CHEMOKINES IN BRONCHOALVEOLAR LAVAGE FLUID IN SUMMER-TYPE HYPERSENSITIVITY PNEUMONITIS

Hypersensitivity pneumonitis (HP) is a granulomatous interstitial lung disease caused by the inhalation of a variety of antigens and is char acterized by a dramatic accumulation of inflammatory cells, including neutrophils, lymphocytes and macrophages, in the lung, The mechanisms implicated in the inflammatory cell recruitment observed in hypersensi tivity pneumonitis are unknown. We examined the concentrations of two important chemokines; interleukin-8 (IL-8) and monocyte chemoattractan t protein-1/monocyte chemotactic and activating factor (MCP-1/MCAF), i n the bronchoalveolar lavage fluid (BALF) of patients with summer-type hypersensitivity pneumonitis (n=8), and compared them with those in p atients with sarcoidosis (n=13) and with controls (n=8). In the BALF o f slammer-type hypersensitivity pneumonitis, the levels both of IL-8 a nd MCP-1 were significantly increased compared with levels measured in control subjects, On the other hand, compared to the control value, t he MCP-1 level in the BALF of the sarcoidosis patients was significant ly increased, but IL-8 was only slightly and nonsignificantly increase d. Since IL-8 is a chemoattractant for neutrophils and T-lymphocytes, whereas MCP-1 acts mainly on monocytes/macrophages, our findings may i ndicate that these two chemokines participate in the cellular accumula tion observed in hypersensitivity pneumonitis.