Specific immunoglobulin E, interleukin-4, and soluble vascular cell adhesion molecule-1 in sera in patients with seasonal allergic rhinitis.

This study included 23 nonatopic volunteers and 84 patients with seasonal allergic rhinitis due to Japanese cedar pollen. Serum interleukin-4 (IL-4) and soluble vascular cell adhesion molecule-1 (sVCAM-1) in the patients were significantly higher than those in the nonatopic individuals, even outside of the pollen season. Both the good responders and the poor responders to antihistamine tablets showed significant increases in IL-4 and specific IgE during the pollen season, whereas such seasonal increases were not observed in the good responders to immunotherapy. Seasonal increases in IL-4 were significantly correlated with those of specific IgE. However, seasonal increases in sVCAM-1 were not significant. Seasonal increases in sVCAM-1 were not significantly different between the good responders and the poor responders to pharmacotherapy or immunotherapy. In conclusion, serum IL-4 and sVCAM-1 are increased in patients with seasonal allergic rhinitis, even outside of the pollen season; this finding might suggest underlying preponderant in vivo activation of T helper cell-2-like cells and inflammatory events in seasonal allergic rhinitis. A seasonal increase in IL-4 in sera might be at least partly involved in the seasonal increase in specific IgE in sera. Immunotherapy's inhibitory effect on IL-4 production and specific IgE response might be one of its working mechanisms.