IL-4 AND IL-3 EXPRESSION IN CHRONIC SINUSITIS - RELATIONSHIP WITH CELLULAR INFILTRATE AND EFFECT OF TOPICAL CORTICOSTEROID TREATMENT

Objective: Chronic sinusitis with allergy (ACS) and without allergy (N CS) are inflammatory diseases with considerable morbidity. The present study was undertaken to investigate, by in situ hybridization, the ex pression of IL-13 and IL-4 mRNA in sinus biopsy sections. Method: Spec imens were obtained from subjects with NCS (n = 12), ACS (n = 13), ACS on steroid therapy (n = 11), and normal controls (n = 11). The compos ition of the inflammatory infiltrate was also examined in all cases. R esults: The number of cells expressing IL-4 and IL-13 transcripts was significantly higher in subjects with ACS compared to normal controls. In contrast, the numbers of IL-13 but not IL-4 mRNA-positive cells we re increased in the NCS subjects compared to the normal controls. IL-4 and IL-13 mRNA expression was suppressed in ACS subjects on topical s teroid therapy compared to untreated patients. There was no significan t difference in the numbers of eosinophils between the ACS subjects tr eated with steroids and those who were not treated, but the steroid-tr eated patients demonstrated significantly higher numbers of CD8(+) cel ls in the sinus mucosa. Increased numbers of CD8(+) cells were also ob served in subjects with NCS compared with ACS subjects and normal cont rols. Conclusions: These results demonstrate that increased IL-13 expr ession is an important feature of allergic and nonallergic patients wi th chronic sinusitis. Furthermore, our data indicate that IL-13 and IL -4 are under differential regulation in NCS subjects.