Altered levels of the soluble IL-1, IL-4 and TNF receptors, as well as the IL-1 receptor antagonist, in intermittent allergic rhinitis

Background: The effects of cytokines are modulated by soluble cytokine receptors (SCR) and receptor antagonists. Therefore, allergic disease may depend on altered proportions between cytokines, their SCR and receptor antagonists, rather than absolute changes in cytokine levels. Little is known about SCR in intermittent allergic rhinitis (IAR). Objective: To examine the concentrations of SCR, i.e. sIL-1R2, sIL-4R, sIL-6R and sTNFR1, as well as the interleukin-1 receptor antagonist (IL-1Ra) in nasal fluids from allergen-challenged patients with IAR and healthy controls. Methods: 30 patients with birch- or grass-pollen-induced IAR and 30 healthy controls were studied. In the patients nasal fluids were obtained before as well as 1 and 6 h after allergen provocation. Results: Both symptom scores and rhinoscopic signs of rhinitis increased in the patients after allergen challenge. Comparisons between patients and controls showed that sIL-4R was lower in patients before and 1 and 6 h after provocation. IL-1Ra was lower before and 1 h after provocation. In addition, lower concentrations of sTNFR1 were found in patients after 1 h, while sIL-1R2 concentrations were higher after 1 h. Comparisons of patients before and after challenge showed that IL-1Ra and sTNFR1 decreased after 1 h, while sIL-1R2 increased. No significant differences were found compared to 6 h. sIL-6R did not significantly differ between the study groups. Conclusions: After allergen challenge, significant changes in the nasal fluid levels of IL-1Ra, sIL-1R2 and sTNFR1 were found. By contrast, sIL-4R remained at lower levels than in controls both before and after challenge. Since sIL-4R modulates IgE synthesis, this may play a role in the pathogenesis of IAR. Copyright (C) 2004 S. Karger AG, Basel.