Rational application of adenosine deaminase activity in cerebrospinal fluid for the diagnosis of tuberculous meningitis

Diagnostic Accuracy of Cerebrospinal Fluid (CSF) Adenosine Deaminase (ADA) for Tuberculous Meningitis (TBM) in Adults: A Systematic Review and Meta-Analysis

Tuberculous meningitis is the most serious complication of tuberculosis. Early diagnosis is crucial to start relevant treatment to prevent death and disability. Electronic databases PubMed, Google Scholar, and Cochrane Library were used to find relevant articles from January 1980 to June 2022. The random-effect model in terms of pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with 95% confidence interval was adopted to derive the diagnostic efficacy of cerebrospinal fluid (CSF) adenosine deaminase (ADA) for the diagnosis of tuberculous meningitis (TBM) in adult patients. A total of 22 studies (20 prospective and two retrospective data) have been included in this meta-analysis, having 1927 participants. We perceived acceptable pooled sensitivity, specificity, summary receiver operating characteristics (SROCs), and diagnostic odds ratio (DOR) of 0.85 (95% CI: 0.77-0.90), 0.90 (95% CI: 0.85-0.93), 0.94 (95% CI: 0.91-0.96) and 48 (95% CI: 26-86), respectively, for CSF-ADA for differentiating TBM from non-TBM in adult patients. To ascertain the certainty of evidence for CSF-ADA as a diagnostic marker for TBM, Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) analysis was used. CSF-ADA is an auspicious diagnostic test with a high degree of specificity and acceptable sensitivity for the diagnosis of tuberculous meningitis, however, with very low certainty of evidence.

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.

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.

Neurobrucellosis: Brief Review

BACKGROUND

Brucella are small, nonmotile, intracellular, and aerobic gram-negative bacteria. Of the 10 species that currently form the genus Brucella, 5 were shown to be pathogenic in humans.

REVIEW SUMMARY

The epidemiology, clinical manifestations, diagnosis and imaging, and treatment of neurobrucellosis will be reviewed.Brucellosis's transmission to humans occurs by direct contact with contaminated animals. Older patients are at increased risk of nervous system involvement in brucellosis. Brucella spp. can lead to central nervous system involvement through direct damage via invasion of neural tissue or indirect damage caused by endotoxins or immune inflammatory reactions elicited by the presence of the bacteria in the body. Patients can have general nonspecific symptoms in addition to neurological and psychiatric symptoms. There are 4 diagnostic criteria for the diagnosis of neurobrucellosis, which include signs and symptoms suggestive of neurobrucellosis, a positive finding of Brucella spp. in the cerebrospinal fluid (CSF), and/or a positive titer of antibodies targeting brucella in the CSF, lymphocytosis with high protein levels and low glucose levels in CSF, and imaging findings (either cranial magnetic resonance imaging or computed tomography) peculiar to neurobrucellosis. For the treatment, a combined therapy is favored over monotherapy for the eradication of Brucella. Moreover, a multirouted therapy has been associated with increased treatment efficacy. The prognosis of neurobrucellosis is dependent on patients' clinical presentation: brucellar meningitis is associated with a good prognosis, whereas diffuse central nervous system involvement is associated with the development of long-term sequelae.

CONCLUSIONS

Neurobrucellosis affects patients globally and in endemic areas. Neurologists should familiarize themselves with its clinical presentation, diagnosis, and treatment to provide optimal care for their patients.

HIV-Tuberculous Meningitis Co-Infection: A Systematic Review and Meta-Analysis

Human Immunodeficiency Virus (HIV)-infected persons are at a higher risk of developing Tuberculous Meningitis (TBM). We aimed to estimate the prevalence of TBM-HIV co-infection. We systematically searched Pubmed/Medline, Embase and Cochrane library databases from January 1, 2000, to January 31, 2017, to find relevant studies. We employed the random-effects meta-analysis model to estimate the pooled prevalence of TBM-HIV co-infection. Twenty-six eligible studies showed the prevalence of HIV in TBM patients. In the pooled analyses, the prevalence of HIV was 30% (95% CI: 12-47) in patients with confirmed TBM, and 12.1% (95% CI: 7.3-19.2) in patients with suspected TBM. This study shows a high prevalence of TBM-HIV co-infection. Establishing proper diagnostic criteria and preventive measures for TBM infections could assist in the prevention and management of TBM infection, particularly TBM-HIV co-infection.

Characteristics and biomarkers of patients with central nervous system infection admitted to a referral hospital in Northern Vietnam

Background

Laboratory facilities for etiological diagnosis of central nervous system (CNS) infection are limited in developing countries; therefore, patients are treated empirically, and the epidemiology of the pathogens is not well-known. Tubercular meningitis is one of the common causes of meningitis, which has high morbidity and mortality, but lacks sensitive diagnostic assays. The objectives of this study were to determine the causes of meningitis in adult patients by using molecular assays, to assess the risk factors associated with them, and to explore whether biomarkers can differentiate tubercular meningitis from bacterial meningitis.

Methods

We conducted a cross-sectional study in the Department of Infectious Diseases, Bach Mai Hospital, Hanoi, Vietnam, from June 2012 to May 2014. All patients who were 16 years old and who had meningoencephalitis suggested by abnormal cerebrospinal fluid (CSF) findings (CSF total cell >5/mm3 or CSF protein 40 mg/dL) were included in the study. In addition to culture, CSF samples were tested for common bacterial and viral pathogens by polymerase chain reaction (PCR) and for biomarkers: C-reactive protein and adenosine deaminase (ADA).

Results

Total number of patients admitted to the department was 7506; among them, 679 were suspected to have CNS infection, and they underwent lumbar puncture. Five hundred eighty-three patients had abnormal CSF findings (meningoencephalitis); median age was 45 (IQR 3158), 62.6% were male, and 60.9% were tested for HIV infection. Among 408 CSF samples tested by PCR, out of them, 358 were also tested by culture; an etiology was identified in 27.5% (n=112). S. suis (8.8%), N. meningitis (3.2%), and S. pneumoniae (2.7%) were common bacterial and HSV (2.2%), Echovirus 6 (0.7%), and Echovirus 30 (0.7%) were common viral pathogens detected. M. tuberculosis was found in 3.2%. Mixed pathogens were detected in 1.8% of the CSF samples. Rural residence (aOR 4.1, 95% CI 1.214.4) and raised CSF ADA (10 IU/L) (aOR 25.5, 95% CI 3.1212) were associated with bacterial meningitis when compared with viral meningitis; similarly, raised CSF ADA (10 IU/L) (aOR 42.2, 95% CI 2.0882) was associated with tubercular meningitis.

Conclusions

Addition of molecular method to the conventional culture had enhanced the identification of etiologies of CNS infection. Raised CSF ADA (10 IU/L) was strongly associated with bacterial and tubercular meningitis. This biomarker might be helpful to diagnose tubercular meningitis once bacterial meningitis is ruled out by other methods.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41182-021-00322-2.

Tuberculosis Meningoencephalomyelitis in Good's Syndrome: a Case Report

Good's syndrome is a rare disease characterized by thymoma associated with combined B- and T-cell immunodeficiency in adults. Due to the lack of early onset of symptoms, it is difficult to diagnose this disorder. A 44-year-old man diagnosed with thymic carcinoma was admitted to the hospital with quadriplegia for 6 months. Brain abscess and meningoencephalitis were identified in the magnetic resonance imaging (MRI) of the brain. Antibiotics, steroid, and intravenous immunoglobulin treatment were provided for 3 months. Follow-up MRI showed progression to C7-level. The radiologic findings were consistent with tuberculosis infection and thus, the patient was treated with anti-tuberculosis medication. MRI of the brain and spine showed an improved state of meningoencephalomyelitis. In a laboratory study, there were decreased levels of peripheral B-cell and CD4 T-cell and decreased CD4:CD8 ratio; therefore, it confirmed that cellular immunity deteriorated. In addition to clinical findings, we were able to diagnose the patient with Good's syndrome. Good's syndrome is a highly suspicious disease in patients with thymoma who have recurrent unusual infections. Immunologic tests should be performed for diagnosis in which it can prevent delayed diagnosis and allow timely treatment.

Tuberculosis: a focused review for the emergency medicine clinician

INTRODUCTION

Tuberculosis (TB) is a common disease worldwide, affecting nearly one-third of the world's population. While TB has decreased in frequency in the United States, it remains an important infection to diagnose and treat.

OBJECTIVE

This narrative review discusses the evaluation and management of tuberculosis, with an emphasis on those factors most relevant for the emergency clinician.

DISCUSSION

TB is caused by Mycobacterium tuberculosis and is highly communicable through aerosolized particles. A minority of patients will develop symptomatic, primary disease. Most patients will overcome the initial infection or develop a latent infection, which can reactivate. Immunocompromised states increase the risk of primary and reactivation TB. Symptoms include fever, prolonged cough, weight loss, and hemoptysis. Initial diagnosis often includes a chest X-ray, followed by serial sputum cultures. If the patient has a normal immune system and a normal X-ray, active TB can be excluded. Newer tests, including nucleic acid amplification testing, can rapidly diagnose active TB with high sensitivity. Treatment for primary and reactivation TB differs from latent TB. Extrapulmonary forms can occur in a significant proportion of patients and involve a range of different organ systems. Patients with human immunodeficiency virus are high-risk and require specific considerations.

CONCLUSIONS

TB is a disease associated with significant morbidity and mortality. The emergency clinician must consider TB in the appropriate setting, based on history and examination. Accurate diagnosis and rapid therapy can improve patient outcomes and reduce the spread of this communicable disease.

Human immunodeficiency virus in patients with tuberculous meningitis: systematic review and meta-analysis

INTRODUCTION

Human immunodeficiency virus (HIV)-infected individuals are at increased risk for all forms of extrapulmonary tuberculosis (TB), including tuberculous meningitis (TBM). This study aimed to investigate the frequency of HIV in patients with TBM.

METHODS

PubMed, Embase, Web of Science and Cochrane Library were searched for articles including relevant data. Stata version 14.0 (StataCorp, College Station, Texas, USA) was used to analyse the data.

RESULTS

Twenty studies were identified. The pooled frequency of HIV among adult patients with TBM was 38.0% (95% CI: 21.0-57.0; I² = 97%). In children (under the age of 15 years), 6.0% (95% CI: 1.0-13.0; I² = 0.0%) had HIV infection. In patients with bacterial meningitis other than TBM, 36.0% (95% CI: 19.0-53.0; I² = 100%) were HIV-infected.

CONCLUSIONS

A relatively high frequency of HIV in patients with TBM was indicated by our study. Establishment of diagnostic criteria and effective treatment strategies for TBM/HIV co-infection are recommended for better management of patients with TBM+HIV.

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.

Cerebrospinal fluid metabolomic profiling in tuberculous and viral meningitis: Screening potential markers for differential diagnosis

BACKGROUND

Tuberculous meningitis (TBM) is the most severe and frequent form of central nervous system tuberculosis. The current lack of efficient diagnostic tests makes it difficult to differentiate TBM from other common types of meningitis, especially viral meningitis (VM). Metabolomics is an important tool to identify disease-specific biomarkers. However, little metabolomic information is available on adult TBM.

METHODS

We used ¹H nuclear magnetic resonance-based metabolomics to investigate the metabolic features of the CSF from 18 TBM and 20 VM patients. Principal component analysis and orthogonal signal correction-partial least squares-discriminant analysis (OSC-PLS-DA) were applied to analyze profiling data. Metabolites were identified using the Human Metabolome Database and pathway analysis was performed with MetaboAnalyst 3.0.

RESULTS

The OSC-PLS-DA model could distinguish TBM from VM with high reliability. A total of 25 key metabolites that contributed to their discrimination were identified, including some, such as betaine and cyclohexane, rarely reported before in TBM. Pathway analysis indicated that amino acid and energy metabolism was significantly different in the CSF of TBM compared with VM.

CONCLUSIONS

Twenty-five key metabolites identified in our study may be potential biomarkers for TBM differential diagnosis and are worthy of further investigation.