The Diagnostic Performance of Pleural Fluid Lactate Dehydrogenase to Adenosine Deaminase Ratio in Differentiating Infectious from Non-Infectious Pleural Effusions: A cross- sectional study: Diagnostic Utility of Pleural Fluid LDH/ADA Ratio

Abstract: Objective: To determine the diagnostic performance of the pleural fluid lactate dehydrogenase to adenosine deaminase ratio in differentiating infectious from non-infectious pleural effusions.

Methods

This prospective analytical cross-sectional study was conducted at department of Pulmonology, Sahiwal Teaching Hospital, Pakistan, over six months. A total of 170 patients with pleural effusion were enrolled using a non-probability consecutive sampling technique. Adult patients with radiologically confirmed pleural effusion and pleural fluid adenosine deaminase levels >33 U/L were included. Infectious pleural effusions comprised tuberculous pleural effusion, parapneumonic pleural effusion and empyema, while non-infectious pleural effusions included malignant and transudative pleural effusions. Pleural fluid lactate dehydrogenase and adenosine deaminase levels were measured and the LDH/ADA ratio was calculated. Receiver Operating Characteristic curve analysis was performed to assess diagnostic performance.