Cerebrospinal Fluid Parameters Predicting Contralateral Isolated Lateral Ventricle in Adult Tuberculous Meningitis with Hydrocephalus Post-Ventriculoperitoneal Shunt.

OBJECTIVE: Hydrocephalus, a major complication in tuberculous meningitis (TBM) patients, often necessitates treatment via ventriculoperitoneal shunt (VPS). However, post-VPS, some patients develop a complication called contralateral isolated lateral ventricle (CILV), leading to persistent hydrocephalus symptoms. This study aims to evaluate cerebrospinal fluid (CSF) parameters in predicting CILV occurrence post-VPS in adult TBM patients. METHODS: A retrospective analysis was conducted, focusing on the relationship between preoperative CSF parameters and the development of CILV in 40 adult TBM patients who underwent VPS. The study compared CSF parameters from lumbar puncture after admission with those from ventricular CSF post-external ventricular drainage tube insertion. RESULTS: CILV was observed in 6 of the 40 patients following VPS. Statistical analysis showed no significant difference between the CSF parameters obtained via lumbar and ventricular punctures. Notably, the mean CSF glucose level in patients with CILV was significantly lower (1.92 mmol/L) compared to the non-CILV group (3.03 mmol/L). Conversely, the median adenosine deaminase (ADA) level in the CILV group was higher (5.69 U/L) compared to the non-CILV group (3.18 U/L). The optimal cutoff values for CSF glucose and ADA levels were 1.90 mmol/L and 4.80 U/L, respectively, with a sensitivity of 66.67% and 83.33% and a specificity of 88.24% and 79.41%. CONCLUSIONS: The study identified elevated ADA levels and decreased glucose levels in CSF as potential risk factors for CILV development in adult TBM patients post-VPS. These findings suggest the necessity for more tailored surgical approaches, in patients with altered CSF parameters to mitigate the risk of CILV.

Study of the Role of Cerebrospinal Fluid C-reactive Protein and Adenosine Deaminase to differentiate Various Types of Meningitis.

OBJECTIVE: (1) To study cerebrospinal fluid (CSF) adenosine deaminase (ADA) and CSF C-reactive protein (CRP) levels in the differentiation of viral, pyogenic, and tuberculous meningitis (TBM). (2) To estimate the borderline levels of CRP in CSF in viral, pyogenic, and TBM. METHODS: A prospective and cross-sectional study was conducted at the Department of Medicine, SRN Hospital, Prayagraj, Uttar Pradesh, India, between August 2016 and September 2018. In this study, a total of 100 patients with meningitis were included applying specific inclusion and exclusion criteria after proper ethical approval. RESULTS: Out of 100 patients, 61 were TBM, 31 were pyogenic meningitis, and eight were viral meningitis (VM). CSF CRP level was significantly increased in pyogenic meningitis (1.05 ± 0.36 mg/dL) compared to nonpyogenic meningitis [TBM (0.42 ± 0.13 mg/dL) and VM (0.37 ± 0.09 mg/dL)]. At the cut-off level of CRP in CSF > 0.6 mg/dL, its diagnostic sensitivity in pyogenic meningitis was 93.55% and specificity 94.20%. While CSF ADA levels were higher in the TBM group (13.32 ± 3.21 U/L) compared to the other two groups [pyogenic meningitis (6.15 ± 1.27 U/L) and VM (4.86 ± 0.88 U/L)]. At a cut-off, CSF ADA level of >10 U/L, its diagnostic sensitivity for TBM was 91.67% and specificity 90%. CONCLUSION: Cerebrospinal fluid (CSF) CRP levels were found to be raised in pyogenic meningitis, and CSF ADA was found to be elevated in TBM. While both ADA level and CRP level in CSF are found low in VM.

Cerebrospinal fluid adenosine deaminase for the diagnosis of tuberculous meningitis.

Background: A consensus on the diagnostic utility of cerebrospinal fluid adenosine deaminase (ADA) for tuberculous meningitis (TBM) is lacking. Methods: Patients aged ≥12 years admitted with CNS infections were enrolled prospectively. ADA was measured with spectrophotometry. Results: We enrolled 251 TBM and 131 other CNS infections. The optimal cutoff of ADA was calculated at 5.5 U/l against microbiological reference standard with area under curve 0.743, sensitivity 80.7%, specificity 60.3%, positive likelihood ratio 2.03 and negative likelihood ratio 3.12. The widely used cutoff value 10 U/l had specificity 82% and sensitivity 50%. The discriminating power was higher for TBM versus viral meningoencephalitis than bacterial or cryptococcal meningitis. Conclusion: Cerebrospinal fluid ADA has a low-to-modest diagnostic utility.

The diagnosis of tuberculosis (TB) of the brain is mainly made by testing cerebrospinal fluid, a clear liquid that flows in and around the brain and spinal cord. Adenosine deaminase (ADA) is a protein whose production and activity are increased in many diseases, such as TB. ADA testing in cerebrospinal fluid is widely used for the diagnosis of brain TB. However, the experts have split opinions regarding its confirmatory role. This study explores ADA measurement in cerebrospinal fluid for differentiating TB from other brain infections. The report says that this simple and inexpensive test can be helpful, but it cannot make or refute the diagnosis of brain TB and should only be considered along with other tests.

Adenosine deaminase from the cerebrospinal fluid for the diagnosis of tuberculous meningitis: A meta-analysis.

OBJECTIVE: To comprehensively evaluate the diagnostic efficacy of adenosine deaminase in cerebrospinal fluid (CSF) for tuberculous meningitis (TBM), and the potential influence of patients' age groups and cutoffs of measured adenosine deaminase. METHODS: Systematic review and meta-analysis of relevant studies retrieved from PubMed, Embase, and Web of Science databases. Pooled sensitivity and specificity were calculated with a random-effect model. RESULTS: Overall, 43 studies with 1653 patients with TBM and 3417 controls without were included. Pooled results showed that adenosine deaminase in CSF is associated with satisfactory diagnostic efficacy for TBM, with a pooled sensitivity of 0.86 (95% confidence interval [CI]: 0.82-0.90), specificity of 0.89 (95% CI: 0.86-0.91), positive likelihood ratio of 7.70 (95% CI: 6.16-9.63), and negative likelihood ratio of 0.15 (95% CI: 0.12-0.20). The pooled receiver operating characteristic (AUC) was 0.94 (95% CI: 0.91-0.96), suggesting good performance. Subgroup analyses showed good diagnostic efficacies of adenosine deaminase in CSF for both adults (AUC 0.95) and children (AUC 0.96) with TBM. AUCs indicating the diagnostic accuracies of adenosine deaminase in CSF for TBM were 0.93 for studies with cutoffs <10 U/L and and 0.94 for a cutoff =10 U/L, but only 0.90 for studies with cutoffs >10 U/L. CONCLUSIONS: Measuring adenosine deaminase of CSF shows satisfactory diagnostic efficacy for TBM in children and adults, particularly if using a cutoff ≤10 U/L.

Study of cerebrospinal fluid levels of lactate, lactate dehydrogenase and adenosine deaminase in the diagnosis and outcome of acute meningitis.

BACKGROUND: Meningitis is a serious clinical health issue in most developing countries. Late diagnosis and treatment result in significant morbidity and mortality. This research aims to study the utility of CSF lactate, lactate dehydrogenase (LDH), and adenosine deaminase (ADA) as diagnostic markers in acute meningitis, and to differentiate among varied aetiologies of acute meningitis and their outcomes. METHOD: A cross-sectional observational case-control study was conducted in 30 patients of suspected meningitis of varied aetiologies and 30 controls without any pre-existing neurological disorder and who underwent lumbar puncture during spinal anesthesia. A fresh CSF sample was collected in a heparinized vial following an aseptic lumbar puncture. The levels of lactate, LDH and ADA were estimated and recorded. RESULT: CSF lactate was significantly elevated in bacterial meningitis (BM) and cryptococcal meningitis, with 100% sensitivity when compared to controls. Elevated LDH was found only in BM, hence elevated LDH levels may strongly signify bacterial etiology. Significantly elevated ADA levels were noted in tuberculous meningitis. Significantly elevated levels of lactate and ADA were suggestive of slower clinical recovery and a prolonged hospital stay (p < 0.001). CONCLUSION: Estimation of CSF lactate, LDH, and ADA levels is a rapid, inexpensive and simple procedure and can play a major role in the early differentiation of bacterial, viral, tuberculous, and fungal meningitis. This would facilitate the initiation of appropriate treatment as early as possible, thereby decreasing mortality and complications.

A case of idiopathic hypertrophic pachymeningitis with high adenosine deaminase in cerebrospinal fluid.

Adenosine deaminase (ADA) in cerebrospinal fluid (CSF) has been reported as useful to diagnose tuberculous meningitis and hypertrophic pachymeningitis (HP). The case of a 59-year-old woman with impaired vision and an auditory disturbance due to massive intracranial HP is presented. Although acid-fast bacillus cultures and polymerase chain reaction tests for Mycobacterium tuberculosis in the CSF were negative, tuberculous HP was diagnosed clinically because of the high ADA in CSF, and anti-tuberculosis drugs were administered with prednisolone because idiopathic HP (IHP) could not be ruled out. Since the impaired vision worsened with prednisolone reduction despite the continuation of anti-tuberculosis drugs, a dural biopsy was performed, and the patient was diagnosed with IHP. ADA is associated with lymphocyte proliferation and differentiation and increased by activation of cell-mediated immunity. Elevated CSF-ADA might be caused by lymphocyte infiltration in the thickened dura mater.

Elevation of CSF adenosine deaminase in HIV patient with meningitis from retroviral rebound syndrome, a case report.

Adenosine deaminase (ADA) in cerebrospinal fluid (CSF) is considered to be a useful biomarker in differentiating tuberculous meningitis (TBM) from other meningitis in non-HIV patients. However, its specificity decreases in patients with HIV, and other diseases such as cytomegalovirus encephalitis, toxoplasmosis or meningeal lymphomatosis can also elevate ADA in CSF. We here report a rare case of retroviral rebound syndrome in a HIV patient, whose ADA in CSF was elevated.

Determination of cerebrospinal fluid adenosine deaminase activity cut-off for the diagnosis of tuberculous meningitis in Hong Kong.

AIMS: Tuberculous meningitis (TBM) is a severe infection which may lead to serious complication and mortality. Prompt diagnosis and treatment are essential. There is a need for a simple and fast laboratory test to differentiate TBM from other causes. METHODS: Retrospective review was conducted for cerebrospinal fluid adenosine deaminase (CSF-ADA) activity which was measured at the Chemical Pathology Laboratory of Princess Margaret Hospital, the sole centre providing such service in Hong Kong, for 51 patients with suspected meningitis from nine local hospitals between June 2014 and July 2017. TBM diagnosis was defined by positive culture and/or nucleic acid amplification test result of Mycobacterium tuberculosis complex in CSF. RESULTS: CSF-ADA activity was significantly higher in the TBM group (8.6±2.1 IU/L, n=8) than that of the non-TBM group (2.8±5.9 IU/L, n=43). The optimal clinical cut-off of 5.1 U/L for TBM diagnosis in our laboratory yielded 100% sensitivity, 91% specificity, positive likelihood ratio of 10.8 and negative likelihood ratio of 0. In rare circumstance, false elevation may be seen in non-tuberculous cause, such as central nervous system lymphoma and fungal infection. CONCLUSIONS: We recommend the use of CSF-ADA activity, which is a simple, fast and robust test for early differentiation of TBM from other causes, to facilitate timely initiation of antituberculous treatment and potentially improve patients' outcome.

Longitudinal cerebrospinal fluid assessment in a patient with tuberculous meningitis-A case report.

BACKGROUND: Dynamic assessment of cerebrospinal fluid (CSF) is essential for diagnosis, treatment, and prognosis of tuberculous meningitis, one of the most severe forms of central nervous system (CNS) infection. CASE PRESENTATION: A 45-year-old man sought care as he developed confusion, clonic convulsion, and coma. Longitudinal, comprehensive analyses of cytological, biochemical, and microbial changes in CSF specimen were assessed for this patient. On day 1 of hospitalization, modified Ziehl-Neelsen staining of CSF identified positive acid-fast bacilli, cytological analysis revealed neutrophilic-predominant pleocytosis (neutrophils 77%), and adenosine deaminase (ADA) was substantially elevated. Therefore, tuberculous meningitis was diagnosed and first-line standard anti-tuberculosis treatment was initiated. Interestingly, after 7-day treatment, the patient was greatly improved, and CSF disclosed a dominant percentage of lymphocytes (82%) as well as macrophages engulfing Mycobacterium tuberculosis. Later, the dose of dexamethasone was reduced, large number of neutrophils (57%) was present and protein level was immediately elevated in CSF specimen, indicating a possible relapse of tuberculous meningitis. Since the clinical condition of the patient was not worsening, the patient was stick to reduced dose of dexamethasone and standard anti-tuberculosis agents. He was discharged from the hospital on day 34, with 1-year continuation standard anti-tuberculosis therapy, and was clinically resolved from tuberculous meningitis. CONCLUSION: Detailed analyses of cellular composition, biochemical results, and microbial tests of CSF specimen provide the physician direct evidence of the immune surveillance status during tuberculous meningitis, which facilitates early diagnosis, optimal treatment, and improved prognosis.

A case with neurological abnormalities caused by Rickettsia raoultii in northwestern China.

BACKGROUND: The number of new rickettsial species are rapidly increasing, and increasing numbers of Rickettsia raoultii (R. raoultii) infection cases have been detected in humans. However, neurological abnormalities caused by R. raoultii are rarely reported, especially in northwestern China. CASE PRESENTATION: A 36-year-old Kazakh shepherd with an attached tick on part temporalis, presented with right eyelid droop, lethargy, fever, headache, fever (38.0-41.0 °C) and erythematous rash. The examination of cerebrospinal fluid (CSF) showed cerebrospinal pressure of 200 mm H2O, leukocyte count of 300.0 × 106/L, adenosine deaminase of 2.15 U/L, and total protein concentration of 0.93 g/L. The diagnosis of R. raoultii infection was confirmed by six genetic markers, and semi-quantified by enzyme-linked immunosorbent assay for rickettsial antigen. The patient gradually recovered after treatment with doxycycline and ceftriaxone. R. raoultii DNA was found both in a tick detached from this patient and in 0.18% (2/1107) of blood samples collected from local shepherds. CONCLUSIONS: This is the first reported case with neurological abnormalities caused by R. raoultii in northwestern China. It is vital to detect rickettsial agents both in blood and CSF for tick bite patients with neurological abnormalities. Public health workers and physicians should pay attention to neurological abnormalities caused by Rickettsia.

[A case of tuberculous meningitis with pleural effusion as a manifestation of a paradoxical reaction during anti-tuberculosis therapy].

We present a case of tuberculous meningitis (TBM), wherein pleural effusion developed as a manifestation of paradoxical reaction during anti-tuberculosis therapy. An 87-year-old diabetic man was referred to our clinic for fever and impaired consciousness. He did not obey vocal commands. No ocular motor deficit, facial palsy, or limb weakness was observed. He had hyponatremia due to inappropriate antidiuresis. Examination of the cerebrospinal fluid revealed lymphocytosis and high adenosine deaminase (ADA) activity, suggestive of TBM. He was treated with isoniazid, rifampicin, and pyrazinamide, after which his symptoms quickly resolved. Lymphocyte count, ADA activity, and protein concentration in the cerebrospinal fluid decreased. However, approximately 30 days after the initiation of therapy, he developed mild hypoxemia. A chest CT scan revealed pleural effusion. The pleural fluid was exudate with elevated ADA activity, which was consistent with tuberculous pleural effusion. Shortly after the use of a herbal medicine, Goreisan extract, hyponatremia and hypoproteinemia improved, and the pleural effusion was reduced. Approximately one-third of patients with TBM are reported to develop a paradoxical reaction, such as tuberculoma, hydrocephalus, and optochiasmatic and spinal arachnoiditis. The present case suggests that extra-central nervous system manifestations, including pleural effusion, should be considered when treating TBM.

Elevated Adenosine Deaminase Levels in the Cerebrospinal Fluid in Immune Checkpoint Inhibitor-induced Autoimmune Encephalitis.

Immune checkpoint inhibitors (ICIs) are promising drugs for various cancers. However, immune activation by ICIs can lead to immune-related adverse events (irAEs). Autoimmune encephalitis is a rare irAE, and its clinical features remain unknown. We herein report two patients with ICI-associated autoimmune encephalitis who, saliently, showed elevated adenosine deaminase (ADA) levels in the cerebrospinal fluid (CSF). This is the first report of increased ADA levels in the CSF of patients with ICI-induced autoimmune encephalitis. Although the mechanism of the ADA increase is poorly understood, elevated ADA in the CSF may be informative in the diagnosis of this rare disorder.

Clinical characteristics of autoimmune GFAP astrocytopathy.

The clinical features of autoimmune glial fibrillary acidic protein (GFAP) astrocytopathy remain to be elucidated. We describe here the clinical features of 14 patients with GFAP astrocytopathy confirmed by detection of GFAP-IgG in cerebrospinal fluid (CSF). The novel findings of this study are as follows. First, over half of the patients presented with movement disorders (tremor, myoclonus, and ataxia), autonomic dysfunction (mainly urinary dysfunction), and hyponatremia. Second, most patients showed transient elevation of adenosine deaminase activity levels in CSF. Finally, some patients showed bilateral hyperintensities in the posterior part of the thalamus on brain magnetic resonance imaging.

Study of Central Nervous System Tuberculosis.

Aims and Objective: To assess the clinical features, complications and outcome in patients with central nervous system tuberculosis (CNS TB) and to correlate the clinical, laboratory and radiological findings of CNS TB. Materials and Methods: In a cross sectional study, total 50 diagnosed cases of CNS TB (either TB meningitis or tuberculoma) were studied. The data on demographic factors, clinical features, complications and laboratory findings, details of treatment and outcome were recorded and analyzed. Follow up was done during hospital stay and at the end of six months after completion of chemotherapy. Results: Out of 50, 42 patients had TBM (tuberculous meningitis) and 8 patients had tuberculoma. Mean age of patients was 33.5 yrs with male preponderance (M: F = 6.2:1), 66% patients had duration of symptoms more than 4 weeks. Common symptoms were fever (100%), headache (70%) and vomiting (64%). CSF staining for AFB was positive in 8% patients, mean CSF protein was 157 mg%, 32 patients had CSF lymphocytosis, (count >90%), CSF PCR was positive in 92.85%, CSF ADA levels were high (> 10 U/L) in 90.47%. On neuroimaging, 62 % patients had meningeal enhancement and 8 patients had tuberculomas. 10 patients were in stage I of disease, 24 in stage II and 16 in stage III. 30% mortality was observed, more in HIV positive patients with stage III disease. On followed up after 6 months of discharged patients (n=35), 10 patients had full recovery and 17 had recovery with neurological deficit, however 8 patients lost follow up. Conclusion: Diagnosis of CNS TB should be based on clinical features and 3 or more supportive criteria rather than CSF positivity on staining or culture. Rapid and early diagnosis by positive CSF PCR and CT/MRI findings should replace CSF AFB staining and culture in further for the diagnosis of CNS TB.

Development of a clinical prediction rule for tuberculous meningitis in adults in Lima, Peru.

OBJECTIVES: Diagnosis of tuberculous meningitis (TM) is a challenge in countries with a high burden of the disease and constrained resources and clinical prediction rules (CPRs) could be of assistance. We aimed at developing a CPR for diagnosis of TM in a Latin American setting with high tuberculosis incidence and a concentrated HIV epidemic. METHODS: We enrolled adult patients with clinical suspicion of TM attending two hospitals in Lima, Peru. We obtained information on potential anamnestic, clinical and laboratory predictive findings that are easy to collect and promptly available. We independently diagnosed TM according to a composite reference standard that included a series of microbiological tests. We performed bivariate analysis and constructed a logistic regression model to select the predictive findings associated with TM. With the selected predictors included in the model, we developed a score-based CPR. We assessed its internal validity and diagnostic performance. RESULTS: Of 155 analysed patients, 59 (38%) had TM. The CPR we derived includes three predictors: cough for 14 days or more, 10-500 cells in CSF and adenosine deaminase ≥ 6 U/l in CSF. It classifies patients into high-, moderate- or low-score groups and has an overall area under the ROC curve of 0.87. 59% of patients were assigned to either the high- or the low-score group, permitting prompt decision-making. In patients in the high-score group, it attains a positive likelihood ratio for TM of 10.6 and in patients with low scores, a negative likelihood ratio of 0.10. Bootstrap analysis indicated high internal validity. CONCLUSION: This CPR could support decision-making in patients with clinical suspicion of TM. External validation and further assessment of its clinical impact are necessary before application in other settings.

Qualitative and Quantitative Comparison of Contrast-Enhanced Fluid-Attenuated Inversion Recovery, Magnetization Transfer Spin Echo, and Fat-Saturation T1-Weighted Sequences in Infectious Meningitis.

OBJECTIVE: To compare the contrast-enhanced fluid-attenuated inversion recovery (CE-FLAIR), the CE T1-weighted (CE-T1W) sequence with fat suppression (FS) and magnetization transfer (MT) for early detection and characterization of infectious meningitis. MATERIALS AND METHODS: Fifty patients and 10 control subjects were evaluated with the CE-FLAIR and the CE-T1W sequences with FS and MT. Qualitative assessment was done by two observers for presence and grading of abnormal leptomeningeal enhancement. Quantitative assessment included computation of net meningeal enhancement, using single pixel signal intensity software. A newly devised FLAIR based scoring system, based on certain imaging features including ventricular dilatation, ependymal enhancement, infarcts and subdural effusions was used to indicate the etiology. Data were analysed using the Student's t test, Cohen's Kappa coefficient, Pearson's correlation coefficient, the intraclass correlation coefficient, one way analysis of variance, and Fisher's exact test with Bonferroni correction as the post hoc test. RESULTS: The CE-FLAIR sequence demonstrated a better sensitivity (100%), diagnostic accuracy (95%), and a stronger correlation with the cerebrospinal fluid, total leukocyte count (r = 0.75), protein (r = 0.77), adenosine deaminase (r = 0.81) and blood glucose (r = -0.6) values compared to the CE-T1W sequences. Qualitative grades and quantitative meningeal enhancement on the CE-FLAIR sequence were also significantly greater than those on the other sequences. The FLAIR based scoring system yielded a diagnostic accuracy of 91.6% and a sensitivity of 96%. A strong inverse Pearson's correlation (r = -0.95) was found between the assigned score and patient's Glasgow Coma Scale at the time of admission. CONCLUSION: The CE-FLAIR sequence is better suited for evaluating infectious meningitis and could be included as a part of the routine MR imaging protocol.

[Cerebrospinal fluid adenosine deaminase and its dynamic changes in tuberculous meningitis].

Objective: To explore the diagnostic value of cerebrospinal fluid (CSF) adenosine deaminase (ADA) level in tuberculous meningitis. Methods: We retrospectively analyzed 139 patients (73 males, 66 females) who visited Beijing Chest Hospital for suspected TBM from January 2010 to June 2015. Of them, 99 patients were diagnosed to have TBM, with 45 males and 54 females, and a mean age of (33±15) years. Forty patients were diagnosed as having Non-TBM, with 28 males and 12 females, and a mean age of (35±18) years. All patients underwent lumbar puncture, and CSF ADA, routine, biochemical and bacteriological tests were performed. Thirty-five TBM patients reviewed CSF ADA test after treatment for 4 weeks, 8 weeks and 6 months. Results: The level of CSF ADA in TBM group was higher than that in the non-TBM group, the difference being statistically significant (5.6 U/L vs 2.3 U/L, P=0.000). When the cut-off value of the CSF ADA was 3.8 U/L , the sensitivity and specificity for diagnosis of TBM were 60.6% (95%CI 50.3%-70.1%) and 87.5% (95%CI 72.4%-95.3%), respectively, and the area under the ROC curve was 0.734.The CSF ADA level was (6.7±4.2) U/L in the 35 cases of TBM before treatment. After 4 weeks, 8 weeks and 6 months of anti-tuberculosis treatment, the CSF ADA levels were (4.5±3.3) U/L, (3.7±2.7) U/L and (2.0±1.5) U/L, respectively; all significantly decreased as compared to that before treatment (P<0.001). There was no significant change in the ADA level between 8 weeks and 4 weeks (P=0.128). After 6 months of treatment, the level of CSF ADA was significantly lower than those after 4 and 8 weeks' treatment (P<0.001). Conclusions: CSF ADA in TBM patients was significantly higher than in non-TBM patients. The sensitivity of CSF ADA level in the diagnosis of TBM was poor, but the specificity was better. CSF ADA was significantly reduced and showed dynamic changes with effective anti-tuberculosis treatment and maybe helpful in evaluating the effect of treatment.

Raised adenosine deaminase in the cerebrospinal fluid: A tool for the diagnosis of tuberculous meningitis in developing countries.

CONTEXT: The rapid diagnosis followed by the early treatment of tuberculous meningitis (TBM) is important in preventing fatal outcomes. The mainstay of diagnosis lies in cerebrospinal fluid (CSF) analysis, radiological investigations, and clinical findings. AIM: The present study was conducted to determine the efficacy, sensitivity, and specificity of raised adenosine deaminase (ADA) level in CSF to differentiate TBM from non-TBM cases as a rapid, cost-effective, and noninvasive test. PATIENTS AND METHODS: This was a retrospective study conducted over a 1-year period in a tertiary teaching institute of Malwa region, India. A total of 143 patients presented with symptoms and signs of meningitis were included and divided into TBM and non-TBM groups on the basis of the diagnostic criteria. CSF ADA estimation was drafted and analyzed by using ≥10 U/L as a cutoff value. A statistical comparison of the ADA levels between the study groups was made by using unpaired Student's t-test. RESULTS: Out of the 143 cases, 40 were TBM, and 103 were non-TBM. The mean ADA level in TBM and non-TBM cases was 17.18 ± 9.59 and 6.33 ± 2.48, respectively, and the difference was statistically significant. Using a cutoff level ≥10 U/L, CSF ADA had a sensitivity of 92.5% and a specificity of 89.32%. Positive and negative likelihood ratios of the test were 8.66 and 0.08, respectively, and positive and negative predictive values, were 77.08 and 96.84%, respectively. CONCLUSION: The present study reflects the importance of a CSF ADA level ≥10 U/L in the diagnosis of TBM. Thus, it can be used as an adjunctive diagnostic tool to differentiate TBM from other non-TBM cases, when there is a diagnostic dilemma.

Diagnostic test accuracy of adenosine deaminase for tuberculous meningitis: A systematic review and meta-analysis.

INTRODUCTION: The measurement of adenosine deaminase (ADA) level in cerebrospinal fluid (CSF) has generated as a suitable test for tuberculous meningitis (TBM) diagnosis. The main objective in the present meta-analysis focused on analyzing the ADA test accuracy in order to diagnose TBM. METHODS: We searched several databases including Medline, Embase and Cochrane databases to identify studies addressing the diagnosis of TBM. The quality of included reports were assessed by RevMan5 software (via QUADS2 checklist). Accuracy measures of ADA test (sensitivity, specificity and others) pooled with random effects models. In addition, the data was elicited by using midas and metan packages in stata (version 12). RESULT: Twenty studies were eligible for inclusion within the meta-analysis. The pooled sensitivity and specificity for TBM diagnosis hallmarks were 89% (95% CI: 0.84-0.92) and 91% (95% CI: 0.87-0.93), respectively. The positive likelihood ratio was 9.4 (95% CI: 7-12.8), negative likelihood ratio was 0.12 (95% CI: 0.09-0.17), and diagnostic odds ratio was 77 (95% CI: 45-132). Indeed, the area under the summary receiver operating characteristic (SROC) was 0.96. CONCLUSION: It was magnificently attained that ADA test had a relatively high accuracy for TBM diagnosis.

Multiple sclerosis showing elevation of adenosine deaminase levels in the cerebrospinal fluid.

An 80-year-old man developed dysarthria, quadriplegia, sensory disturbance and ataxia in all limbs. Brain and spinal magnetic resonance imaging (MRI) revealed multiple enhanced lesions. Cerebrospinal fluid (CSF) levels of adenosine deaminase (ADA) remarkably elevated. Tuberculosis DNA was not detected, and tuberculosis was not cultured either in the CSF. Brain biopsy revealed the inflammatory demyelinating lesions. With the diagnosis of multiple sclerosis, corticosteroid therapy resulted in rapid improvement of his symptoms and MRI abnormalities. CSF levels of ADA also decreased. Multiple sclerosis should be included in differential diagnosis of disorders with ADA elevation in the CSF.