Usefulness of Pleural Adenosine Deaminase in Children for the Differentiation Tuberculous Pleural Effusion from Mycoplasma pneumonia with Pleural Effusion / 소아알레르기및호흡기학회지

ABSTRACT

PURPOSE: Determination of adenosine deaminase (ADA) in pleural fluid has been suggested as another tool to establish early diagnosis of tuberculous pleural effusion. However, there are few studies concerning its usefulness in children. The objective of this study was to evaluate the utility of the determination of ADA level in pleural fluid for the differential diagnosis between tuberculous pleural effusion (TPE) and Mycoplasma pneumonia with pleural effusion (MP) in children. METHODS: We retrospectively reviewed the clinical records of 13 TPE patients and 21 MP patients with pleural effusion. Also, we analyzed ADA levels, and clinical, biochemical, microbiologic and cytologic findings in the pleural fluid. RESULTS: The pleural fluid of all the subjects revealed exudative rather than transudate characteristics. The mean ADA level in the TPE group was significantly higher than that in the MP group (106.27+/-43.71 IU/L vs. 65.28+/-26.27 IU/L, P=0.003). The area under the curve in receiver operating characteristic analysis was 0.810. With a cut-off level for ADA of 60 U/L, the sensitivity, specificity, positive predictive value, and negative predictive value were 92.3%, 61.9%, 60.0%, and 92.9%, respectively. As many as 38.9% of patients with MP were false-positive with this ADA cut-off setting. CONCLUSION: Although the measurement of ADA activity in pleural fluid can help TPE diagnosis, we should consider that some cases of MP with pleural effusion showed high ADA activities. Accordingly, the utility of the ADA level in pleural fluid for the differentiation of TPE from MP declines and additional relevant studies are required.