Increased Expression of IL-4, IL-5, IFN-gamma, IL-6, IL-8, and TGF-beta MRNAs in Maxillary Mucosa of Patients with Chronic Sinusitis

This study aimed to investigate expression of various cytokine mRNAs, including IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma in maxillary sinus mucosa of patients with chronic sinusitis. Maxillary sinus mucosae of six patients with chronic sinusitis and turbinate mucosae of six healthy subjects were obtained. We performed RT-PCR and Southern blot to examine gene expression of the cytokines IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma in maxillary sinus mucosa and compared the results with cytokine gene expressions in normal turbinate mucosa. IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma mRNAs were expressed more frequently in maxillary sinus mucosa from patients with chronic sinusitis than in normal turbinate mucosa. All the maxillary sinus mucosa specimens revealed relatively higher mean density ratio for each cytokine investigated than did normal turbinate mucosa. IL-6, IL-8, TGF-beta, IL-4, IL-5, and IFN-gamma mRNAs were expressed simultaneously in maxillary sinus mucosa of chronic sinusitis. These cytokines may be responsible for recruitment of inflammatory cells and for mucosal thickening in chronic sinusitis, and thus chronicity of the disease.