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Test Code PLP Pyridoxal 5-Phosphate, Plasma

Additional Codes

CNE Order Code: Pyrid5Phos

Useful For

Determining the concentration of pyridoxal 5-phosphate in the assessment of vitamin B6 status

Method Name

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

Reporting Name

Pyridoxal 5-Phosphate (PLP), P

Specimen Type

Plasma Heparin


Shipping Instructions


Ship specimen in amber vial to protect from light.



Specimen Required


Patient Preparation:

1. Patient should fast overnight (12-14 hours); infants-should have specimen collected before next feeding. Water can be taken as needed.

2. For 24 hours before specimen collection, patient must not take multivitamins or vitamin supplements.

Supplies: Amber Frosted Tube, 5 mL (T915)

Collection Container/Tube: Green top (sodium or lithium heparin) or plasma gel separator (PST)

Submission Container/Tube: Amber vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge at 4° C within 2 hours of collection.

2. Aliquot all plasma into amber vial and freeze immediately.


Specimen Minimum Volume

0.75 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Heparin Frozen 29 days LIGHT PROTECTED

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

5-50 mcg/L

Interpretation

Levels for fasting individuals falling in the range of 3 to 30 mcg/L for pyridoxic acid (PA) and 5 to 50 mcg/L for pyridoxal 5-phosphate (PLP) are indicative of adequate nutrition.

 

The following are interpretative guidelines based upon PLP and PA results:

If PLP is >100 mcg/L and PA is ≤30 mcg/L:

-The increased pyridoxal 5-phosphate is suggestive of hypophosphatasia. Consider analysis of serum alkaline phosphatase isoenzymes (ALKI / Alkaline Phosphatase, Total and Isoenzymes, Serum) and urinary phosphoethanolamine (AAPD / Amino Acids, Quantitative, Random, Urine).

 

If PLP is >100 mcg/L and PA is 31 to 100 mcg/L or PLP is 81 to 100 mcg/L and PA is < or=30 mcg/L:

-The increased pyridoxal 5-phosphate is likely related to dietary supplementation; however, a mild expression of hypophosphatasia cannot be excluded. Consider analysis of serum alkaline phosphatase isoenzymes (ALKI / Alkaline Phosphatase, Total and Isoenzymes, Serum) and urinary phosphoethanolamine (AAPD / Amino Acids, Quantitative, Random, Urine).

 

If PLP is 51 to 80 mcg/L or PLP is 81 to 100 mcg/L and PA is >30 mcg/L; or PLP is >100 mcg/L and PA is >100 mcg/L:

-The elevated pyridoxal 5-phosphate is likely due to dietary supplementation.

Day(s) Performed

Monday through Thursday, Saturday, Sunday

Report Available

1 to 7 days

Performing Laboratory

Mayo Clinic Laboratories in Rochester

CPT Code Information

84207

LOINC Code Information

Test ID Test Order Name Order LOINC Value
PLP Pyridoxal 5-Phosphate (PLP), P 30552-4

 

Result ID Test Result Name Result LOINC Value
4047 Pyridoxal 5-Phosphate (PLP), P 30552-4

Forms

If not ordering electronically, complete, print, and send a General Request (T239) with the specimen.