RESULTS: Of the patients, 10% (19/200) had tuberculous pleural effusions containing predominantly PMNs. The diagnostic yields of Mycobacteria on culture (78.9% vs. 22.7%, P < 0.01) and MTB positivity on PCR of pleural fluid (31.6% vs. 5.0%, P = 0.01) were significantly higher in patients with PMN-dominant compared with lymphocyte-dominant effusions. The risk of co-existing parenchymal tuberculosis (as revealed by a positive AFB culture) was significantly higher in the PMN-dominant group (57.9 vs. 30.9%, P = 0.018). In addition, the PMN-predominant group had higher lactate dehydrogenase (1402 vs. 653 U/L, P < 0.001) and lower glucose (77 vs. 91 mg/dL, P = 0.020) levels than lymphocyte-dominant effusions on pleural fluid analysis. While there were no differences in the clinical manifestations (fever, cough, sputum, and pleuritic chest pain) between the two groups, the PMN-predominant group had higher inflammatory serum markers, such as the white blood cell count (8520 vs. 6,040/μL, P = 0.001) and C-reactive protein (8.61 vs. 4.5 mg/dL, P = 0.001) than lymphocyte-dominant effusions.