Pleural Fluid Adenosine Deaminase Values in Diagnosis of Tuberculous Pleural Effusion in South Khorasan Province

Background Due to variability of pleural fluid ADA measures in pleural tuberculosis, researchers have recommended the necessity of regional studies for determination of specific regional values. Objectives The purpose of the present study was to evaluate the values of pleural fluid ADA in diagnosis of Tuberculous pleural effusion in South Khorasan province. Methods A cross-sectional study was conducted on patients > 12 years old with exudative pleural effusion in South Khorasan province (east of Iran). Light criteria were used to define exudative effusion. Total ADA was determined calorimetrically by Diazyme ADA assay. The data were analyzed using t test, ANOVA and χ² tests through Spss 16 version software. Results We studied 255 cases including 139 (54.5%) males and 116 (45.5%) females with mean age of 63.8 ± 18 years. There were 36 (14.1%) cases with Tuberculous pleural effusion and 219 (85.9%) cases of non-Tuberculous pleural effusion. Malignant and acute bacterial infection comprise 106 (41.6%) and 29 cases (11.4%), respectively. The mean levels and optimal cut off point of ADA in Tuberculous pleural effusion were40.2 ± 24.7 and 30 IU/L respectively. ADA in Tuberculous pleural effusion showed negative correlation with age (r = -0.40, p = 0.01), but weak positive correlation with fluid protein(r = 0.44, P = 0.007) and LDH (r = 0.32, P = 05). Conclusions Mean and cut off point of ADA was relatively low in patients with Tuberculous pleural effusion in South Khorasan province. The age of patients and fluid levels of protein, and LDH must be considered in interpretation of pleural fluid ADA levels.