PURPOSE: To determine the appropriate cutoff level of pleural fluid ADA measurement by Diazyme Commercial Kit (Giusti G method and kinetic calorimetry) for confirmation of the diagnosis pleural tuberculosis in Ramathibodi Hospital.
METHODS: Retrospective study in patients with the presence of symptomatic pleural effusion and their pleural fluid were characterized by exudative lymphocytic predominate. All of pleural fluid specimens were sent to immunology lab for ADA level measurement by Diazyme between January 2005 and December 2006.
RESULTS: One hundred seventy eighth patients eligible for study and the definite diagnosis including TB pleuritis (n=59), malignant pleural effusion (n=78 that classified as 67 solid tumor and 21 hematologic malignancy) and 31 patients having diagnosis other than TB and malignancy . The mean values (SEM) of pleural fluid ADA was 44.77(2.81) U/L in patients with TB pleura vs. 17.12(2.23) U/L in patients with a malignant pleural effusion (p value < 0.001) vs 15.06 U/L in patients with diagnosis other than TB pleuritis and malignancy (< 0.001). A receiver operating characteristic curve (ROC) for identification of the best cutoff pleural fluid ADA level that provide the greatest sensitivity (0.82) and specificity (0.91) is 30 U/L.
CONCLUSION: Pleural fluid ADA is useful minimal invasive test for making diagnosis of clinically suspected tuberculous pleural effusion patients. The cutoff level for ADA by Diazyme commercial kit in Ramathibodi is 30 U/L.
CLINICAL IMPLICATIONS: The Diazyme commercial kit can be used as effective as the conventional technique of ADA measurement however this test kit provides the faster turn around time.
DISCLOSURE: Theerasuk Kawamatawong, None.