Factors Affecting The Level Of Pleural Effusion Adenosine Deaminase And Its Significance In The Diagnosis Of Tuberculous Pleural Effusion

OBJECTIVETo investigate the factors affecting the level of pleural effusion adenosine deaminase(ADA)and its significance in the diagnosis of tuberculous pleural effusion(TPE).METHODSA retrospective study of 160 patients with pleural effusion(samples from September 2016 to June 2018 in hospital)included demographics,pleural effusion characteristics,and changes in peripheral blood,Use the receiver operating characteristic(ROC)curve to select the critical value of ADA based on age.RESULTSThere was a significant correlation between pleural fluid ADA and age,pleural fluid protein.Average pleural ADA in TPE group was significantly higher than in Non-TPE patients(51±22IU/L vs 13±12IU/L).For the diagnosis of TPE,patients aged ?60 years,The area under curve(AUC)of the ADA's ROC was 0.909.At this time,the optimal value of pleural effusion ADA is 34IU/L,the sensitivity is 88.7%,and the specificity is 90.0%.The positive predictive value(PPV)of TPE was 94.0%,and the negative predictive value(NPV)was 81.8%.When the age was >60 years old,the AUC was 0.817,and the optimal ADA of the pleural effusion was 21IU/L,the sensitivity was 69.2%,the specificity was 90.6%,the PPV was 60.0%,and the NPV was 93.5%.CONCLUSIONSThe ADA level of pleural effusion is greatly affected by the age and pleural effusion protein,decreases with age,and increases with pleural fluid protein.For the diagnosis of TPE,the lower ADA threshold should be used to diagnose TPE;the higher level of ADA threshold in younger patients may improve the accuracy of TPE diagnosis.