Diagnosis Of Tubercular Meningitis Research Articles

Diagnostic challenges in tuberculous meningitis: a case report with negative genexpert result.

Tuberculous meningitis (TBM) is a severe form of tuberculosis affecting the meninges, primarily caused by Mycobacterium tuberculosis. Diagnosis of TBM poses numerous challenges due to its nonspecific clinical presentation and the limitations of diagnostic tests like GeneXpert. The authors report a case of a 22-year-old female from Eastern Nepal presenting with acute-onset fever, headache, vomiting, and neck pain. Cerebrospinal fluid (CSF) analysis showed lymphocytic pleocytosis, elevated protein, low glucose levels, and cobweb coagulum indicative of TBM. However, the GeneXpert test revealed negative results. In resource-limited settings like Nepal, where access to GeneXpert MTB/Rif is limited, CSF analysis and clinical algorithms play a crucial role in diagnosing TBM. Relying solely on GeneXpert results may lead to false negatives, so a high level of suspicion based on patient risk factors is essential. Prompt initiation of empirical antitubercular therapy is vital for a favorable outcome in TBM cases. Negative MTB PCR results from CSF can be misleading in diagnosis of tubercular meningitis. Therefore, comprehensive evaluations, including detailed patient history, physical examination, and CSF fluid analysis, are crucial in high tuberculous prevalence countries to ensure accurate and timely diagnosis.

Acute Ischemic Stroke in Tubercular Meningitis Patients Without Conventional Vascular Risk Factors: A Retrospective Case Control Study.

Ischemic stroke is a common complication in patients with tubercular meningitis (TBM). However, the risk factors for Ischemic stroke in TBM patients are not fully understood, especially in those patients without conventional vascular risk factors. The aim of the present study was to explore the clinical features and independent risk factors for tubercular meningitis-related Ischemic stroke (TBMRIS). Tubercular meningitis patients with acute Ischemic stroke without conventional vascular risk factors were recruited between July 2010 and July 2020 as the TBMRIS group. Patients who solely had tubercular meningitis were recruited as the control group (TMB group). Demographic characteristics, clinical presentations, and cerebrospinal fluid (CSF) examinations were collected, and multiple logistic regression analysis was applied to analyse the independent risk factors for TBMRIS. A total of 70 TBMRIS patients and 70 TMB patients were enrolled. Most (82.86%) of the TBMRIS patients experienced Ischemic stroke events within 3 months after the diagnosis of tubercular meningitis. The multiple logistic regression analysis revealed that variation in red blood cell distribution width (RDW-CV), mean platelet volume (MVP), C-reactive protein (CRP), CSF glucose and Modified Research Council Grade II (MRC Grade II) were independent risk factors for TBRIS. The AUC of the identification model was 0.808, with a sensitivity of 68.60% and a specificity of 84.30%. This study revealed that RDW-CV, MVP, CRP, CSF glucose and MRC Grade II are potential independent risk factors for TBMRIS. The identification model established in this study may help monitor TBM patients who are at high risk of developing TBMRIS.

An Observational, Cross-sectional Study on Epidemiology and Clinical Spectrum of Tuberculous Meningitis in a Tertiary Care Hospital in Eastern India and Role of CSF CBNAAT for Rapid Diagnosis

Background: Tubercular meningitis (TBM) accounts for 70 to 80 percent of all neurological tuberculosis and is a major health issue in a country like India. But we don’t have adequate amount of data regarding the epidemiology and clinical pattern of TBM. In this study we aimed at exploring the epidemiological, clinical picture of TBM and compared different diagnostic modalities for early detection. Methods and Materials: 50 patients with history and clinical features compatible with tuberculous meningitis were assessed through a detailed history and clinical examination followed by CSF study and an MRI of the brain. Results: CSF study showed lymphocytic pleocytosis (92% cases) along with raised mean CSF protein 182.2±80.2 mg/dl (Mean ± SD) and reduced mean sugar 35.8 ±12.3mg/dl. CSF for AFB had least sensitivity (4%) but highest specificity (100%). CBNAAT showed both acceptable sensitivity (77%) and specificity (96%). CSF ADA had high sensitivity (85%)but low specificity (18%). Age >40 years, Altered consciousness, GCS<10, TBM stage 3, CSF glucose ≤30mg/dl& Presence of hydrocephalus were significantly associated with mortality from TBM (p-value<0.05). Conclusion: CSF CBNAAT having acceptable sensitivity and specificity for diagnosis of TBM and can be used for early diagnosis as an alternative to CSF culture due to its rapidity and other bio-medical advantages. Factors associated with adverse outcome can be used in future as components of risk prediction models.

MR vessel wall imaging in tubercular meningitis.

Tubercular meningitis (TBM) has the propensity to cause secondary vasculitis through various mechanisms leading to development of cerebrovascular complications. These vascular involvements can be detected by vessel wall imaging (VWI). In this study, we aimed to study detailed findings of vessel wall imaging in cases of tubercular meningitis. All consecutive patients of suspected tubercular meningitis in whom diagnosis of TBM could be made according to diagnostic criteria given by Ahuja et al. were included in thestudy. High-resolution MR VWI and time of flight (TOF) magnetic resonance angiography (MRA) were done along with routine MRI sequences. Arteries up to second-order branches were studied, and statistical analyses were done with respect to stage of tubercular meningitis, infarctions and TOF MRA findings. Out of all 101 cases of TBM, infarctions were found in 49 cases (48.5%), and vessel wall enhancement was seen in 67 cases (66.3%). With increasing severity of disease, more severe vascular involvement was seen on VWI. There was significant association between enhancement of individual arteries and infarctions in their territories. VWI had better sensitivity than the MRA, while MRA had better specificity than VWI for detection of vascular complications. Tubercular vasculitis can be detected by VWI in the form of nodular or smooth segmental enhancement of vessel wall with or without stenosis. Incorporation of VWI in routine MR imaging can play a greater role in early detection and management of cerebrovascular complications which can help to improve prognosis of the disease.

Utility of polymerase chain reaction technique in the diagnosis of tubercular meningitis in Indian children

Utility of polymerase chain reaction technique in the diagnosis of tubercular meningitis in Indian children

Adenosine deaminase, an aid in the diagnosis of tubercular meningitis – hospital based study

Introduction: Tubercular meningitis (TBM) is the most prevalent and most grave form of extrapulmonary tuberculosis. It is associated with high mortality rate. The confounding factor for this is the delay in diagnosing the disease and initiation of treatment. The present study aims to look for the diagnostic utility of ADA estimations in Tubercular meningitis patients. Materials and Methods: For this study the patients with the signs and symptoms of meningitis and attending our hospital within a st ipulated period of one year approximately, were taken as subjects. As per the accepted criteria, the patients were segregated into two broad groups: tubercular meningitis cases and nontubercular meningitis cases. CSF specimens were collected and ADA levels were estimated on semiautoanalyser in the laboratory. Results: Out of 31 patients of tubercular meningitis, 27 showed ADA levels above 10 U/L while 2 showed lower values. On the other hand 32 cases of non- tubercular meningitis showed ADA levels below 10 U/L and 4 showed higher values, thereby supporting the fact that ADA evaluation in CSF is of substantial value in diagnosing TBM. It also illustrious that if CSF ADA value of 10 U/L is taken as bench mark then the sensitivity for diagnosing TBM is 93.10% and specificity is 88.87% which is fairly good. Conclusion: Therefore, just by evaluating CSF ADA levels we can diagnose the TBM cases with respectably good sensitivity and high specificity and consuming least time and resources. Therefore, ADA estimation is a valuable adjunct to routine investigations in diagnosis of TBM. Keywords: Tubercular Meningitis (TBM), Cerebrospinal fluid (CSF), Adenosine Deaminase (ADA).

The Utility of CSF Xpert MTB/RIF in Diagnosis of Tubercular Meningitis in Children.

To determine the utility of CSF Xpert MTB/RIF (GeneXpert) in diagnosis of tubercular meningitis in children in the age group of 2 mo to 12 y. This hospital based prospective observational study was conducted at Department of Pediatrics, Karnataka Institute of Medical Sciences (KIMS), Hubli from December 2015 through November 2016. All children with clinically suspected tuberculous meningitis (TBM) were included in the study. These children underwent a detailed history taking, clinical examination, blood investigations, lumbar puncture and CT brain. Cerebrospinal fluid (CSF) samples were sent for CSF GeneXpert examination. Statistical analysis was done using IBM SPSS Statistics Version 20. A total of 28 children were enrolled in the study. Six (21.4%), 4 (14.3%) and 18 (64.3%) cases were definite, probable and possible TBM cases respectively. Most common age group affected was <5 y (83.33%) with median age 2.5 y (IQR 4.875). Male:female ratio was 1.5:1. CSF GeneXpert was tested positive in 6 cases (21.4%). The sensitivity of the test against the clinical scoring (>/=10) was 46.15% (95% CI, 19.22-74.87) and specificity was 100% (95% CI, 78.20-100). There was a significant association between CSF GeneXpert and Mantoux test (P= 0.002), CSF cell type >50% lymphocytes (P= 0.005) and CSF protein >100mg/dl (P= 0.025) along with CT hydrocephalus (P= 0.021), granuloma (P= 0.009) and basal exudates (P= 0.025). None of the cases were tested smear positive for acid-fast bacilli (AFB). CSF GeneXpert is superior to smear for AFB in TBM.

Role of Cartridge Based Nucleic Acid Amplification Test of Cerebrospinal Fluid in the Diagnosis of Tubercular Meningitis

Role of Cartridge Based Nucleic Acid Amplification Test of Cerebrospinal Fluid in the Diagnosis of Tubercular Meningitis

Utility of pyrosequencing for rapid detection of tubercular meningitis (TBM) and associated susceptibility directly from CSF specimens

Tubercular meningitis (TBM) is a serious form of tuberculosis (TB). The diagnosis of TBM & susceptibility/resistance is difficult as TB MGIT culture lacks sensitivity & timeliness. Timely and accurate diagnosis of the TBM is the need of the hour for initiation of appropriate therapy. We have exploited pyrosequencing to detect TB and associated Multi/extensively drug resistant (MDR/ XDR-TB) directly from Cerebrospinal Fluid (CSF) specimens.

Accuracy of Gene-Xpert In Diagnosis of Suspected Tuberculous Meningitis

Background: The diagnosis of Extra Pulmonary Tuberculosis, especially tubercular meningitis (TBM) is challenging due to frequent atypical clinical presentation, inadequate clinical sample, and paucibacillary nature of the biological samples, which frequently results in a delay or deprivation of treatment. A semi quantitative, nested, real time PCR Gene-Xpert test is showing promising result in diagnosing pulmonary TB diagnosis, but its role in TBM is yet to be validated. Methods: It was a cross sectional observational study carried out on 40 clinically suspected TBM patients admitted in neuromedicine, medicine and pediatric medicine at CMCH. Clinical, radiological evaluation and conventional tests were done before PCR (Gene-Xpert) using cerebrospinal fluid. Results: The mean age of the study population was 28.59 (±16.87) years. Seventeen (42.5%) were male and 23 (57.5%) were female with a male to female ratio of 1:1.35. Out of 40 study cases AFB was presesnt in direct microscopy in only 1(2.5%) case, positive growth on culture in 5 (12.5%) cases and positive Gene-Xpert test in 9 (22.5%) cases. Sensitivity, specificity, PPV, NPV and diagnostic accuracy of Gene-Xpert (PCR) was 44.44%, 96.77%, 80%, 85.71%, and 85.0% respectively considering culture as gold standard. Sensitivity of Gene-Xpert in CSF was 22.5% as compared to culture which was only 12.5 % among the study cases. Conclusion: PCR (Gene-Xpert) is highly sensitive and speed in diagnosis of TBM compared to conventional methods. Bangladesh Journal of Neuroscience 2018; Vol. 34 (1): 1-8

Tuberculous Meningitis in PD Patients

Tuberculous meningitis is a very rare, but serious extrapulmonary complication of mycobacterial infections in immuno compromised patients, such as peritoneal dialysis recipients. A retrospective study of 455 peritoneal dialysis patients was made to determine the incidence and understand the demographic features of patients that lead to the development of Tuberculous meningitis on the basis of CSF for cell count, routine, ADA estimation, ZN Stain, culture&PCR. Between Jan 2000 and March 2017 4.39% patients of the total patients studied had Tuberculous meningitis. CSF smear was positive for AFB in 22.2% patients, CSF culture isolated AFB in 52.8% patients, PCR was found positive in 36.1% cases, and 4.39% patients were found to be having CSF ADA above cut off value. Pearson correlation indicates that lymphocyte counts and protein levels both increase as ADA increases, however sugar decreases as ADA, lymphocyte counts and protein increase in Tuberculous meningitis patients which is also proven by regression analysis. Outcome analysis revealed 30% mortality rate in diagnosed Tuberculous meningitis cases while maximum loss of life (36.36%) was seen in diabetic patients. It is concluded that the incidence of Tuberculous meningitis in peritoneal dialysis recipients was 4.39% and mortality rate was 30%. The rapid diagnosis of Tubercular meningitis is fundamental to clinical outcome. The present study clearly states that ADA is a rapid and fairly specific method for the diagnosis of Tuberculous meningitis. The early diagnosis and treatment help in achieving an improved outcome for PD patients. However, other techniques like AFB smear, PCR for M.tuberculosis and rapid culture would be required for confirmation of the diagnosis.

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

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&lt;0.05). In case of TBM, the mean CSF-ADA level increased statistically significantly with increase in CSF protein level (p&lt;0.05). In case of TBM, there was no significant difference in the mean ADA value according to CSF sugar level (p&lt;0.10). In case of TBM, the mean CSF-ADA level increased significantly with increase in CSF cell count (p&lt; 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.

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

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 &gt; 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 &gt; 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.

GeneXpert for Diagnosis of Tubercular Meningitis.

Diagnosis of tubercular meningitis (TBM) is difficult in children. The GeneXpert MTB/RIF assay has been recommended by WHO in 2013 to be used in children and in extra pulmonary clinical specimens. The present study was designed to assess the diagnostic utility of GeneXpert in detecting Mycobacterium tuberculosis in cerebrospinal fluid (CSF) in TBM cases and to compare the results with liquid culture BACTEC 460. Thirty four subjects <15y were diagnosed as TBM based on clinical, CSF and imaging details. Sensitivity of GeneXpert in CSF was 38.24% as compared to Bactec culture which was only 14.71% (p 0.0279). To conclude, GeneXpert MTB/RIF test is able to rapidly confirm diagnosis of TBM with higher sensitivity as compared to conventional methods and liquid culture.

Comparison of recoveries of Mycobacterium tuberculosis using the Automated BACTEC MGIT 960 System and Lowenstein-Jensen Medium in clinically suspected cases of tubercular meningitis in children

Background: Tubercular meningitis (TBM) remains a major complication in children with a considerable mortality and morbidity. Inconsistent and variable clinical features coupled with lack of rapid, sensitive and specific tests poses a diagnostic challenge to the clinical acumen. This study was carried out to diagnose TBM by a combination of direct microscopy by Ziehl-Neelsen (ZN) staining, culture by conventional Lowenstein Jensen (LJ) media and Bactec MGIT 960 system in clinically suspected cases TBM and compare the utility of these diagnostic modalities in the diagnosis of paediatric TBM. Methods: A total of 50 cerebrospinal fluid (CSF) samples from suspected cases of TBM in children aged 0-12 years of age were processed for direct acid fast bacilli (AFB) smear examination, and culture on LJ media and automated Bactec MGIT 960 system. Results: The study comprised of 32 male and 18 female patients in the age group of 0-12 years with a male to female ratio of 1.77: 1. 1 (2%) out of 50 samples was positive for AFB by ZN staining. Overall culture was positive in 15 cases (30%). Culture by LJ media was positive in 4 (8%) of the cases while culture by Bactec MGIT 960 system was positive in 14 cases (28%). The mean time of detection of Mycobacterium tuberculosis in LJ media and MGIT were 13.2 days and 32.4 days, respectively. Conclusion: Automated Bactec MGIT 960 system increases the sensitivity of diagnosing TBM in comparison to conventional microscopy and culture and reduces the mean time to diagnosis.

Cerebrospinal Fluid Adenosine Deaminase Activity: A Valid Ancillary Test for Tubercular Meningitis

Background: Tuberculosis affects 1.80 million persons every year with 3.70 lakh annual deaths, ~ 10% of which are of meningeal involvement. Diagnosis of Tubercular meningitis is difficult with often under or over diagnosis. Delay in diagnosis and initiation of treatment results in poor prognosis and sequel in up to 25% of cases. Cerebrospinal fluid (CSF) Adenosine deaminase (ADA) is a simple, reliable, cost effective and rapid diagnostic test that can even be done in small clinical laboratory set up. We evaluated CSF-ADA as an ancillary test for tubercular meningitis (TBM). Materials and Methods: Total 118 CSF samples were analyzed in this study under four different groups viz. TBM (n= 30), pyogenic meningitis (PM, n=24), aseptic meningitis (AM, n=20) and Controls (no meningeal involvement, n=44). Diagnosis of meningitis was done by clinicians on the basis of presence of signs of meningeal irritation and cytological and biochemical examination of CSF. CSF-ADA was estimated by method based on Berthelot reaction, which is the formation of a colored indophenol complex from ammonia liberated from adenosine, and quantified colorimetrically. Kruskal-Wallis test with Dunnett’s multiple comparison post-test was done to compare CSF-ADA activity in different groups. ROC curve analysis was done for CSF-ADA cutoff value. Result: Mean CSF-ADA (U/L) value in TBM patients were significantly higher (24.37±10.73) than in PM (14.28±5.979), AM (10.32±5.554) and Controls (6.520±4.801), p-value

Outcome analysis of ventriculoperitoneal shunt procedures in hydrocephalus due to tubercular meningitis and non-infective cases

Background: Hydrocephalus is one of the most common clinical conditions affecting the central nervous system. There have been several studies which show that the outcome of VP shunt in tubercular meningitis hydrocephalus is worse. We have conducted the present study to find whether VP shunt procedure complication rates are different in these two sub class patients or if the prognosis in TBM patients is worse due to the primary disease process. Methods: Ours is a retrospective analysis conducted in a tertiary care centre of 50 patients each of hydrocephalus due to tubercular meningitis (TBM) and non-meningitis patients. The data was collected over a period of 3 years. The diagnosis of tubercular meningitis was established by clinical history with examination, cerebrospinal Fluid (CSF) analysis and computed tomography brain (CT - Plain and contrast). All patients underwent Ventriculo Peritoneal shunt (VPS) in a standard protocol. All patients of TBM were put on 4 drugs anti Kochs treatment (AKT) for 3 months and 2 drugs AKT for 1 year. The follow up ranged between 3 years to 6 years. Results: Data in the form of age, sex, clinical signs/symptoms and shunt related complications were noted in a prescribed format. The complications in the two groups were statistically compared for significance using p value. Conclusions: There is no statistically significant increase in complication rate of VP shunt in TBM patients versus non infective cases. The worse prognosis of TBM patients may probably be due to the primary disease process rather than functioning of shunt.

Have we made any headway in the diagnosis of neurotuberculosis? Place of real time PCR or real time PCR

The diagnosis of Central Nervous System tuberculosis (CNS TB) had been always an enigma as yield of Mycobacterium tuberculosis in cerebrospinal fluid (CSF) is very low and diagnosis mainly rested on combination of clinical, CSF analysis and radiological findings. We attempted to find whether 16s rRNA primer based real time Polymerase chain reaction (PCR) aids in diagnosis of tubercular meningitis (TBM) and tuberculoma. Literature is flooded with newer techniques for the diagnosis of neuro-tuberculosis by real time PCR. But no clear cut guidelines are available about their role. 40 cases of tubercular meningitis, diagnosed on basis of Modified Ahuja Criteria and 40 controls were included in this prospective study. All patients were evaluated clinically and investigated in detail including cerebrospinal fluid analysis, Acid Fast Bacilli staining, culture for TB by Bac T Alert 3-D system,16s rRNA real time PCR assay, chest X ray, computed tomography scans of head, contact survey using chest X-ray, Mantoux test and hemogram. Comparative analysis of real time PCR were done in control group vs. cases of TBM diagnosed on the basis of Modified Ahuja criteria. Results: CSF for tuberculosis by real time PCR was positive in 26/40 cases (65%) of TBM, as against 2/40 controls. Keeping the CSF culture as the gold standard its sensitivity is 62.50 (95% confidence intervals- 54.7, 85.2), specificity is 77.40 (95% confidence intervals- 54.7, 85.2), positive predictive value is 46.15 and negative predictive value is 88.89. Modified Ahuja criteria can serve as useful tool in diagnosis. CSF analysis by real time PCR has shown better sensitivity and quicker results than culture. However, it cannot be recommended alone as it was negative in about a third of cases. But its significance is underlined in early diagnosis and as an adjunct to culture.

A Hospital Based Study on Estimation of Adenosine Deaminase Activity (ADA) in Cerebrospinal Fluid (CSF) in Various Types of Meningitis.

Tuberculosis kills 3.70 lakh patients in India every year,out of which 7-12 % are meningeal involvement. Delay in its diagnosis and initiation of treatment results in poor prognosis and squeal in up to 25% of cases. The aim of the present study is to look for a simple, rapid, cost effective, and fairly specific test in differentiating tubercular aetiology from other causes of meningitis. In the present study we measured the adenosine deaminase activity (ADA) in Cerebrospinal Fluid (CSF) of Tubercular Meningitis (TBM) and non-TBM patients. Fifty six patients attending hospital with symptoms and signs of meningitis were selected and divided into three groups: tubercular, pyogenic, and aseptic meningitis, depending upon the accepted criteria. CSF was drawn and ADA estimated. Out of 32 tubercular patients, 28 had CSF-ADA at or above the cut-off value while four had below. Out of 24 non-tuberculous patients (pyogenic and aseptic meningitis), two aseptic meningitis (AM) patient had ADA levels at or above the cut-off value while 22 had below this value. RESULTS of our study indicate that ADA level estimation in CSF is not only of considerable value in the diagnosis of TBM, CSF, and ADA level 10 U/L as a cut-off value with sensitivity 87.5% and specificity 83.33% and positive predictive value of the test was 87.5%.and 83.3% negative predictive value. It can be concluded that ADA estimation in CSF is not only simple, inexpensive and rapid but also fairly specific method for making a diagnosis of tuberculous aetiology in TBM, especially when there is a dilemma of differentiating the tuberculous aetiology from non-tuberculous ones. For this reason ADA estimation in TBM may find a place as a routine investigation.

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.