The acute porphyrias include AIP, HCP, VP and may present with the following symptoms: abdominal pain, psychiatric disorders, peripheral neuropathy. 75% of attacks are precipitated by either drugs (including oral contraceptives) or alcohol. With the exception of AIP, all the above can be associated with dermatological problems. Lab screen for AIP: measure urine PBG. If negative, provided sample has been collected during an acute attack, AIP is unlikely, though not impossible. Clinical indication for request: all types of acute porphyria and all types of cutaneous porphyria. Patients who present with dermatological involvement require full assessment: urine, faeces and blood should be analysed.
Tube
08 (UR) – Urine
ID
Tests&Tubes0235
Additional Information
Protect samples from light.
Clinical details are essential to ensure the most appropriate investigations are carried out.
If acute porphyria is suspected, collect samples when the patient is symptomatic, contact Duty Biochemist (0113 39 26922 option 2) or National Acute Porphyria Service (029 2074 7747) for advice if required.
If urgent analysis is required please contact the duty biochemist (26922 Opt 2) or on-call duty consultant (via switchboard). Measurement of urinary PBG alone is used as the screening for acute porphyria (test may be unreliable if creatinine < 4 mmol/L).
If cutaneous porphyria suspected please also send 2x 5mL EDTA blood samples (purple top) for blood porphyrin analysis.
Further guidance on sample selection is available at the Cardiff and Vale University Health Board.
Turn Around
Turnaround time stated by Cardiff porphyria service: 10 working days.
Send to
Blood Sciences LGI
(Test referred to: Cardiff porphyria service).
Contact
For further details please contact Leeds Pathology customer services: [email protected].
Advice
Full information on all referred tests can be found on the referred tests information database, EQMS reference BSF2REC17003.
Collection Con
Instructions to lab: store in fridge until dispatch. Note on telepath (specimen comment) whether sample was light-protected, and if not, how long the sample was exposed to light. 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:10 mL urine
Sample REQ
Urine.
Ref. Range Notes
Total urine porphyrin < 40 nmol/mmol creat
Porphobilinogen < 1.5 umol/mmol creat
Adult ALA <3.8 umol/L/mmol creat
Child ALA <5.2 umol/L/mmol crea