The Diagnostic Accuracy of Pleural Fluid Lactate Dehydrogenase to Adenosine Deaminase ratio in Pleural Tuberculosis

Authors

Abstract

Objective: To determine diagnostic accuracy of the pleural fluid lactate dehydrogenase to adenosine deaminase ratio in diagnosis of pleural tuberculosis.

Methods

The study was conducted at “Department of the Pulmonology, Mayo Hospital, Lahore from 01-03-2025 to 31-08-2025.Ethical approval was obtained before enrolling 63 Pulmonology outpatients who met the selection criteria. All participants gave Informed consent before participation. Patient data, including name, age, gender, BMI, symptom duration, and medical history (e.g., diabetes, hypertension, smoking, tuberculosis), were recorded. Pleural fluid was collected via thoracentesis by a research team. The sample was divided into two sterile containers: one for LDH and ADA testing, and the other for culture. Pleural tuberculosis was diagnosed with an LDH/ADA ratio <10. Culture results were documented after 4-6 weeks. Data analysis was conducted using SPSS 28.

Results

 We found mean age of 42.22±16.56 years. The majority of participants were male (60.3%, n=38), while females constituted 39.7% (n=25) of the study population. Based on LDH/ADA ratio, 76.2% tested positive and 23.8% negative. Culture report confirmed 77.8% positive and 22.2% negative. Using culture as the reference, the LDH/ADA ratio showed sensitivity of 95.92%, specificity of 92.86%, PPV 97.92%, NPV 86.67%, and overall accuracy of 95.24%.

Conclusion

 Pleural fluid LDH/ADA ratio was found to be comparable to pleural fluid mycobacterial culture in diagnosing pleural tuberculosis.

Keywords:

Diagnostic accuracy, lactate dehydrogenase, pleural fluid, pleural tuberculosis

Published

2026/08/21

Issue

Vol. Volume 7-issue 3

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