Adenosine deaminase activity in cerebrospinal fluid: diagnostic investigation in central nervous system disorders in children

Abstract

Background: Tubercular meningitis (TBM) is an endemic disease in developing countries. Adenosine deaminase activity (ADA) has been of great importance for many years in TBM diagnosis. The objective of this study was to determine the CSF-ADA levels in different CNS disorders, to compare the CSF-ADA activity in different types of meningitis, to find out the sensitivity and specificity of CSF-ADA in the diagnosis of TBM and to establish the prognostic value of CSF-ADA in TBM in comparison to Control group.Methods: For control group CSF was collected from the patients of simple febrile convulsions and idiopathic epilepsy.Results: The present study was carried out in the 112 cases of different CNS disorders, age ranging from 4 months to 12 years with a mean age of 4.12 years and 38 cases (27+11) of control group (simple febrile convulsion and idiopathic epilepsy). In the present study CSF-ADA level was statistically significantly increased in all types of meningitis (p<0.05). In case of TBM, the mean CSF-ADA level increased statistically significantly with increase in CSF protein level (p<0.05). In case of TBM, there was no significant difference in the mean ADA value according to CSF sugar level (p<0.10). In case of TBM, the mean CSF-ADA level increased significantly with increase in CSF cell count (p< 0.01) mainly lymphocytes.Conclusions: Thus it can be concluded from our study that CSF-ADA estimation is relatively simple and inexpensive procedure in the early diagnosis of tuberculous meningitis with high sensitivity (100%) and specificity (97.5%) at a cut-off level of 5IU/L and can be used in differentiating TBM from other types of meningitis. Along with diagnostic utility of CSF-ADA, it has also prognostic value in the follow-up case of tuberculous meningitis.