ASSESSMENT OF LDH/ADA RATIO IN PATIENTS WITH AND WITHOUT TUBERCULAR PLEURAL EFFUSION

Main Article Content

Dr. Rajeev Jaiswal
Dr. Gyanendra Kumar Saxena

Keywords

Tubercular pleural effusion, LDH/ADA ratio, adenosine deaminase, lactate dehydrogenase, pleural fluid diagnostics.

Abstract

Background: Tubercular pleural effusion (TPE) is a common manifestation of extrapulmonary tuberculosis, especially in high-burden countries. The diagnostic evaluation typically includes pleural fluid adenosine deaminase (ADA) and lactate dehydrogenase (LDH) levels. Recent studies suggest that the LDH/ADA ratio may enhance diagnostic accuracy and help differentiate TPE from other etiologies.


Aim: To assess the LDH/ADA ratio in patients with confirmed tubercular pleural effusion and evaluate its diagnostic utility.


Methods: This cross-sectional study included 100 patients with exudative pleural effusion, of which 70 had confirmed TPE based on microbiological, histopathological, or clinical criteria, and 30 had non-tubercular exudative effusion. Pleural fluid ADA, LDH, and LDH/ADA ratio were measured. Statistical analysis included ROC curve analysis, sensitivity, specificity, and predictive values.


Results: Mean ADA levels in TPE patients were significantly higher than in non-TPE cases (p<0.001). LDH levels were elevated in both groups, but the LDH/ADA ratio was significantly lower in TPE patients (mean 12.4 ± 4.1) compared to non-TPE patients (mean 28.6 ± 5.9, p<0.001). ROC analysis showed an LDH/ADA ratio cut-off of ≤16.0 had a sensitivity of 91.4% and specificity of 88.3% for diagnosing TPE.


 Conclusion: The LDH/ADA ratio is a simple, cost-effective, and valuable adjunctive tool in differentiating tubercular pleural effusion from other exudative pleural effusions.

Abstract 257 | Pdf Downloads 67

References

1. WHO Global Tuberculosis Report 2023.
2. Light RW. Update on tuberculous pleural effusion. Respirology. 2010;15(3):451-8.
3. Vorster MJ, et al. The immunopathogenesis of tuberculous pleural effusion. Tuberculosis. 2015;95(6):701-708.
4. Burgess LJ, et al. Use of ADA in the diagnosis of tuberculous pleuritis. Chest. 1995;107(2):295-299.
5. Sharma SK, et al. ADA in the diagnosis of TPE in India. Int J Tuberc Lung Dis. 2001;5(10):978-983.
6. Valdés L, et al. ADA in pleural fluids. Eur Respir J. 1993;6:955-958.
7. Porcel JM, et al. ADA in non-tuberculous effusions. Chest. 2003;124:199-204.
8. Light RW, et al. Pleural effusions: diagnostic approach. N Engl J Med. 2002;346:1971- 1977.
9. Heffner JE, et al. Diagnostic utility of LDH in pleural fluid. Chest. 1997;111:970-980.
10. Burgess LJ, et al. LDH/ADA ratio in pleural effusions. Chest. 1995;108(2):414-419.
11. Diacon AH, et al. Combination biomarkers in TPE diagnosis. Eur Respir J. 2003;21:220- 224.
12. Aggarwal AN, et al. Novel markers in TPE. Lung India. 2005;22(3):131-136.
13. Kaya S, et al. LDH/ADA ratio in differential diagnosis of pleural effusions. Clin Biochem. 2013;46(7-8):649-653.
14. Liang QL, et al. Meta-analysis of ADA and LDH/ADA ratio in TPE diagnosis. Respir Med. 2008;102(3):377-381.
15. Wu YB, et al. Role of LDH/ADA ratio in differentiating malignant and tuberculous effusions. J Thorac Dis. 2014;6(6):845-851.