Comparative study on effects of pentoxifylline, prednisolone and colchicine in experimental alveolitis

Neutrophil alveolitis is a hallmark of cryptogenic fibrosing alveolitis (CF A), known for its poor prognosis. Corticosteroids, as the remedy of choice, are ineffective in a majority of patients. More and more evidence indicate s that pentoxifylline (POF) could be an effective therapeutic alternative. Furthermore, colchicine has been proposed for therapy of CFA for many years now. We conducted an experimental study comparing the efficacy of these dr ugs in preventing neutrophil alveolitis in vivo. Alveolitis was induced in male rats by intratracheal instillation of bleomy cin. Treatment consisted of dairy injections of POF i.p., colchicine i.p., or prednisolone i.m. After 8 days the animals were sacrificed and body weig hts, cell differentials in BAL, amount of proliferating interstitial cells as determined by KI-67 staining of lung tissue, and collagen concentrations in lungs were determined. Bleomycin instillation was followed by a significant weight loss in the ani mals, a neutrophil alveolitis in BAL and an increased amount of proliferati ng cells in lung interstitium. POF significantly inhibited any of the param eters named, whereas prednisolone and colchicine had little effect. Data cannot be applied directly in human disease. There are however many si milarities between CFA and bleomycin-induced lung injury and alveolitis. We conclude that POF is an effective inhibitor of neutrophil alveolitis, wher eas neither colchicine nor prednisolone exerted significant influence in ou r model. We suggest POF effects should be further investigated regarding an ti-inflammatory and anti-fibrotic properties. (C) 1998 International Societ y for Immunopharmacology. Published by Elsevier Science Ltd.