Porphyria is an accumulation in the body of the precursors to heme production, the part of the red blood cell that contains iron and binds oxygen. It occurs due to decreased activity of the enzymes that produce each step in the process (different enzyme deficiencies lead to different types of porphyria), and it’s generally thought of as a rare genetic disease.
But it can also be acquired, due to various toxic exposures.
Symptoms of Porphyria
The type of porpyria associated with toxic exposure is primarily Acute Intermittent Porphyria (AIP) and it leads to accumulation of porphobilinogen (PBG) and δ-aminolevulinic acid (ALA)—both of which can be tested for in urine. (More on this in the testing section.)
Symptoms of AIP are quite varied, but can be consolidated as “The 5 P’s” (one of those med student tricks for memorization):
- Painful abdomen: can be just intense pain, or cramping, constipation, diarrhea, nausea, and/or vomiting.
- Polyneuropathy: this means pain, weakness, or numbness in multiple nerves. Strange or unusual nerve symptoms are common. Other nervous system disturbances might include dizziness, or intolerance to stimuli (such as light, sound, temperature, smells, and EMF fields.)
- Psychological Disturbances: These might include anxiety, depression, panic attacks, or insomnia.
- Purple urine: the heme precursors in the urine contain iron—and oxidized iron is what gives blood its red color. Therefore, the urine tends to look red or purple, though this is not always the case. Sometimes the urine color is normal.
- Precipitated by triggers: A drug or toxic substance increases production of heme. This overwhelms the enzyme, and then (like a bottleneck), the precursors accumulate.
Drugs That Can Cause Secondary Porphyria
Drugs that tend to trigger porphyria are those that speed up enzymes higher in the biochemical production of heme, causing a bottleneck at PBG and ALA. These include seizure medications, benzodiazepines, sulfa drugs, birth control pills, and the NSAID ketorolac/Toradol.
Progesterone can also act as a trigger (and in this case study, it was the body’s own progesterone during the luteal phase of the menstrual cycle!)
Toxins That Can Cause Secondary Porphyria
The best known toxin to trigger porphyria is lead poisoning. However, there are certainly others.
- Alcohol can lead to either acute or chronic secondary porphyria.
- Smoking is another trigger for recurrent porphyria attacks.
- Emotional stress can trigger episodes, although other forms of stress can cause episodes as well, such as the trauma of surgery.
- Industrial chemicals: exposure to such chemicals as halogenated hydrocarbons (byproducts of industrial chemical reactions or waste incineration), and fungicides, can trigger episodes.
- Infection: this article associates acute mononucleosis from Epstein Barr with an episode.
Testing For Porphyria
Traditional labs can test for PBG and ALA in the urine. It’s best to test during a symptomatic episode, as the test is most likely to be positive at that time. Because porphyrins are light sensitive, it’s also advisable to keep the sample in a dark container until it can be analyzed.
For acute and severe cases of porphyria, treatment is called hemin, which basically replaces heme. This then sends feedback suppression to earlier parts of the pathway (telling the body that there’s enough heme, you don’t need to keep making more of it.) This enables the enzymes to play catch-up.
Other less invasive treatments include carbs, or specifically glucose. This is because glucose will help to shut down one of the enzymes higher in the biochemical pathway, producing more of the heme precursors.
Activated charcoal also seems to work well as a binder, for elimination of porphyrin.
Also, if you’ve experienced porphyria, you may be deficient in Vitamin B12. (This seems to be because one of the downstream products of the heme production process also turns into B12.) Supplementing with B12 after an episode may therefore be helpful.