The indication and effectiveness of low-dose erythromycin therapy in pediatric patients with bronchial asthma.

To elucidate the mechanisms of intractable pediatric bronchial asthma and the indication of low-dose erythromycin (EM) therapy, the serum chemokine levels of and the angiogenic factor were evaluated in 55 pediatric patients with bronchial asthma; 7.4 +/- 3.5 yr old, who had been treated with inhaled steroid, leukotriene receptor antagonist, theophylline and others for more than a year. Both the levels of interleukin (IL) 8 (p = 0.036) and vascular endothelial growth factor (VEGF) (p = 0.005) were higher in patients with severe type than those of patients with the milder type, while other chemokine levels such as serum eotaxin and MCP1 did not show the correlation with the severity of bronchial asthma. Induction of therapy with low-dose EM induced improvement of the clinical symptoms in patients with severe type and decrease of their serum chemokine levels: IL8; from 736 +/- 88 to 75 +/- 85 pg/ml (p < 0.0005), and VEGF; from 352.0 +/- 160.5 to 132.2 +/- 59.9 pg/ml (p = 0.021) within the next 6 months. Moreover, low-dose EM resulted in a decreased daily peak-trough fluctuation rate of the serum theophylline concentration; (C(max )- C(min))/C(min), from 1.3 +/- 0.5 to 0.5 +/- 0.3, which led to the maintenance of effective serum levels. These results indicated that IL8 and VEGF affect the severity of standard therapies resistance intractable bronchial asthma. Through the suppression of these chemokines and maintenance of effective theophylline levels, low-dose EM therapy improves the symptoms of bronchial asthma.