An Overview of Acute Hepatic Porphyrias: Clinical Implications, Diagnostic Approaches, and Management Strategies.

Porphyrias are inborn errors of heme biosynthesis pathway that result in neurovisceral and/ or cutaneous manifestations which occur with episodic attacks, usually accompanied by a multisystemic involvement. Acute hepatic porphyrias include acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and aminolevulinic acid dehydratase deficiency porphyria. Acute hepatic porphyrias may present with symptoms of an affected central, peripheral, and autonomic nervous system and are generally diagnosed in time of an acute neurovisceral attack. In children, clinical picture is more complicated and presents with neurological findings predominantly. First-line investigation should be the urinary porphobilinogen and aminolevulinic acid performance when acute hepatic porphyria is clinically suspected. Comprehensive testing including urine porphyrin separation, fluorescence scanning of diluted plasma at neutral pH, evaluation of fecal porphyrins, and measurement of erythrocyte porphobilinogen deaminase activity is indicated for confirmation or exclusion of the porphyria and define the type of acute hepatic porphyrias. The main aim of the treatment is to decrease aminolevulinic acid, porphobilinogen, and porphyrins by reducing hepatic ALAS1 activity. The first measure should always be the avoidance of any porphyrinogenic drugs. Hemin therapy should not be delayed in the treatment of a severe acute attack. Gonadotropin-releasing hormone analogs and prophylactic hemin protocols can be used for selected cases with more than 4 attacks per year. Givosiran is a promising treatment option for severe cases.