Coproporphyrin I is a porphyrin metabolite arising from heme synthesis.
Porphyrins are natural chemicals in the body that help form many important substances in the body. One of these is hemoglobin, the protein in red blood cells that carries oxygen in the blood.
Porphyrins build up among patients with hereditary enzyme disorders known as porphyrias. Porphyrias affect the heme biosynthetic pathway and cause increased urine excretion of porphyrinogens, by-products known as porphyrins and porphyrinogen precursors-including delta aminolevulinic acid (ALA) and porphobilinogen (PBG).
Porphyrins can be measured in the urine or blood.
Increased levels:
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 often 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.
References:
https://porphyriafoundation.org/patients/about-porphyria/testing-porphyria/tests-porphyria-diagnosis
https://r.details.loinc.org/LOINC/13960-0.html?sections=Comprehensive
https://www.gdx.net/core/interpretive-guides/Porphyrins-IG.pdf
http://www.hmdb.ca/metabolites/HMDB0000643
https://jamanetwork.com/journals/jama/article-abstract/298948
http://www.clinsci.org/content/65/5/527
https://www.ncbi.nlm.nih.gov/pubmed/12699241
Disclaimer:
Test results may vary depending on your age, gender, health history, the method used for the test, and other things. Your test results may not mean you have a problem. Ask your healthcare provider what your test results mean for you.
The information on healthmatters.io is NOT intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice.
HealthMatters.io - Lab results explained 