The Leeds Teaching Hospitals NHS Trust

Porphyrins (faeces)

Analysis of porphyrin compounds in faeces. Second line investigation of all types of acute porphyria and all types of cutaneous porphyria. If an acute porphyria is suspected, it is essential to request a urine PBG. Urgent PBG analysis is available: urgency will depend upon the clinical condition of the patient and should be discussed with the National Acute Porphyria Service 029 2074 7747. Faecal porphyrin analysis is not available as an urgent test. Interpretation: Increased levels of faecal porphyrins may be seen in PCT, HCP, VP and protoporphyria. Ratio of Coproporphyrin isomers essential for diagnosis of HCP.

Tube Stool collection pot
ID Tests&Tubes0234
Additional Information PROTECT SAMPLES FROM LIGHT.
CLINICAL DETAILS ESSENTIAL to ensure the most appropriate investigations are carried out.

Please also send 2x 5mL EDTA blood samples (purple top) for blood porphyrin analysis and 10-20 mL early morning urine for urine porphyrin analysis (unless these have already been sent).

Further guidance on sample selection available at:
Turn Around Turnaround time stated by Cardiff porphyria service: 15 working days
Send to Blood Sciences LGI
(Test referred to: Cardiff porphyria service.)
Contact For further details please contact Leeds Pathology customer services:
Advice Full information on all referred tests can be found on the referred tests information database, EQMS reference BSF2REC17003.
Collection Con Instructions to lab: Sample stable in fridge for 1 day. For longer storage before dispatch, sample must be stored frozen. Note on telepath (specimen comment) whether sample was light-protected, if not, protect from light and state in the comment how long the sample was exposed to light for. Samples that have not been protected from light are ok to send to Cardiff if < 6h. Samples exposed to light for > 6h should not be sent.
Minimum volume: 5g faeces.
Ref. Range Notes Total faecal porphyrin <200 nmol/g dry weight
Interpretation will be provided with the report.
Telepath LGI superset LPORFR. SJUH superset JPORFR.