DPB has been known as a chronic respiratory infection with poor prognosis until introduction of erythromycin (EM) therapy with low-dose and long-term administration. As symptoms and prognosis of DPB were improved enormously under EM therapy, EM therapy on DPB was analyzed to clarify the action and mechanisms.
EM in a daily dose of 600 mg was administered to 9 patients with DPB for about 38 months and 7 normal volunteers for 2 months. Most patients with DPB showed the relief of symptoms within 2 months, although the EM concentrations in the blood and sputa were lower than the antibacterial therapeutic level. Immunological examination revealed the decrease in cold agglutinin titer and CD4/CD8 ratio after EM therapy. The neutrophil chemotactic factor (NCF) derived from the mononuclear cell culture of DPB patients was higher than that in the normal control. EM therapy decreased the level of NCF not only in patients with DPB but also in normal volunteers.
These findings indicate that the immunological effects of EM play an important role in the treatment of DPB.
