Interleukin 1β, Tumor Necrosis Factor Alpha, and Interleukin 8 in Bronchoalveolar Lavage Fluid of Patients with Diffuse Panbronchiolitis: A Potential Mechanism of Macrolide Therapy

Abstract

We measured the levels of interleukin (IL) 1β, tumor necrosis factor alpha, and IL-8 in bronchoalveolar lavage fluid (BALF) and sera of patients with diffuse panbronchiolitis (DPB) before and after administration of erythromycin or roxithromycin. The pretreatment levels of IL-1β and IL-8 were significantly higher in the BALF of patients with DPB than in the BALF of patients with sarcoidosis and controls. The tumor necrosis factor alpha level was also higher than in controls, but not statistically significant. There was a significant correlation between percentage of neutrophils and IL-8 level in the BALF of DPB patients (r = 0.509; p < 0.05) on the one hand and between IL-1β and IL-8 on the other (r = 0.476; p < 0.04). Treatment for 1-24 months significantly reduced BALF levels of IL-1β and IL-8 of DPB patients in parallel with a reduction in BALF neutrophils. The serum level of IL-8 of DPB patients was higher, albeit insignificant, than that of controls and significantly lower than that in the BALF of the same patients (p = 0.0088). Serum IL-1β was below the detection limit. In addition, the concentration of IL-8 in alveolar macrophages obtained from 2 volunteers before and after oral erythromycin administration also decreased ex vivo. Our results indicate that IL-8 induces the migration of neutrophils to inflammatory sites. It is possible that the macrolides impair production and/or secretion of these cytokines, ultimately reducing neutrophil accumulation in the airway.