Elevated chemokine levels in bronchoalveolar lavage fluid of patients with eosinophilic pneumonia

Background: Allergic lung inflammation is caused by accumulation and activation of different leukocyte subsets, such as eosinophils and T lymphocytes, in the lung, The chemokines are a large group of chemotactic cytokines that regulate leukocyte trafficking and may play an important role in allergic lung inflammation. Objective: The purpose of this study was to evaluate the role of various chemokines, including eotaxin, RANTES, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1 beta, and IL-8 in the pathogenesis of eosinophilic pneumonia (EP). Methods: The concentrations of eotaxin, RANTES, MCP-1, MIP-1 beta, and IL-8 in bronchoalveolar lavage fluid (BALF) were measured by using ELISA in 15 patients with EP, 10 with idiopathic pulmonary fibrosis, 10 with sarcoidosis, and 11 healthy volunteers. Results: Eotaxin in BALF was high only in patients with EP, and its level correlated significantly with the number of eosinophils in BALF of patients with EP and healthy volunteers. MCP-1 and MIP-1 beta in BALF were preferentially increased in patients with EP. There was a significant correlation between MCP-1 levels and the number of macrophages in BALF of patients with EP and healthy volunteers. Conclusion: Our findings suggest that these CC chemokines contribute to the pathogenesis of EP through the specific recruitment of leukocyte subsets in the lung.