PURPOSE: This study analyses our experiences of role of adenosine deaminase(ADA) activity in etiological diagnosis of exudative pleural effusions.
METHODS: A total of 60 patients with clinical and radiological evidence of pleural effusions were investigated out of which 4 turned out to be transudative (protein <3gm %) and 6 did not turned up for follow up were excluded from the study. Remaining 50 patients were further investigated particularly for ADA levels and followed up at 4 and 8 weeks. For tubercular effusions the response to therapy over a period of 6 weeks was taken as diagnostic criteria.
RESULTS: Maximum patients were in the age group of 21-30 years. Male:Female ratio 2.3:1. Out of 60 patients, 56 (93.33%) turned out to be exudative. Exudative effusions were right sided in 58%, left 38% and bilateral 4%. Most common presenting symptoms were fever in 82% and chest pain in 78%. Color of pleural fluid varied from straw color in 40(80%), hemorrhagic in 6(12%), yellowish in 3(6%) and frank pus in 1(2%). 70% patients were found to be having chronic inflammatory with lymphocytic predominance while 18% acute inflammatory with polymorphonuclear predominance. Hemorrhagic effusions constituted remaining 12% including 4% having malignant cells. Etiology in 84% turned out to be tubercular, 8% malignant, 6% parapneumonic effusion while 2% empyema. 95% tubercular effusions were straw colored. Tubercular effusions had ADA activity ranging 70.83U/L to 125.00U/L with mean 96.56U/L and SD ±14.90. Non tubercular effusions had ADA activity ranging 18.75U/L to 38.46U/L with mean 28.96U/L and SD ±8.39 out of which pyogenic had higher ADA ranging 32.69U/L to 38.46U/L while malignant had relatively lower ADA ranging 18.75U/L to 23.31 U/L.
CONCLUSION: Exudative pleural effusions are 14 times more common than transudative with majority due to tuberculosis. The ADA activity is significantly higher in tubercular than in non tubercular pleural effusions.
CLINICAL IMPLICATIONS: ADA activity determination is an easy, time sparing, cost-effective investigation and should be used routinely to differentiate tubercular from non tubercular pleural effusions.
DISCLOSURE: Naveen Pandhi, No Financial Disclosure Information; No Product/Research Disclosure Information