Role of pleural fluid adenosine deaminase in etiological diagnosis of pleural effusion

Lokeswara Reddy .A; Ramanjula Reddy.C; Yugandhar.P; Satyasri.S

Volume : V, Issue : VI, June - 2015

Role of pleural fluid adenosine deaminase in etiological diagnosis of pleural effusion

Lokeswara Reddy . A, Ramanjula Reddy. C, Yugandhar. P, Satyasri. S

Abstract :

Pleural effusion is a common respiratory problem which is a manifestation of various underlying disorders that includes respiratory,renal,cardiovascular,connective tissue and other diseases.Inspite of good history,thorough clinical,radiological,complete examination of aspirated fluid and pleural biopsy1 , etiological diagnosis cannnot be established in about 20% of cases. So there is a need of simple, rapid and reliable diagnostic test to establish etiology of pleural effusion.Considering this, a prospective study was designed to find out how much is pleural fluid ADA level useful in establishing diagnosis of pleural effusion. This study was carried out in 75 patients in age group of 18–75 years both Out and In patients in ASRAM hospital,Eluru with intial diagnosis of Pleural effusion during September 2013–Feuary 2014.Complete evaluation with clinical history,physical examination and chest imaging was done.Pleural fluid analysis using Lights criteria was followed to differentiate exudate/transudate.Sputum smear for AFB,Pleural biopsy,pleural fluid for cytology and ADA estimation by Galanti and Giusti2 calorimetric method was done. 55 subjects were categorised as Tuberculosis,10 subjects as malignancy,7 subjects as transudative effusion and 3 subjects as empyema.Pleural fluid ADA was more than 40IU/L in TB,less than 40IU/Lin malignancy,Transudates and Empyema.The mean ADA activity in tuberculous pleural effusion is significantly high when compared to malignant and transudate effusions (p<0.01).When ADA 40 IU/L is taken as cut off point ,tuberculous effusions had sensitivity of 98.8%,specificity 100% with positive predictive value of 100%. Pleural fluid ADA is a very good parameter to differentiate tubercular from non–tubercular effusion.It is a simple, low cost investigation and should be considered routinely in all cases of pleural effusion .