Free erythrocyte protoporphyrin (FEP)

FEP is a test offered by the SAAS Porphyria Service in Reference Biochemistry at King’s College Hospital. Quantitative measurement of FEP is reported with zinc protoporphyrin (ZPP) using fluorescence spectroscopy.
Clinical details: 
FEP is present in red blood cells and combines with iron to form haem. FEP is elevated in patients with erythropoietic protoporphyria (EPP) and X-linked protoporphyria (XLPP).
Reference range: 

<200 nmol/L red cells

Synonyms or keywords: 
Sample type and Volume required: 
5 – 10 ml whole blood collected into EDTA or heparin. Separate red cells and plasma if delay in dispatch. Specimens should be protected from light.
Turnaround time: 
1-2 weeks
Storage and transport: 
Specimens can be sent by first class post without ice packs. Specimens are stable for several weeks if frozen while awaiting despatch.
Reference Biochemistry Department at King's College Hospital
020 3299 4107
King's College Hospital
Denmark Hill
London SE5 9RS
Porphyrins and Gastrointestinal Laboratory at King's College Hospital
Porphyrins - 020 3299 3856, Gut Permeability - 020 3299 4133
King's College Hospital
Denmark Hill
London SE5 9RS
For clinical advice or interpretation of results, please contact the laboratory in the first instance.

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Last updated: 03/02/2017