Diagnostic dilemma in tuberculous pleural effusion

Aim: To evaluate the clinical use of interferon gamma release assays (QuantiFERON-TB Gold (In-Tube Method)) for the diagnosis of pleural tuberculosis and comparing it with ADA as a method for diagnosis TB effusion.Patients and methods: 40 patients presenting with pleural effusions were classified according to their final diagnosis in two groups.Group I: Include 20 cases with tuberculous pleural effusions, group II: Control group: 20 cases divided into 2 subgroups: Subgroup11a: para pneumonic pleural effusions: 8 cases, Subgroup11b: malignant pleural effusions: 12 cases.Results: Tuberculous pleural effusion showed statistically significantly lower mean age than non-tuberculous effusion. Tuberculous group showed statistically significantly highest mean ADA. This was followed by para pneumonic group then malignant group. ADA showed sensitivity (98%), specificity (55%), diagnostic accuracy (75%), negative predictive value (PV−) (67.9%) and positive predictive value (PV+) (91.7%) in diagnosing tuberculous effusion QuantiFERON-TB Gold showed sensitivity 65%, specificity 70%, PPV (68.4%), NPPV (66.7%) and diagnostic accuracy (67.5%) in diagnosing tuberculous effusion.Conclusion: It was concluded that ADA measurement in the pleural fluid is an appropriate, fast diagnostic tool for the diagnosis of tuberculous pleural effusion, with higher sensitivity (98%) and diagnostic accuracy (75%). QuantiFERON-TB Gold which is technically more complicated, expensive and has lower sensitivity (65%) and diagnostic accuracy (67.5%) than ADA