ABSTRACT
<p><b>OBJECTIVE</b>To investigate the changes in serum protease and cytokine in patients with silicosis, tuberculosis, and lung cancer.</p><p><b>METHODS</b>Serum samples of patients with silicosis, tuberculosis, and lung cancer were collected. The variation trends of the expression of granzyme A, cathepsin G, apolipoprotein A, and interferon-β (IFN-β) were analyzed using enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>The concentration of apolipoprotein A of the silicosis group was 200 µg/ml, significantly higher than those of the tuberculosis and lung cancer groups (P < 0.05), and the lung cancer group had a significantly higher concentration of apolipoprotein A compared with the tuberculosis group (P < 0.05). The silicosis group had significantly higher expression of cathepsin G compared with the tuberculosis and lung cancer groups (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in the concentration of cathepsin G (P > 0.05). The tuberculosis group had a significantly higher concentration of granzyme A than the silicosis and lung cancer groups (P < 0.05), and the silicosis group and lung cancer group had similar protein concentration trends (P > 0.05). The tuberculosis group and lung cancer group had significantly higher concentration of IFN-β compared with the silicosis group (P < 0.05), and the tuberculosis group and lung cancer group showed no significant difference in IFN-β concentration (P > 0.05).</p><p><b>CONCLUSION</b>This study may offer diagnostic markers for the clinical diagnosis of silicosis, tuberculosis, and lung cancer, and could provide a basis for the research, as well as potential molecular targets for the diagnosis and treatment of these diseases.</p>