Porphyrin Metabolism Disorders

Porphyrin Metabolism Disorders

Joseph Misdraji, MD

Hematoxylin & eosin section of erythropoietic protoporphyria shows cholestasis and rust-brown deposits image in hepatocytes and canaliculi.

Hematoxylin & eosin section of erythropoietic protoporphyria viewed under polarized light shows birefringent protoporphyrin deposits that are brightly birefringent and have a Maltese cross appearance image.



  • Porphyria cutanea tarda (PCT)

  • Erythropoietic protoporphyria (EP)


  • EP has also been called erythrohepatic protoporphyria and protoporphyria


  • Heterogeneous group of inherited and acquired disorders of heme biosynthesis

    • PCT and EP are associated with hepatic pathology

    • “Hepatic” and “erythropoietic” porphyrias are characterized by accumulation of intermediates in liver and erythroid cells, respectively


Genetic Disorder

  • Sporadic PCT is associated with partial deficiency of uroporphyrinogen decarboxylase activity, only in liver

  • Familial PCT is due to deficiency of uroporphyrinogen decarboxylase activity in all tissues

  • EP is due to partial deficiency of ferrochelatase activity

Sporadic Disease

  • Sporadic PCT is primarily an acquired disorder

    • Occurs in patients without genetic defects although partial deficiency of uroporphyrinogen decarboxylase may contribute

    • Associated with genetic conditions that increase iron absorption (e.g., HFE mutations)

    • Approximately half of all patients have hepatitis C virus infection (HCV)

    • Other contributory substances or conditions include alcohol, HIV infection, estrogen use, smoking, low vitamin C, and carotenoid status

Jul 7, 2016 | Posted by in PATHOLOGY & LABORATORY MEDICINE | Comments Off on Porphyrin Metabolism Disorders

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