Clarithromycin Decreases IL-6 Concentration in Serum and BAL Fluid in Patients with Cryptogenic Organizing Pneumonia.

BACKGROUND: Inflammatory cytokines are involved in the development of cryptogenic organizing pneumonia (COP). It has been shown that macrolides inhibit cytokine production in the alveolar macrophages of COP patients.

OBJECTIVES: The aim of the study was to assess the concentrations of interleukin 1β (IL-1β), IL-6, IL-8 and transforming growth factor β (TGF-β) in serum and in bronchoalveolar lavage fluid (BAL-f) in COP patients treated with clarithromycin (CAM).

MATERIAL AND METHODS: The study involved 26 patients (18 women and 8 men, mean age 56.46 ± 8.83 years) with biopsy-proven COP. After being treated with CAM, a complete recovery was achieved in 22 patients, while four patients did not respond to the treatment. The ELISA method was used to measure the serum and BAL-f concentrations of IL-1β, IL-6, IL-8 and TGF-β.

RESULTS: Before treatment, the serum IL-1β1, IL-6, IL-8 and TGF-β1 concentrations were similar in responders and non-responders. Significant decreases in serum concentrations of IL-6 (8.98 ± 13.26 pg/mL vs. 3.1 ± 6.95 pg/mL; p = 0.005), IL-8 (20.14 ± 25.72 pg/mL vs. 10.14 ± 6.8 pg/mL; p = 0.007) and TGF-β1 (37.89 ± 12.49 ng/mL vs. 26.49 ± 12.45 ng/mL; p = 0.001) were found after treatment, as well as a significant decrease in the BAL-f concentration of IL-6 (30.56 ± 56.78 pg/mL vs. 4.53 ± 5.84 pg/mL; p = 0.036). Clarithromycin treatment resulted in a significantly lower mean value of serum IL-6 responders than non-responders.

CONCLUSIONS: In COP patients, response to clarithromycin treatment was associated with decreases in serum concentrations of IL-6, IL-8 and TGF-β, and of rations, and of the BAL-f concentration of IL-6.