Role of ADA in CSF for Diagnosis of Tubercular Meningitis

The present study was undertaken to evaluate the CSF ADA activity in patients of tubercular meningitis and efficacy of CSF ADA activity in differentiating various types of meningitis. A total of 97 patients including 18 controls were enrolled in the study. Further, total 79 study patients were divided into three groups depending upon the clinical picture and investigatory findings i.e. pyogenic meningitis (n=20), tubercular meningitis (n=35) and viral meningitis (n=24). In this study ADA level in CSF was determined in patients of tuberculous, pyogenic and viral meningitis admitted to medical wards of Subharti Hospital. This study concluded that cerebrospinal fluid (CSF) ADA activity can be reliably used for differentiating tuberculous meningitis from viral meningoencephalitis. CSF ADA activity cannot be reliably used to differentiate tuberculous meningitis from pyogenic meningitis. CSF ADA activity cannot be used in all cases for differentiating pyogenic meningitis from viral meningoencephalitis. CSF ADA activity has got prognostic value in patients of tuberculous meningitis. Duration of illness and mortality increases with progressive rise in CSF ADA activity. CSF ADA activity should be measured in all patients of meningitis, since it can differentiate those patients of TBM, whose presentation and CSF biochemical parameters are similar to patients of viral meningoencephalitis and can lead to early initiation of therapy in these patients.