respiratory chain complex, tricarboxylic acid cycle disorders and pyruvate carboxylase deficiency. Respiratory chain defects usually result in L:P ratios above 20.

 

A low L:P ratio (disproportionately elevated pyruvic acid) may indicate an inherited disorder of pyruvate metabolism. Defects of the pyruvate dehydrogenase complex result in L:P ratios below 10.

 

The L:P ratio is characteristically normal in other patients. An artifactually high ratio can be found if the patient is acutely ill.

 

Cerebrospinal fluid (CSF) L:P ratio may assist in evaluation of patients with neurologic dysfunction and normal blood L:P ratios. Blood and CSF specimens should be collected at the same time.

Method Description

Pyruvate, in the presence of excess nicotinamide adenine dinucleotide, hydrogen ions, and lactic dehydrogenase is reduced to lactate. The reaction is stoichiometric; the decrease in absorbance at 340 nm is directly proportional to the concentration of pyruvate.(Fleischer WR, Forman DT, Huckabee WE, Antonis A, Young K. Enzymatic methods for lactic and pyruvic acids. In: MacDonald RP, ed. Standard Methods of Clinical Chemistry. Vol 6. 1970:245-259; Huckabee WE. Relationships of pyruvate and lactate during anaerobic metabolism. I. Effects of infusion of pyruvate or glucose and of hyperventilation. J Clin Invest. 1958;37:244-254; Cowan T, Pasquali M. Laboratory investigations of inborn errors of metabolism. In: Sarafoglou K, Hoffman GF, Roth KS, eds. Pediatric Endocrinology and Inborn Errors of Metabolism. 2nd ed. McGraw-Hill; 2017:1139-1158)

Report Available

2 to 5 days

Specimen Retention Time

3 weeks

Reject Due To

Gross hemolysis OK
Gross lipemia OK

Method Name

Spectrophotometry (SP)

Secondary ID

8657