Cytokine production in peripheral blood cells during and outside the pollen season in birch-allergic patients and non-allergic controls
Article first published online: 14 JAN 2004
Clinical & Experimental Allergy
Volume 34, Issue 1, pages 123–130, January 2004
How to Cite
Wosinska-Becler, K., Plewako, H., Håkansson, L. and Rak, S. (2004), Cytokine production in peripheral blood cells during and outside the pollen season in birch-allergic patients and non-allergic controls. Clinical & Experimental Allergy, 34: 123–130. doi: 10.1111/j.1365-2222.2004.01850.x
- Issue published online: 14 JAN 2004
- Article first published online: 14 JAN 2004
- Submitted 14 May 2003; revised 15 August 2003; accepted 10 October 2003
- seasonal allergy;
- T cells
Background The naturally occurring pollen season permits observation of the kinetic changes in the process of allergic inflammation. We examined cytokine production in peripheral blood (PB) T cells and monocytes obtained from birch-allergic patients both during and outside the pollen season.
Methods PB from 16 patients and six healthy controls was obtained during the alder pollen season, at the beginning and the peak of the birch pollen season and outside the pollen season. Mononuclear cells (MNC) were stimulated with allergen and polyclonal activators. For flow cytometric analysis, MNC were stained with monoclonal antibodies (MoAbs) against the cell surface markers CD3, CD8, CD14 and the intracellular cytokines IL-4, IL-5, IL-10, IL-12, IL-13, granulocyte macrophage-colony stimulating factor (GM-CSF) and IFN-γ.
Results In allergic patients, significant increases in clinical symptoms, use of medication, eosinophil numbers and birch-specific IgE were found during the pollen season. In vitro allergen stimulation increased the number of GM-CSF+ monocytes (P<0.01) and this increase was dependent on allergen exposure. The IL-4/IFN-γ ratio rose (P<0.001) at the peak of birch pollen season and the ratio correlated with symptom scores during the birch season. In the CD4+ cell population, the numbers of GM-CSF+ cells were higher throughout the alder and birch seasons compared with outside the pollen season (P<0.05). No such changes were seen in the healthy controls.
Conclusions The main finding of our study was the increased percentage of GM-CSF+ monocytes in atopic subjects compared with healthy controls. In allergic patients, natural seasonal pollen exposure resulted in increased numbers of GM-CSF+ cells among both monocytes and CD4+ T cells. We have also shown that a seasonal change in Th2/Th1 cytokine ratio requires an adequate and prolonged allergen stimulation that is seen late in the pollen season.