The Pleural and blood gene expression level of GBP5 and STAT1 were associated with pleural tuberculosis: TB pleura diagnostic biomarkers

<b>Background:</b> Pleural tuberculosis (TB pleura) is the most common treatable cause of lymphocytic exudative pleural effusion. Differentiation of TB pleura from malignant pleural effusion (MPE) is often problematic in clinical practice. The blood TB-specific genes expression and its diagnostic implication in active pulmonary tuberculosis has been observed, but data in TB pleura is lacking. <b>Objective:</b> This study was aimed to investigate the TB-specific genes expression in pleural fluid and blood samples in settings of lymphocytic exudative pleural effusion. <b>Methods:</b> Each patient with lymphocytic exudative pleural effusion was asked to provide 3 ml of pleural fluid and 3 ml of blood samples, separately collected into the RNA collection tube, processed through the RNA isolation kit, used in the quantitative real-time PCR to measure the expression levels of 10 TB-specific genes (<i>FCGR1B1, FCGR1B2, FCGR1A, MAFB, GBP5, APOL1, KCNJ15, STAT1, KAZN and CD53</i>) and compared the level of each gene between TB pleura and MPE groups. <b>Results:</b> Total 16 TB pleura and 18 MPE patients were prospective enrolled during 2018-2019. The pleural <i>GBP5</i> (8.0 vs. 0.8, p&lt;0.001) and pleural <i>STAT1</i> (11.1 vs. 3.1, p&lt;0.001) were significantly higher expressed in TB pleura comparing to MPE group and also correlated with the blood <i>GBP5</i> (r=0.384, p=0.025) and blood <i>STAT1</i> (r=0.436, p=0.010). The pleural <i>GBP5</i> had highest AUROC 97.9% (93.5-100%) and its cut point at 3.0 had sensitivity 93.8%, specificity 100%, PPV 100% and NPV 94.7%. <b>Conclusion:</b><i>GBP5</i> and <i>STAT1</i> in both pleural fluid and blood samples were associated with TB pleura. Pleural fluid and blood <i>GBP5</i> can be used in TB pleura diagnosis.