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Porphyrins, Feces

Reporting Name

Porphyrins, F
Seattle Children's Hospital Note:

Clinical System Name: Miscellaneous Test

Useful For

Evaluation of patients who present with signs or symptoms suggestive of porphyria cutanea tarda, hereditary coproporphyria, variegate porphyria, congenital erythropoietic porphyria, erythropoietic protoporphyria, or X-linked dominant protoporphyria


Specimen Required


Container/Tube: Stool container (T291)

Specimen Volume: Entire collection (48, 72, or 96 hour). 24-Hour collection is adequate if the collection volume is approximately 100 g.

Collection Instructions:

1. Patient should be instructed to refrain from red meat and aspirin-containing medications for 3 days prior to, as well as during, specimen collection. Compliance should be indicated.

2. No barium, laxatives, or enemas may be used within 24 hours of starting the collection.

Additional Information:

1. Length of collection period is required.

2. Specimens smaller than 100 g may not provide interpretable results.

3. Include a list of medications the patient is currently taking.


Specimen Type

Fecal

Specimen Minimum Volume

10 g

Specimen Stability Information

Specimen Type Temperature Time
Fecal Frozen (preferred) 14 days
  Refrigerated  14 days

Day(s) and Time(s) Performed

Monday through Friday; 1 p.m.

Performing Laboratory

Mayo Medical Laboratories in Rochester

Method Name

High-Performance Liquid Chromatography (HPLC)

Porphyrins are quantified by fluorescence.

Method Description

The porphyrins are separated according to numbers of carboxyl units and isomer status. Analytic specificity is based on the combination of chromatographic behavior and the uniqueness of the porphyrins among substances in human specimens in terms of fluorescence spectra. Components quantified are 10 specific porphyrins of isomer series I and III, 4 groups of "isoporphyrins" (isomers other than of series I and III), and protoporphyrin.(Unpublished Mayo method)

Reference Values

UROPORPHYRIN I

<120 mcg/24 hours

 

UROPORPHYRIN III

<50 mcg/24 hours

 

HEPTACARBOXYL PORPHYRIN I

<40 mcg/24 hours

 

HEPTACARBOXYL PORPHYRIN III

<40 mcg/24 hours

 

ISOHEPTACARBOXYL PORPHYRINS

<30 mcg/24 hours

 

HEXACARBOXYL PORPHYRIN I

<10 mcg/24 hours

 

HEXACARBOXYL PORPHYRIN III

<10 mcg/24 hours

 

ISOHEXACARBOXYL PORPHYRINS

<10 mcg/24 hours

 

PENTACARBOXYL PORPHYRIN I

<20 mcg/24 hours

 

PENTACARBOXYL PORPHYRIN III

<20 mcg/24 hours

 

ISOPENTACARBOXYL PORPHYRINS

<80 mcg/24 hours

 

COPROPORPHYRIN I

<500 mcg/24 hours

 

COPROPORPHYRIN III

<400 mcg/24 hours

 

ISOCOPROPORPHYRIN

<200 mcg/24 hours

 

PROTOPORPHYRINS

<1,500 mcg/24 hours

 

COPROPORPHYRIN III/COPROPORPHYRIN I RATIO

<1:20

 

See The Heme Biosynthetic Pathway in Special Instructions.

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

84126

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FQPPS Porphyrins, F In Process

 

Result ID Test Result Name Result LOINC Value
W6 Total weight 30078-0
TM70 Collection Duration 13363-7
15517 Uroporphyrin I 26691-6
15518 Uroporphyrin III 33585-1
15519 Heptacarboxyl I 49900-4
15520 Heptacarboxyl III 49901-2
15521 Isoheptacarboxyl 23885-7
15522 Hexacarboxyl I 23874-1
15523 Hexacarboxyl III 23875-8
15524 Isohexacarboxyl 23886-5
15525 Pentacarboxyl I 33623-0
15526 Pentacarboxyl III 33624-8
15527 Isopentacarboxyl 23887-3
15528 Coproporphyrin I 23845-1
15529 Coproporphyrin III 23846-9
15530 Isocoproporphyrin 33625-5
15534 Protoporphyrin 2891-0
15545 CoproIII/CoproI ratio 33618-0
81652 Interpretation (FQPPS) 59462-2
35013 Reviewed By No LOINC Needed

Reject Due To

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

Specimen <10 grams

Testing Algorithm

The following algorithms are available in Special Instructions:

-Porphyria (Acute) Testing Algorithm

-Porphyria (Cutaneous) Testing Algorithm

Forms

New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.