title: Omalizumab-induced decrease of FcξRI expression in patients with severe allergic asthma.
abstract: 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.
  
  
  BACKGROUND
  The study was registered with ClinicalTrials.gov (identifier: NCT00454051) and the European Clinical Trials Database, EudraCT (identifier: 2006-003591-35).
authors.affiliation: INSERM U 600, CNRS UMR 6212, Université de la Méditerranée, Marseille, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Chanez
authors.forename: Cécile
authors.initials: C
authors.lastname: Contin-Bordes
authors.forename: Gilles
authors.initials: G
authors.lastname: Garcia
authors.forename: Christophe
authors.initials: C
authors.lastname: Verkindre
authors.forename: Alain
authors.initials: A
authors.lastname: Didier
authors.forename: Frédéric
authors.initials: F
authors.lastname: De Blay
authors.forename: Manuel Tunon
authors.initials: MT
authors.lastname: de Lara
authors.forename: Patrick
authors.initials: P
authors.lastname: Blanco
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Moreau
authors.forename: Philip
authors.initials: P
authors.lastname: Robinson
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bourdeix
authors.forename: Patrick
authors.initials: P
authors.lastname: Trunet
authors.forename: Vincent
authors.initials: V
authors.lastname: Le Gros
authors.forename: Marc
authors.initials: M
authors.lastname: Humbert
authors.forename: Mathieu
authors.initials: M
authors.lastname: Molimard
mesh_terms: D000328:Adult; D000368:Aged; D018926:Anti-Allergic Agents / Q000627:therapeutic use*; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized; D001249:Asthma / Q000188:drug therapy* / Q000276:immunology / Q000503:physiopathology; D001491:Basophils / Q000187:drug effects* / Q000276:immunology; D003713:Dendritic Cells / Q000187:drug effects* / Q000276:immunology; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007141:Immunoglobulin Fc Fragments / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D000069444:Omalizumab; D010919:Placebos; D012129:Respiratory Function Tests; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D018926:Anti-Allergic Agents; D000888:Antibodies, Anti-Idiotypic; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D007141:Immunoglobulin Fc Fragments; D010919:Placebos; D000069444:Omalizumab