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.

Population Pharmacokinetic Analysis of Rifampicin in Plasma, Cerebrospinal Fluid, and Brain Extracellular Fluid in South African Children with Tuberculous Meningitis.

Limited knowledge is available on the pharmacokinetics of rifampicin in children with tuberculous meningitis (TBM) and its penetration into brain tissue, which is the site of infection. In this analysis, we characterize the distribution of rifampicin in cerebrospinal fluid (CSF), lumbar (LCSF) and ventricular (VCSF), and brain extracellular fluid (ECF). Children with TBM were included in this pharmacokinetic analysis. Sparse plasma, LCSF, and VCSF samples were collected opportunistically, as clinically indicated. Brain ECF was sampled using microdialysis (MD). Rifampicin was quantified with liquid chromatography with tandem mass spectrometry in all samples, and 25-desacetyl rifampicin in the plasma samples. The data were interpreted with nonlinear mixed-effects modeling, with the CSF and brain ECF modeled as "effect compartments." Data were available from 61 children, with median (min-max) age of 2 (0.3 to 10) years and weight of 11.0 (4.8 to 49.0) kg. A one-compartment model for parent and metabolite with first-order absorption and elimination via saturable hepatic clearance described the data well. Allometric scaling, maturation, and auto-induction of clearance were included. The pseudopartition coefficient between plasma and LCSF/VCSF was ~5%, while the value for ECF was only ~0.5%, possibly reflecting low recovery of rifampicin using MD. The equilibration half-life between plasma and LCSF/VCSF was ~4 h and between plasma and ECF ~2 h. Our study confirms previous reports showing that rifampicin concentrations in the LCSF are lower than in plasma and provides novel knowledge about rifampicin in the VCSF and the brain tissue. Despite MD being semiquantitative because the relative recovery cannot be quantified, our study presents a proof-of-concept that rifampicin reaches the brain tissue and that MD is an attractive technique to study site-of-disease pharmacokinetics in TBM.

A pilot study of inflammatory mediators in brain extracellular fluid in paediatric TBM.

Tuberculous meningitis (TBM) is the most fatal form of tuberculosis and frequently occurs in children. The inflammatory process initiates secondary brain injury processes that lead to death and disability. Much remains unknown about this cerebral inflammatory process, largely because of the difficulty in studying the brain. To date, studies have typically examined samples from sites distal to the site of disease, such as spinal cerebrospinal fluid (CSF) and blood. In this pilot study, we examined the feasibility of using direct brain microdialysis (MD) to detect inflammatory mediators in brain extracellular fluid (ECF) in TBM. MD was used to help guide neurocritical care in 7 comatose children with TBM by monitoring brain chemistry for up to 4 days. Remnant ECF fluid was stored for offline analysis. Samples of ventricular CSF, lumbar CSF and blood were collected at clinically indicated procedures for comparison. Inflammatory mediators were quantified using multiplex technology. All inflammatory markers, with the exception of interleukin (IL)-10 and IL-12p40, were detected in the ECF. Cytokine concentrations were generally lower in ECF than ventricular CSF in time-linked specimens. Individual cases showed ECF cytokine increases coinciding with marked increases in ECF glycerol or decreases in ECF glucose. Cytokine levels and glycerol were generally higher in patients with more severe disease. This is the first report of inflammatory marker analysis from samples derived directly from the brain and in high temporal resolution, demonstrating feasibility of cerebral MD to explore disease progression and possibly therapy response in TBM.

18FDG-PET is sensitive tool for detection of extracranial tuberculous foci in central nervous system tuberculosis - Preliminary observations from a tertiary care center in northern India.

PURPOSE: To study the role of 18FDG- PET (Flourodeoxyglucose positron emission tomography) in a) determining the extent of cranial and extra-cranial disease and b) diagnosis as well as prognosis of CNS TB (central nervous system tuberculosis) including TBM (tuberculous meningitis). PATIENTS AND METHODS: This prospective observational study (n = 70) was carried out at a tertiary care institute in Northern India from 1.1.2017 to 30.6.2018. Diagnosis of TBM was made according to modified Ahuja's criteria. All patients were evaluated in detail and treated as per standard guidelines. All patients underwent 18FDG-PET scanning of brain and whole body at baseline. RESULTS: Mean age was 35.2 ±â€¯14.8 years. There were 37 men. Majority of patients (n = 47; 67.1%) were below 40 years of age. 43 (61.4%) patients were in stage II TBM. The mean duration of illness was 77 ±â€¯101.9 days. Majority of patients presented with fever (94.3%), headache (90%) and vomiting (84.3%). MRI was abnormal at baseline in 67 (95.7%) of patients, most common abnormalities being meningeal enhancement (68.6%) and tuberculomas (57.1%). PET was abnormal in 66 (95.7%) of patients. All these patients had either lung lesions (n = 62, 88.6%) or lymphadenopathy (n = 61; 87.1%). 18FDG-PET revealed evidence of brain lesions in 52 (74.3%) patients. It revealed vertebral involvement in 19 (27.1%) and genitourinary lesions in 9 (12.9%) patients. PET evidence of lymphadenopathy correlated significantly (p = .04) with good outcome in CNS TB. Conclusion 18FDG-PET does seem to have a promising role in initial evaluation of patients with CNS TB.

Delamanid Central Nervous System Pharmacokinetics in Tuberculous Meningitis in Rabbits and Humans.

Central nervous system tuberculosis (TB) is devastating and affects vulnerable populations. Multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculous meningitis (TBM) specifically are nearly uniformly fatal, with little information being available to guide the treatment of these patients. Delamanid (DLM), a nitro-dihydro-imidazooxazole, is a new, well-tolerated anti-TB drug with a low MIC (1 to 12 ng/ml) against Mycobacterium tuberculosis It is used for the treatment of pulmonary MDR-TB, but pharmacokinetic (PK) data for DLM in the central nervous system (CNS) of patients with TBM are not available. In the present study, we measured DLM concentrations in the brain and cerebrospinal fluid (CSF) of six rabbits with and without experimentally induced TBM receiving single-dose DLM. We report the steady-state CSF concentrations from three patients receiving DLM as part of multidrug treatment who underwent therapeutic drug monitoring. Drug was quantified using liquid chromatography-tandem mass spectrometry. In rabbits and humans, mean concentrations in CSF (in rabbits, 1.26 ng/ml at 9 h and 0.47 ng/ml at 24 h; in humans, 48 ng/ml at 4 h) were significantly lower than those in plasma (in rabbits, 124 ng/ml at 9 h and 14.5 ng/ml at 24 h; in humans, 726 ng/ml at 4 h), but the estimated free CSF/plasma ratios were generally >1. In rabbits, DLM concentrations in the brain were 5-fold higher than those in plasma (means, 518 ng/ml at 9 h and 74.0 ng/ml at 24 h). All patients with XDR-TBM receiving DLM experienced clinical improvement and survival. Collectively, these results suggest that DLM achieves adequate concentrations in brain tissue. Despite relatively low total CSF drug levels, free drug may be sufficient and DLM may have a role in treating TBM. More studies are needed to develop a fuller understanding of its distribution over time with treatment and clinical effectiveness.

Enhanced brain penetration of pretomanid by intranasal administration of an oil-in-water nanoemulsion.

AIM: To enhance the drug delivery to the brain with an oil-in-water nanoemulsion of pretomanid via intranasal (IN) administration. MATERIALS & METHODS: The study involved 70 male Sprague-Dawley rats (160-180 g) that received either 20 mg/kg body weight (b.w.) a nanoemulsion or a 20 mg/kg b.w. of pretomanid in solution via the IN route. The drug was quantified by liquid chromatography-tandem mass spectrometry to investigate whole tissue-drug concentrations, and mass spectrometric imaging to visualize drug localization in the brain. RESULTS: Nanoemulsion delivery concentrations of pretomanid in the brain reached peak concentrations (Cmax) of 12,062.3 ng/g that is significantly higher than the required therapeutic level. The mass spectrometric imaging analysis clearly showed a time dependent and uniform distribution in the brain. CONCLUSION: The results of this study show that IN delivery of oil-in-water nanoemulsion may be very promising for targeting anatomical tuberculosis reservoirs, such as the brain.

Mass spectrometry-based metabolomics for tuberculosis meningitis.

Tuberculosis meningitis (TBM) is a prevalent form of extra-pulmonary tuberculosis that causes substantial morbidity and mortality. Diagnosis of TBM is difficult because of the limited sensitivity of existing laboratory techniques. A metabolomics approach can be used to investigate the sets of metabolites of both bacteria and host, and has been used to clarify the mechanisms underlying disease development, and identify metabolic changes, leadings to improved methods for diagnosis, treatment, and prognostication. Mass spectrometry (MS) is a major analysis platform used in metabolomics, and MS-based metabolomics provides wide metabolite coverage, because of its high sensitivity, and is useful for the investigation of Mycobacterium tuberculosis (Mtb) and related diseases. It has been used to investigate TBM diagnosis; however, the processes involved in the MS-based metabolomics approach are complex and flexible, and often consist of several steps, and small changes in the methods used can have a huge impact on the final results. Here, the process of MS-based metabolomics is summarized and its applications in Mtb and Mtb-related diseases discussed. Moreover, the current status of TBM metabolomics is described.

A study of atrial and brain natriuretic peptides in tuberculous meningitis and acute encephalitis.

OBJECTIVE: To report atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels in patients with tuberculous meningitis (TBM) and acute encephalitis syndrome (AES), and evaluate their relationship with hyponatraemia. METHODS: Consecutive patients with TBM and AES were included in the study. Hyponatraemia was categorised as cerebral salt wasting (CSW), syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and a miscellaneous group based on clinical and laboratory criteria. Serum ANP and BNP levels were measured upon hospital admission, at the time of diagnosis of hyponatraemia and upon correction of hyponatraemia. Outcome at 3 months was assessed using the modified Rankin scale (mRS) as good (mRS 2) and poor (mRS >2). RESULTS: There were 67 patients with TBM and 77 with AES. Hyponatraemia was more common in TBM than in AES (65.7% vs. 27%, P < 0.01). Forty-one (63.1%) patients had CSW, 6 (9.2%) SIADH and 18 (27.7%) had miscellaneous causes of hyponatraemia. During hyponatraemia, ANP (180 ± 45 vs. 106 ± 32 pg/ml, P < 0.01) and BNP (263 ± 118 vs. 163 ± 91 pg/ml, P  0.01) levels were significantly increased compared with baseline, and remained high even after Na+ correction. CONCLUSION: ANP and BNP levels were increased during hyponatraemia and remained high even after correction of hyponatraemia in TBM and AES, especially in patients with CSW. However, ANP and BNP levels could not be used to differentiate CSW from SIADH.

Cerebral tryptophan metabolism and outcome of tuberculous meningitis: an observational cohort study.

BACKGROUND: Immunopathology contributes to the high mortality of tuberculous meningitis, but the biological pathways involved are mostly unknown. We aimed to compare cerebrospinal fluid (CSF) and serum metabolomes of patients with tuberculous meningitis with that of controls without tuberculous meningitis, and assess the link between metabolite concentrations and mortality. METHODS: In this observational cohort study at the Hasan Sadikin Hospital (Bandung, Indonesia) we measured 425 metabolites using liquid chromatography-mass spectrometry in CSF and serum from 33 HIV-negative Indonesian patients with confirmed or probable tuberculous meningitis and 22 control participants with complete clinical data between March 12, 2009, and Oct 27, 2013. Associations of metabolite concentrations with survival were validated in a second cohort of 101 patients from the same centre. Genome-wide single nucleotide polymorphism typing was used to identify tryptophan quantitative trait loci, which were used for survival analysis in a third cohort of 285 patients. FINDINGS: Concentrations of 250 (70%) of 351 metabolites detected in CSF were higher in patients with tuberculous meningitis than in controls, especially in those who died during follow-up. Only five (1%) of the 390 metobolites detected in serum differed between patients with tuberculous meningitis and controls. CSF tryptophan concentrations showed a pattern different from most other CSF metabolites; concentrations were lower in patients who survived compared with patients who died (9-times) and to controls (31-times). The association of low CSF tryptophan with patient survival was confirmed in the validation cohort (hazard ratio 0·73; 95% CI 0·64-0·83; p<0·0001; per each halving). 11 genetic loci predictive for CSF tryptophan concentrations in tuberculous meningitis were identified (p<0·00001). These quantitative trait loci predicted survival in a third cohort of 285 HIV-negative patients in a prognostic index including age and sex, also after correction for possible confounders (p=0·0083). INTERPRETATION: Cerebral tryptophan metabolism, which is known to affect Mycobacterium tuberculosis growth and CNS inflammation, is important for the outcome of tuberculous meningitis. CSF tryptophan concentrations in tuberculous meningitis are under strong genetic influence, probably contributing to the variable outcomes of tuberculous meningitis. Interventions targeting tryptophan metabolism could improve outcomes of tuberculous meningitis. FUNDING: Royal Dutch Academy of Arts and Sciences; Netherlands Foundation for Scientific Research; Radboud University; National Academy of Sciences; Ministry of Research, Technology, and Higher Education, Indonesia; European Research Council; and PEER-Health.

Correlation of Lactate Concentration in Peripheral Plasma and Cerebrospinal Fluid with Glasgow Outcome Scale for Patients with Tuberculous Meningitis Complicated by Acute Hydrocephalus Treated with Fluid Diversions.

BACKGROUND: Tuberculous meningitis (TBM) is an endemic infectious disease in developing countries, and it can become a serious illness in children. Treatment of TBM is more difficult and prone to failure than treatment of pulmonary tuberculosis. TBM causes hydrocephalus, cerebral edema, increased intracranial pressure, global ischemia, and neurologic deficits, which disturb cellular metabolism and increase lactate levels. A reliable, widely available clinical indicator of TBM severity is needed. Successful treatment of TBM is assessed using the Glasgow Outcome Scale (GOS). METHODS: This prospective cohort study included 34 patients with TBM and acute hydrocephalus who had undergone fluid diversions and were admitted to Dr. Hasan Sadikin Hospital in Bandung from 2014 to 2015. A portable machine for blood glucose measurement was used to measure lactate concentrations. Statistical significance was defined as P ≤ 0.05. RESULTS: Average levels of plasma and cerebrospinal fluid (CSF) lactate were 1.99 ± 0.70 mmol/L and 3.04 ± 1.05 mmol/L, respectively. A significantly higher level of lactate was observed in CSF compared with plasma. Preoperative plasma lactate was negatively correlated to GOS (r = -0.539; P = 0.013), and CSF lactate was negatively correlated to GOS (r = -0.412; P = 0.027). Average lactate levels in CSF (central) were higher than plasma (peripheral) levels. GOS scale of patients decreased with increased plasma and CSF lactate levels. CONCLUSIONS: Examination of plasma and CSF lactate levels should be included in routine examinations to determine extent of cellular damage and GOS score in patients with TBM and acute hydrocephalus who have undergone fluid diversions.

Application value of procalcitonin in patients with central nervous system infection.

OBJECTIVE: To study the application value of procalcitonin (PCT) in patients with central nervous system (CNS) infection. PATIENTS AND METHODS: A total of 66 patients, including 24 patients with suppurative meningitis, 20 patients with viral meningitis and 22 patients with tuberculous meningitis, were enrolled. 20 patients admitted to the hospital due to epilepsy or headache without infection in the same period were enrolled as the control group. PCT, high-sensitivity C-reactive protein (Hs-CRP), high-sensitivity C-reactive protein (Hs-CRP), protein quantification, chloride and glucose in serum and cerebrospinal fluid, were collected. RESULTS: The serum PCT level in suppurative meningitis group was significantly higher than that in other three groups. The dynamic monitoring of suppurative meningitis group on admission, at 72 h and 1 week after treatment showed that the serum PCT level was significantly decreased. PCT levels in cerebrospinal fluid in suppurative meningitis group, viral meningitis group and tuberculous meningitis group were decreased successively, and the differences were statistically significant. The detection of PCT in cerebrospinal fluid was more valuable than serum PCT detection in distinguishing tuberculous meningitis from viral meningitis. Continuous monitoring of changes in PCT in cerebrospinal fluid showed that there was no statistically significant difference before and after treatment. PCT level in cerebrospinal fluid was positively correlated with the serum PCT, cerebrospinal fluid white blood cell (WBC), and protein content in cerebrospinal fluid. CONCLUSIONS: The dynamic changes of serum PCT in patients with suppurative meningitis can be used to evaluate the disease, guide the clinical medication, and monitor the prognosis.

Tuberculous meningitis.

Tuberculosis remains a global health problem, with an estimated 10.4 million cases and 1.8 million deaths resulting from the disease in 2015. The most lethal and disabling form of tuberculosis is tuberculous meningitis (TBM), for which more than 100,000 new cases are estimated to occur per year. In patients who are co-infected with HIV-1, TBM has a mortality approaching 50%. Study of TBM pathogenesis is hampered by a lack of experimental models that recapitulate all the features of the human disease. Diagnosis of TBM is often delayed by the insensitive and lengthy culture technique required for disease confirmation. Antibiotic regimens for TBM are based on those used to treat pulmonary tuberculosis, which probably results in suboptimal drug levels in the cerebrospinal fluid, owing to poor blood-brain barrier penetrance. The role of adjunctive anti-inflammatory, host-directed therapies - including corticosteroids, aspirin and thalidomide - has not been extensively explored. To address this deficit, two expert meetings were held in 2009 and 2015 to share findings and define research priorities. This Review summarizes historical and current research into TBM and identifies important gaps in our knowledge. We will discuss advances in the understanding of inflammation in TBM and its potential modulation; vascular and hypoxia-mediated tissue injury; the role of intensified antibiotic treatment; and the importance of rapid and accurate diagnostics and supportive care in TBM.

Cerebrospinal fluid matrix metalloproteinase 9 levels, blood-brain barrier permeability, and treatment outcome in tuberculous meningitis.

OBJECTIVES: Tuberculous meningitis is characterized by elevated levels of matrix metalloproteinase 9 (MMP9) in the cerebrospinal fluid (CSF). However, it is unclear whether elevated MMP9 levels are associated with poor treatment outcome. We tested the hypothesis that pretreatment MMP9 levels in the CSF would be higher in tuberculous meningitis patients experiencing a poor treatment outcome. METHODS: We prospectively assessed the treatment outcome in a consecutive sample of human immunodeficiency virus-negative patients with tuberculous meningitis. We defined good outcome as survival without severe neurological disability (modified Rankin scale scores 0-2). We estimated levels of MMP9 and its tissue inhibitor (TIMP1) on pretreatment CSF samples. We used albumin index to assess blood-brain barrier permeability. RESULTS: We studied 40 patients (23 males [58%]) with tuberculous meningitis. Sixteen patients (40%) had stage 3 disease. On follow-up, 18 (45%) patients had a poor treatment outcome-15 patients died and 3 had severe neurological disability. Pretreatment MMP9 levels were not associated with treatment outcome (median [interquartile range], 254 [115-389] vs. 192 [60-383] ng/mL in good vs. poor outcome groups; P = 0.693). MMP9 levels did not correlate with the albumin index (Spearman's rho = 0.142; P = 0.381). However, MMP9 levels significantly correlated with CSF glucose levels (rho = -0.419; P = 0.007) and admission Glasgow coma scale score (rho = 0.324; P = 0.032). Likewise, TIMP1 levels also did not differ by treatment outcome (1239 [889-1511] vs. 1522 [934-1949] ng/mL; P = 0.201). MMP9/TIMP1 ratio that reflects net proteolytic activity was also not different between the two groups (0.191 [0.107-0.250] vs. 0.163 [0.067-0.34]; P = 0.625). CONCLUSION: Our findings do not support the hypothesis that pretreatment levels of MMP9 would be higher in tuberculous meningitis patients experiencing a poor treatment outcome. Further, MMP9 levels in the CSF did not correlate with blood-brain barrier permeability in patients with tuberculous meningitis.

Metabolomics variable selection and classification in the presence of observations below the detection limit using an extension of ERp.

BACKGROUND: ERp is a variable selection and classification method for metabolomics data. ERp uses minimized classification error rates, based on data from a control and experimental group, to test the null hypothesis of no difference between the distributions of variables over the two groups. If the associated p-values are significant they indicate discriminatory variables (i.e. informative metabolites). The p-values are calculated assuming a common continuous strictly increasing cumulative distribution under the null hypothesis. This assumption is violated when zero-valued observations can occur with positive probability, a characteristic of GC-MS metabolomics data, disqualifying ERp in this context. This paper extends ERp to address two sources of zero-valued observations: (i) zeros reflecting the complete absence of a metabolite from a sample (true zeros); and (ii) zeros reflecting a measurement below the detection limit. This is achieved by allowing the null cumulative distribution function to take the form of a mixture between a jump at zero and a continuous strictly increasing function. The extended ERp approach is referred to as XERp. RESULTS: XERp is no longer non-parametric, but its null distributions depend only on one parameter, the true proportion of zeros. Under the null hypothesis this parameter can be estimated by the proportion of zeros in the available data. XERp is shown to perform well with regard to bias and power. To demonstrate the utility of XERp, it is applied to GC-MS data from a metabolomics study on tuberculosis meningitis in infants and children. We find that XERp is able to provide an informative shortlist of discriminatory variables, while attaining satisfactory classification accuracy for new subjects in a leave-one-out cross-validation context. CONCLUSION: XERp takes into account the distributional structure of data with a probability mass at zero without requiring any knowledge of the detection limit of the metabolomics platform. XERp is able to identify variables that discriminate between two groups by simultaneously extracting information from the difference in the proportion of zeros and shifts in the distributions of the non-zero observations. XERp uses simple rules to classify new subjects and a weight pair to adjust for unequal sample sizes or sensitivity and specificity requirements.

Mir-29a expressions in peripheral blood mononuclear cell and cerebrospinal fluid: Diagnostic value in patients with pediatric tuberculous meningitis.

To evaluate the value of miR-29a expression in peripheral blood mononuclear cell (PBMC) and cerebrospinal fluid (CSF) in the diagnosis of pediatric tuberculous meningitis (TBM). Our study enrolled 112 children with TBM and 130 healthy children, from which PBMC and CSF were collected. The quantitative real-time polymerase chain reaction (qRT-PCR) was used to measure the expression of miR-29a in PBMC and CSF, and then analyze the diagnostic value. Compared with control group, the miR-29a expressions in PBMC and CSF were increased in TBM children (both P<0.05), and the expressions were associated with following factors: intracranial hypertension, conscious disturbance, focal cerebral symptoms, meningeal irritation, hydrocrania, abnormal electroencephalogram and extra-cerebral tuberculous (all P<0.05). The receiver operating characteristic (ROC) curve showed that the sensitivity, specificity and area under the curve (AUC) of miR-29a in PBMC was 67.20%, 88.50% and 0.852, respectively, and that in CSF was 81.10%, 90.00% and 0.890, respectively, and that in combination of PBMC and CSF was 84.40%, 95.38% and 0.934, respectively. miR-29a expression in PBMC and CSF may provide a reference for the diagnosis of pediatric TBM.

Adjunctive role of MMP-9 inhibition along with conventional anti-tubercular drugs against experimental tuberculous meningitis.

Tuberculous meningitis (TBM) is an outcome of neuroinflammatory degeneration caused due to Mycobacterium tuberculosis infection and leads to death or neurological disabilities in the affected individuals. It causes the highest morbidity and mortality amongst all forms of tuberculosis. Matrix metalloproteinase-9 levels increase and cause inflammatory destruction during progression of the disease. Although corticosteroids are usually given as an adjuvant therapy to overcome these complications, treatment outcome is contradictory. This study was designed to evaluate whether specific inhibition of MMP-9 can be beneficial in management of the disease. MMP-9 levels were inhibited using SB-3CT or dexamethasone along with conventional drugs for treatment of tuberculous meningitis. Both SB-3CT and dexamethasone decreased the elevated levels of MMP-9 in sera and tissues of the infected mice. However, dexamethasone administration had an inhibitory effect on bacillary clearance, while SB-3CT potentiated the bacillary clearance, suggesting that MMP-9, if specifically inhibited, can be beneficial in the management of TBM.

Adequacy of Rifampin Absorption after Jejunostomy Tube Administration.

It is not always possible to administer antituberculosis pharmacotherapy orally for reasons that may be a direct consequence of tuberculosis itself. To our knowledge, no published literature is available regarding antituberculosis drug absorption via feeding tube. We present the case of a patient with tuberculosis meningitis who required medication administration via percutaneous endoscopic jejunostomy (PEJ) tube. Blood samples were collected during the continuation phase of antituberculosis therapy, immediately before dose administration, and then at 1, 2, 4, and 6 hours after dose administration for quantification of serum rifampin concentrations. Assaying these concentrations by high-pressure liquid chromatography demonstrated a peak serum rifampin level (C(max)) of 18 µg/ml and total rifampin exposure (area under the curve from 0-6 hours [AUC(0-6)]) of 50.1 µg/ml. These are high compared with rifampin C(max) and AUC(0-6) values reported in patients after oral rifampin administration; C(max) tends to range between 4.0-10.5 µg/ml and AUC(0-6) 7.0-52.9 µg/ml after oral administration of 600 mg at steady state. Based on our patient's results, therefore, rifampin administered by PEJ tube appears to be well absorbed, with preservation of adequate C(max) and AUC values. It is worth noting that this was in the context of drug administration in the fasted state. In the absence of any published evidence of adequate absorption via jejunal feeding tube in the nonfasted state, it would seem prudent to ensure that patients are fasted when rifampin is administered via PEJ tube, just as patients are when oral rifampin is administered. This report represents the first documented evidence, to our knowledge, of adequate rifampin absorption when administered via PEJ tube and provides important reassurance for health care providers, patients, and families facing similar clinical scenarios.

Elevated host lipid metabolism revealed by iTRAQ-based quantitative proteomic analysis of cerebrospinal fluid of tuberculous meningitis patients.

PURPOSE: Tuberculous meningitis (TBM) remains to be one of the most deadly infectious diseases. The pathogen interacts with the host immune system, the process of which is largely unknown. Various cellular processes of Mycobacterium tuberculosis (MTB) centers around lipid metabolism. To determine the lipid metabolism related proteins, a quantitative proteomic study was performed here to identify differential proteins in the cerebrospinal fluid (CSF) obtained from TBM patients (n = 12) and healthy controls (n = 12). METHODS: CSF samples were desalted, concentrated, labelled with isobaric tags for relative and absolute quantitation (iTRAQ™), and analyzed by multi-dimensional liquid chromatography-tandem mass spectrometry (LC-MS/MS). Gene ontology and proteomic phenotyping analysis of the differential proteins were conducted using Database for Annotation, Visualization, and Integrated Discovery (DAVID) Bioinformatics Resources. ApoE and ApoB were selected for validation by ELISA. RESULTS: Proteomic phenotyping of the 4 differential proteins was invloved in the lipid metabolism. ELISA showed significantly increased ApoB levels in TBM subjects compared to healthy controls. Area under the receiver operating characteristic curve analysis demonstrated ApoB levels could distinguish TBM subjects from healthy controls and viral meningitis subjects with 89.3% sensitivity and 92% specificity. CONCLUSIONS: CSF lipid metabolism disregulation, especially elevated expression of ApoB, gives insights into the pathogenesis of TBM. Further evaluation of these findings in larger studies including anti-tuberculosis medicated and unmedicated patient cohorts with other center nervous system infectious diseases is required for successful clinical translation.

Spinal cord and spinal nerve root involvement (myeloradiculopathy) in tuberculous meningitis.

Most of the information about spinal cord and nerve root involvement in tuberculous meningitis is available in the form of isolated case reports or case series. In this article, we evaluated the incidence, predictors, and prognostic impact of spinal cord and spinal nerve root involvement in tuberculous meningitis.In this prospective study, 71 consecutive patients of newly diagnosed tuberculous meningitis were enrolled. In addition to clinical evaluation, patients were subjected to magnetic resonance imaging (MRI) of brain and spine. Patients were followed up for at least 6 months.Out of 71 patients, 33 (46.4%) had symptoms/signs of spinal cord and spinal nerve root involvement, 22 (30.9%) of whom had symptoms/signs at enrolment. Eleven (15.4%) patients had paradoxical involvement. Paraparesis was present in 22 (31%) patients, which was of upper motor neuron type in 6 (8.4%) patients, lower motor neuron type in 10 (14%) patients, and mixed type in 6 (8.4%) patients. Quadriparesis was present in 3 (4.2%) patients. The most common finding on spinal MRI was meningeal enhancement, seen in 40 (56.3%) patients; in 22 (30.9%), enhancement was present in the lumbosacral region. Other MRI abnormalities included myelitis in 16 (22.5%), tuberculoma in 4 (5.6%), cerebrospinal fluid (CSF) loculations in 4 (5.6%), cord atrophy in 3 (4.2%), and syrinx in 2 (2.8%) patients. The significant predictor associated with myeloradiculopathy was raised CSF protein (>250 mg/dL). Myeloradiculopathy was significantly associated with poor outcome.In conclusion, spinal cord and spinal nerve root involvement in tuberculous meningitis is common. Markedly raised CSF protein is an important predictor. Patients with myeloradiculopathy have poor outcome.

Modulation of angiogenic factor VEGF by DNA-hsp65 vaccination in a murine CNS tuberculosis model.

Tuberculosis (TB) is a serious public health problem. Development of experimental models and vaccines are essential to elucidate physiopathological mechanisms and to control the disease. Vascular endothelial growth factor (VEGF) is a potent activator of vascular permeability and angiogenesis. VEGF seems to participate in breakdown of the blood brain-barrier (BBB) in tuberculous meningitis (TBM), contributing to worsening of disease. Therefore, the objective here was to extent the characterization of our previously described murine model of central nervous system TB (CNS-TB) by describing the VEGF participation in the CNS disease, and suggesting a vaccination plan in mice. Plasmid encoding DNA protein antigen DNA-hsp65 has been described as a protector against TB infection and was used here to test its effectiveness in the prevention of VEGF production and TB disease. Vaccinated mice and its controls were injected with Mycobacterium bovis bacillus Calmette-Guerin (BCG) in cerebellum. Four weeks after BCG injection, mice were perfused and brains were paraffin-embedded for VEGF expression analysis. We observed VEGF immunohistochemical expression in TBM and granulomas in non-vaccinated mice. The DNA-hsp65 treatment blocked the expression of VEGF in mice TBM. Therefore, our murine model indicated the VEGF participation in the physiopathology of CNS-TB and the potential prevention of the DNA-hsp65 in the disease progression.