Tuberculous meningitis (TBM) is the most lethal form of tuberculosis, and new treatments that improve outcomes are required. We randomly assigned adults with TBM to treatment with standard antituberculosis treatment alone or in combination with ciprofloxacin (750 mg/12 h), levofloxacin (500 mg/12 h), or gatifloxacin (400 mg/24 h) for the first 60 days of therapy. Fluoroquinolone concentrations were measured with plasma and cerebrospinal fluid (CSF) specimens taken at predetermined, randomly assigned times throughout treatment. We aimed to describe the pharmacokinetics of each fluoroquinolone during TBM treatment and evaluate the relationship between drug exposure and clinical response over 270 days of therapy (Controlled Trials number ISRCTN07062956). Sixty-one patients with TBM were randomly assigned to treatment with no fluoroquinolone (n = 15), ciprofloxacin (n = 16), levofloxacin (n = 15), or gatifloxacin (n = 15). Cerebrospinal fluid penetration, measured by the ratio of the plasma area under the concentration-time curve from 0 to 24 h (AUC(0-24)) to the cerebrospinal fluid AUC(0-24), was greater for levofloxacin (median, 0.74; range, 0.58 to 1.03) than for gatifloxacin (median, 0.48; range, 0.47 to 0.50) or ciprofloxacin (median, 0.26; range, 0.11 to 0.77). Univariable and multivariable analyses of fluoroquinolone exposure against a range of different treatment responses revealed worse outcomes among patients with lower and higher plasma and CSF exposures than for patients with intermediate exposures (a U-shaped exposure-response). TBM patients most likely to benefit from fluoroquinolone therapy were identified, along with exposure-response relationships associated with improved outcomes. Fluoroquinolones add antituberculosis activity to the standard treatment regimen, but to improve outcomes of TBM, they must be started early, before the onset of coma.

OBJECTIVE

Cryptococcal meningitis (CM) and tuberculous meningitis (TBM) are common in HIV-infected adults in Africa and difficult to diagnose. Inaccurate diagnosis results in adverse outcomes. We describe patterns of meningitis in a Malawian hospital, focusing on features which differentiate CM and TBM with the aim to derive an algorithm using only clinical and basic laboratory data available in this resource-poor setting.

METHODS

Consecutive patients admitted with meningitis were prospectively recruited, clinical features were recorded and cerebrospinal fluid (CSF) was examined.

RESULTS

A total of 573 patients were recruited, and 263 (46%) had CSF consistent with meningitis. One hundred and twelve (43%) had CM and 46 (18%) had TBM. CM was associated with high CSF opening pressure and low CSF leukocyte count. Fever, neck stiffness and reduced conscious level were associated with TBM. A diagnostic index was constructed demonstrating sensitivity 83%and specificity 79% for the differentiation of CM and TBM. An algorithm was derived with 92% sensitivity for the diagnosis of CM, but only 58% specificity.

CONCLUSIONS

Although we demonstrate features associated with CM and TBM, a sufficiently sensitive and specific diagnostic algorithm could not be derived, suggesting that the diagnosis of CM and TBM in resource-limited settings still requires better access to laboratory tools.

Imaging traits are thought to have more direct links to genetic variation than diagnostic measures based on cognitive or clinical assessments and provide a powerful substrate to examine the influence of genetics on human brains. Although imaging genetics has attracted growing attention and interest, most brain-wide genome-wide association studies focus on voxel-wise single-locus approaches, without taking advantage of the spatial information in images or combining the effect of multiple genetic variants. In this paper we present a fast implementation of voxel- and cluster-wise inferences based on the random field theory to fully use the spatial information in images. The approach is combined with a multi-locus model based on least square kernel machines to associate the joint effect of several single nucleotide polymorphisms (SNP) with imaging traits. A fast permutation procedure is also proposed which significantly reduces the number of permutations needed relative to the standard empirical method and provides accurate small p-value estimates based on parametric tail approximation. We explored the relation between 448,294 single nucleotide polymorphisms and 18,043 genes in 31,662 voxels of the entire brain across 740 elderly subjects from the Alzheimer's disease neuroimaging initiative (ADNI). Structural MRI scans were analyzed using tensor-based morphometry (TBM) to compute 3D maps of regional brain volume differences compared to an average template image based on healthy elderly subjects. We find method to be more sensitive compared with voxel-wise single-locus approaches. A number of genes were identified as having significant associations with volumetric changes. The most associated gene was GRIN2B, which encodes the N-methyl-d-aspartate (NMDA) glutamate receptor NR2B subunit and affects both the parietal and temporal lobes in human brains. Its role in Alzheimer's disease has been widely acknowledged and studied, suggesting the validity of the approach. The various advantages over existing approaches indicate a great potential offered by this novel framework to detect genetic influences on human brains.

Tuberculous meningitis (TBM) is the most devastating form of tuberculosis. Both intracerebral and peripheral blood immune responses may be relevant to pathogenesis, diagnosis, and outcome. In this study, the relationship between pretreatment host response, disease phenotype, and outcome in Vietnamese adults with TBM was examined. Before treatment, peripheral blood IFN-gamma ELISPOT responses to the Mycobacterium tuberculosis Ags ESAT-6, CFP-10, and purified protein derivative (PPD) were a poor diagnostic predictor of TBM. Cerebrospinal fluid IL-6 concentrations at presentation were independently associated with severe disease presentation, suggesting an immunological correlate of neurological damage before treatment. Surprisingly however, elevated cerebrospinal fluid inflammatory cytokines were not associated with death or disability in HIV-negative TBM patients at presentation. HIV coinfection attenuated multiple cerebrospinal fluid inflammatory indices. Low cerebrospinal fluid IFN-gamma concentrations were independently associated with death in HIV-positive TBM patients, implying that IFN-gamma contributes to immunity and survival. Collectively, these results reveal the effect of HIV coinfection on the pathogenesis of TBM and suggest that intracerebral immune responses, at least in HIV-negative cases, may not be as intimately associated with disease outcome as previously thought.

To examine the ultrastructural distribution of laminin within kidney basement membranes, we prepared rat anti-mouse laminin mAbs to use in immunolocalization experiments. Epitope domains for these mAbs were established by immunoprecipitation, immunoblotting, affinity chromatography, and rotary shadow EM. One mAb bound to the laminin A and B chains on blots and was located to a site approximately 15 nm from the long arm-terminal globular domain as shown by rotary shadowing. Conjugates of this long arm-specific mAb were coupled to horseradish peroxidase (HRP) and intravenously injected into mice. Kidney cortices were fixed for microscopy 3 h after injection. HRP reaction product was localized irregularly within the renal glomerular basement membrane (GBM) and throughout mesangial matrices. In addition, this mAb bound in linear patterns specifically to the laminae rarae of basement membranes of Bowman's capsule and proximal tubule. This indicates the presence of the long arm immediately beneath epithelial cells in these sites. The laminae densae of these basement membranes were negative by this protocol. In contrast, the lamina rara and densa of distal tubular basement membranes (TBM) were both heavily labeled with this mAb. A different ultrastructural binding pattern was seen with eight other mAbs, including two that mapped to different sites on the short arms by rotary shadowing and five that blotted to a large pepsin-resistant laminin fragment (P1). These latter mAbs bound weakly or not at all to GBM but all bound throughout mesangial matrices. In contrast, discrete spots of HRP reaction product were seen across all layers of Bowman's capsule BM and proximal TBM. These same mAbs, however, bound densely across the full width of distal TBM. Our findings therefore show that separate strata of different basement membranes are variably immunoreactive to these laminin mAbs. The molecular orientation or integration of laminin into the three dimensional BM meshwork therefore varies with location. Alternatively, there may be a family of distinct laminin-like molecules distributed within basement membranes.

Our objective was to investigate grey matter (GM) contraction in patients with amyotrophic lateral sclerosis (ALS) using tensor based morphometry (TBM). Using a 1.5 Tesla scanner, T1-weighted MRI scans were obtained at baseline and at follow-up (mean interval, 9 months) from 16 ALS and 10 controls. Standard TBM procedures in Statistical Parametric Mapping (SPM2) were used for image processing and statistical analyses. The frontotemporal cortex and basal ganglia were considered areas of interest, based on pathological studies. Eight patients showed rapid clinical progression of ALS during the follow-up period. Compared to controls, all ALS patients showed progression of GM atrophy in left premotor cortex and right basal ganglia. Patients with rapidly progressing ALS showed GM atrophy changes in a larger motor cortical-subcortical area and in extramotor frontal regions compared to both controls and to non-rapidly progressing cases. Thus, TBM detected longitudinal atrophy changes in the motor network in ALS occurring over less than one year. The faster the clinical progression, the greater was the GM loss in motor and prefrontal areas. Further advances in tracking longitudinal changes in cortical and subcortical regions in ALS may provide an objective marker for monitoring disease progression, and the disease-modifying effect of potential treatments.

The concentrations of the chemokines IL-8, monocyte chemotactic protein-1 (MCP-1) and macrophage inflammatory protein-1alpha (MIP-1alpha) were measured in 120 CSF samples from 23 patients with pyogenic meningitis and from 11 patients with tuberculous meningitis (TBM) and in 10 CSF from subjects with non-infectious neurological diseases. The chemokine concentrations in patients with meningitis were significantly higher than in control subjects (P<0.0001). The highest CSF levels were found for IL-8 (median 2917 pg/ml) and MCP-1 (median 2557 pg/ml), whereas those of MIP-1alpha were less significantly elevated (median 24 pg/ml) (P<0.0001). Patients with pyogenic meningitis had higher levels of IL-8 and MCP-1 than those with TBM (P<0.0001). In serial samples from patients with pyogenic meningitis IL-8 levels declined before MCP-1 and MIP-alpha. In the case of TBM, IL-8, MCP-1 and MIP-1alpha decreased more gradually during treatment and were detectable in the CSF for several weeks, without any characteristic time course of elimination. These data indicate that patients with pyogenic meningitis and TBM show different chemokine profiles in CSF. The distinct chemokine pattern could be responsible for a differential attraction and activation of leucocytes in the CSF which is reflected in differences in the inflammatory response and clinical course of pyogenic meningitis and TBM.

BACKGROUND

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.

METHODS

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).

RESULTS

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.

CONCLUSIONS

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.

Tuberculous meningitis is an uncommon but potentially devastating form of tuberculosis. Current antituberculous drugs are highly effective when treatment is initiated early, before the onset of altered mentation or focal neurologic deficits. Because the clinical outcome depends greatly on the stage at which therapy is initiated, early recognition is of paramount importance. Patients with the meningoencephalitis syndrome and CSF findings of low glucose levels, elevated protein levels, and pleocytosis should be treated immediately if there is evidence of TB elsewhere in the body, or if prompt evaluation fails to establish an alternative diagnosis. Examination of CSF is the best diagnostic approach; with sufficient diligence, serial AFB smears and cultures will usually yield positive results, even days after therapy has been started. The CT scan is an important and highly effective tool for the diagnosis and management of patients with TBM. In a patient with compatible clinical features, the combination of basilar meningeal enhancement and any degree of hydrocephalus is strongly suggestive of the diagnosis of TBM. Serial evaluation by CT scanning is useful for following the course of hydrocephalus and tuberculoma, particularly in reference to the need for, or response to, adjunctive therapy with corticosteroids and surgery. The decision to administer corticosteroids should be based on careful correlation of the clinical and radiographic features of the case. Surgical shunting should be considered early in the patient with hydrocephalus and symptoms of raised intracranial pressure. Tuberculomas are best treated medically, often in conjunction with corticosteroids where cerebral edema is believed to contribute to neurologic decline. The recommended chemotherapy regimen is isoniazid and rifampin in all patients, together with pyrazinamide for the first 2 months.

The level of tumor necrosis factor (TNF)-alpha, soluble TNF receptors p75 (sTNFR-75) and sTNFR-55, interferon (IFN)-gamma, and interleukin (IL)-10 and IL-12 were measured in 59 cerebrospinal fluid (CSF) samples from 15 patients with tuberculous meningitis (TBM). TBM was associated with elevated concentrations of TNF-alpha, sTNFR-75, sTNFR-55, IFN-gamma, and IL-10, while CSF IL-12 was undetectable in all TBM patients. A significant correlation between cytokines and CSF adenosine deaminase activity was also found. The levels of TNF-alpha did not decrease over time, being still detectable in the CSF 16 months after starting antibiotic therapy, whereas IFN-gamma along with anti-inflammatory mediators sTNFR-75, sTNFR-55, and IL-10 remained elevated in the CSF for 4-8 months. The chronic release of cytokines in the CSF compartment was related neither to the TBM stage nor to the clinical outcome of the disease, thus suggesting the presence of a continuous activity of the inflammatory process at the site of infection.

BACKGROUND

Mycobacterium tuberculosis is a common, devastating cause of meningitis in HIV-infected persons. Due to international rollout programs, access to antiretroviral therapy (ART) is increasing globally. Starting patients with HIV-associated tuberculous meningitis (TBM) on ART during tuberculosis (TB) treatment may increase survival in these patients. We undertook this study to describe causes of meningitis at a secondary-level hospital in a high HIV/TB co-infection setting and to determine predictors of mortality in patients with TBM.

METHODS

A retrospective review of cerebrospinal fluid findings and clinical records over a six-month period (March 2009-August 2009). Definite, probable and possible TBM were diagnosed according to published case definitions.

RESULTS

TBM was diagnosed in 120/211 patients (57%) with meningitis. In 106 HIV-infected patients with TBM, six-month all-cause mortality was lower in those who received antiretroviral therapy (ART) during TB treatment; hazard ratio = 0.30 (95% CI = 0.08-0.82). Factors associated with inpatient mortality in HIV-infected patients were 1) low CD4(+) count at presentation; adjusted odds ratio (AOR) = 1.4 (95% confidence interval [CI] = 1.03-1.96) per 50 cells/µL drop in CD4(+) count and, 2) higher British Medical Research Council TBM disease grade (2 or 3 versus 1); AOR = 4.8 (95% CI = 1.45-15.87).

CONCLUSIONS

Starting ART prior to or during TB treatment may be associated with lower mortality in patients with HIV-associated TBM. Advanced HIV and worse stage of TBM disease predict in-hospital mortality in patients presenting with TBM.

Outcome from tuberculous meningitis (TBM) is believed to be dependent on the severity of the intracerebral inflammatory response. We have recently shown that dexamethasone improved survival in adults with TBM and postulated that the clinical effect would be associated with a measurable systemic and intracerebral impact on immunological markers of inflammation. Prolonged inflammatory responses were detected in all TBM patients irrespective of treatment assignment (placebo or dexamethasone). The inflammatory response in the cerebrospinal fluid was characterized by a leukocytosis (predominantly CD3(+)CD4(+) T lymphocytes, phenotypically distinct from those in the peripheral blood), elevated concentrations of inflammatory and anti-inflammatory cytokines, chemokines, and evidence of prolonged blood-brain barrier dysfunction. Dexamethasone significantly modulated acute cerebrospinal fluid protein concentrations and marginally reduced IFN-gamma concentrations; other immunological and routine biochemical indices of inflammation were unaffected. Peripheral blood monocyte and T cell responses to Mycobacterium tuberculosis Ags were also unaffected. Dexamethasone does not appear to improve survival from TBM by attenuating immunological mediators of inflammation in the subarachnoid space or by suppressing peripheral T cell responses to mycobacterial Ags. These findings challenge previously held theories of corticosteroid action in this disease. An understanding of how dexamethasone acts in TBM may suggest novel and more effective treatment strategies.

Computational neuroanatomy is emerging as an exciting new methodology to characterise shape and neuroanatomical configuration of different brains. It encompasses a triad of techniques: Voxel-based morphometry (VBM), which compares neuroanatomical differences on a voxel by voxel basis, Deformation-based morphometry (DBM), which provides information about global differences in brain shape and Tensor-based morphometry (TBM) which provides information about local shape differences. This review will describe the methodology and clinical applications of these techniques.

There is paucity of studies on predictors of long-term sequelae of tuberculous meningitis (TBM). We report the neurological sequelae of TBM at 1 year and their predictors. Patients with TBM who were followed up for 1 year were included. The diagnosis of TBM was based on clinical, cerebrospinal fluid (CSF) and computed tomography (CT) scan findings. Detailed neurological examinations at admission and at 1 year were carried out. All the patients received four-drug antitubercular therapy. The frequency of sequelae at 1 year were noted and the role of various demographic (age, sex, duration of illness, BCG vaccination), clinical (weakness, seizure, extra central nervous system tuberculosis, Glasgow Coma Scale (GCS) score, cranial nerve palsy, stage, corticosteroid, drug-induced hepatitis, shunt surgery), and laboratory findings (erythrocyte sedimentation rate (ESR), CSF cell and protein, CT scan evidences of hydrocephalus, basal exudates, infarctions and tuberculoma) at presentation were evaluated employing logistic regression analysis. Sixty-five patients with TBM were included in this study whose age ranged between 13 and 80 years (mean 33.2), 27 of whom were females. Complete neurological recovery at 1 year occurred in 21.5% patients only although about 50% were independent for activities of daily living. Neurological sequelae were observed in 78.5% patients, which included cognitive impairment in 55%, motor deficit in 40%, optic atrophy in 37% and other cranial nerve palsy in 23%. On logistic regression analysis, focal motor deficit at admission was the most important predictor of neurologic deficits at 1 year. GCS score predicted the cognitive and motor sequelae. Neurological sequelae at year occurred in 78.5% patients with TBM in the form of cognitive impairment, motor deficit and optic atrophy. Sequelae were common in patients who had focal motor deficit and altered sensorium at admission.

BACKGROUND

Confirming the clinical suspicion of tuberculous meningitis (TBM) has always been problematic. Whilst smear and culture positivity are diagnostic, these tests have low sensitivity. The polymerase chain reaction (PCR) assay has given variable results.

OBJECTIVE

This study attempted to improve the diagnostic yield by: (a) increasing the cerebrospinal fluid (CSF) volumes; (b) testing the yield from three specimens of CSF assumed to represent lumbar, cervico-thoracic cord, and base of brain CSF samples; (c) undertaking PCR assays using multiple primer sets; and (d) using real-time PCR.

METHODS

Patients suspected of having cranial or spinal meningeal tuberculosis were entered into the study. Three aliquots of CSF were subjected to smear, culture, and conventional and real-time PCR. Three sets of primers - IS6110, MPB64, and PT8/9 - were used. Patients were retrospectively classified into four categories: 'definite TB' (culture positive), 'probable TB' (clinical and other tests suggestive of TB), 'not TB', and 'uncertain diagnosis'.

RESULTS

A total of 68 patients were studied. There were 20 patients classified as definite TB, 24 probable TB, 17 not TB, and seven uncertain diagnosis. Forty-eight of 57 (84.2%) patients tested were HIV seropositive. The IS6110 PCR was positive in 27 patients which included 18/20 culture positive cases, six in the probable TB group, and three in the not TB group. The MPB64 and PT8/9 primers did not increase the yield. Real-time PCR was positive in seven additional patients. Combining the definite and probable TB, the sensitivity of all PCR assays was 70.5% (31/44) and specificity 87.5% (21/24).

CONCLUSIONS

Targeting multiple sites of the TB genome using conventional PCR did not increase the number of positive cases. Real-time PCR was more sensitive. However, all the current techniques are still too insensitive to confidently exclude the diagnosis on laboratory grounds.

Measures of brain changes can be computed from sequential MRI scans, providing valuable information on disease progression for neuroscientific studies and clinical trials. Tensor-based morphometry (TBM) creates maps of these brain changes, visualizing the 3D profile and rates of tissue growth or atrophy. In this paper, we examine the power of different nonrigid registration models to detect changes in TBM, and their stability when no real changes are present. Specifically, we investigate an asymmetric version of a recently proposed Unbiased registration method, using mutual information as the matching criterion. We compare matching functionals (sum of squared differences and mutual information), as well as large-deformation registration schemes (viscous fluid and inverse-consistent linear elastic registration methods versus Symmetric and Asymmetric Unbiased registration) for detecting changes in serial MRI scans of 10 elderly normal subjects and 10 patients with Alzheimer's Disease scanned at 2-week and 1-year intervals. We also analyzed registration results when matching images corrupted with artificial noise. We demonstrated that the unbiased methods, both symmetric and asymmetric, have higher reproducibility. The unbiased methods were also less likely to detect changes in the absence of any real physiological change. Moreover, they measured biological deformations more accurately by penalizing bias in the corresponding statistical maps.

The renal expression of transforming growth factor-beta1 (TGF-beta1) is enhanced following induction of ischemic injury in rat. In cultured renal cells, TGF-beta stimulates the synthesis of extracellular matrix. To link TGF-beta1 expression with the regulation of extracellular matrix postischemia, we characterized the expression of several genes known to regulate extracellular matrix synthesis at various times during recovery from acute ischemic renal injury in rat. Levels of mRNA for plasminogen activator inhibitor-1 (PAI-1), tissue inhibitor of metalloprotease-1 (TIMP-1), alpha1(IV) collagen, and fibronectin-EIIIA (FN-EIIIA) mRNAs were significantly enhanced in kidneys within 12 h to 3 days after injury and remained elevated at 7-28 days postischemia relative to levels in kidneys of sham-operated controls. PAI-1 mRNA and peptide were localized in regenerating proximal tubules at 3 and 7 days postischemic injury. alpha1(IV) Collagen and FN-EIIIA mRNAs were expressed primarily in regenerating proximal tubule cells. Immunoreactivity for FN-EIIIA was enhanced in the tubular basement membrane (TBM) of regenerating proximal tubules, and alpha1(IV) collagen immunoreactivity was detected in thickened tubulointerstitial spaces. In contrast, TIMP-1 immunoreactivity was enhanced in distal nephron structures postischemia. Immunoneutralization of TGF-beta in vivo attenuated the increases in FN-EIIIA, alpha1(IV) collagen, PAI-1, and TIMP-1 mRNAs by 52%, 73%, 43%, and 27%, respectively. These data are consistent with TGF-beta expression postischemic injury participating in renal regeneration of extracellular matrix homeostasis in the proximal TBM.

METHODS

Hospital in-patients with suspected tuberculous meningitis (TBM), predominantly in India.

OBJECTIVE

To determine whether interferon-gamma (IFN-gamma) secreting Mycobacterium tuberculosis antigen-specific T-cells are present in the cerebrospinal fluid (CSF) of patients with TBM and to evaluate the feasibility of CSF enzyme-linked immunospot (ELISpot) for the diagnosis of active TBM.

METHODS

Prospective blinded hospital-based study.

RESULTS

The overnight ELISpot assay detected M. tuberculosis antigen-specific IFN-gamma secreting T-cells in CSF from nine of 10 prospectively recruited patients with TBM, and zero of seven control patients with meningitis of other aetiology. This corresponds to a diagnostic sensitivity of 90% (95%CI 56-100) and specificity of 100% (95%CI 59-100).

CONCLUSIONS

This pilot study demonstrates proof-of-principle for a new T-cell-based diagnostic test for TBM which is rapid, sensitive and specific.

BACKGROUND

Although CT scanning is used widely for making the diagnosis and detecting the complications of tuberculous meningitis (TBM) in children, the radiological features are considered non-specific. CT is particularly suggestive of the diagnosis when there is a combination of basal enhancement, hydrocephalus and infarction, and even then the diagnosis may be in doubt. In this paper we introduce a new CT feature for making the diagnosis of TBM, namely, hyperdensity in the basal cisterns on non-contrast scans, and we assess which of the recognized CT features is most sensitive and specific.

OBJECTIVE

To determine the sensitivity and specificity of the presence of high-density exudates in the basal cisterns (on non-contrast CT) and basal enhancement (on contrast-enhanced CT) for the diagnosis of TBM in children, and to correlate these with the complications of infarction and hydrocephalus.

METHODS

Retrospective review of CT scans with readers blinded to the diagnosis, which was based on a definitive culture of cerebrospinal fluid (CSF) for TBM or other bacteria. Computer-aided conversion of hard-copy film density to Hounsfield units was employed as well as a density threshold technique for determining abnormally high densities.

RESULTS

The most specific feature for TBM is hyperdensity in the basal cisterns prior to IV contrast medium administration (100%). The most sensitive feature of TBM is basal enhancement (89%). A combination of features (hydrocephalus, infarction and basal enhancement) is as specific as pre-contrast hyperdensity, but has a lower sensitivity (41%). There were statistically significant differences in the presence of hydrocephalus (p=0.0016), infarcts (P=0.0014), basal enhancement (P<0.0001) and pre-contrast density (P<0.0001) between the negative and positive TBM patient groups. The presence of granulomas was not statistically significant between the two groups (P=0.44).

CONCLUSIONS

The presence of high density within the basal cisterns on non-contrast CT scans is a very specific sign for TBM in children. This will enhance diagnostic confidence, allow early institution of therapy and could reduce expenditure on contrast medium, scan time and radiation exposure. With the use of threshold techniques we believe that the pre-contrast hyperdensity may be detectable by a computer program that will facilitate diagnosis, and may also be modified to detect abnormal enhancement. Basal enhancement is a sensitive sign for the diagnosis of TBM and should be sought after contrast medium administration when no hyperdensity is seen in the basal cisterns or when this finding needs to be confirmed. The CT scan feature of hyperdense exudates on pre-contrast scans should be added to the inclusion criteria for the diagnosis of TBM in children.

BACKGROUND

Three costimulation blockade-based regimens have been explored after transplantation of hearts from pigs of varying genetic backgrounds to determine whether CTLA4-Ig (abatacept) or anti-CD40mAb+CTLA4-Ig (belatacept) can successfully replace anti-CD154mAb.

METHODS

All pigs were on an α1,3-galactosyltransferase gene-knockout/CD46 transgenic (GTKO.CD46) background. Hearts transplanted into Group A baboons (n=4) expressed additional CD55, and those into Group B (n=3) expressed human thrombomodulin (TBM). Immunosuppression included anti-thymocyte globulin with anti-CD154mAb (Regimen 1: n=2) or abatacept (Regimen 2: n=2) or anti-CD40mAb+belatacept (Regimen 3: n=2). Regimens 1 and 2 included induction anti-CD20mAb and continuous heparin. One further baboon in Group B (B16311) received a modified Regimen 1. Baboons were followed by clinical/laboratory monitoring of immune/coagulation parameters. At biopsy, graft failure, or euthanasia, the graft was examined by microscopy.

RESULTS

Group A baboons survived 15 to 33 days, whereas Group B survived 52, 99, and 130 days, respectively. Thrombocytopenia and reduction in fibrinogen occurred within 21 days in Group A, suggesting thrombotic microangiopathy (TM), confirmed by histopathology. In Group B, with follow-up for >4 m, areas of myofiber degeneration and scarring were seen in two hearts at necropsy. A T-cell response was documented only in baboons receiving Regimen 2.

CONCLUSIONS

The combination of anti-CD40mAb+belatacept proved effective in preventing a T-cell response. The expression of TBM prevented thrombocytopenia and may possibly delay the development of TM and/or consumptive coagulopathy.

Tuberculous meningitis (TBM) is a severe infection of the central nervous system, particularly in developing countries. Prompt diagnosis and treatment are necessary to decrease the high rates of disability and death associated with TBM. The diagnosis is often time and labour intensive; thus, a simple, accurate and rapid diagnostic test is needed. The adenosine deaminase (ADA) activity test is a rapid test that has been used for the diagnosis of the pleural, peritoneal and pericardial forms of tuberculosis. However, the usefulness of ADA in TBM is uncertain. The aim of this study was to evaluate ADA as a diagnostic test for TBM in a systematic review. A systematic search was performed of the medical literature (MEDLINE, LILACS, Web of Science and EMBASE). The ADA values from TBM cases and controls (diagnosed with other types of meningitis) were necessary to calculate the sensitivity and specificity. Out of a total of 522 studies, 13 were included in the meta-analysis (380 patients with TBM). The sensitivity, specificity and diagnostic odds ratios (DOR) were calculated based on arbitrary ADA cut-off values from 1 to 10 U/l. ADA values from 1 to 4 U/l (sensitivity >93% and specificity <80%) helped to exclude TBM; values between 4 and 8 U/l were insufficient to confirm or exclude the diagnosis of TBM (p = 0.07), and values >8 U/l (sensitivity <59% and specificity >96%) improved the diagnosis of TBM (p < 0.001). None of the cut-off values could be used to discriminate between TBM and bacterial meningitis. In conclusion, ADA cannot distinguish between bacterial meningitis and TBM, but using ranges of ADA values could be important to improve TBM diagnosis, particularly after bacterial meningitis has been ruled out. The different methods used to measure ADA and the heterogeneity of data do not allow standardization of this test as a routine.

OBJECTIVE

To investigate the usefulness of polymerase chain reaction (PCR) from cerebrospinal fluid (CSF) for rapid diagnosis and assessing treatment response of tuberculous meningitis (TBM) in AIDS patients.

METHODS

Forty-four CSF samples from 10 patients with TBM confirmed by autopsy or by a culture of CSF (41 samples) and from two patients with highly probable TBM (three samples) were analysed. CSF specimens were collected before and during standard antituberculous treatment. CSF samples from 24 AIDS patients with autopsy evidence of other neurologic diseases were studied as controls.

METHODS

A nested PCR amplifying a 123 base-pair fragment of the IS6110 sequence was developed. Heating to 95 degrees C for 15 min was used for pre-PCR treatment of samples.

RESULTS

Detection limit was 10(2) colony-forming units per ml or 10 fg purified Mycobacterium tuberculosis DNA. M.tuberculosis DNA was detected in CSF from all the 12 confirmed or highly probable TBM cases. CSF was positive by nested PCR in 17 of 17 (100%) and 18 of 27 (67%) samples collected before and during therapy, respectively. Clinical and microbiological follow-up>> or = 2 weeks was available for seven patients. PCR-positive CSF converted to M. tuberculosis DNA negative in four patients that showed improvement during treatment, but it remained positive in three patients who died of disseminated tuberculosis. All the CSF samples from the non-TBM controls were negative by nested PCR.

CONCLUSIONS

Nested PCR for detection of M. tuberculosis DNA is specific for diagnosis of TBM and more sensitive than conventional bacteriology. Moreover, nested PCR could be a useful method for assessing treatment response in AIDS patients with TBM.

BACKGROUND

Revised National Tuberculosis Control Program (RNTCP) has focused on adults with smear positivity a tool not so well used in children with tuberculosis. There is a need to redefine standardization of diagnosis and management protocols for childhood tuberculosis.

METHODS

Indian Academy of Pediatrics constituted a Working Group to develop consensus statement on childhood tuberculosis (TB). Members of the Group were given individual responsibilities to review the existing literature on different aspects of the childhood TB. The group deliberated and developed a consensus which was circulated to all the members for review. Efforts were made to ensure that the recommendations are standardized.

OBJECTIVE

To produce recommendations and standard protocols for reasonably accurate diagnosis and rational treatment of tuberculosis in children.

CONCLUSIONS

Fever and or cough>> 2 weeks with loss of weight and recent contact with infectious case should arouse suspicion of TB. Chest Xray and trial with broad-spectrum antibiotic for 7-10 days is justified. In case of clinical and radiological non-response, Mantoux test and sputum or gastric aspirate for AFB is recommended. If AFB is positive, diagnosis is confirmed. If AFB is negative but chest Xray is suggestive and Mantoux test is positive, it is a probable case and if these tests are negative, alternate diagnosis must be sought and referral made to an expert. Ideally it is recommended to use 1TU of PPD for Mantoux test but 2 or 5 TU may be acceptable (but less preferred). Cut-off point of 10 mms for natural infection may be used for test done with 1, 2 or 5 TU. There is no linear relation of reaction to tuberculin strength and so no more than 5 TU should be used. BCG test is not recommended. Diagnosis must not be made without an attempt to look for AFB in gastric aspirate or sputum, as it is possible to get AFB even in primary complex. Elisa and PCR tests for TB are not recommended. There is no place for trial of anti tubercular therapy. Lymphnode enlargement>> 2 cm with or without typical findings suggestive of TB and failure of antibiotic response demands FNAC for histopathology and bacteriology. Clinical suspicion of tubercular meningitis (TBM) should be confirmed by CSF examination and CT scan though none of these investigations are confirmatory and hence should not be considered in isolation. CSF tests for TB antibody and PCR are not recommended for routine use. Diagnosis of abdominal TB is made on circumstantial evidence and there are no standard guidelines. For treatment, disease is divided into three categories. The Category I and III are recommended for different types of new cases i.e. those who have received treatment for not more than 4 weeks. Category III includes primary pulmonary complex, one site peripheral lymphadenitis and pleural effusion, while all other forms of TB are included in Category I, that corresponds to smear positive TB in adults. This is because AFB is often found in many Category I disease in children. Category II includes defaulters, relapses and failure cases irrespective of the site of disease. Standard protocol is followed for each of these categories. Intermittent thrice weekly therapy with higher dose has been found to be equally effective as daily therapy and so is recommended in DOTS Direct Observed Therapy Short term. Compliance of treatment must be ensured. Repeat chest X-ray is ideal at the end of therapy. Liver function tests are not routinely recommended. Recommendations are also made for special situations such as MDRTB, TB and HIV and neonate born to mother suffering from TB.

Several nucleic acid-based amplification tests are available for the detection of Mycobacterium tuberculosis, but few data are available on their use in the diagnosis of tuberculous meningitis (TBM). We performed a prospective study to assess the Roche AMPLICOR Mycobacterium tuberculosis PCR test (TB AMPLICOR) for use in the diagnosis of TBM and compared it with direct Ziehl-Neelsen staining of smears, radiometric culture for M. tuberculosis, and clinical and cerebrospinal fluid (CSF) findings. Eighty-three CSF specimens collected from 69 patients with suspected meningitis in South Africa were tested by TB AMPLICOR. On the basis of clinical and laboratory findings, 40 of these patients were treated for TBM and 29 patients were not treated for TBM. Ten CSF samples from 10 patients were positive by TB AMPLICOR. Seven of these 10 patients were classified as having definite TBM, 2 were classified as having probable TBM, and 1 was classified as having possible TBM. The sensitivity of TB AMPLICOR for detecting cases of definite and probable TBM in patients from whom CSF specimens had been collected less than 10 days into antituberculosis treatment was 60.0%. Specimens from all 29 patients not treated for TBM were negative by the TB AMPLICOR, giving a 100% specificity. TB AMPLICOR is therefore more sensitive than the combination of Ziehl-Neelsen staining of smears and radiometric culture for M. tuberculosis and is a rapid and highly specific diagnostic test for TBM.