Leukotriene E4: perspective on the forgotten mediator

J Allergy Clin Immunol. 2009 Sep;124(3):417-21. doi: 10.1016/j.jaci.2009.04.020. Epub 2009 May 30.


Leukotriene (LT) E(4) mediates many of the principal features of bronchial asthma, such as bronchial constriction, hyperresponsiveness, eosinophilia, and increased vascular permeability. Furthermore, it is the most stable of the cysteinyl leukotrienes (CysLTs) and can be active at the site of release for a prolonged time after its synthesis. There might be several reasons why LTE(4) has been forgotten. LTE(4) demonstrated low affinity for CysLT(1) and CysLT(2) receptors in equilibrium competition assays. It was less potent than other CysLTs in functional assays, such as calcium flux, in cells transfected with CysLT(1) and CysLT(2). The introduction of CysLT(1) antagonists into clinical practice diverted interest into CysLT(1)-related mechanisms, which were mediated mainly by LTD(4). However, experiments with animal models and human studies have revealed that LTE(4) has unique characteristics that cannot be explained by the current knowledge of CysLT(1) and CysLT(2). These activities include its potency relative to other CysLTs to increase airway responsiveness to histamine, to enhance eosinophilic recruitment, and to increase vascular permeability. Asthmatic airways also demonstrate marked in vivo relative hyperresponsiveness to LTE(4), especially in patients with aspirin-sensitive respiratory disease. This has stimulated a search for additional LT receptors that would respond preferentially to LTE(4) stimulation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Aspirin / adverse effects
  • Asthma / drug therapy
  • Asthma / immunology*
  • Bronchial Hyperreactivity / drug therapy
  • Bronchial Hyperreactivity / immunology*
  • Drug Hypersensitivity / drug therapy
  • Drug Hypersensitivity / immunology*
  • Histamine
  • Humans
  • Leukotriene C4 / immunology
  • Leukotriene D4 / immunology
  • Leukotriene E4 / immunology*
  • Methacholine Chloride
  • Receptors, Leukotriene / immunology
  • Skin / drug effects
  • Skin / immunology
  • Skin / pathology


  • Receptors, Leukotriene
  • Methacholine Chloride
  • Leukotriene C4
  • Leukotriene D4
  • Leukotriene E4
  • Histamine
  • Aspirin