Rapid Diagnosis Of Tuberculous Meningitis Research Articles

The value of nanopore sequencing as a diagnostic tool in tuberculous meningitis: A protocol of systematic review and meta-analysis.

Rapid diagnosis of tuberculous meningitis (TBM) remains very difficult. Nanopore sequencing is gaining ground in the field of rapid tuberculosis (TB) diagnostics. The purpose of this study was to complete a protocol to guide the conduct of a systematic review and meta-analysis evaluating the accuracy of nanopore sequencing for the rapid diagnosis of TBM. In accordance with the Preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) guidelines, we completed this protocol, which was also registered on the PROSPERO platform. We will search the EMBASE, PubMed, the Cochrane Library, Wanfang database, and China National Knowledge Infrastructure databases for literature that evaluated the accuracy of nanopore sequencing for rapid diagnosis of TBM and screen them according to the inclusion and exclusion criteria, and qualified literature will be extracted with relevant data for further analysis. Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) will be used for evaluating the methodological quality of included studies. Stata (V 15.0; Stata Corp., College Station, TX, the USA) with midas module will be used to perform relevant meta-analysis. Heterogeneity between studies will be assessed by I2 statistics. When significant heterogeneity exists between studies, we will conduct meta-regression analyses, subgroup analyses and sensitivity analyses to further explore the sources of heterogeneity. We completed this study protocol, and this systematic review and meta-analysis will be the first systematic evaluation of the role of nanopore sequencing in the rapid diagnosis of TBM, which will allow clinicians to have a better understanding of the test. Systematic review registration PROSPERO Registration number: CRD42024549837.

Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics.

The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of <150cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts > 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a "one-size-fits-all" approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.

Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics

The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of &lt;150 cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts &gt; 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a “one-size-fits-all” approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.

Comparative evaluation of IS6110 and protein antigen b PCR in cerebrospinal fluid for rapid diagnosis of tuberculous meningitis in children.

Introduction. Childhood tuberculosis meningitis is a severe form of tuberculosis with high morbidity and mortality. The diagnosis is frequently missed and delayed due to lack of sensitive tests like acid-fast bacilli (AFB) smear and delayed results by culture.Aims. To compare the role of IS6110 and protein antigen b PCR in cerebrospinal fluid (CSF) for rapid diagnosis of tuberculous meningitis (TBM) in children.Methodology. Forty-five cases of TBM and 20 controls were enrolled in this prospective study.Results. The mean ages of cases and controls were 4.2±0.5 years and 4.5±0.7 years, respectively. In the TBM group, two-thirds of the children were <4 years of age, and 62 % were males. Sensitivities of AFB smear examination, Löwenstein-Jensen (LJ) medium and bactenecin (BACTEC) culture in cases were 4.4, 0 and 2.2%, respectively. The protein antigen b PCR was most sensitive as it was positive in 35 (77.8 %) of TBM patients; IS6110 PCR was positive in 27 (60 %) patients. Both PCR-based tests had higher positivity than conventional tests and BACTEC culture. No significant difference was seen between the PCR tests. Excellent agreement was observed between both PCR-based tests as they were concordant for 26 positive samples and 35 negative samples.Conclusion. Protein b PCR is a sensitive and rapid method for the diagnosis of TBM (sensitivity 77.8 %). Both PCRs were more sensitive than smear, LJ and BACTEC. The specificity of both PCR was 100 %.

Metagenomic Next-Generation Sequencing (mNGS) in cerebrospinal fluid for rapid diagnosis of Tuberculosis meningitis in HIV-negative population

ObjectiveMetagenomic Next-Generation Sequencing (mNGS) has been applied as a novel method of detection pathogens for infectious diseases, but its value in the rapid diagnosis of tuberculous meningitis(TBM)has not been clarified based on large samples. MethodsA retrospective analysis was conducted on 51 inpatients with suspected TBM who underwent mNGS and four other tests in cerebrospinal fluid (CSF). ResultsAmong 51 included patients, 45 cases were diagnosed as TBM (38 definite, 5 probable, 2 possible) and 6 cases as non-TBM. Using final diagnosis as reference standard, the sensitivity, specificity, PPV (positive predictive value), and NPV (negative predictive value) of mNGS in CSF for TBM were 84.44%(38/45, 69.94%–93.01%), 100%(6/6, 51.68%–100%), 100%(40/40, 88.57%–100%) and 46.15%(6/13, 20.40%–73.88%). The diagnostic sensitivity of mNGS(84.4%)was significantly higher than that of AFB (0%, P = 0.000), MGIT960 culture(22.2%, P = 0.000), MTB PCR(24.4%, P = 0.000) and Xpert MTB/RIF(40%, P = 0.000). The ROC curve showed that CSF protein quantification and CSF cell count might be valuable in the prediction of NGS positive detection of MTB (Mycobacterium tuberculosis). ConclusionCSF mNGS had high sensitivity, specificity and PPV in the diagnosis of TBM. Patients with a significant increase in CSF cell number and protein quantification might have a higher likelihood of positive MTB detection of NGS.

Recent Developments in Tuberculous Meningitis Pathogenesis and Diagnostics.

The pathogenesis of Tuberculous meningitis (TBM) is poorly understood, but contemporary molecular biology technologies have allowed for recent improvements in our understanding of TBM. For instance, neutrophils appear to play a significant role in the immunopathogenesis of TBM, and either a paucity or an excess of inflammation can be detrimental in TBM. Further, severity of HIV-associated immunosuppression is an important determinant of inflammatory response; patients with the advanced immunosuppression (CD4+ T-cell count of <150cells/μL) having higher CSF neutrophils, greater CSF cytokine concentrations and higher mortality than those with CD4+ T-cell counts > 150 cells/μL. Host genetics may also influence outcomes with LT4AH genotype predicting inflammatory phenotype, steroid responsiveness and survival in Vietnamese adults with TBM. Whist in Indonesia, CSF tryptophan level was a predictor of survival, suggesting tryptophan metabolism may be important in TBM pathogenesis. These varying responses mean that we must consider whether a "one-size-fits-all" approach to anti-bacillary or immunomodulatory treatment in TBM is truly the best way forward. Of course, to allow for proper treatment, early and rapid diagnosis of TBM must occur. Diagnosis has always been a challenge but the field of TB diagnosis is evolving, with sensitivities of at least 70% now possible in less than two hours with GeneXpert MTB/Rif Ultra. In addition, advanced molecular techniques such as CRISPR-MTB and metagenomic next generation sequencing may hold promise for TBM diagnosis. Host-based biomarkers and signatures are being further evaluated in childhood and adult TBM as adjunctive biomarkers as even with improved molecular assays, cases are still missed. A better grasp of host and pathogen behaviour may lead to improved diagnostics, targeted immunotherapy, and possibly biomarker-based, patient-specific treatment regimens.

Structural switching electrochemical DNA aptasensor for the rapid diagnosis of tuberculous meningitis.

BackgroundTuberculous meningitis (TBM) is the most devastating manifestation of extra-pulmonary tuberculosis. About 33% of TBM patients die due to very late diagnosis of the disease. Conventional diagnostic methods based on signs and symptoms, cerebrospinal fluid (CSF) smear microscopy or liquid culture suffer from either poor sensitivity or long turnaround time (up to 8 weeks). Therefore, in order to manage the disease efficiently, there is an urgent and unmet need for a rapid and reliable diagnostic test.MethodsIn the current study, to address the diagnostic challenge of TBM, a highly rapid and sensitive structural switching electrochemical aptasensor was developed by combining the electrochemical property of methylene blue (MB) with the molecular recognition ability of a ssDNA aptamer. To demonstrate the clinical diagnostic utility of the developed aptasensor, a blinded study was performed on 81 archived CSF specimens using differential pulse voltammetry.ResultsThe electrochemical aptasensor developed in the current study can detect as low as 10 pg HspX in CSF background and yields a highly discriminatory response (P<0.0001) for TBM and not-TBM categories with ~95% sensitivity and ~97.5% specificity and has the ability to deliver sample-to-answer in ≤30 minutes.ConclusionIn summary, we demonstrate a new aptamer-based electrochemical biosensing strategy by exploiting the target-induced structural switching of H63 SL-2 M6 aptamer and electroactivity of aptamer-tagged MB for the detection of HspX in CSF samples for the diagnosis of TBM. Further, the clinical utility of this sensor could be extended for the diagnosis of other forms of tuberculosis in the near future.

Interferon-Gamma Release Assay Performance of Cerebrospinal Fluid and Peripheral Blood in Tuberculous Meningitis in China.

The aim of this study was to examine the performance of T-SPOT.TB on cerebrospinal fluid (CSF) and peripheral blood (PB) in diagnosis of tuberculous meningitis (TBM) in China. Of 100 patients with presumed TBM prospectively enrolled from Sep 2012 to Oct 2014, 53 were TBM (21 definite and 32 probable TBM cases) and 37 were non-TBM cases; the other 10 patients were excluded from analysis due to inconclusive diagnosis, no sufficient CSF samples, or incomplete follow-up. T-SPOT.TB on CSF and PB and routine laboratory tests of CSF were performed simultaneously. The receiver operating characteristic (ROC) curve and cut-off value of CSF T-SPOT.TB and routine CSF parameters were established between TBM and non-TBM group. The area under ROC curve (AUC) of the T-SPOT.TB on CSF and PB was 0.81 and 0.89, which was higher than that of the routine CSF parameters (AUC 0.67–0.77). Although the sensitivity of CSF T-SPOT.TB was lower than that of PB T-SPOT.TB (60.8% versus 90.6%, P < 0.001), the specificity of CSF T-SPOT.TB was significantly higher than that of PB T-SPOT.TB (97.2% versus 75.7%, P = 0.007). These results indicated that the diagnostic accuracies of PB and CSF T-SPOT.TB are higher than routine laboratory tests. Furthermore, the higher specificity of CSF T-SPOT.TB makes it a useful rule-in test in rapid diagnosis of TBM.

Diagnostic value of Cobas Amplicor MTB and Rotorgene Real Time PCR for tuberculous meningitis: A six-year retrospective study

Objective: Tuberculous meningitis (TBM) is the most severe and lethal form of tuberculosis (TB).Bacteriologic confirmation of TBM is difficult and slow. Therefore, most patients receive antituberculosis treatment based only on clinical and cerebrospinal fluid (CSF) characteristics. Rapid diagnosis of TBM is important to decrease morbidity and mortality. The aim of the study was to demonstrate that COBAS Amplicor MTB and Rotorgene Real Time (RT) PCR is a rapid method of diagnosing TBM before and after initiating anti-tuberculosis treatment. Methods: A retrospective study was conducted between December 2002 and January 2009 in 468 patients with suspected TBM. Clinical specimens were collected from different hospitals in Ankara. All specimens were evaluated by smear microscopy and culture methods with Lowenstein-Jensen (LJ) and MGIT culture system. Results: Using culture results as a gold standard, the sensitivity, specificity, positive predictive values (PPV), and negative predictive values (NPV) were 71.0%, 98.8%, 97.8% and 75.0%, respectively, for COBAS Amplicor MTB and 80%, 98.9%, 99.0% and 80.0%, respectively, for Rotorgene RT PCR. Statistical analysis showed no significant differences between the COBAS Amplicor MTB and Rotorgene RT PCR (p≥0.05). All isolates were susceptible to isoniazid, rifampin, streptomycin, and ethambutol with proportion method in LJ medium. All isolates were defined as LAM7-TUR by spoligotyping. Conclusion: Retrospective analysis of COBAS Amplicor MTB and Rotorgene RT PCR found that both tests are effective in rapidly diagnosing MTB using CSF. It was concluded that Rotorgene RT PCR test is more sensitive (81.0%) than COBAS Amplicor MTB (71.0%). J Microbiol Infect Dis 2015;5(4): 156-161 Key words: Tuberculous meningitis, COBAS Amplicor MTB, Rotorgene Real Time PCR

Adenosine Deaminase (ADA) in Tuberculous Meningitis

Abstract not availableBangladesh J Medicine Jul 2014; 25 (2) : 61-71

Tuberculous and brucellosis meningitis differential diagnosis.

The Thwaites and Lancet scoring systems have been used in the rapid diagnosis of tuberculous meningitis (TBM). However, brucellar meningoencephalitis (BME) has similar characteristics with TBM. The ultimate aim of this study is to infer data to see if BME should be included in the differential diagnosis of TBM when these two systems suggest the presence of TBM. BME and TBM patients from 35 tertiary hospitals were included in this study. Overall 294 adult patients with BME and 190 patients with TBM were enrolled. All patients involved in the study had microbiological confirmation for either TBM or BME. Finally, the Thwaites and Lancet scoring systems were assessed in both groups. The Thwaites scoring system more frequently predicted BME cases (n=292, 99.3%) compared to the TBM group (n=182, 95.8%) (P=0.017). According to the Lancet scoring system, the mean scores for BME and TBM were 9.43±1.71 and 11.45±3.01, respectively (P<0.001). In addition, TBM cases were classified into "probable" category more significantly compared to BME cases, and BME cases were categorized into the "possible" category more frequently. When the Thwaites or Lancet scoring systems indicate TBM, brucellar etiology should also be taken into consideration particularly in endemic countries.

Evaluation of IS6110 PCR in CSF for the rapid diagnosis of tuberculous meningitis

Background: Tuberculous meningitis (TBM) is a major, global public health problem and its diagnosis remains problematic even after years of experience. Early diagnosis and treatment are of paramount importance as a delay in diagnosis can lead to irreversible central nervous system damage and mortality. Aims: To evaluate the role of cerebrospinal fluid (CSF) IS6110-based tuberculosis (TB) polymerase chain reaction analysis (PCR) as an efficient diagnostic tool for the diagnosis of TBM. Materials and Methods: This is a cross-sectional study carried out with patients clinically suspected to have TBM. A total of 102 cases were enrolled, out of which 15 patients were excluded from the study because of alternative diagnoses. An in-house IS6110-PCR method using a specific pair of primers designed to amplify the insertion sequence, IS6110 in the Mycobacterium tuberculosis genome was used to analyze CSF. Results: Our study showed PCR positivity in 51.7% cases. PCR gave a sensitivity of 100% and specificity of 68.9% against the cases of TBM confirmed by culture. Conclusion: IS6110 TB-PCR is a novel diagnostic tool that can diagnose a greater number of individuals with clinically suspected TBM with its rapidity, accuracy, and reliability, and its positivity even after 4 weeks of starting treatment makes it the diagnostic tool of choice.

Performance of an interferon-gamma release assay in the diagnosis of tuberculous meningitis in children / Performanţa testului bazat pe eliberarea interferonului gamma în diagnosticul meningitei tuberculoase la copil

AbstractThe new immunodiagnostic tests based on the Mycobacterium tuberculosis specific antigen, early secretory antigenic target 6 (ESAT-6) and culture filtrate protein 10 (CFP-10), showed promising results in the diagnosis of tuberculosis infection. However, there are only few studies in the published literature on performance tests in cerebrospinal fluid. We investigated whether a rapid diagnosis of tuberculous meningitis (TBM) could be established by interferon-γ blood and cerebrospinal fluid (CSF) tests in children.We used the QuantiFERON-TB Gold in Tube test (QFT-IT) on blood and the QuantiFERON-TB Gold test (QFT-G) on the CSF of 63 subjects with TBM (including 25 case of definite TBM and 38 cases of probable TBM) and 62 controls.The CSF analyses indicated possible TBM in 63.4% of cases. The sensitivity of the CSF culture for Mycobacterium tuberculosis was only 39.6%. The sensitivity of the tuberculin skin test (TST) was 49.2% and the specificity was 88.6%. The estimated sensitivities of the QFT-G for the CSF and QFT-IT for the blood in culture confirmed TBM cases (gold standard) were 84% and 80%, respectively. The estimated specificities were 98.2% for the CSF and 87.9% for the blood. This study showed that the sensitivity of QFT for the CSF could be higher than TST and culture and slightly higher in CSF than in blood. The specificity of QFT-G for the CSF was higher those of the TST, but the specificity of QFT-IT is lower.QFT-G of the CSF is a useful diagnostic marker of tuberculosis that may improve the management of TBM, but the test results must be correlated with clinical, radiological and characteristics of CSF. New researches are needed to investigate the performance of QFT-G in the CSF compared with ELISPOT and PCR

Diagnosis and Treatment of Tuberculous Meningitis

Tuberculous meningitis (TBM) is the most fatal form among various types of tuberculosis. It is also the most difficult form for diagnosis. The prevalence of TBM is still high in South Korea compared to that in Western countries. TBM should be differentiated from viral or bacterial meningitis. However, diagnosing TBM is challenging. Clinical samples obtained from cerebrospinal fluid (CSF) are paucibacillary that decreases the sensitivity of mycobacterial diagnostic tests such as acid-fast bacilli (AFB) and Mycobacterium tuberculosis culture. Adenosine deaminase (ADA) is widely used as an adjunct diagnosis of TBM. However, ADA is not a specific marker for TBM. Therefore, more specific test is urgently needed for the confirmation of TBM. Recently, IFN-gamma releasing assay using peripheral blood mononuclear cells and CSF-mononuclear cells as well as the newly-developed Xpert MTB/RFP showed promising results in the rapid diagnosis of TBM. In general, anti-tuberculous therapy for patients with TBM except adjuvant steroid use is similar to that for patients with pulmonary tuberculosis. However, treatment of TBM can be occasionally complicated due to paradoxical response during anti-tuberculous therapy. Key Words: Tuberculosis; Meningitis; Diagnosis; Treatment

Diagnosis and Treatment of Tuberculous Meningitis

Tuberculous meningitis (TBM) is the most fatal form among various types of tuberculosis. It is also the most difficult form for diagnosis. The prevalence of TBM is still high in South Korea compared to that in Western countries. TBM should be differentiated from viral or bac terial meningitis. However, diagnosing TBM is challenging. Clinical samples obtained from cerebrospinal fluid (CSF) are paucibacillary that decreases the sensitivity of mycobacterial diagnostic tests such as acid-fast bacilli (AFB) and Mycobacterium tuberculosis culture. Adenosine deaminase (ADA) is widely used as an adjunct diagnosis of TBM. However, ADA is not a specific marker for TBM. Therefore, more specific test is urgently needed for the confirmation of TBM. Recently, IFN-gamma releasing assay using peripheral blood mononuclear cells and CSF-mononuclear cells as well as the newly-developed Xpert MTB/RFP showed promising results in the rapid diagnosis of TBM. In general, anti-tuberculous therapy for patients with TBM except adjuvant steroid use is similar to that for patients with pulmonary tuberculosis. However, treatment of TBM can be occasionally complicated due to paradoxical response during anti-tuberculous therapy. J Neurocrit Care 2014;7(2):78-85

Detection of Mycobacterium tuberculosis GlcB or HspX Antigens or devR DNA Impacts the Rapid Diagnosis of Tuberculous Meningitis in Children

BackgroundTuberculous meningitis (TBM) is the most common form of neurotuberculosis and the fifth most common form of extrapulmonary TB. Early diagnosis and prompt treatment are the cornerstones of effective disease management. The accurate diagnosis of TBM poses a challenge due to an extensive differential diagnosis, low bacterial load and paucity of cerebrospinal fluid (CSF) especially in children.Methodology/Principal FindingsWe describe the utility of ELISA and qPCR for the detection of Mycobacterium tuberculosis (M. tb) proteins (GlcB, HspX, MPT51, Ag85B and PstS1) and DNA for the rapid diagnosis of TBM. CSF filtrates (n = 532) derived from children were classified as ‘Definite’ TBM (M. tb culture positive, n = 29), ‘Probable and Possible’ TBM (n = 165) and ‘Not-TBM’ including other cases of meningitis or neurological disorders (n = 338). ROC curves were generated from ELISA and qPCR data of ‘Definite’ TBM and Non-Tuberculous infectious meningitis (NTIM) samples and cut-off values were derived to provide ≥95% specificity. devR qPCR, GlcB, HspX and PstS1 ELISAs showed 100% (88;100) sensitivity and 96–97% specificity in ‘Definite’ TBM samples. The application of these cut-offs to ‘Probable and Possible’ TBM groups yielded excellent sensitivity (98%, 94;99) and specificity (98%, 96;99) for qPCR and for GlcB, HspX and MPT51 antigen ELISAs (sensitivity 92–95% and specificity 93–96%). A test combination of qPCR with GlcB and HspX ELISAs accurately detected all TBM samples at a specificity of ∼90%. Logistic regression analysis indicated that these tests significantly added value to the currently used algorithms for TBM diagnosis.ConclusionsThe detection of M. tb GlcB/HspX antigens/devR DNA in CSF is likely to improve the utility of existing algorithms for TBM diagnosis and also hasten the speed of diagnosis.

Rapid Diagnosis of Pulmonary and Extrapulmonary Tuberculosis in HIV-Infected Patients. Comparison of LED Fluorescent Microscopy and the GeneXpert MTB/RIF Assay in a District Hospital in India

HIV-related tuberculosis is difficult to diagnose and is associated with high morbidity and mortality. Recently, the World Health Organization has endorsed the GeneXpert MTB/RIF (Xpert) assay for the diagnosis of pulmonary tuberculosis in HIV-infected patients from developing countries, but information about the use of Xpert for the diagnosis of extrapulmonary tuberculosis is scarce. In this study, we compared the performance of light-emitting diode (LED) auramine fluorescent microscopy and the Xpert assay for the diagnosis of tuberculosis in HIV infected patients in a district hospital of India. Although at higher cost, Xpert outperformed LED fluorescent microscopy in all type of specimens, especially in cerebrospinal fluid where the number of positive results was increased 11 times. Pleural fluid, ascitic fluid, pus, and stool specimens also yielded positive results with the Xpert assay. When collecting two additional early-morning sputum samples, the increase of the number of positive results with the Xpert assay was lower than previously reported for HIV infected patients. Rifampicin resistance was observed in 2.2% of the cases. The results of this study show that the Xpert assay can dramatically improve the rapid diagnosis of tuberculous meningitis and other types of extrapulmonary tuberculosis of HIV infected patients.

Comparative Utility of Cytokine Levels and Quantitative RD-1-Specific T Cell Responses for Rapid Immunodiagnosis of Tuberculous Meningitis

The rapid diagnosis of tuberculous meningitis (TBM) is problematic. We found in 150 patients with suspected TBM that, similar to RD-1-specific quantitative cerebrospinal fluid (CSF) T-cell responses, unstimulated CSF gamma interferon (IFN-γ) levels when used together with other rapid confirmatory tests (Gram stain and cryptococcal latex agglutination test) may allow the accurate and rapid diagnosis of TBM in a setting in which tuberculosis (TB) and HIV are endemic. In resource-poor settings, a clinical prediction rule (CPR) may be useful to clinicians, and thus the IFN-γ assay may potentially need to be used only when the clinical score is below a prespecified threshold. These preliminary findings will need to be confirmed in further studies.

Multiplex PCR for rapid diagnosis of tuberculous meningitis

Rapid and specific diagnosis of tubercular meningitis is of paramount importance to decrease morbidity and mortality. The aim of the study was to evaluate multiplex PCR using protein b, MPB 64, and IS6110 primers directed against M. tuberculosis complex for the diagnosis of tuberculous meningitis (TBM). Multiplex PCR was performed on 18 TBM confirmed cases (culture was positive), 92 clinically suspected TBM cases and 100 non-TBM (control group) patients. Multiplex PCR had a sensitivity of 94.4% for confirmed cases and specificity of 100% for confirmed TBM cases. In 92 clinically diagnosed but unconfirmed TBM cases, multiplex PCR was positive in 84.78% cases. The overall sensitivity of microscopy, culture and multiplex cases were 1.81, 16.73, and 86.63% and specificity was 100, 100, and 100% respectively. Multiplex PCR using protein b, MPB 64, and IS6110 primers has a high sensitivity and specificity in diagnosis of tubercular meningitis.

Rapid Diagnosis of Tuberculous Meningitis by T Cell–Based Assays on Peripheral Blood and Cerebrospinal Fluid Mononuclear Cells

The role of the new Myocbacterium tuberculosis-specific enzyme-linked immunosorbent spot (ELISPOT) assay for diagnosis of tuberculous meningitis (TBM) has not yet been fully assessed. Here, we conducted a prospective, blinded, observational study to evaluate the diagnostic accuracy of this assay, compared with the conventional tests, for diagnosing TBM. All adult patients with suspected TBM were enrolled at a tertiary care hospital (Seoul, South Korea) during a 12-month period. ELISPOT assays were performed on peripheral mononuclear cells and mononuclear cells from cerebrospinal fluid (CSF). Eighty-nine patients with suspected TBM were enrolled. Of these, 31 (35%) were classified as having TBM (10 confirmed, 6 highly probable, and 15 probable cases), and 55 (62%) were classified as not having active tuberculosis. The remaining 3 (3%) with possible TBM were excluded from the final analysis. The sensitivities and specificities, respectively, of the tested methods for diagnosing TBM were as follows: CSF adenosine deaminase level >5.8 U/L, 89% (95% confidence interval [CI], 69%-98%) and 73% (95% CI, 58%-84%); peripheral mononuclear cells ELISPOT, 71% (95% CI, 51%-86%) and 57% (95% CI, 42%-70%); and CSF mononuclear cells ELISPOT assay, 59% (95% CI, 36%-79%) and 89% (95% CI, 72%-98%). The combined sensitivity of an adenosine deaminase level >5.8 U/L or a positive peripheral mononuclear cells ELISPOT assay result was 94% (95% CI, 79%-99%), conferring a negative likelihood ratio of 0.14 (95% CI, 0.03-0.55) when both test results were negative. ELISPOT assays using peripheral mononuclear cells and CSF mononuclear cells are useful adjuncts to the current tests for diagnosing TBM, particularly when used in combination with the assessment of adenosine deaminase level in CSF.