Influence of allergy on the immunomodulatory and clinical effects of long-term low-dose macrolide treatment of nasal polyposis.

AIMS Cytokine levels in nasal secretions reflect the inflammatory status of the nasal and paranasal sinus mucosa and the development of mucosal disease. The results of previous investigations suggest that macrolide antibiotics can be effective in treatment of chronic rhinosinusitis and nasal polyposis. The aim of this prospective study was to compare the immunomodulatory and clinical effects of long-term low-dose macrolide treatment of nonatopic and atopic patients with nasal polyposis. METHODS Forty (n = 40) patients with nasal polyposis, 22 allergic and 18 nonallergic were administered clarithromycin (CAM) 500 mg/day single oral dose for eight weeks. We measured the levels of proinflammatory Th1 cytokines TNF-α and IL-1β, Th2 cytokines IL-4, IL-5 and IL-6, and chemokine IL-8 in the nasal fluid samples, before and after treatment, using flow cytometric method. We also scored each of the 40 patients before and after therapy according to nasal symptom score and endoscopic score. RESULTS Following treatment, we found significantly reduced levels of IL-8 (p<0.01) and TNF-α (p<0.01) in nasal secretions in nonallergic patients. In subjects with nasal polyposis and allergy, we found decreased levels of IL-8 (p<0.01), IL-6 (p<0.05) and IL-1β (p<0.01). Macrolide therapy decreased the size of polyps in 45.45% of nonatopic and in 50% of atopic patients. After macrolide treatment, we found 67.83% patients in nonallergic group and 55.55% patients in allergic group with improved nasal symptoms. CONCLUSIONS Long-term low-dose treatment with CAM was effective in the management of nasal polyposis. Our results showed that macrolide treatment of nasal polyposis have different immunomodulatory and similar clinical effects in allergic and nonallergic patients.