The diagnostic value and validation of Th17-related cytokines in tuberculosis pleural effusion

Abstract Background There has been a great deal of evidence indicating that cytokines participate in tuberculosis immune defense. This study aimed to evaluated the levels of Th17-related cytokines in pleural effusion to discriminate tuberculosis pleurisy with malignant pleurisy. Methods 82 patients with pleural effusion were included in training cohort and 76 patients with pleural effusion were included in validation cohort. Individuals were divided into tuberculosis and malignant pleurisy group. The concentrations of Th17-related cytokines in pleural effusion were detected using multiplex cytokine assay. The threshold value was calculated according the ROC analysis to help diagnose tuberculosis pleurisy. Furthermore, the combination diagnosis was validated in validation cohort. Results The pleural effusion levels of Th17-related cytokines among the patients with tuberculosis infection were all higher than malignant pleurisy group (all P < 0.05). The AUC was ≥ 0.920 for the IL-22, sCD40L, IFN-γ, TNF-α and IL-31 found significantly increased in TPE in training cohort. A threshold value of 95.80 pg/mL in IFN-γ, 41.80 pg/mL in IL-31 and 18.87 pg/mL in IL-22 could be used to obtain sensitivity and specificity ≥ 90% to discriminate between tuberculosis pleurisy and malignant pleurisy in training cohort. IL-22 associated with sCD40L had the best sensitivity and specificity (94.0% and 96.9%) in diagnosis of tuberculosis pleurisy and was validated in validation cohort. Conclusion We demonstrated that the level of Th17-related cytokines in pleural effusion had significant difference between tuberculosis pleurisy and malignant pleurisy. IL-22 ≥ 18.87 pg/mL and sCD40L ≥ 53.08 pg/mL can be clinically utilized as an efficient diagnosis strategy for tuberculosis pleurisy.