Porphyrin (feces) | Laboratory research

General Information

Determination of porphyrin in feces is a laboratory test used to diagnose porphyria – a group of rare metabolic diseases associated with impaired heme synthesis.

Determination of porphyrin in feces

Porphyrins are cyclic compounds, also involved in the formation of hemoglobin and other hemoproteins (blood proteins) and are involved in the process of oxygen transport.

Porphyrias belong to a group of diseases, the cause of which is a deficiency of enzymes at the stage of heme formation. (Heme is an iron-containing pigment, the precursor of hemoglobin). Deficiency of the enzyme leads to the accumulation of porphyrins and its precursor compounds in the blood, which is followed by the manifestation of the corresponding symptom complex.

Accumulation of porphobilinogen and aminolevulenic acid (porphyrin precursors) causes acute abdominal pain and neuropsychiatric symptoms.

Accumulation of porphyrin (without accumulation of precursors) leads to increased sensitivity to light.

Enzyme deficiency can be genetic (inherited) or acquired, which can be provoked by: alcohol intoxication, lead poisoning and others. Porphyrins accumulate in plasma, erythrocytes, urine and feces.

Conditions in which there is an increase in the number of porphyrins:

• Intoxication: alcohol, halogenated organic compounds, heavy metals (especially lead)
• Liver diseases: hepatitis, cirrhosis, fatty liver, narcotic or alcoholic hepatopathies, hemochromatosis.
• Hematological disorders: hemolytic, sideroblastic, aplastic anemias, leukemias, hemopoiesis disorders
• Infectious diseases
• diabetes
• Disorders of iron metabolism: hemosiderosis, hemochromatosis
• Hereditary hyperbilirubinemia: Dubin-Johnson syndrome, Rotor syndrome
• Malignant tumors: lymphogramulomatosis
• Myocardial infarction
• Side effects of medicines: as a result of taking analgesics, sedatives, antibiotic sulfonylurea derivatives, estrogens, oral contraceptives, anesthetics.

Chronic lead poisoning often results in moderate coproporphyrinuria (350-1500ng/24h in urine), while in acute poisoning, total porphyrins reach 10000ng/24h in urine, 80% of which is coproporphyrin.