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Order Code PTP Porphyrins, Total, Plasma

Additional Codes

Mayo Test ID:  PTP

Reporting Name

Porphyrins, Total, P

Useful For

Monitoring treatment of patients with porphyria cutanea tarda

Specimen Type

Plasma


Shipping Instructions


Ship specimen in amber vial to protect from light.



Necessary Information


Include a list of medications the patient is currently taking.



Specimen Required


Patient Preparation: Patient must not consume any alcohol for 24 hours before specimen collection.

Supplies: Amber Frosted Tube, 5 mL (T915)

Collection Container/Tube:

Preferred: Green top (sodium or lithium heparin)

Acceptable: Lavender top (EDTA)

Submission Container/Tube: Amber vial

Specimen Volume: 3 mL

Collection Instructions:

1. Centrifuge specimen and aliquot plasma into amber vial.

2. Send plasma frozen.


Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type Temperature Time Special Container
Plasma Frozen 14 days LIGHT PROTECTED

Reject Due To

Gross hemolysis OK
Gross lipemia OK
Gross icterus OK

Reference Values

≤1.0 mcg/dL

Performing Laboratory

Mayo Clinic Laboratories in Rochester

Day(s) Performed

Monday through Friday

Method Name

PTP: Extraction and Scanning Spectrofluorometry

PFP: High-Performance Liquid Chromatography (HPLC)

CPT Code Information

84311-Porphyrins, total

82542-Porphyrins, fractionation (if appropriate)

Reflex Tests

Test ID Reporting Name Available Separately Always Performed
PFP Porphyrins, Fractionation, P No No

Testing Algorithm

If total porphyrins are above 1.0 mcg/dL, then porphyrin fractionation will be performed at an additional charge.

 

The following algorithms are available:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Genetics Test Information

Plasma specimens from patients with active porphyria cutanea tarda, congenital erythropoietic porphyria, and erythropoietic protoporphyria may exhibit increased plasma porphyrin levels. However, a definitive diagnosis cannot be made by plasma analysis alone.

Method Description

The plasma porphyrins profile is performed as a 2-step analysis. First, the total plasma porphyrins concentration is determined by extracting the porphyrins from plasma with a mixture of ethyl acetate and acetic acid. The porphyrins are then back extracted into dilute hydrochloric acid. Total porphyrins are quantified on this extract via scanning spectrofluorometry. If the total plasma porphyrin concentration is elevated, the extract is submitted for high-performance liquid chromatography analysis, whereby the individual porphyrin analytes are separated by differential partitioning between a stationary aliphatic surface and a moving aqueous buffer solution. As the porphyrins emerge separately from the column, the quantity of each is monitored with a fluorescence detector.(Unpublished Mayo method)