Pyruvate

Label Mnemonic:	PYRCF
Epic code:	LAB3942
Downtime form:	Doctor/Provider Orders - Pathology Core and Specialty Care Nursery

Commercial Mailout Laboratory
6240-8 RCP
356-8593

Specimen(s):

CSF

Collection Medium:

CSF collection kit

Minimum:

Preferred Minimum: 0.6 mL CSF from CSF tube #4
Absolute Minimum: 0.3 mL CSF from CSF tube #4

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