Comparative analysis of cerebrospinal fluid adenosine deaminase levels in infective meningitis of different aetiologies

Abstract

Background: Meningitis can be caused by bacteria, viruses, parasites, and fungi as well as by non-infectious conditions including inflammatory disorders (e.g., systemic lupus erythematosis or Kawasaki disease) and neoplasia (e.g., leukemic meningitis). The objective of this study were to study cerebrospinal fluid (CSF) adenosine deaminase (ADA) levels in infective meningitis of different aetiologies. And to assess the role of cerebrospinal fluids (CSF) adenosine deaminase (ADA) levels in differentiating tubercular from non-tubercular meningitis.Methods: The study was conducted on 70 patients of meningitis at Postgraduate Department of Paediatrics, in G. B. Pant Hospital, an associated hospital of Government Medical College Srinagar. Out of 70 patients included in the study 27 cases were Aseptic Meningitis (AM), 14 cases partially treated pyogenic -meningitis (PTM), 19 cases pyogenic meningitis (PM), and 10 cases were tubercular meningitis (TBM). ADA activity of CSF was quantified by colorimetry.Results: In our study we observed a significant high level of ADA 30.0±3.2U/L (20.0, 54.0) among the tubercular meningitis (TBM) patients and its respective level among Aseptic Meningitis (AM), was 8.1±0.3U/L (4.0, 11.5), partially treated pyo -meningitis (PTM) was 7.6±0.4U/L (5.0, 11.0), pyogenic meningitis (PM) was 11.6±0.5U/L (8.0, 14.5). In total Non-TBM ADA level was 9.1±0.3U/L (4.0, 14.5) units/liter. At cut off of > or equal to 10U/L sensitivity was 100% specificity66.67% positive predictive value33.33% negative predictive value of 100% diagnostic accuracy 71.43%. At a higher cut off of > or equal to 12U/L sensitivity was 100% and specificity increased to 81.67% positive predictive value 47.62% negative predictive value100% diagnostic accuracy was 84.29%.Conclusions: The sensitivity and specificity of CSF ADA activity is markedly high in differentiating TBM from non-TBM. Hence CSF ADA activity may be used as a simple, cost-effective and reliable test for early diagnosis of TBM.