Purpurinuria, porphyrinuria (porphyrins in the urine)

Автор: ,

Purpurinuria, porphyrinuria (porphyrins in the urine)

Porphyrinuria is an increase in porphyrins in the urine, can be a symptom of porphyria or liver disease, intoxication, cytostatic therapy, infection, iron deficiency, and hemolytic anemia, lymphogranulomatosis, leukemia.

Porphyrins are intermediates in heme synthesis (the non-protein portion of hemoglobin). They are formed from the amino acid glycine and a derivative of succinic acid - succinyl-coenzyme A. The main amounts of porphyrins are synthesized in the bone marrow (for the formation of hemoglobin heme) and liver (for the synthesis of redox enzymes, heme myoglobin, myelin, bone, and other tissues).

Normally, small amounts of uro- and coproporphyrins are excreted in the urine. Increased excretion of porphyrins (porphyrinuria) is observed with liver damage. A healthy liver is able to oxidize and excrete the metabolic products of porphyrins in the form of copro- and protoporphyrins in the feces. When this pathway is turned off, pigments return to the bloodstream, pass the renal filter, and are excreted in increased quantities in the urine (porphyrinuria).

Alcohol intake, X-rays, physical stress, hemolysis of erythrocytes, myoglobinuria lead to an increase in the level of urine porphyrins (porphyrinuria). With renal failure, the content of porphyrins in the urine decreases.

Urinary excretion of porphobilinogen (PBG) stains urine red or pink and is characteristic of acute intermittent porphyria, which is accompanied by lesions of the muscular, central and peripheral nervous system. The heterozygous form has a long latent course, the homozygous form has a severe polysyndromic disease.