Why am I having this test?
A zinc protoporphyrin (ZPP) test can be used to check for lead poisoning. It can also be used to detect an iron deficiency in children. A health care provider may recommend this test to check for these conditions if symptoms are present.
Symptoms of lead poisoning include:
- Numbness and tingling.
- Abdominal pain.
- Headache.
- Weakness.
- Fatigue.
- Confusion.
- High blood pressure.
- Constipation.
Symptoms of iron deficiency in children include:
- Tiredness.
- Weakness.
- Headaches.
- Dizziness.
- Shortness of breath.
- Pale skin.
What is being tested?
This test measures the amount of ZPP in the blood. ZPP is a substance that can form when a person has lead poisoning or an iron deficiency.
Normally, a substance in red blood cells called protoporphyrin binds to iron and forms part of the hemoglobin molecule (heme). Hemoglobin is the protein in red blood cells that carries oxygen to all the cells in the body. People with an iron deficiency or lead poisoning may not have enough iron to form heme normally. Lead blocks iron from binding to protoporphyrin. When a person has an iron deficiency or lead poisoning, protoporphyrin will bind to zinc instead, forming ZPP. ZPP builds up over time.
What kind of sample is taken?
A blood sample is required for this test. It is usually collected by inserting a needle into a blood vessel.
How do I prepare for this test?
- Do noteat or drink anything other than water for 12 hours before the test or as told by your health care provider.
Tell a health care provider about:
- All medicines you are taking, including vitamins, herbs, eye drops, creams, and over-the-counter medicines.
- If you or members of your family have been diagnosed with porphyria.
- Any other medical conditions you have. Recent infection and some long-term diseases can affect the result of this test.
How are the results reported?
Your test results will be reported as values. Your health care provider will compare your results to normal ranges that were established after testing a large group of people (reference ranges). Reference ranges may vary among labs and hospitals. For this test, a common reference range is:
- 0–69 μmol ZPP/mol heme.
What do the results mean?
Results within the reference range are considered normal. Increased levels of ZPP may indicate:
- Exposure to lead during the previous few months.
- Iron deficiency (in children).
Talk with your health care provider about what your results mean.
Questions to ask your health care provider
Ask your health care provider, or the department that is doing the test:
- When will my results be ready?
- How will I get my results?
- What are my treatment options?
- What other tests do I need?
- What are my next steps?
Summary
- A zinc protoporphyrin (ZPP) test can be used to check for lead poisoning. It can also be used to detect an iron deficiency in children.
- For this test, a blood sample is usually collected by inserting a needle into a blood vessel.
- ZPP is a substance that can form in the blood when a person has lead poisoning or an iron deficiency.
- Talk with your health care provider about what your results mean.
