Omalizumab-induced decrease of FcξRI expression in patients with severe allergic asthma

Respir Med. 2010 Nov;104(11):1608-17. doi: 10.1016/j.rmed.2010.07.011. Epub 2010 Aug 30.


Background: It is documented that omalizumab treatment reduces the cell surface expression of immunoglobulin E high-affinity receptor (FcɛRI) on several cell types. This has not been investigated in patients with uncontrolled severe persistent allergic asthma.

Methods: In a double-blind, randomized, placebo-controlled study, patients with severe allergic asthma uncontrolled by high dose inhaled corticosteroids and long-acting β(2)-agonist received either omalizumab (n = 20) or placebo (n = 11) over 16 weeks at appropriate doses and frequencies. Baseline and end of study (week 16) FcɛRI expression on basophils and plasmacytoid dendritic cells was determined by flow cytometry for the primary endpoint. Secondary efficacy endpoints included asthma control and lung function as part of an initial investigation into the use of FcɛRI expression as a marker of response.

Results: In the omalizumab group, and with respect to placebo, FcɛRI expression was significantly reduced at end of study on basophils (-82.6%, p < 0.01) and plasmacytoid dendritic cells (-44.2%, p = 0.029). FcɛRI expression reduction was not found to be correlated with clinical response.

Conclusions: Long-term omalizumab treatment induced reduction of FcɛRI expression on circulating basophils and plasmacytoid dendritic cells. These changes were not associated with those of clinical features related to severe asthma, which does not support further investigation into its use as a predictive marker of response.

Trial registration: The study was registered with (identifier: NCT00454051) and the European Clinical Trials Database, EudraCT (identifier: 2006-003591-35).

Publication types

  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Anti-Allergic Agents / therapeutic use*
  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal / therapeutic use*
  • Antibodies, Monoclonal, Humanized
  • Asthma / drug therapy*
  • Asthma / immunology
  • Asthma / physiopathology
  • Basophils / drug effects*
  • Basophils / immunology
  • Dendritic Cells / drug effects*
  • Dendritic Cells / immunology
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Humans
  • Immunoglobulin Fc Fragments / metabolism*
  • Male
  • Middle Aged
  • Omalizumab
  • Placebos
  • Respiratory Function Tests
  • Treatment Outcome
  • Young Adult


  • Anti-Allergic Agents
  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Immunoglobulin Fc Fragments
  • Placebos
  • Omalizumab

Associated data