Original Paper Int Arch Allergy Immunol 2004;134(suppl 1):7–11 DOI: 10.1159/000077786 Correlation of Allergen-Induced IL-5 and IL-13 Production by Peripheral Blood T Cells of Asthma Patients Tomomi Hashimoto a Kazuo Akiyama a Hiroshi Kawaguchi a Yuji Maeda a Masami Taniguchi a Noriaki Kobayashi b Akio Mori a a Clinical Research Center for Allergy and Rheumatology, National Sagamihara Hospital, Kanagawa, and b Department of Biotechnology, Tokyo Technical College, Kunitachi, Tokyo, Japan Correspondence to: Dr. A. Mori 18-1 Sakuradai Sagamihara, Kanagawa 228-8522 (Japan) Tel. +81 42 742 8311, Fax +81 42 742 7990 E-Mail mori-kkr@umin.ac.jp ABC Fax + 41 61 306 12 34 E-Mail karger@karger.ch www.karger.com © 2004 S. Karger AG, Basel 1018–2438/04/1345–0007$21.00/0 Accessible online at: www.karger.com/iaa Key Words Atopic dermatitis W Bronchial asthma W IL-5 W IL-13 W T cell Abstract Background: Helper T cells and T cell cytokines are impli- cated in allergic disorders such as asthma and atopic dermatitis (AD). We reported enhanced interleukin-5 (IL- 5) production by peripheral blood T cells of asthmatic patients. Production of cytokines, particularly IL-5 and IL- 13, by peripheral blood mononuclear cells (PBMC) ob- tained from bronchial asthma (BA) and AD patients was investigated in the present study. Methods: PBMC were cultured in the presence of either polyclonal activator, phorbol ester plus Ca 2+ ionophore or Dermatophagoides farinae (Df) antigen. The resulting supernatants were assayed for IL-4, IL-5, and IL-13 by specific ELISAs. Results: IL-5 and IL-13 production in response to Df anti- gen is significantly higher in allergic groups compared to control subjects. IL-5 responses induced by Df antigen were strongly correlated with IL-13 responses. Conclu- sion: In spite of IL-13 gene proximity to IL-4 gene, IL-5 production was more strongly correlated to IL-13 pro- duction in the BA group, suggesting a common control mechanism that regulates the IL-5 and IL-13 gene. Copyright © 2004 S. Karger AG, Basel Introduction The critical role of activated T cells and T cell cyto- kines in bronchial asthma (BA) and atopic dermatitis (AD) has been well established [1–3]. Th2 cells influence allergic diseases through the secretion of an array of cyto- kines (IL-4, IL-5, IL-13) that activate inflammatory and residential cells both directly and indirectly. IL-5 is a key factor for eosinophilia and thought to be responsible for the tissue damage observed in chronic asthma [2, 3]. IL-4 is essential for IgE synthesis by B cells. Increased IL-4 and decreased interferon gamma production have been postu- lated to promote IgE production in AD [4]. IL-13 shares many of the properties of IL-4. IL-13 and IL-4 genes are located a short distance apart and tend to be coordinately expressed [5]. On the other hand, other investigators reported that IL-4 and IL-13 production was indepen- dently regulated [6, 7]. We previously reported that IL-5 production by peripheral blood T cells of asthmatic pa- tients in response to Dermatophagoides farinae (Df) anti- gen was highly enhanced compared to healthy subjects [8]. IL-13 production in response to Df antigen has never been examined so far. Therefore, in this study we investi- gated cytokine production by peripheral blood mononu- clear cells (PBMC) obtained from AD and BA patients, and a possible correlation between IL-5 and IL-13 synthe- sis was explored.