Differentiating tuberculous pleuritis from other exudative lymphocytic pleural effusions

Abstract

Background: Recently, the combination of clinical and pleural fluid data can be used to calculate a score which helps facilitate differential diagnosis between tuberculous pleuritis (TBP) and No-TBP effusions. However, a reliable determination of adenosine deaminase (ADA) remains difficult to obtain in Thailand. Therefore, the aim of our study was set out to develop a scoring which makes use of clinical and pleural fluid data. Methods: A retrospective study involved 15 patients with TBP and 41 patients with no-TBP. The clinical and pleural fluid data of all patients from January 1, 2011, 32 to December 31, 2014, were collected. The diagnostic sensitivity, specificity, positive and negative predictive value were calculated. Results: The parameters were superior in detecting TBP, including the ADA ≥17.5 U/L, In scoring I [ADA ≥40 U/L, age <35 years, temperature ≥37.8 °c, and RBC <5x109/L] as ≥1.5 points, and scoring II [no previous history of cancer, age <35 years, temperature ≥37.8 °c RBC <5x109/L, pleural protein ≥50 g/L, and LDH ratio ≥2.2] as ≥4.5 points, since the area under curve (AUC) 74.0%, 74.0%, and 81.0%, sensitivity 73.3%, 73.3%, and 71.4%, and specificity 68.7%, 62.5%, and 71.1%, respectively). Moreover, no previous history of cancer and lower RBC <5x109/L indicated sensitivity (90.6% and 65.5%), and specificity (70.0% and 44.4%), respectively. Summated scores of ≥5 points in model 1 and ≥6 points in model 2 yielded measures of sensitivity (46.7% and 57.1%), and specificity (84.4% and 80.5%), respectively. Conclusions: The high pleural fluid ADA, high scores model 1, high scores model 2, lower RBC, and no previous history of cancer may help to categorize patients into probable TBP for further clinical decision-making.