Pleural effusion adenosine deaminase is not accurate in diagnosis of pediatric tuberculous pleural effusion: a retrospective study.

Objective: Pleural effusion (PE) adenosine deaminase (ADA) has good performance in detection of tuberculous pleural effusion (TPE). However, few study was conducted for its value in pediatric patients. To evaluate PE ADA in diagnosis of pediatric TPE, a retrospective study was performed.
Patients and Methods: 204 pediatric PE patients were enrolled, and then were grouped into TPE group (77 cases, aged 11.51 ± 0.40 years) and non-TPE group (127 cases, aged 6.39 ± 0.35 years). Man-Whitney U test was used to compare difference in pleural ADA between the two groups. The correlation between age and ADA activity was analyzed by Spearman's correlation coefficient analysis.
Results: In our study, there was no difference in pleural ADA between TPE (62.1 ± 4.2 U/L) and non-TPE patients (87.7 ± 10.0 U/L). Compared with empyema patients (183.8 ± 30.0 U/L), pleural ADA was lower in parapneumonic effusion (PPE) patients (63.4 ± 3.8, p < 0.01), or TPE patients (p <0.01). Correlation analysis showed that there were no correlation between age and pleural ADA within TPE, PPE or both patients (all p > 0.05). Meanwhile, there was no significant difference in PE ADA level between genders.
Conclusions: Considering the fact that the majority of pediatric PEs is TPE and PPE, our study suggests that PE ADA isn't accurate in detection of pediatric TPE. Meanwhile, an extremely high ADA activity should raise suspicion of empyema or lymphoma.