CYTOKINES IN THE BRONCHOALVEOLAR LAVAGE FLUID OF PATIENTS WITH ACTIVEPULMONARY SARCOIDOSIS

Numerous cytokines are thought to be important in the pathogenesis of granulomatous inflammation and subsequent fibrosis in sarcoidosis. Int erleukin (IL)-6 and IL-8, two recently described cytokines with a broa d spectrum of proinflammatory effects, could participate in this disea se. We obtained bronchoalveolar lavage fluid (BALF) from 16 subjects ( 13 African-American, three Caucasian) with untreated active pulmonary sarcoidosis and 10 healthy nonsmoking volunteers (nine Caucasian, one African-American), Concentrated BALF was analyzed by an ELISA for IL-6 , IL-8, and albumin. The median IL-6 level was 9.8 pg/mg albumin (rang e, 0-278) for the sarcoid group compared with 0.14 pg/mg (range, 0.14- 9.8) in the control subjects (p = 0.001). The corresponding values for 11-8 were 202 pg/mg (range, 35-2179) versus 5.0 pg/mg (range, 0-44) i n the control subjects (p < 0.001). Among the sarcoid patients, BALF I L-6 and IL-8 levels correlated with each other (r = 0.96, p < 0.001), and both cytokines correlated with the BALF neutrophil percentage (r = 0.96 and 0.95, respectively; p < 0.001 for both). No difference was d etected in IL-8 concentrations as measured by ELISA in culture superna tants of alveolar macrophages obtained from five sarcoid patients and five control subjects. We conclude that IL-6 and IL-8 are elevated in BALF of patients with active sarcoidosis and may be important modulato rs of the disease process.