Porphyrins (urine)
The acute porphyrias include AIP, HCP, VP and may present with the following symptoms: abdominal pain, psychiatric disorders, peripheral neuropathy. 75% of attacks are precipiated 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 assesment: urine, faeces and blood should be analysed.
| Tube | 08 (UR) - Urine |
|---|---|
| ID | Tests&Tubes0235 |
| Additional Information | PROTECT SAMPLES FROM LIGHT. CLINICAL DETAILS ESSENTIAL to ensure the most appropriate investigations are carried out. If acute porphyria is suspected, collect samples when 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 available at: https://cavuhb.nhs.wales/our-services/laboratory-medicine/medical-biochemistry-and-immunology/porphyria-service-cardiff/sample-advice |
| 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: leedsth-tr.pathologycustomerservice@nhs.net. |
| 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 |
| Telepath | LGI superset LPORUR. SJUH superset JPORUR. |
