Neutrophil chemotactic activity in bronchoalveolar lavage fluid recovered from patients with diffuse panbronchiolitis

The present study was aimed at elucidating the role of inflammatory cells in the pathogenesis of the chronic inflammatory changes in the bronchioles of patients with diffuse panbronchiolitis (DPB) and at determining the mechanism for the clinical efficacy of erythromycin (EM) therapy for these patients. For this purpose, neutrophil percentages, neutrophil chemotactic activity (NCA), IL-8 and TNF-alpha in the bronchoalveolar lavage fluid (BALF) were measured in 9 patients with DPB. Significantly higher neutrophil percentages, NCA and IL-8 concentrations were demonstrated in the BALF from DPB patients than from chronic bronchitis (CB) patients or healthy control subjects. The levels of these indicators of chronic inflammation in the BALF from DPB patients were significantly decreased after EM therapy. TNF-alpha was elevated in the BALF from both DPB- and CB-patients and was not decreased by treatment of the DPB patients with EM. From the above results, it can be concluded that IL-8, not TNF-alpha, is the major chemoattractant for neutrophils and that the inhibition of IL-8 production by EM induces the subsequent depression of neutrophil accumulation in the peripheral airways, and consequently, prevents the peripheral airway tissue damage due to accumulated and activated neutrophils.