Original Research Article
Year: 2020 | Month: April-June | Volume: 5 | Issue: 2 | Pages: 21-25
Study of Pleural Fluid Adenosine Deaminase Levels in Subjects with Tubercular and Non-Tubercular Pleural Effusion
Dharampal, Arun Sharma
Assistant Professor, Dept. of General Medicine, World College of Medical Sciences and Research, Jhajjar, Haryana
Corresponding Author: Arun Sharma
ABSTRACT
Introduction: Tuberculosis is the communicable infectious disease usually caused by Mycobacterium Tuberculosis Bacteria (MTB). Tuberculosis generally affects lungs, but can also affect other parts of the body. As of 2018 one-quarter of the world’s population is thought to be infected with TB. Tuberculous pleuritis occurs due to delayed hypersensitivity reaction with paucity of bacillary load in the fluid. Lymphocytic exudate alone is not able to confirm the diagnosis of tuberculosis. ADA has been found to be useful parameter to conclude the tubercular etiology.
Material and Methods: 80 subjects suspected of tuberculous pleuritis were subjected to cytological and ADA evaluation. Tuberculosis was confirmed by ZN stain, AFB culture and other relevant investigations.
Result: Out of the 80 subjects, 59 (73.7%) were males and 21 (26.5%) were females. The mean age and SD in males is 46±16.18 and females is 45.9±16.4 respectively. ADA levels were measured in all the subjects, out of which 46 were found to have ADA <40 IU/L and 34 were having ADA >40 IU/L. Cytological examination revealed lymphocytic exudates in 55 (68.5%) subjects and 25 (31.25%) had <50% lymphocytic exudates. Pleural fluid protein was elevated (>3gm/dL) was seen in 31(38.75%) subjects were positive for AFB and 49 (61.25%) had pleural fluid protein <3gm/dL. Total numbers of tubercular cases were 31 (38.75% cases). Out of 31 tubercular subjects, 27 (87%) had elevated ADA >40 IU/L and 4 (12.9%) had ADA levels <40 IU/L. Diagnostic validity of ADA test between tubercular and non-tubercular pleuritis revealed Sensitivity of 87%, Specificity of 85.7%, PPV of 79.4% and NPV of 91.3%.
Conclusion: ADA estimation with cytology increases the sensitivity, specificity and predictive value of ADA in the diagnosis of tuberculous pleuritis. Therefore, ADA should be included as routine investigation for pleural fluid analysis.
Keywords: ADA, pleural fluid, predictive value, Sensitivity, specificity