Prognostic factors of chronic rhinosinusitis under long-term low-dose macrolide therapy

We studied the immunological and histopathological factors that affect the prognosis of chronic rhinosinusitis under long-term low-dose macrolide ther apy. Sixteen patients with chronic rhinosinusitis were given 200 mg clarith romycin or 150 mg roxithromycin orally once a day without other concurrent treatments for 2-3 months. Measurement of the serum IgE level, blood cell c ount and differential leukocyte count of the peripheral blood, cytological assessment of the nasal smear and computed tomographic (CT) scans of the pa ranasal sinuses were performed before treatment. The opacity of the sinuses was estimated and scored by the CT images. After treatment, anterior ethmo idal mucosa samples were collected, an infiltrated inflammatory cells, inte rferon (IFN)gamma-positive cells and interleukin (IL)-4-positive cells were examined histologically and immunohistochemically. The severity of nasal s ymptoms was scored before and after treatment, and the improvement rate of the score (symptomatic improvement rate) was calculated. Patients with norm al levels of serum IgE (less than or equal to 250 U/ml) showed a significan tly higher symptomatic improvement rate than those with high levels of seru m IgE (42.1 +/- 11.2 vs. 4.9 +/- 3.1%, p = 0.046). The symptomatic improvem ent rate was inversely correlated with the eosinophil counts in the periphe ral blood (r = -0.51, p = 0.04), in the nasal smear (r = -0.54, p = 0.045) and in the sinus mucosa (r = -0.54, p = 0.02). Meanwhile, the CT score, the number of IFN-gamma-positive cells and IL-4-positive cells in the sinus mu cosa and neutrophil counts in the nasal smear and in the sinus mucosa faile d to correlate with the symptomatic improvement rate. These results suggest that macrolide therapy is indicated for patients without atopy or smear/ti ssue/peripheral blood eosinophilia. On the contrary, the severity of the di sease, Th1/Th2 dominance in the sinus mucosa and neutrophilia are unlikely to be prognostic factors of chronic rhinosinusitis under long-term low-dose marolide therapy. Copyright (C) 2000 S. Karger AG. Basel.