Background: Bronchial asthma patients may
develop various asthmatic response types to bronchial challenge with allergen,
such as immediate (IAR), late (LAR), dual (DAR) or delayed (DYAR), due to
different immunologic mechanisms. The DYAR, beginning between 26-32 hrs and lasting up to 56
hrs after the allergen challenge, differs from the IAR, LAR and DAR in clinical,
diagnostic and immunologic aspects. The aim of this study was to investigate
the concentrations of the particular intracellular cytokines released by blood
cells stimulated with relevant allergens “in
vitro”, before and during the DYAR. Methods: In 23 patients, the repeated DYAR (p < 0.001) was supplemented with
cytokine determination in the supernatants of the blood cells stimulated with
relevant allergens before and up to 72 hours after the bronchial challenge, by
means of enzyme-linked immunoassay. Results: The significantly elevated
pre-challenge concentrations (p < 0.05)
of IL-2, IL-17, IFN-γ and G-CSF released by
allergen-stimulated blood cells “in vitro”
were recorded in the DYAR patients as compared with healthy controls. The
significantly increased post-challenge concentrations (p < 0.05) of IL-1β, IL-2, IL-8, IL-12p70, IL-18, IFN-γ and TNF-α, whereas decreased concentrations of IL-4, IL-6 and IL-17, were
released by blood cells stimulated with relevant allergens “in vitro”, as compared both with their
pre-challenge concentrations and with the corresponding PBS control values.
Conclusions: The profiles of cytokines released by allergen-stimulated peripheral blood cells
during the DYAR would suggest an activation of Th1 cells, neutrophils,
monocytes and probably also bronchial macrophages, epithelial and endothelial
cells and their involvement in the immunologic mechanism(s) underlying the
clinical DYAR.