Interleukin-4, interleukin-5, and granulocyte-macrophage colony-stimulating factor receptor expression in chronic...

Chronic sinusitis and its associated eosinophilic infiltrate are believed to be mediated, at least in part, by the upregulation of Th-2 cytokines, including interleukin-4, interleukin-5, and granulocyte-macrophage colony-stimulating factor (GM-CSF). Interleukin-4 is involved in IgE production and in eosinophil recruitment through upregulation of vascular cell adhesion molecule-1. Interleukin-5 and GM-CSF are involved in eosinophil growth and survival. The aim of this study was to investigate the expression of receptors for these cytokines in the sinus mucosa of subjects with chronic sinusitis. Using the technique of in situ hybridization to detect specific cytokine receptor messenger RNA, we studied the sinus mucosa of subjects with nonallergic chronic sinusitis, subjects with allergic chronic sinusitis, subjects with allergic chronic sinusitis treated with topical steroids, and normal controls. Our data demonstrate higher expression of interleukin-4 receptor in subjects with allergic chronic sinusitis than in controls (p < 0.001) and higher expression of interleukin-5 receptor in both subjects with nonallergic chronic sinusitis and subjects with allergic chronic sinusitis than in controls (p < 0.001, p < 0.001). The expression of interleukin-4 receptor and interleukin-5 receptor was higher in subjects with allergic chronic sinusitis than in subjects with nonallergic chronic sinusitis (p < 0.001). GM-CSF receptor expression was also found to be higher in subjects with allergic chronic sinusitis and subjects with nonallergic chronic sinusitis than in controls (p < 0.001, p < 0.001). In contrast to interleukin-4 receptor and interleukin-5 receptor, however, expression of GM-CSF receptor was higher in subjects with nonallergic chronic sinusitis than in subjects with allergic chronic sinusitis (p < 0.001). In subjects with allergic chronic sinusitis treated with topical corticosteroids, the expression of interleukin-4 receptor and interleukin-5 receptor messenger RNA levels was significantly lower than levels in patients with allergic chronic sinusitis who were not taking topical steroids (p < 0.001, p < 0.001). Steroid treatment had no effect on GM-CSF receptor messenger RNA expression. In conclusion, our data support a role for Th-2 cytokine receptors in the pathophysiology of chronic sinusitis. Further, our data lend support to the theory that differential activation of distinct cytokine pathways mediates inflammation in chronic sinusitis depending on whether there is associated allergy. Finally, treatment with topical corticosteroids has been demonstrated in chronic sinusitis to downregulate receptors for interleukin-4 and interleukin-5.