Abstract: Objective To investigate the expression levels of lactate dehydrogenase (LDH), adenosine deaminase (ADA), and soluble growth stimulation expressed gene 2 (sST2) in patients with tuberculous pleural effusion and to analyze the diagnostic value of the three combined for tuberculous pleural effusion (TPE). Method From September 2021 to September 2023, 101 patients with pleural effusion who visited Western Theater Command General Hospital were selected. They were grouped into a TPE group of 52 cases and a control group of 49 cases (non tuberculosis infection) based on the presence of tuberculosis infection. General information was collected, pleural effusion was collected from patients through thoracentesis, enzyme colorimetry was applied to detect LDH level, pois colorimetric method was applied to detect ADA level, enzyme linked immunosorbent assay (ELISA) was applied to detect the level of sST2; receiver operating characteristic (ROC) curve was applied to analyze the diagnostic value of pleural fluid LDH, ADA, and sST2 for TPE; multivariate Logistic regression was applied to analyze the influencing factors of TPE occurrence. Result LDH, ADA and sST2 levels in pleural fluid were higher in the TPE group than in the control group, and the difference was statistically significant (P<0.05). ROC curve results showed that the AUC of LDH, ADA and sST2 alone and in combination in predicting TPE in patients with pleural effusion was 0.865, 0.867, 0.880, and 0.954, respectively, the combined diagnosis of the three was superior to the individual diagnosis of LDH, ADA, and sST2 (Z=2.981, 2.232, 2.689, P<0.05). Multifactorial Logistic regression analysis showed that LDH, ADA, and sST2 were all influential factors in the development of TPE (P<0.05). Conclusion LDH, ADA, and sST2 levels are increased in patients with tuberculous pleural effusion, and the combination of the three tests has some diagnostic value in tuberculous pleural effusion.

Key words: Tuberculous pleural effusion, Lactate dehydrogenase, Adenosine deaminase, Growth stimulation expressed gene 2