EFFICACY OF PLEURAL FLUID ADENOSINE DEAMINASE AND C-REACTIVE PROTEIN LEVELS IN EARLY DIFFERENTIAL DIAGNOSIS OF PLEURAL EFFUSION.

Pleural effusion occurs secondary to various diseases.Common causes of exudative effusion are tuberculosis, bacterial pneumonia, and malignancy.Transudative effusion is due to systemic diseases like cardiac failure, cirrhosis of liver.Conventional methods of diagnosis may not be able to establish the cause of pleural effusion.Early diagnosis and management reduces the morbidity and mortality.AIM:The objective of the study is to estimate pleural fluid Adenosine Deaminase (ADA) and C -reactive protein (CRP) levels and to evaluate their efficacy in differential diagnosis of transudative and exudative, tuberculous and non tuberculous and inflammatory and non inflammatory effusions.MATERIAL AND METHODS: Fifty two patients of pleural effusion were investigated and divided into four groups based on diagnosis.Group I, II, III and IV had 24 cases of tuberculous effusion, 13 cases of transudative effusion, 08 cases of malignant effusion and 07 cases of parapneumonic effusion respectively.Pleural fluid was analyzed for ADA (Guisti and Galanti's method) and CRP (turbidometric immunoassay).STATISTICAL ANALYSIS: The statistical analysis was done using unpaired student't' test and p value < 0.05 was considered statistically significant.RESULTS: In the present study pleural fluid ADA revealed highly significant increase in tuberculous effusion than non tuberculous effusions (p <0.001) and also when compared with non tuberculous subgroups, transudative effusion (p < 0.001), malignant effusion (p<0.001), and PPE (p<0.01).ADA levels at a cutoff value of 40U/L, showed sensitivity, specificity, positive predictive value and negative predictive value of 91.67%, 89.3%, 88% & 92.6% respectively in tuberculous effusion.Pleural fluid CRP levels in parapneumonic effusion were significantly higher compared to other types of effusions (p<0.001).Significantly higher levels of CRP were seen in exudative effusion compared to transudative effusion (p<0.001) and in inflammatory effusion compared to non inflammatory effusion (p<0.001).