Coproporphyrin I

Porphyrins appear elevated in urine when the cellular pathway for heme synthesis is blocked by natural or man-made toxicants or when genetic disorders that affect the enzymes of the porphyrin pathway are present.

Coproporphyrin and uroporphyrin excretion in urine is markedly increased during a cute attacks of hereditary coproporphyria. Increased uroporphyrinogen, uroporphyrin, and coproporphyrin excretion occurs in porphyria cutanea tarda.

Increased levels of coproporphyrins may be a sign of:

- Congenital erythropoietic porphyria

- Hepatic coproporphyria

- Sideroblastic anemia

- Variegate porphyria

- Hereditary coproporphyria

- Liver disease

- Bone marrow disorders

- Lead poisoning

- Arsenic poisoning

Increases in urine coproporphyrin are sometimes not due to Porphyria. When total urine porphyrins are increased due to Porphyria Cutanea Tarda (PCT) or Hepatoerythropoietic Porphyria (HEP), the increase is predominantly accounted for by uroporphyrin and heptacarboxyl porphyrin.

Coproporphyrin I is a porphyrin metabolite arising from heme synthesis.