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 therapy. Sixteen patients with chronic rhinosinusitis were given 200 mg clarithromycin or 150 mg roxithromycin orally once a day without other concurrent treatments for 2-3 months. Measurement of the serum IgE level, blood cell count and differential leukocyte count of the peripheral blood, cytological assessment of the nasal smear and computed tomographic (CT) scans of the paranasal sinuses were performed before treatment. The opacity of the sinuses was estimated and scored by the CT images. After treatment, anterior ethmoidal mucosa samples were collected, an infiltrated inflammatory cells, interferon (IFN)-gamma-positive cells and interleukin (IL)-4-positive cells were examined histologically and immunohistochemically. The severity of nasal symptoms was scored before and after treatment, and the improvement rate of the score (symptomatic improvement rate) was calculated. Patients with normal levels of serum IgE (