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Test ID PLP Pyridoxal 5-Phosphate (PLP), Plasma

Useful For

Determining vitamin B6 status, including in persons who present with progressive nerve compression disorders, such as carpal tunnel and tarsal tunnel syndromes

 

Determining the overall success of a vitamin B6 supplementation program

 

Diagnosis and evaluation of hypophosphatasia

Method Name

Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS)

Reporting Name

Pyridoxal 5-Phosphate (PLP), P

Specimen Type

Plasma Heparin

Collection Container/Tube: Green top (sodium or lithium heparin)

Submission Container/Tube: Amber vial (T192)

Specimen Volume: 1 mL

Collection Instructions:

1. Fasting-overnight (12-14 hours) (infants-draw prior to next feeding).

2. Patient must not ingest vitamin supplements for 24 hours before the specimen is drawn.

3. Centrifuge at 4° C, then aliquot all plasma into amber vial to protect from light.

Forms: If not ordering electronically, complete, print, and send a General Request Form (T239) with the specimen (http://www.mayomedicallaboratories.com/it-mmfiles/general-request-form.pdf).

Specimen Minimum Volume

0.5 mL

Specimen Stability Information

Specimen Type Temperature Time
Plasma Heparin Refrigerated (preferred) 7 days
  Frozen  14 days

Clinical Information

Vitamin B6 is a complex of 6 vitamers: pyridoxal, pyridoxol, pyridoxamine, and their 5'-phosphate esters. Due to its role as a cofactor in a number of enzymatic reactions, pyridoxal phosphate (PLP) has been determined to be the biologically active form of vitamin B6.

 

Vitamin B6 deficiency is a potential cause of burning mouth syndrome and a possible potentiating factor for carpal tunnel and tarsal tunnel syndromes. Persons who present chronic, progressive nerve compression disorders may be deficient in vitamin B6 and should be evaluated. Vitamin B6 deficiency is associated with symptoms of scaling of the skin, severe gingivitis, irritability, weakness, depression, dizziness, peripheral neuropathy, and seizures. In the pediatric population, deficiencies have been characterized by diarrhea, anemia, and seizures.

 

Markedly elevated PLP in conjunction with low levels of pyridoxic acid are observed in cases of hypophosphatasia, a disorder characterized by low levels of alkaline phosphatase and a range of skeletal abnormalities.

Reference Values

5-50 mcg/L

Cautions

Reference ranges were established using healthy fasting volunteers who abstained from vitamin supplementation for 24 hour prior to draw. Vitamin supplementation and non-fasting may result in elevated plasma vitamin concentrations.

Day(s) Performed

Monday through Friday

Report Available

1 day

Performing Laboratory

Mayo Medical Laboratories in New England

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information

84207

NY State Approved

Yes