ALA (Aminolevulinic acid), porphobilinogen, and porphyrins blood test

 Your doctor will perform this blood test if he/she suspects that you are showing symptoms of porphyrias. 

The symptoms of cutaneous porphyrias include:

• Blisters
• Scarring
• Hyperpigmentation 
• Swelling
• Itching 
• Burning sensation
• Redness

These symptoms will appear on the areas of the skin which are exposed to the sun. 

The test may also be performed in people with acute porphyrias, when a urine sample cannot be collected, such as in patients with renal failure. 

Symptoms of acute porphyrias include:

• Confusion
• Hallucinations
• Tingling sensation in the hands and feet
• Numbness of the hands and feet
• Abdominal pain and nausea
• Constipation 
• Urinary retention 

These symptoms occur together as acute attacks and may last for days or even weeks. They could be triggered by factors such as stress, changes in the diet, various medications and exposure to toxins. 

In individuals who have already been diagnosed with porphyria, this test may be done regularly to monitor the condition.

It is also important to note that in some porphyrias, the individual may experience both neurological and skin symptoms. 

Abstain from alcohol for at least 24 hours before the test. 

You will also be instructed to not eat anything at least 12-14 hours before getting tested. Though you can drink water right before the test. 

In case you have symptoms of neurologic porphyria, it is best to collect the sample during an acute attack. 

Your doctor will use a sterile needle to withdraw a small amount of blood from a vein in your arm. You may feel no pain from the needle or just a quick sting or pinch. 

After the test, some people feel dizzy after the test and/or notice a bruise at the needle insertion site. However, all of these symptoms are temporary and would subside on their own. If the bruise doesn’t fade within a few days, please consult your doctor. 

Normal results:

Plasma levels of porphobilinogen and aminolevulinic acid are as follows:

• Aminolevulinic Acid: ≤0.5 nmol/mL
• Porphobilinogen: ≤0.5 nmol/mL

The reference values of porphyrins in blood are as follows:

• Total porphyrin levels: 0-1 mcg/dL
• Uroporphyrin levels: <2mcg/dL
• Protoporphyrin level: 16-60 mcg/dL
• Coproporphyrin level: <2mcg/dL

Normal results indicate that you have a normal level of porphyrins in the blood and you do not have porphyria. It is likely that your symptoms are being caused by another condition. 

Abnormal results:

High levels of porphyrins in the blood are considered abnormal and indicate that you may have porphyria.

For example:

• In people suffering from congenital erythropoietic porphyria, a type of cutaneous porphyria, the levels of uroporphyrin, protoporphyrin and coproporphyrin are elevated in the blood.
• In erythropoietic protoporphyria, another cutaneous porphyria, mostly protoporphyrin levels are elevated with free protoporphyrin levels being higher than Zn-protoporphyrin (a type of porphyrin present in RBCs due to excess lead or less iron in body).
• In X-linked protoporphyria, protoporphyrin levels are raised with free protoporphyrin levels being equal to Zn-protoporphyrin.

Your doctor may suggest more tests to confirm the diagnosis and find the type of porphyria you have. Although this condition has no cure (yet), it can be managed with the help of lifestyle changes.

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.