Effects of erythromycin on experimental extrinsic allergic alveolitis

Background Recent clinical studies have demonstrated the efficacy of erythromycin for treating patients with chronic lower respiratory tract inflammation. Mechanisms related to the anti-inflammatory action are yet to be determined. Objectives The therapeutic efficacy of erythromycin in experimental extrinsic allergic alveolitis (EAA) was evaluated. Methods A murine model of EAA was developed by intratracheal inoculations with particulate Trichosporon mucoides followed by erythromycin or josamycin treatment. Cell populations, specific antibodies, chemotactic activities, TNF-α, IL-1β, MIP-2 and KC of bronchoalveolar lavage fluid (BALF); histopathology of the lung and footpad reaction; myeloperoxidase of the whole lung; and immunohistochemistry of intercellular adhesion molecule-1 (ICAM-1), at 6 and 96 h after the challenge, were examined. Results There was a marked neutrophilic alveolitis and bronchiolitis at 6 h, and lymphocytic alveolitis and perivenule cuffing at 96 h after the challenge. Increase in total inflammatory cells and neutrophils in BALF at 6 h was significantly suppressed by pre-treatment with 5 mg/kg/day of erythromycin intraperitoneally for 5 days (P