This site is intended for healthcare professionals

Go to /sign-in page

You can view 5 more pages without signing in

Acute intermittent porphyria

Authoring team

Acute intermittent porphyria (AIP) is a particularly severe form of porphyria which results from a deficiency of porphobilinogen deaminase.

  • is an autosomal dominant metabolic disorder characterized by a deficiency in heme biosynthesis
  • Heme biosynthesis occurs throughout the body, but it is most prominent in the erythroblastic system and liver
    • AIP is a hepatic porphyria whereby the liver is the source of toxic heme metabolites
    • clinical manifestations of AIP result from a genetic mutation that leads to partial function of porphobiliogen deaminase (PBGD)
      • causes an accumulation of upstream, neurotoxic metabolites

In common with the other acute porphyrias the clinical course is one of clinical latency followed by an acute episode following a precipitating event. The main clinical features of an attack are gastrointestinal disturbance and neuropsychiatric disorders

  • symptoms include but are not limited to peripheral neuropathies, autonomic neuropathies and psychiatric manifestations
  • AIP can be life threatening and clinical signs and symptoms are often heterogeneous and non-specific

Haem infusions

  • are presently, in most settings, the preferred specific treatment for sporadic acute attacks (2)
    • haem restores hepatic haem
    • haem infusions are usually well tolerated and successful in the treatment of sporadic acute attacks
    • mechanism of action:
      • to produce haem, the body needs to convert porphyrin precursor chemicals ALA and PBG (5-aminolaevulinic acid and porphobilinogen) into more complicated substances called porphyrins. These are then converted from one type of porphyrin into another to form haem
      • by replenishing hepatic haem stores the initial rate-limiting enzyme ALA synthase is inhibited by a process of negative feedback. The formation of porphyrins and their precursors, ALA and PBG, is reduced and symptoms improve
      • after haem administration, urine ALA, PBG and porphyrins will fall within the first 24 hours

Reference:

  • Spiritos Z, Salvador S, Mosquera D, Wilder J. Acute Intermittent Porphyria: Current Perspectives And Case Presentation. Ther Clin Risk Manag. 2019 Dec 16;15:1443-1451. doi: 10.2147/TCRM.S180161. PMID: 31908464; PMCID: PMC6930514.
  • Bustad HJ, Kallio JP, Vorland M, Fiorentino V, Sandberg S, Schmitt C, Aarsand AK, Martinez A. Acute Intermittent Porphyria: An Overview of Therapy Developments and Future Perspectives Focusing on Stabilisation of HMBS and Proteostasis Regulators. Int J Mol Sci. 2021 Jan 12;22(2):675. doi: 10.3390/ijms22020675. PMID: 33445488; PMCID: PMC7827610

Create an account to add page annotations

Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.

The content herein is provided for informational purposes and does not replace the need to apply professional clinical judgement when diagnosing or treating any medical condition. A licensed medical practitioner should be consulted for diagnosis and treatment of any and all medical conditions.

Connect

Copyright 2024 Oxbridge Solutions Limited, a subsidiary of OmniaMed Communications Limited. All rights reserved. Any distribution or duplication of the information contained herein is strictly prohibited. Oxbridge Solutions receives funding from advertising but maintains editorial independence.