The expression of Th1 markers, IFNγ and IL-12 receptor β2 (IL-12Rβ2), and Th2 markers, IL-4 and CD30, was investigated in the paranasal sinus mucosa of patients with chronic sinusitis in an attempt to elucidate the Th1-Th2 balance in situ in this disease.
Anterior ethmoidal mucosae were surgically obtained from 27 patients with chronic sinusitis. The patients were classified into three group: those without atopic state (nonallergic group, n=13), those with allergic rhinitis (allergic rhinitis group, n=9) and those with bronchial asthma (asthma group, n=5). IFNγ+, IL-4+ and CD30+ cells were examined by immunohistochemistry, and IL-12Rβ2 mRNA was quantitatively analyzed by reverse transcription-polymerase chain reaction.
The numbers of eosinophi-s, IL-4+ cells, CD30+ cells and the ratio of IL-4+ cells/IFNγ+ cells were significantly larger in the asthma group compared to the nonallergic group. This indicates that Th2 is more dominant in the asthma group than in the nonallergic group, which may be responsible for the intractability and the tendency to recurrence of sinusitis in asthmatic patients. Meanwhile, there were no significant differences in the numbers of eosinophi-s, IL-4+, CD30+ and IFNγ+ cells, and the expression leve-of IL-12Rβ2 mRNA between the nonallergic and allergic rhinitis groups. Subjects with high and low values of Th2/Th1 ratios, i. e., IL-4+ cells/IFNγ+ cells and CD30+ cells/IL-12Rβ2, were intermingled both in the nonallergic and allergic rhinitis groups, indicating the discrepancy between the clinical diagnosis of allergic sinusitis and the profile of inflammatory reactions in situ.
It is concluded that allergic and nonallergic sinusitis should be diagnosed on the basis of direct evidence for the characteristics of inflammatory reactions in the paranasal sinus mucosa rather than indirect evidence such as nasal smear, rhinoscopic finding, skin tests, or serological tests. Accurate evaluation of the sinus mucosa would be useful for the choice of appropriate medication in the treatment of patients with chronic sinusitis.
