Erythropoietin ameliorates chemotherapy-induced fibrosis of the lungs in a preclinical murine model.

Organ toxicity induced by chemotherapeutic drugs is a serious obstacle in the effective treatment of patients suffering from cancer and autoimmune disease. A strong association exists between pulmonary toxicity, particularly fibrosis, and chemotherapeutic drugs. Attempts have been made to identify compounds capable of suppressing fibrosis. In addition to its erythropoietic activity, erythropoietin (EPO) has been shown to have effects on nonhemopoietic cells. Therefore, we postulated that EPO may exert beneficial effects on lung tissue during chemotherapy. To test our hypothesis, we investigated pulmonary changes caused by bleomycin, a fibrosis-inducing agent, in animals treated with the drug alone and in combination with EPO. Fibrosis, cellular alterations and structural changes were assayed by blind analysis of the lung sections. A 6-fold decrease in the number of prominent endothelial cells--suspected to be indicative of cellular activation and inflammatory response--was observed in lung sections derived from mice treated with bleomycin and EPO compared to animals injected with bleomycin alone (p < 0.008). Additionally, there was twice the number of ICAM1-positive endothelial cells in animals treated with bleomycin alone compared with the number in the bleomycin and EPO-treated group (p < 0.05). Alveolar mononuclear phagocytic hyperplasia was reduced by as much as 100% in animals treated with bleomycin and EPO compared to animals treated with bleomycin alone (p < 0.03). Finally, a 5-fold decrease in interstitial fibrosis was observed in lung sections obtained from animals treated with bleomycin and EPO (p < 0.02). We conclude that EPO can ameliorate drug-induced fibrosis and endothelial damage caused by chemotherapeutic agents.