| Consultant Chemical Pathologist: |
Dr Vivion Crowley
Email: [email protected]
Tel: -353-1-4162935
|
| Porphyrin Laboratory: |
Ms Cindy Darby
Email: [email protected]
Tel: -353-1-4162058
|
The laboratory provides a clinical advisory and comprehensive analytical service for the Republic of Ireland. Intermediates of haem biosynthesis are measured in urine, faeces, plasma & whole blood using ion-exchange chromatography, fluorimetry, haematofluorimetry, plasma emission scanning and HPLC with fluorescent detection. Pre and post analytical advice is available and fully interpreted reports are issued to referring clinicians. Family screening is available and follow-up of diagnosed cases is by appropriate test selection. Copies of drug lists considered safe in cases of acute porphyrias are available. The laboratory participates in RCPA-AACB (Australia) Porphyrin QC scheme.
Contact details:
Porphyrin Laboratory,
Biochemistry Dept.
LabMed Directorate,
St James’s Hospital,
James’s St,
Dublin 8,
Tel 353-1- 4162058,
Fax 353-1- 4103466
AVAILABLE ASSAYS
Urine :
|
– Emergency porphobilinogen screen
– Quantitative delta aminoleuvulinate (ALA) & porphobilinogen (PBG)
– Total porphyrin analysis & HPLC fractionation of individual porphyrins & isomers |
Faeces :
|
– Quantitative total faecal porphyrin
– HPLC fractionation of individual porphyrins & isomers |
Blood :
|
– Quantitative red cell free and zinc protoporphyrin
– Plasma fluorescent emission scan
– Quantitative plasma porphyrins
– Erythrocyte PBG deaminase |
|
TURNAROUND TIME
• Emergency urinary PBG – qualitative within 1 hour, quantitative- same day
• Full porphyrin screen – 1 week
• Family studies – 2-3 weeks
SAMPLE REQUIREMENTS
It is the current policy of the laboratory that in any case of suspected porphyria all four sample types (urine, faeces, plasma & EDTA whole blood) are required.
However if this is not easily achieved the following minimum requirements apply :
| CLINICAL PRESENTATION |
SAMPLE
|
COMMENT
|
SUSPECTED ACUTE ATTACK
(AIP, HCP,VP, ALADP) |
– Random urine |
Preferably collected when symptomatic |
CONFIRMED ACUTE ATTACK
(AIP,HCP,VP, ALADP) |
– Urine
– Faeces
– Plasma
– EDTA blood |
|
ACUTE PHOTOSENSITIVITY
(EPP) |
– Plasma
– EDTA whole blood |
Samples must be sent to lab as soon as possible |
OTHER SKIN LESIONS
(PCT,VP, HCP, CEP) |
– Urine
– Faeces
– Plasma
– EDTA blood |
|
FAMILY STUDIES
AIP (PBG Deaminase) |
– Red cells |
By arrangement with lab only if index case has been identified |
FAMILY STUDIES
VP, HCP |
– Faeces
– Plasma |
|
| GENETIC STUDIES |
– EDTA whole blood |
Currently available only in confirmed cases & by prior arrangement as referred elsewhere at present |
|
TYPES OF PORPHYRIA
AIP (Acute Intermittent Porphyria), HCP (Hereditary Coproporphyria), VP (Variegate Porphyria), ALADP (ALA Dehydratase Porphyria), PCT (Porphyria Cutanea Tarda),
EPP (Erythropoietic Protoporphyria), CEP (Congenital Erythroietic Porphyria)
ALL SAMPLES TO BE PROTECTED FROM LIGHT
Urine :
|
– Random or 50 ml aliquot of 24 hr collection of unpreserved urine |
Faeces :
|
– Random sample (~10g) |
Blood :
|
– EDTA whole blood |
Plasma :
|
– Lithium Heparin blood separated – haemolysed samples unsuitable |
|
ADDITIONAL INFORMATION
1)
|
Light protected containers available from laboratory on request. |
2)
|
Samples must be clearly labelled with name, date of birth, medical record number & date of collection. |
3)
|
Laboratory must be contacted by telephone if urinary PBG required urgently in cases of suspected acute attack. |
4)
|
High risk samples must be indicated. |
5)
|
Accompanying information : |
| |
– Patient details – name, address & date of birth. |
| |
– Name of referring hospital, clinician & medical record number. |
| |
– Details of current symptoms in cases of suspected acute attack. |
| |
– Clinical details indicating cutaneous or neurological manifestations. |
| |
– Details of family history of porphyria & name of index case if appropriate. |
| |
– Invoicing details. |
|
STORAGE & TRANSPORT
|
• Random urine for emergency PBG should be dispatched immediately.
• All other samples should arrive in laboratory within 24-48 hrs after collection.
• If a delay is anticipated, urine, faeces & plasma samples should be frozen
• EDTA whole blood samples should be stored at 4�C – DO NOT FREEZE
|
