Analysis of cerebrospinal fluid adenosine deaminase levels in meningitis

Background: A precise etiological diagnosis of meningitis is required so that appropriate therapy can be started at the earliest. Due to inconsistent clinical presentations and the lack of a rapid, sensitive and specific test, tuberculous meningitis (TBM) is particularly difficult to diagnose. The present study was done to analyze the utility of adenosine deaminase (ADA) activity in CSF for differentiating TBM from other forms of meningitis.Methods: In our study, ADA activity measured in 26 TBM, 15 pyogenic meningitis (PM) and 10 aseptic/viral meningitis (AM) cases. A cut-off ADA level of 10 IU/L was used for differentiation of TBM cases from other meningitis cases.Results: The mean ADA levels in CSF were highest in TBM patients as compared to PM and AM. The sensitivity, specificity and accuracy of ADA were 96.15%, 92% and 94.11% respectively for detection TBM cases from non-tuberculous meningitis cases.Conclusions: Since ADA test is simple, rapid and inexpensive, it can be used as rapid diagnostic test for differential diagnosis of CSF and confirmation of TBM cases.