Expressions and diagnostic value of the cytokines in tuberculous and malignant pleural effusion

Abstract

Objective To analyze the levels of pro-inflammatory cytokines, anti-inflammatory cytokines and chemokines in tuberculous and malignant pleural effusion using Luminex method, and to evaluate their diagnostic value in tuberculous pleural effusion. Methods Fifty-three patients with tuberculous pleural effusion and 28 patient with malignant pleural effusion were included in this study. Luminex method was applied to detect the levels of pro-inflammatory cytokines (interleukin [IL]-1β, IL-6, IL-12, interferon [IFN]-γ and tumor necrosis factor [TNF]-α), anti-inflammatory cytokines (IL-1 receptor antagonist [IL-1ra], IL-4, and IL-10), and chemokines (IFN-γ inducible protein [IP]-10, macrophage inflammatory protein [MIP]-1α, MIP-1β, and monocyte chemo-attractant protein [MCP]-1) in all patients. The levels of cytokines were compared using Mann-Whitney test. Results The levels of IFN-γ (1 064.33 pg/mL vs 294.78 pg/mL, U=130.5, P<0.01) and IP-10 (39 179.86 pg/mL vs 9 411.73 pg/mL, U=98.0, P<0.01) in tuberculous pleural effusion were significantly higher than those in malignant pleural effusion, while the IL-10 level (11.52 pg/mL vs 17.77 pg/mL, U=565.5, P=0.017) was significantly lower than that in malignant pleural effusion. Furthermore, IFN-γ/IL-10 (100.07 vs 16.19, U=116.0, P<0.01) and IP-10/IL-10 (2 930.91 vs 591.18, U=75.0, P<0.01) in tuberculous pleural effusion were significantly higher than those in malignant pleural effusion. Area under the curve of receiver operating characteristic of IFN-γ, IP-10, IFN-γ/IL-10, and IP-10/IL-10 were 0.91, 0.93, 0.92 and 0.95, respectively, with the cut-off value of 483.5 pg/mL, 20 340 pg/mL, 41.11 and 1 614. For the diagnosis of tuberculous pleural effusion, the sensitivities and specificities of IFN-γ≥483.5 pg/mL, IP-10≥20 340 pg/mL, IFN-γ/IL-10≥41.11, and IP-10/IL-10≥1 614 were 0.830(95%CI: 0.702-0.920) and 0.962(95%CI: 0.804-0.999), 0.906(95%CI: 0.793-0.969) and 0.923(95%CI: 0.749-0.991), 0.811(95%CI: 0.680-0.906) and 0.923(95%CI: 0.749-0.991), 0.868(95%CI: 0.747-0.945) and 0.923(95%CI: 0.749-0.991), respectively. Conclusions The expression levels of IFN-γ, IP-10 and IL-10 in pleural effusion detected by Luminex method is convenient, rapid, noninvasive, sensitive and specific, which is helpful for the diagnosis of tuberculous pleural effusion. Key words: Cytokines; Tuberculosis, pleural; Pleural effusion, malignant; Diagnosis, differential