Effect of omalizumab treatment on peripheral eosinophil and T-lymphocyte function in patients with allergic asthma

J Allergy Clin Immunol. 2006 Jun;117(6):1493-9. doi: 10.1016/j.jaci.2006.02.028. Epub 2006 Apr 27.


Background: Omalizumab is a recombinant monoclonal anti-IgE antibody with proven efficacy in allergic diseases and further anti-inflammatory potency in the treatment of asthma.

Objectives: To explore the anti-inflammatory mechanism of omalizumab, we investigated the induction of immunologic changes leading to eosinophil apoptosis and examined T-lymphocyte cytokine profiles in patients with allergic asthma.

Methods: Nineteen patients with allergic asthma were enrolled and received omalizumab at a dose of at least 0.016 mg/kg/IgE (IU/mL) every 4 weeks. Peripheral eosinophils and T-lymphocyte cytokine profiles were evaluated by fluorescence-activated cell sorting before treatment (baseline), at 12 weeks of treatment, and 12 weeks after discontinuation of treatment with omalizumab or placebo.

Results: Markers of eosinophil apoptosis (Annexin V) were significantly increased in omalizumab recipients compared with placebo, whereas no changes in markers of necrosis (7-amino-actinomycin) or eosinophil activation CD69 or Fas receptor (CD95) were detected. GM-CSF+ lymphocytes were reduced in omalizumab recipients compared with placebo. Fewer IL-2+ and IL-13+ lymphocytes were evident in omalizumab recipients than in the placebo group. There were no significant differences in IL-5, IFN-gamma, or TNF-alpha between the omalizumab and placebo groups.

Conclusion: These findings provide further evidence that omalizumab has additional anti-inflammatory activity demonstrated by induction of eosinophil apoptosis and downregulation of the inflammatory cytokines IL-2 and IL-13. Further studies are needed to determine the underlying mechanisms.

Clinical implications: These findings support the critical role of IgE in the regulation of inflammation in allergic asthma: influencing the inflammation is the key to control the more severe type of asthma.

Publication types

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

MeSH terms

  • Adult
  • Aged
  • Allergens / immunology*
  • Anti-Asthmatic Agents / pharmacology*
  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal / pharmacology*
  • Antibodies, Monoclonal, Humanized
  • Apoptosis / drug effects
  • Apoptosis / immunology
  • Asthma / drug therapy*
  • Asthma / immunology*
  • Asthma / pathology
  • Cytokines / metabolism
  • Eosinophils / drug effects*
  • Eosinophils / immunology
  • Eosinophils / pathology
  • Female
  • Humans
  • Male
  • Middle Aged
  • Omalizumab
  • T-Lymphocytes / drug effects*
  • T-Lymphocytes / immunology*
  • T-Lymphocytes / metabolism


  • Allergens
  • Anti-Asthmatic Agents
  • Antibodies, Anti-Idiotypic
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Cytokines
  • Omalizumab