Abstract
Omalizumab is a recombinant anti-IgE antibody with proven efficacy in severe allergic asthma. Little is known about immunological changes affected by decreasing free IgE during omalizumab therapy. In the present study T-lymphocyte cytokine profiles and frequency of regulatory T-cells before and during omalizumab therapy in patients with severe allergic asthma were examined.
Twenty patients with severe allergic asthma (14 female) who met the criteria for omalizumab therapy were enrolled. Before and after 16 weeks of therapy peripheral blood mononuclear cells were isolated and activated with anti-CD3/anti-CD28 antibodies. Cells were processed for intracellular cytokine staining and frequency of CD3+ CD4+ interleukin (IL) 4, 5, 10, 17, interferon γ (IFN-γ) positive cells was assessed. The frequency of CD4+ CD25+FOX-P3+CD127- regulatory T-cells was assessed.
Anti-IgE treatment did not lead to a significant change of intracellular IL 4, 5, 10 and IFN-γ in CD3+ CD4+ T-lymphocytes (mean at baseline: IL-4 5,9±3,8%; IL-5 1,1±1,1%; IL-10 4,5±3,2%; IL-17 2,0±2,0%; IFN-γ 9,2±5,6%, intraindividual difference in week +16: IL-4 1,3±3,8% p=0,164; IL-5 0,2±1,2% p=0,474; IL-10 0,3±5,0% p=0,774; IL-17 -1,4±6,4% p=0,376; IFN-γ 2,0±4,5% p=0,056). Additionally, there was no significant change in frequency of regulatory T-cells (mean at baseline: Treg 11,4±5,7%, intraindividual difference in week +16 Treg 0,4±5,5% p=0,730).
In this study there was no significant difference of the tested intracellular cytokines before and after anti-IgE therapy. Frequency of regulatory T-cells did not change significantly 16 weeks after initiation of anti-IgE therapy.
- © 2011 ERS
