Adenosine Deaminase Assay in Different Body Fluids for the Diagnosis of Tubercular Infection

摘要

Diagnosis of tuberculosis from different body fluids remains challenging due to various limitations of the conventional and molecular methods. We studied the role of adenosine deaminase (ADA) assay to diagnose tubercular infection in cerebrospinal fluid, peritoneal fluid and pleural fluid. Fifty three patients with tubercular meningitis, peritonitis and pleuritis were enrolled in this study on the basis of clinical, radiological, cytological, biochemical and somewhere bacteriological evidences. Cases positive by AFB smear, culture or PCR were considered as confirmed TB and other as probable TB cases. Another 28 non-TB cases were included as control. In 53 suspected TB cases ADA was found positive in highest 42 (79.2%) cases, whereas smear and/ culture in 10 (18.7%) and PCR in 18 (33.9%) cases. ADA assay revealed 100% positivity in confirmed TB cases and 14.3% in non TB cases. The sensitivity and specificity of ADA was found 79% and 86% respectively when the cut off value was used ≥ 10 IU/L for CSF and ≥ 40 IU/L for pleural or peritoneal fluid. Mean ADA values of confirmed and probable TB cases were found significantly higher than that of non TB cases (< 0.05). Significance of difference was determined by ANOVA and Kruskal-Wallis test. Thus, adenosine deaminase assay in body fluids has proved to be efficient, reliable and simple method to diagnose tubercular meningitis, peritonitis and pleuritis.