Lipocortin I gene expression is higher in blood monocytes than in BAL fluid macrophages in patients with pulmonary sarcoidosis.

BACKGROUND AND AIM OF WORK: Lipocortin I, induced by corticosteroids in vivo is considered to be related to cell activation and differentiation in mononuclear phagocytes, key cells in the process of epithelioid cell granuloma formation in sarcoidosis. Therefore, we focused on the expression of lipocortin I gene in mononuclear phagocytes in patients with sarcoidosis. METHOD: The amounts of transcripts of lipocortin I gene obtained from both BAL fluid macrophages and blood monocytes were measured by RT-PCR and HPLC, and then standardized as the ratio of lipocortin I/beta-actin for comparison. RESULTS: 1. Smoking did not affect the expression of lipocortin I gene in BAL fluid macrophages and monocytes. 2. There were no differences in the amounts of expression in BAL fluid macrophages between patient groups (nonsmokers and smokers), or between patients and healthy subjects. 3. The gene expression in BAL fluid macrophages was higher than that in monocytes in patients with IPF (macrophages 1.23 +/- 0.48, vs monocytes 0.50 +/- 0.38, p < 0.05) and healthy subjects (nonsmokers: 1.66 +/- 1.17, vs 0.34 +/- 0.26, p < 0.05, smoker: 1.98 +/- 0.96, vs 0.34 +/- 0.48, p < 0.05, but sarcoidosis patients showed a higher expression of lipocortin I gene even in monocytes (2.62 +/- 1.87, vs 2.66 +/- 2.21). CONCLUSION: The increase in lipocortin I gene expression in monocytes was a disease-related finding in sarcoidosis.