Cerebrospinal fluid Adenosine deaminase: its evaluation as a marker for diagnosing tuberculous meningitis in paediatric patients.

Abstract

Five hundred thousand patients of tuberculosis die every year in India. Delay in diagnosis and in initiating treatment results in poor prognosis. This disease is affecting the children more and more. Meningeal tuberculosis has acquired an endemic shape with about 12% incidence. The aim of the present study is to evaluate Cerebrospinal fluid Adenosine deaminase: as a marker for diagnosing tuberculous meningitis Eighty paediatric patients of age group 6-24 months having symptoms and signs of meningitis were divided into two groups; tuberculous and non-tuberculous, as per the accepted criteria. The CSF was drawn and ADA levels estimated in all patients. Out of 38 tuberculous patients, 36 had CSF ADA at or above the cutoff value, while 02 had below. Out of 42 non-tuberculous patients, 04 patients had at or above while 38 were below the cutoff value. Results of our study indicate that ADA levels in CSF are not only of considerable value in the diagnosis of TBM; CSF ADA level 10 IU/L as a cutoff value exhibited 94.73% sensitivity;90.47% specificity; 90.00% positive predictive value and 95.00% negative predictive value. Cerebrospinal fluid Adenosine deaminase estimation is less expensive, rapid and fairly specific method for the diagnosis of tuberculous etiology in TBM; it may prove to be diagnostic marker for diagnosing tuberculous meningitis in paediatric patients. KeyWords: Adenosine deaminase (ADA), Cell-mediated immunity (CMI), Cerebrospinal fluid (CSF), Tuberculous meningitis (TBM),