Synonyms: FEP; ZPP

Why It Is Done

To screen for and monitor chronic exposure to lead, detect iron deficiency in children, help diagnose certain porphyrias (inherited conditions that affect the production of heme)

Test Overview

The zinc protoporphyrin (ZPP) test is a blood test that can identify a disruption in the formation of heme.

Heme is an essential component of hemoglobin, the protein in red blood cells (RBCs) that carries oxygen from the lungs to the body's tissues and cells. The formation of heme occurs in a series of enzymatic steps that conclude with the insertion of an iron atom into the center of a molecule called protoporphyrin.

If there is not enough iron available, or if ferrochelatase (the enzyme responsible for the incorporation of iron) is blocked, then protoporphyrin combines with zinc instead of iron to form zinc protoporphyrin. Since it cannot transport oxygen, ZPP serves no useful purpose in the RBCs that contain it.

How To Prepare

No special preparation needed