Original article / research
Year : 2026 Month : April Volume : 15 Issue : 2 Page : BO09 - BO12 Full Version

Diagnostic Accuracy of Light’s Criteria, Alkaline Phosphatase, Total Cholesterol, and D-dimer in Differentiating Transudative and Exudative Pleural Effusion: A Cross-sectional Study
Lalit Kumar Kumawat, Nitin Tangri, Guntas Gill, Priyanka Tangri, Prabhaker Mishra
1. Senior Resident, Department of Respiratory Medicine, Jaipur National University Institute of Medical Sciences and Research Centre, Jaipur, Rajasthan, India. 2. Professor and Head, Department of Respiratory Medicine, Adesh Medical College and Hospital, Kurukshetra, Haryana, India. 3. Assistant Professor, Department of General Medicine, Adesh Medical College and Hospital, Kurukshetra, Haryana, India. 4. Professor, Department of Biochemistry, Adesh Medical College and Hospital, Kurukshetra, Haryana, India. 5. Additional Professor, Department of Biostatistics and Health Informatics, Sanjay Gandhi Post Graduate Institute of Medical Sciences, Lucknow, Uttar Pradesh, India.
 
Correspondence Address :
Priyanka Tangri,
Department of Biochemistry, Adesh Medical College and Hospital, Shahabad (M),
Kurukshetra, Haryana, India.
E-mail: dr.priyankatangri@gmail.com
 
ABSTRACT
: Introduction: Pleural Effusion (PE) results from an imbalance between pleural fluid production and absorption. It may occur due to multiple aetiologies, including heart failure, infections, malignancies, and liver disease. While Light’s criteria remain the gold standard for classification, they misclassify up to 25% of transudates. Additional biochemical markers such as pleural fluid cholesterol, Alkaline Phosphatase (ALP), and D-dimer have shown promise in enhancing diagnostic accuracy.

Aim: To compare the diagnostic efficacy of pleural fluid total cholesterol, pleural ALP, and D-dimer levels with Light’s criteria in differentiating exudative from transudative PEs.

Materials and Methods: The present hospital-based cross-sectional study was conducted jointly in the Departments of Respiratory Medicine and Biochemistry at Adesh Medical College and Hospital, Shahabad (M), Kurukshetra, Haryana, India, from November 2022 to October 2023. A total of 100 adult patients presenting with PE were recruited. Each patient underwent detailed clinical history, physical examination, chest radiography or Computed Tomography (CT) when indicated, and routine laboratory investigations. Pleural fluid samples were analysed for protein, Lactate Dehydrogenase (LDH), cholesterol, ALP, and D-dimer, while corresponding serum levels were also measured. Effusions were classified as transudative or exudative using Light’s criteria. Data were statistically analysed using independent t-test, Chi-square or Fisher’s exact test, binary logistic regression, and Receiver Operating Characteristic (ROC) curve analysis. A p-value <0.05 was considered statistically significant.

Results: In the present study, 71% of participants were male, and the mean age was comparable between the exudative and transudative groups. Pleural fluid cholesterol, pleural ALP, pleural/serum ALP ratio, pleural D-dimer, and pleural/serum D-dimer ratio were significantly higher in exudates than in transudates (p <0.001). ROC analysis demonstrated that all parameters had an Area Under the Curve (AUC) of 1.0, with 100% sensitivity and specificity at the identified cut-off values. Logistic regression analysis identified serum ALP as a protective factor and the pleural/serum LDH ratio as an independent predictor of exudative effusion.

Conclusion: Pleural fluid cholesterol, ALP, and D-dimer, along with their respective ratios, are highly reliable in differentiating exudative from transudative PEs and may serve as valuable adjuncts to Light’s criteria. These findings warrant validation in larger multicentric studies.
Keywords : Fluid accumulation, Interstitial space, Lactate dehydrogenase, Pleural fluid biomarkers, Transudative fluid
DOI and Others : DOI: 10.7860/NJLM/2026/84154.2964 Date of Submission: Sep 07, 2025 Date of Peer Review: Nov 13, 2025 Date of Acceptance: Jan 08, 2026 Date of Publishing: Apr 01, 2026 AUTHOR DECLARATION: • Financial or Other Competing Interests: None • Was Ethics Committee Approval obtained for this study? Yes • Was informed consent obtained from the subjects involved in the study? Yes • For any images presented appropriate consent has been obtained from the subjects. Yes PLAGIARISM CHECKING METHODS: • Plagiarism X-checker: Sep 08, 2025 • Manual Googling: Jan 03, 2025 • iThenticate Software: Jan 07, 2025 (5%) ETYMOLOGY: Author Origin EMENDATIONS: 7
 
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