Single-cell transcriptome reveals highly complement activated microglia cells in association with pediatric tuberculous meningitis.

Background: Tuberculous meningitis (TBM) is a devastating form of tuberculosis (TB) causing high mortality and disability. TBM arises due to immune dysregulation, but the underlying immune mechanisms are unclear. Methods: We performed single-cell RNA sequencing on peripheral blood mononuclear cells (PBMCs) and cerebrospinal fluid (CSF) cells isolated from children (n=6) with TBM using 10 xGenomics platform. We used unsupervised clustering of cells and cluster visualization based on the gene expression profiles, and validated the protein and cytokines by ELISA analysis. Results: We revealed for the first time 33 monocyte populations across the CSF cells and PBMCs of children with TBM. Within these populations, we saw that CD4_C04 cells with Th17 and Th1 phenotypes and Macro_C01 cells with a microglia phenotype, were enriched in the CSF. Lineage tracking analysis of monocyte populations revealed myeloid cell populations, as well as subsets of CD4 and CD8 T-cell populations with distinct effector functions. Importantly, we discovered that complement-activated microglial Macro_C01 cells are associated with a neuroinflammatory response that leads to persistent meningitis. Consistently, we saw an increase in complement protein (C1Q), inflammatory markers (CRP) and inflammatory factor (TNF-α and IL-6) in CSF cells but not blood. Finally, we inferred that Macro_C01 cells recruit CD4_C04 cells through CXCL16/CXCR6. Discussion: We proposed that the microglial Macro_C01 subset activates complement and interacts with the CD4_C04 cell subset to amplify inflammatory signals, which could potentially contribute to augment inflammatory signals, resulting in hyperinflammation and an immune response elicited by Mtb-infected tissues.

Comparative evaluation of intensified short course regimen and standard regimen for adults TB meningitis: a protocol for an open label, multi-center, parallel arms, randomized controlled superiority trial (INSHORT trial).

BACKGROUND: Despite several incremental improvements in the management of tuberculous meningitis (TBM), the mortality rates remain high. In spite of national and international guidelines, variation in the choice, dose, and duration of drugs exist between countries and clinicians. We propose to evaluate a shorter and more effective regimen containing agents with augmented intracerebral drug exposure and anti-inflammatory approaches to improve disability-free survival among patients with TBM. Our strategy incorporates the various developments in the field of TBM over the last two decades and only few trials have evaluated a composite of these strategies in the overall outcomes of TBM. METHODS: An open label, parallel arms, randomized controlled superiority trial will be conducted among 372 participants across 6 sites in India. Eligible participants will be randomly allocated in 1:1:1 ratio into one of the three arms. The intervention arm consists of 2 months of high-dose rifampicin (25 mg/kg), moxifloxacin (400 mg), pyrazinamide, isoniazid, aspirin (150 mg), and steroids followed by rifampicin, isoniazid, and pyrazinamide for 4 months. The second intervention arm includes all the drugs as per the first arm except aspirin and the patients in the control arm will receive treatment according to the National TB Elimination Program guidelines. All participants will be followed up for 1 year after the treatment.  DISCUSSION: Current WHO regimens have agents with poor central nervous system drug exposure and is too long. It does not reflect the accumulating evidence in the field. We propose a comprehensive clinical trial incorporating the emerging evidence accrued over the last two decades to shorten the duration and improve the treatment outcomes. This multi-centric trial may generate crucial evidence with policy and practice implications in the treatment of TBM. TRIAL REGISTRATION: Clinical Trial Registry India CTRI/2023/05/053314. Registered on 31 May 2023 ( https://ctri.nic.in/Clinicaltrials/pmaindet2.php?EncHid=ODYzMzg=&Enc=&userName=CTRI/2023/05/053314 ). CLINICALTRIALS: gov NCT05917340. Registered on 6 August 2023 ( https://classic. CLINICALTRIALS: gov/ct2/show/NCT05917340 ). PROTOCOL VERSION: Version 1.3 dated 12 July 2023.

Surgical treatment for recurrent thoracic ventral intradural arachnoid cyst secondary to tuberculous meningitis: a case report.

INTRODUCTION: Spinal intradural arachnoid cysts (SIACs) are rare spinal entities that are categorized as primary or secondary pathologies. Secondary cysts can arise from various traumatic or inflammatory causes including subarachnoid hemorrhage, intrathecal injection or surgery, and infectious meningitis/arachnoiditis. Only a few cases of SIAC secondary to tuberculous meningitis have been previously reported, without details of the surgical treatment. CASE PRESENTATION: A 27-year-old woman diagnosed with tuberculous meningitis developed myelopathy caused by thoracic ventral SIAC and intradural abscess. The patient underwent abscess evacuation and cyst fenestration; however, cyst recurrence occurred. The 2nd surgery consisted of cyst resection via a posterolateral approach with expansive duraplasty and spinal arthrodesis. Re-recurrence occurred, and at the 3rd surgery, cyst-subarachnoid bypass was performed. One year after the 3rd surgery, the myelopathic symptoms recovered, and MR images demonstrated a decreased cyst size. DISCUSSION: Here, we report a rare case of recurrent thoracic SIAC secondary to tuberculous meningitis and arachnoiditis. Simple fenestration is associated with a high risk of recurrence in this pathology. Ventrally located thoracic cysts can be approached with posterolateral approach with pedicles resected followed by instrumented arthrodesis. Even in cases involving gross total resection of the cyst wall, there is a risk of recurrence. In such cases, cyst-subarachnoid bypass with a large-diameter tube can be effective.

Surgery for Central Nervous System Tuberculosis in Children.

Tuberculosis (TB) is the second most common cause of death due to a single infectious agent worldwide after COVID-19. Central nervous system tuberculosis is widely prevalent in the world, especially in the developing countries and continues to be a socioeconomic problem. It is highly devastating form of tuberculosis leading to unacceptable levels of morbidity and mortality despite appropriate antitubercular therapy. The clinical symptoms are varied and nonspecific. They can be easily overlooked. Tuberculous meningitis is the most common presentation and its sequelae viz. vasculitis, infarction and hydrocephalus can be devastating. The ensuing cognitive, intellectual, and endocrinological outcome can be a significant source of morbidity and mortality, especially in resource constrained countries. Early diagnosis and treatment of tuberculous meningitis and institution of treatment is helpful in limiting the course of disease process. The diagnosis of CNS tuberculosis remains a formidable diagnostic challenge. The microbiological methods alone cannot be relied upon. CSF diversion procedures need to be performed at the appropriate time in order to achieve good outcomes. Tuberculous pachymeningitis and arachnoiditis are morbid sequelae of tuberculous meningitis. Tuberculomas present as mass lesions in the craniospinal axis. Tuberculous abscess can mimic pyogenic abscess and requires high index of suspicion. Calvarial tuberculosis is seen in children and responds well to antituberculous chemotherapy. Tuberculosis of the spinal cord is seen similar to intracranial tuberculosis in pathogenesis but with its own unique clinical manifestations and management. Multidrug-resistant tuberculosis is a formidable problem, and alternate chemotherapy should be promptly instituted. The pathogenesis, clinical features, diagnosis, and management of central nervous system tuberculosis in children are summarized. Heightened clinical suspicion is paramount to ensure prompt investigation. Early diagnosis and treatment are essential to a gratifying outcome and prevent complications.

Acute ischemic stroke in tuberculous meningitis.

Background: The underlying mechanism for stroke in patients with tuberculous meningitis (TBM) remains unclear. This study aimed to investigate the predictors of acute ischemic stroke (AIS) in TBM and whether AIS mediates the relationship between inflammation markers and functional disability. Methods: TBM patients admitted to five hospitals between January 2011 and December 2021 were consecutively observed. Generalized linear mixed model and subgroup analyses were performed to investigate predictors of AIS in patients with and without vascular risk factors (VAFs). Mediation analyses were performed to explore the potential causal chain in which AIS may mediate the relationship between neuroimaging markers of inflammation and 90-day functional outcomes. Results: A total of 1,353 patients with TBM were included. The percentage rate of AIS within 30 days after admission was 20.4 (95% CI, 18.2-22.6). A multivariate analysis suggested that age ≥35 years (OR = 1.49; 95% CI, 1.06-2.09; P = 0.019), hypertension (OR = 3.56; 95% CI, 2.42-5.24; P < 0.001), diabetes (OR = 1.78; 95% CI, 1.11-2.86; P = 0.016), smoking (OR = 2.88; 95% CI, 1.68-4.95; P < 0.001), definite TBM (OR = 0.19; 95% CI, 0.06-0.42; P < 0.001), disease severity (OR = 2.11; 95% CI, 1.50-2.90; P = 0.056), meningeal enhancement (OR = 1.66; 95% CI, 1.19-2.31; P = 0.002), and hydrocephalus (OR = 2.98; 95% CI, 1.98-4.49; P < 0.001) were associated with AIS. Subgroup analyses indicated that disease severity (P for interaction = 0.003), tuberculoma (P for interaction = 0.008), and meningeal enhancement (P for interaction < 0.001) were significantly different in patients with and without VAFs. Mediation analyses revealed that the proportion of the association between neuroimaging markers of inflammation and functional disability mediated by AIS was 16.98% (95% CI, 7.82-35.12) for meningeal enhancement and 3.39% (95% CI, 1.22-6.91) for hydrocephalus. Conclusion: Neuroimaging markers of inflammation were predictors of AIS in TBM patients. AIS mediates < 20% of the association between inflammation and the functional outcome at 90 days. More attention should be paid to clinical therapies targeting inflammation and hydrocephalus to directly improve functional outcomes.

The diagnostic performance of GeneXpert MTB/RIF in tuberculosis meningitis: A multicentre accuracy study.

OBJECTIVES: To evaluate the performance of GeneXpert MTB/RIF (Xpert) for tuberculous meningitis (TBM) and to identify additional indicators to improve diagnostic accuracy. METHODS: An accuracy study was conducted. During 2011-2019, 243 TBM with 140 non-TBM in three TB-designated facilities in China were enrolled. Microbiological evidence of M tuberculosis (Mtb) in CSF was used as the reference. Additional indicators were identified by Boosted-Classification and Regression Tree (CART), the improvement of diagnostic performance was evaluated by ROC. RESULTS: The diagnostic sensitivity of Xpert was 71.1 % for definite TBM, and 5.5 % for probable/possible TBM. The positive rate of Xpert was improved with cerebrospinal fluid (CSF) increasing volume and was associated with CSF color (yellow). The additional indicators obtained by CART were CSF lactate and glucose and increased the sensitivity to 96.1 % (definite TBM) and 84.6 % (probable/possible TBM). CONCLUSIONS: The diagnostic performance of Xpert was satisfactory in definite TBM and would significantly be improved by the additional use of CSF lactate and glucose.

A comparison of clinical features between neurobrucellosis and tuberculous meningitis.

BACKGROUD: This study aims to compare the clinical manifestations, imaging findings, routine tests, biochemistry indicators and cerebrospinal fluid cytology between neurobrucellosis and tuberculous meningitis. The objective is to evaluate the similarities and differences of these two diseases and improve early diagnosis. METHODS: A comprehensive evaluation was conducted by comparing clinical data, imaging results, routine tests findings, biochemistry indicators and cerebrospinal fluid cytology of patients admitted to the Department of Neurology, the Second Hospital of Hebei Medical University from 2019 to 2021. Statistical analysis was applied to identify significant differences and similarities between the two diseases. RESULTS: Preliminary analysis demonstrated both diseases commonly present with symptoms such as fever, headache. However, there were no statistical differences between neurobrucellosis and tuberculous meningitis in early clinical data, imaging results, routine tests findings, biochemistry indicators. Further analysis indicates there is a statistically significantly difference in the lymphocyte ratio and neutrophil ratio in the cerebrospinal fluid between the two groups. CONCLUSIONS: Neurobrucellosis and tuberculous meningitis share similarities in early clinical manifestations, imaging findings and initial cerebrospinal fluid parametes, making early-stage differentiation challenging. The ratio of lymphocytes and neutrophil in the cerebrospinal fluid and a detailed medical history investigation can provide clues for early clinical diagnosis. So the examination of CSF cytology might be a potential to distinguish these two diseases and become a powerful tool in the future.

Chronic meningitis in adults: a comparison between neurotuberculosis and neurobrucellosis.

BACKGROUND: In regions endemic for tuberculosis and brucellosis, distinguishing between tuberculous meningitis (TBM) and brucella meningitis (BM) poses a substantial challenge. This study investigates the clinical and paraclinical characteristics of patients with TBM and BM. METHODS: Adult patients diagnosed with either TBM or BM who were admitted to two referral hospitals between March 2015 and October 2022, were included, and the characteristics of the patients were analyzed. RESULTS: Seventy patients formed the study group, 28 with TBM and 42 with BM, were included. TBM patients had a 2.06-fold (95% CI: 1.26 to 3.37, P-value: 0.003) higher risk of altered consciousness and a 4.80-fold (95% CI: 1.98 to 11.61, P-value: < 0.001) higher risk of extra-neural involvement as compared to BM patients. Cerebrospinal fluid (CSF) analysis revealed a significantly higher percentage of polymorphonuclear leukocytes (PMN) in TBM compared to BM (Standardized mean difference: 0.69, 95% CI: 0.18 to 1.20, P-value: 0.008). Neuroimaging findings indicated higher risks of hydrocephalus (P-value: 0.002), infarction (P-value: 0.029), and meningeal enhancement (P-value: 0.012) in TBM compared to BM. Moreover, TBM patients had a 67% (95% CI: 21% to 131%, P-value:0.002) longer median length of hospital stay and a significantly higher risk of unfavorable outcomes (Risk ratio: 6.96, 95% CI: 2.65 to 18.26, p < 0.001). CONCLUSIONS: Our study emphasizes that TBM patients displayed increased frequencies of altered consciousness, PMN dominance in CSF, extra-neural involvement, hydrocephalus, meningeal enhancement, and brain infarction. The findings emphasize the diagnostic difficulties and underscore the importance of cautious differentiation between these two conditions to guide appropriate treatment strategies.

TB LAMP assay, a beneficial tool for the diagnosis of Tubercular meningitis in resource-limited settings.

INTRODUCTION: Tubercular meningitis (TBM) is a serious public health problem in developing countries as it leads to significant mortality and residual neurological sequelae. The estimated mortality due to TBM in India is 1.5 per 100,000 population. In resource-limited settings, only the Ziehl-Neelsen (ZN) stain, which has very little sensitivity, is available. The World Health Organization recommended the Loop Mediated Isothermal Amplification (TB LAMP) assay for pulmonary tuberculosis only. We evaluated this test for tubercular meningitis as well. METHODOLOGY: In a cross-sectional study of 2-year duration, we have taken 239 cerebrospinal fluid samples from suspected cases of tubercular meningitis patients. ZN staining along with Mycobacteria Growth Indicator Tube (MGIT) TB culture, Xpert MTB/RIF Ultra assay, and commercial TB LAMP assay were performed for each sample. RESULTS: Out of 239 samples, 40 samples (16.73%) were found TB LAMP assay positive, 48 samples (20.08%) were found Xpert ultra-assay positive, 12 samples (5.02%) were MGIT TB culture positive and acid-fast bacillus smear positive in ten samples (4.18 %). Out of 12 MGIT-positive samples, all samples (100%) were TB LAMP and Xpert ultra positive and one sample (8.33%) was ZN smear positive. In 199 negative samples from the TB LAMP assay, eight samples were positive by Xpert, none by MGIT TB culture and AFB smear. Sensitivity and specificity were found as 100% and 87.66%, respectively, for the TB LAMP assay. CONCLUSION: TB LAMP assay is a rapid, cost-effective, sensitive, and specific test for tubercular meningitis infection in resource-limited settings.

An 11-month-old boy with tuberculous meningitis presenting as progressive limb weakness, fever, developmental retardation, and loss of consciousness: a case report.

BACKGROUND: Tuberculous meningitis (TBM) accounts for about 1% of all tuberculosis cases and about 5% of extrapulmonary tuberculosis cases. However, it poses major importance because approximately half of those affected die or become severely disabled. Herein, the successful treatment of an 11-month-old boy with progressive limb weakness, fever, developmental retardation, and loss of consciousness due to tuberculosis, was reported. CASE PRESENTATION: An 11-month-old (Iranian Turk) boy was referred to Loghman Hakim hospital for progressive limb weakness and loss of previously attained developmental milestones for the past 2 months. He also had persistent fever and loss of consciousness for about 14 to 21 days. Before being referred to our center, the patient had been diagnosed with hydrocephalus at another center due to possible acute bacterial meningitis based on a CT scan and MRI imaging. On physical examination, anterior fontanel bulging and neck stiffness were observed on the admission. His body temperature and heart rate were 38.1 C and 86 beats per minute (bpm), respectively. He had left 6 cranial nerve palsy and spastic quadriparesis with a power of grade 3/5. Other systemic examinations were normal. Endoscopic third ventriculostomy (ETV) (and leptomeningeal biopsy) revealed diffuse thickening of the floor and lateral walls of the 3rd ventricle and also a cobblestone appearance in the form of multiple white patchy lesions was detected on the floor of the 3rd ventricle. CSF analysis and polymerase chain reaction confirmed the TB meningitis. During hospitalization, a temporary EVD (external ventricular drain) was initially inserted. Eventually, defervescence was denoted 5-6 days after initiation of anti-TB medications, and a permanent ventriculoperitoneal shunt was inserted due to hydrocephalus. Gradually his truncal and limb tone and motor function improved, as did his emotional responses to his parents and ability to eat. The patient can walk without help in the 15th month following the operation and resolved hydrocephalus demonstrated on follow-up imaging. CONCLUSION: Over half of treated TB meningitis patients die or suffer severe neurological sequelae, mainly due to late diagnosis. Hence, early diagnosis and prompt initiation of TB treatment offer the best chance of a good neurological outcome.

Dancing Out of Step: A Case of Tuberculous Meningitis Presenting as Childhood Chorea.

Background: Acute to subacute pediatric movement disorders require prompt diagnosis to identify potentially treatable diseases. Case Report: We present a 6-year-old male with a three-week history of generalized chorea transitioning to predominantly right-sided hemichorea and then to left hemiplegia. Discussion: We review the mechanisms in tuberculous meningitis underlying his movement abnormalities.

Mortality and sequelae of tuberculous meningitis in a high-resource setting: A cohort study, 1990–2017 / Mortalidad y secuelas de la meningitis tuberculosa en Barcelona (España): Estudio de cohortes, 1990-2017

Introduction: Tuberculous meningitis (TBM), the most serious form of tuberculosis, results in high mortality and long-term disability in low-resource countries. We investigated temporal trends in mortality and sequelae in a high-resource low-incidence country. Methods: We performed a retrospective cohort study of all adult patients with TBM at two third-level teaching hospitals in Barcelona (Spain), between January 1990 and December 2017, assessing temporal trends in mortality and sequelae after 12 months over four consecutive 7-year time windows. Rates observed across the four periods were adjusted for covariates. Results: Of the 135 cases included, all but one started tuberculosis (TB) treatment and 120 (89.6%) received rifampicin, isoniazid, and pyrazinamide, with or without ethambutol. The probability of being alive at month 12 was 81.8%, with no differences among the four periods: in comparison with the 1990–1996 period, the adjusted hazard ratios and 95% confidence intervals (CI) were 2.55 (0.71–9.25), 0.70 (0.13–3.85), and 1.29 (0.28–5.91) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Sequelae were present in 28.3% at month 12, with no differences across the four periods in the adjusted analysis: in comparison with the 1990–1996 period, the odds ratios and 95% CIs were 0.80 (0.09–7.22); 1.94 (0.21–17.96), and 2.42 (0.25–23.07) for the 1997–2003, 2004–2010, and 2011–2017 periods respectively. Conclusion: This study shows that TBM still causes high mortality and disability even in a high-resource low-incidence TB setting and without improvement over time.(AU)

Introducción: La meningitis tuberculosa (TBM), la forma más grave de tuberculosis, provoca una alta mortalidad y discapacidad a largo plazo en países con bajos recursos. Nuestro objetivo es investigar la tendencia temporal de la mortalidad y las secuelas en un país con recursos elevados y baja incidencia. Métodos: Hemos realizado un estudio de cohortes retrospectivo de los pacientes adultos con TBM en dos hospitales universitarios de tercer nivel en Barcelona (España), entre 1990 y 2017, evaluando las tendencias temporales de mortalidad y secuelas a los 12 meses, comparando cuatro periodos consecutivos de siete años. Las tasas observadas en los cuatro periodos se han ajustado por covariables. Resultados: De los 135 casos incluidos, todos menos uno inició tratamiento antituberculoso y 120 (89,6%) recibieron rifampicina, isoniazida y pirazinamida, con o sin etambutol. La probabilidad de estar vivo a los 12 meses fue de 81,8%, sin diferencias entre los cuatro periodos: en comparación con el periodo 1990-1996, los coeficientes de riesgo ajustados y los intervalos de confianza (IC) del 95% fueron 2,55 (0,71-9,25), 0,70 (0,13-3,85) y 1,29 (0,28-5,91) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Las secuelas estaban presentes en 28,3% en el mes 12, sin diferencias entre los cuatro periodos en el análisis ajustado: en comparación con el periodo 1990-1996, los coeficientes de probabilidad y los IC 95% fueron 0,80 (0,09-7,22); 1,94 (0,21-17,96) y 2,42 (0,25-23,07) para los periodos 1997-2003, 2004-2010 y 2011-2017, respectivamente. Conclusión: Este estudio muestra que la TBM todavía causa una alta mortalidad y discapacidad sin mejoría con el tiempo, incluso en un entorno con baja incidencia de tuberculosis y con elevados recursos.(AU)

Predictions of Bedaquiline Central Nervous System Exposure in Patients with Tuberculosis Meningitis Using Physiologically based Pharmacokinetic Modeling.

BACKGROUND AND OBJECTIVE: The use of bedaquiline as a treatment option for drug-resistant tuberculosis meningitis (TBM) is of interest to address the increased prevalence of resistance to first-line antibiotics. To this end, we describe a whole-body physiologically based pharmacokinetic (PBPK) model for bedaquiline to predict central nervous system (CNS) exposure. METHODS: A whole-body PBPK model was developed for bedaquiline and its metabolite, M2. The model included compartments for brain and cerebrospinal fluid (CSF). Model predictions were evaluated by comparison to plasma PK time profiles following different dosing regimens and sparse CSF concentrations data from patients. Simulations were then conducted to compare CNS and lung exposures to plasma exposure at clinically relevant dosing schedules. RESULTS: The model appropriately described the observed plasma and CSF bedaquiline and M2 concentrations from patients with pulmonary tuberculosis (TB). The model predicted a high impact of tissue binding on target site drug concentrations in CNS. Predicted unbound exposures within brain interstitial exposures were comparable with unbound vascular plasma and unbound lung exposures. However, unbound brain intracellular exposures were predicted to be 7% of unbound vascular plasma and unbound lung intracellular exposures. CONCLUSIONS: The whole-body PBPK model for bedaquiline and M2 predicted unbound concentrations in brain to be significantly lower than the unbound concentrations in the lung at clinically relevant doses. Our findings suggest that bedaquiline may result in relatively inferior efficacy against drug-resistant TBM when compared with efficacy against drug-resistant pulmonary TB.

Epidemiology of tuberculosis among children in Beijing, China, 2012-2021.

Data on epidemiology trends of paediatric tuberculosis (TB) are limited in China. So, we investigated the clinical and epidemiological profiles in diagnosed TB disease and TB infection patients at Beijing Children's Hospital. Of 3 193 patients, 51.05% had pulmonary TB (PTB) and 15.16% had extrapulmonary TB (EPTB). The most frequent forms of EPTB were TB meningitis (39.05%), pleural TB (29.75%), and disseminated TB (10.33%). PTB patients were significantly younger and associated with higher hospitalization frequency. Children aged 1-4 years exhibited higher risk of PTB and TB meningitis, and children aged 5-12 years had higher risk of EPTB. The proportion of PTB patients increased slightly from 40.9% in 2012 to 65% in 2019, and then decreased to 17.8% in 2021. The percentage of EPTB cases decreased from 18.3% in 2012 to 15.2% in 2019, but increased to 16.4% in 2021. Among EPTB cases, the largest increase was seen in TB meningitis. In conclusion, female and young children had higher risk of PTB in children. TB meningitis was the most frequent forms of EPTB among children, and young children were at high risk of TB meningitis. The distribution of different types of EPTB differed by age.

Targeted sequencing from cerebrospinal fluid for rapid identification of drug-resistant tuberculous meningitis.

Mortality from tuberculous meningitis (TBM) remains around 30%, with most deaths occurring within 2 months of starting treatment. Mortality from drug-resistant strains is higher still, making early detection of drug resistance (DR) essential. Targeted next-generation sequencing (tNGS) produces high read depths, allowing the detection of DR-associated alleles with low frequencies. We applied Deeplex Myc-TB-a tNGS assay-to cerebrospinal fluid (CSF) samples from 72 adults with microbiologically confirmed TBM and compared its genomic drug susceptibility predictions to a composite reference standard of phenotypic susceptibility testing (pDST) and whole genome sequencing, as well as to clinical outcomes. Deeplex detected Mycobacterium tuberculosis complex DNA in 24/72 (33.3%) CSF samples and generated full DR reports for 22/24 (91.7%). The read depth generated by Deeplex correlated with semi-quantitative results from MTB/RIF Xpert. Alleles with <20% frequency were seen at canonical loci associated with first-line DR. Disregarding these low-frequency alleles, Deeplex had 100% concordance with the composite reference standard for all drugs except pyrazinamide and streptomycin. Three patients had positive CSF cultures after 30 days of treatment; reference tests and Deeplex identified isoniazid resistance in two, and Deeplex alone identified low-frequency rifampin resistance alleles in one. Five patients died, of whom one had pDST-identified pyrazinamide resistance. tNGS on CSF can rapidly and accurately detect drug-resistant TBM, but its application is limited to those with higher bacterial loads. In those with lower bacterial burdens, alternative approaches need to be developed for both diagnosis and resistance detection.

Performance of metagenomic next-generation sequencing in cerebrospinal fluid for diagnosis of tuberculous meningitis.

Purpose. Metagenomic next-generation sequencing (mNGS) has been widely used in the diagnosis of infectious diseases, while its performance in diagnosis of tuberculous meningitis (TBM) is incompletely characterized. The aim of this study was to assess the performance of mNGS in the diagnosis of TBM, and illustrate the sensitivity and specificity of different methods.Methods. We retrospectively recruited TBM patients between January 2021 and March 2023 to evaluate the performance of mNGS on cerebrospinal fluid (CSF) samples, in comparison with conventional microbiological testing, including culturing of Mycobacterium tuberculosis (MTB), acid-fast bacillus (AFB) stain, reverse transcription PCR and Xpert MTB/RIF.Results. Of the 40 enrolled, 34 participants were diagnosed with TBM, including 15(44.12 %) definite and 19(55.88 %) clinical diagnosis based upon clinical manifestations, CSF parameters, brain imaging, pathogen evidence and treatment response. The mNGS method identified sequences of Mycobacterium tuberculosis complex (MTBC) in 11 CSF samples. In patients with definite TBM, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of mNGS were 78.57, 100, 100, 66.67 and 85 %, respectively. Compared to conventional diagnostic methods, the sensitivity of mNGS (78.57 %) was higher than AFB (0 %), culturing (0 %), RT-PCR (60 %) and Xpert MTB/RIF (14.29 %).Conclusions. Our study indicates that mNGS of CSF exhibited an overall improved sensitivity over conventional diagnostic methods for TBM and can be considered a front-line CSF test.

Marked IDO2 expression and activity related to autophagy and apoptosis in brain tissue of fatal tuberculous meningitis.

In about 1% of tuberculosis (TB) patients, Mycobacterium tuberculosis (M. tuberculosis) can disseminate to the meninges, causing tuberculous meningitis (TBM) with mortality rate up to 60%. Chronic granulomatous inflammation (non-necrotizing and necrotizing) in the brain is the histological hallmark of TBM. The tryptophan-catabolizing enzyme indoleamine 2,3-dioxygenase 1 (IDO1) and the generated kynurenine metabolites exert major effector functions relevant to TB granuloma functioning. Here we have assessed immunohistochemically IDO1 expression and activity and its effector function and that of its isoform, IDO2, in post-mortem brain tissue of patients that demised with neurotuberculosis. We also related these findings to brain tissue of fatal/severe COVID-19. In this study, IDO1 and IDO2 were abundantly expressed and active in tuberculoid granulomas and were associated with the presence of M. tuberculosis as well as markers of autophagy and apoptosis. Like in fatal/severe COVID-19, IDO2 was also prominent in specific brain regions, such as the inferior olivary nucleus of medulla oblongata and cerebellum, but not associated with granulomas or with M. tuberculosis. Spatially associated apoptosis was observed in TBM, whereas in fatal COVID-19 autophagy dominated. Together, our findings highlight IDO2 as a potentially relevant effector enzyme in TBM, which may relate to the symptomology of TBM.

Role of MicroRNAs as post transcription regulators of matrix metalloproteinases and their association in tuberculous meningitis.

Matrix metalloproteinases (MMPs) have a role in driving neuroinflammation in infectious as well as non-infectious diseases; however, recent reports have potentiated the role of microRNAs in regulating MMPs at post-transcriptional levels, leading to dysregulation of crucial MMP functions like tissue remodelling, blood brain barrier integrity, etc. In present study, microRNAs regulating MMPs (MMP2 and MMP3) were selected from database search followed by literature support. Expression of these microRNAs i.e., hsa-miR-495-3p, hsa-miR-132-3p and hsa-miR-21-5p was assessed by RT-PCR and the protein levels of MMPs were assessed by ELISA in the cerebrospinal fluid (CSF) of tuberculous meningitis (TBM) patients, healthy controls (HC) and non-infectious neuroinflammatory disease (NID) patients. The expression of hsa-miR-495-3p and hsa-miR-132-3p showed downregulation in TBM while hsa-miR-21-5p was overexpressed as compared to healthy controls. Moreover, MMP levels were found to be deranged with a significant increase in MMP3 levels in the TBM and NID patients compared to HC group. These observations highlight dysregulated microRNAs (hsa-miR-495-3p, hsa-miR-21-5p and hsa-miR-132-3p) levels might impair the levels of MMPs (MMP2 and MMP3) leading to neuroinflammation in TBM and NID population. These findings can further be applied to target these microRNAs for developing newer treatment modalities for better complication management.

The discrimination between autoimmune glial fibrillary acidic protein astrocytopathy and tuberculous meningitis.

OBJECTIVE: The differential diagnosis between autoimmune glial fibrillary acidic protein astrocytopathy (AGFAPA) mimicking tuberculous meningitis and tuberculous meningitis (TBM) remains challenging in clinical practice. This study aims to identify the clinical, laboratory parameters, and clinical score systems that may be helpful in differentiating AGFAPA from TBM. METHOD: Overall 22 AGFAPA patients who were initially misdiagnosed as TBM (AGFAPA-TBM) and 30 confirmed TBM patients were included. The clinical, laboratory, imaging parameters, Thwaites systems, and Lancet consensus scoring systems (LCSS) of all patients were reviewed. Logistic regression was employed to establish a diagnostic formula to differentiate AGFAPA-TBM from TBM. The receiver operating characteristic (ROC) curve was applied to determine the best diagnostic critical point of the formula. RESULTS: Urinary retention was more frequent in AGFAPA-TBM patients (72.7% vs 33.3%, p = 0.012). A significantly lower ratio of T-SPOT. TB was noted in AGFAPA-TBM patients (9.1% vs 82.1%, p < 0.001). We found the LCSS was able to differentiate AGFAPA-TBM from TBM (AUC value 0.918, 95% CI=0.897-0.924). Furthermore, we set up a new scoring system with three variables: urinary retention, T-SPOT. TB, and cerebral imaging criteria in LCSS. The proposed diagnostic score ranges from -8 to 2, and a score of ≥ 0 was suggestive of AGFAPA-TBM (AUC value 0.938, 95% CI=0.878-0.951). CONCLUSIONS: This study is the first to evaluate the Thwaites system and LCSS in AGFAPA-TBM and TBM. We provide an alternative diagnostic formula to differentiate AGFAPA-TBM from TBM and suggest testing for GFAP antibodies to avoid misdiagnosis when this scoring system meets AGFAPA-TBM.