[A mechanism of usefulness of treatment with erythromycin for diffuse panbronchiolitis]

The clinical usefulness of treatment with erythromycin for diffuse panbronchiolitis (DPB) patients have been well reported to date, although its mechanisms remain unknown. In a previous study, we demonstrated that DPB patients were found to have large percentages of neutrophils in their lower respiratory tracts and suggested that neutrophils play an important role in the pathogenesis of DPB (Chest 99: 917-923, 1990). While in vitro and in vivo studies have demonstrated that erythromycin decreases neutrophils directed migration. In the present study, we performed bronchoalveolar lavage (BAL) on eight patients with DPB to clarify the cell populations in the lower respiratory tract before and after treatment with erythromycin. Neutrophils percentages in BAL fluid were significantly reduced after treatment with erythromycin (54.3 +/- 22.4% to 13.1 +/- 13.5%, p less than 0.01). No significant variance of BAL lymphocyte percentages was demonstrated after treatment with erythromycin. These results suggest that a main mechanism of clinical usefulness of treatment with erythromycin for DPB may be inhibition of neutrophils migration into the lower respiratory tract instead of intrapulmonary bactericidal activity against organisms.