Pyruvate
Label Mnemonic: PYRCF
Epic Lab Code: LAB3942
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
CSF
Collection Medium:
CSF collection kit
Minimum:
Preferred Minimum: 0.6 mL CSF from CSF tube #2
Absolute Minimum: 0.3 mL CSF from CSF tube #2
Turn Around Time:
6-8 days upon receipt at reference laboratory
Reference Range:
0.06-0.19 mmol/L
Interpretive Data:
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 >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 <10.

The L:P ratio is characteristically normal in other patients. An artifactually high ratio can be found if the patient is acutely ill.
Comments:
Cautions:
Correct specimen collection and handling is crucial to achieve reliable results.

Pyruvic acid levels alone have little clinical utility. Abnormal concentrations of pyruvic acid, and lactate-to-pyruvate (L:P) ratios, are not diagnostic for a particular disorder but must be interpreted in the context of the patient's clinical presentation and other laboratory studies.

For the L:P ratio, both analytes should be determined on the same specimen.

When comparing blood and cerebrospinal fluid (CSF) L:P ratios, blood and CSF specimens should be collected at the same time.
Test Limitations:
The CSF L:P ratio is considered a helpful (not diagnostic) tool in the evaluation of patients with possible disorders of mitochondrial metabolism, especially in patients with neurologic dysfunction and normal blood L:P ratios. Pyruvic acid levels alone have little clinical utility.
Methodology:
Spectrophotometry (SP)
CPT Code:
84210
 
See also:
Pyruvic Acid, Blood