A STUDY OF MONOKINE RELEASE AND NATURAL-KILLER ACTIVITY IN THE BRONCHOALVEOLAR LAVAGE OF SUBJECTS WITH FARMERS LUNG

We examined the interleukin-1 (IL-1) and tumor necrosis factor alpha (TNFalpha) releasability of alveolar macrophages and the natural killer (NK) cell activity in the bronchoalveolar lavage (BAL) cells of 11 patients with Farmer's lung at different stages of the disease. Although there were some variations in the levels of monokine release, macrophages of patients with acute disease secreted significantly higher spontaneous levels of TNFalpha than did a nonfarming control group (p = 0.0002). Conversely, TNFalpha release stimulated by bacterial lipopolysaccharide (LPS) was similar in patients with acute disease when compared with that in normal control subjects. IL-1 was also spontaneously secreted in significantly greater amounts by patients with acute Farmer's lung than by subjects in a control group (p = 0.0001). However, LPS-induced IL-1 release was significantly diminished in BAL macrophages from patients with acute manifestations of the disease when compared with that in control subjects (p = 0.001). Treating hypersensitivity pneumonitis with corticosteroids or by contact avoidance resulted in a very significant decrease in spontaneous and LPS-stimulated IL-1 production by BAL macrophages (p = 0.0001 and p = 0.03, respectively), as well as in a decrease in spontaneous TNFalpha release that was also significant (p = 0.01). In addition, BAL cells of patients in the acute phase had a significant NK cell activity (mean +/- SEM of 18.33 +/- 2.65%). Treatment of these patients resulted in an increase in NK cell activity (mean of 40.17 +/- 7.86%), which was significantly different from values of patients with acute disease (p = 0.037). Overall, these results suggest that acute hypersensitivity pneumonitis is associated with high levels of spontaneous monokine release as well as with a significant NK cell activity, and treatment or contact avoidance results in a decrease in spontaneous IL-1 and TNFalpha release and an increase in NK cell activity.