Porphobilinogen , 24 hrs Urine Test

Porphyrins are natural chemicals that are found in your body. They are an important part of many
of your body’s functions. Usually, your body makes a small amount of porphyrins when it produces
heme. Heme is an important component of hemoglobin, the protein in red blood cells that carries
oxygen. Heme production involves a multistep process, and a different enzyme controls each step. If
one of these enzymes is defective, this can cause porphyrins to build up in your body and potentially
reach toxic levels. This causes the clinical disease porphyria.
Porphyrin urine testing is used to help diagnose and sometimes to monitor porphyrias. A 24-hour
urine test is painless and just requires a simple urine collection done in three stages.
• Urine test for porphobilinogen (PBG), a porphyrin precursor, is the primary test.
• If the result of the PBG test is abnormal, urine porphyrin testing, which measures
uroporphyrin and coproporphyrin, may be ordered to provide additional information on the
type of neurologic porphyria that is present.
• Aminolevulinic acid (ALA), another porphyrin precursor, is used to diagnose the rare ALA
dehydratase deficiency porphyria.

Your doctor will tell you how to prepare for the test. You may have to fast (not eat or drink) for a certain period of time before taking this test and stop taking certain medications that can interfere with the test results. Tell your doctor about any and all supplements, prescription, and over-the- counter medications that you’re taking, because some medications and foods can interfere with the test results.

The normal range for a 24-hour porphyrins urine test is about 50 to 300 milligrams, although results vary among different laboratories. • Abnormal test results can indicate liver cancer, hepatitis, lead poisoning, or one of the different forms of porphyria. Your doctor will be able to interpret the results for a diagnosis and recommend the best course of treatment.

On day one, you urinate into a toilet upon rising in the morning. Flush this first sample away. • For the rest of the day, you collect all of your urine in a special container and store it in a cool place. • On day two, you urinate into the special container upon rising in the morning. • After that, you return the container to the lab as soon as possible.