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.