What are porphyrin tests?
Porphyrin tests measure the level of porphyrins in your blood, urine, or stool. Porphyrins are chemicals that help make hemoglobin, a type of protein in your red blood cells. Hemoglobin carries oxygen from your lungs to the rest of your body.
It’s normal to have a small amount of porphyrins in your blood and other body fluids. But too much porphyrin may mean you have a type of porphyria. Porphyria is a rare disorder that can cause serious health problems. Porphyria is usually divided into two categories:
- Acute porphyrias, which mainly affect the nervous system and causes abdominal symptoms
- Cutaneous porphyrias, which cause skin symptoms when you are exposed to sunlight
Some porphyrias affect both the nervous system and the skin.
Other names: protoporphyrin; protoporphyrin, blood; protoporhyrin, stool; porphyrins, feces; uroporphyrin; porphyrins, urine; Mauzerall-Granick test; acid; ALA; porphobilinogen; PBG; free erythrocyte protoporphyrin; fractionated erythrocyte porphyrins; FEP
What are they used for?
Porphyrin tests are used to diagnose or monitor porphyria.
Why do I need a porphyrin test?
You may need a porphyrin test if you have symptoms of porphyria. There are different symptoms for the different types of porphyria.
Symptoms of acute porphyria include:
Symptoms of cutaneous porphyria include:
You may also need a porphyrin test if someone in your family has porphyria. Most types of porphyria are inherited, meaning the condition is passed from parent to child.
What happens during porphyrin testing?
Porphyrins can be tested in blood, urine, or stool. The most common types of porphyrin tests are listed below.
- Blood Test
- A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.
- 24-Hour Urine Sample
- You will collect all your urine during a 24-hour period. For this test, your health care provider or laboratory will give you a container and specific instructions on how to collect your samples at home. Be sure to follow all instructions carefully. This 24-hour urine sample test is used because the amounts of substances in urine, including porphyrin, can vary throughout the day. So collecting several samples in a day may give a more accurate picture of your urine content.
- Random Urine Test
- You can provide your sample at any time of day, with no special preparations or handling needed. This test is often done in a health care provider’s office or a lab.
- Stool Test (also called protoporphyrin in stool)
- You will collect a sample of your stool and place it in a special container. Your health care provider will give you instructions on how to prepare your sample and send it to a lab.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for blood or urine tests.
For a stool test, you may be instructed to not eat meat or take any aspirin-containing medicines for three days prior to your test.
Are there any risks to porphyrin tests?
There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
There are no known risks to urine or stool tests.
What do the results mean?
If high levels of porphyrin are found in your blood, urine, or stool, your health care provider will probably order more tests to confirm a diagnosis and to find out what kind of porphyria you have. While there is no cure for porphyria, the condition can be managed. Certain lifestyle changes and/or medicines can help prevent the symptoms and complications of the disease. Specific treatment depends on the type of porphyria you have. If you have questions about your results or about porphyria, talk to your health care provider.
Is there anything else I need to know about porphyrin tests?
While most types of porphyria are inherited, other types porphyria can also be acquired. Acquired porphyria can be caused by a variety of factors, including overexposure to lead, HIV, hepatitis C, excess iron intake, and/or heavy alcohol use.