New and old diagnostic markers of meningitis in cerebrospinal fluid (CSF)

Diagnostic value of cerebrospinal fluid levels of D-lactate, tumour necrosis factor-alpha and interleukin-6, -8, and -17 in suspected nosocomial meningitis

INTRODUCTION

This study aimed to determine the diagnostic value of interleukin (IL)-6, IL-8, IL-17, tumour necrosis factor-alpha (TNF-α) and D-lactate levels in the cerebrospinal fluid (CSF) of nosocomial meningitis patients.

METHODS

The CSF levels of cytokines and D-lactate were compared across 29 episodes of nosocomial meningitis, 38 episodes of pleocytosis (without meningitis) and 54 control subjects.

RESULTS

The CSF levels of IL-6, IL-8, and D-lactate were higher in the group with nosocomial meningitis compared to the control group and the group with pleocytosis without meningitis ( P < 0.05). For IL-6 levels (threshold: >440 pg/mL), the sensitivity and specificity were 55.17% and 94.74%, respectively. For IL-8 levels (threshold: >1,249 pg/mL), the sensitivity and specificity were 44.83% and 84.21%, respectively. In patients with nosocomial meningitis, when the threshold of D-lactate levels was >1.05 μmol/mL, the sensitivity and specificity were 75.86% and 63.16%, respectively. In pleocytosis (without meningitis) CSF samples and in nosocomial meningitis CSF samples, the highest area under the receiver operating characteristic curve (AUC) was calculated for triple combination model of IL-6, IL-8 and D-lactate levels (AUC 0.801, P < 0.001) and double combination model of IL-6 and IL-8 (AUC 0.790, P < 0.001).

CONCLUSION

Our study findings suggest that IL-6, IL-8 and D-lactate levels could be diagnostic markers for nosocomial meningitis.

Comparison between cerebrospinal fluid biomarkers for differential diagnosis of acute meningitis

OBJECTIVES

Given the difficulty in the differential diagnosis of acute bacterial meningitis (BM) and viral meningitis (VM), we aimed to compare the ability of cerebrospinal fluid (CSF) biomarkers, such as lactate, glucose, lactate dehydrogenase (LDH), C-reactive protein (CRP), total white blood cell count, and predominance of neutrophils, as single tests to differentiate microbiologically defined acute BM and VM.

METHODS

CSF samples were divided into three groups: BM (n=17), VM (n=14) (both with the etiological agent identified), and normal control groups (n=26).

RESULTS

All the biomarkers studied were significantly higher in the BM group than in the VM or control groups (p>0.05). CSF lactate showed the best diagnostic clinical performance characteristics: sensitivity (94.12%), specificity (100%), positive and negative predictive value (100 and 97.56%, respectively), positive and negative likelihood ratio (38.59 and 0.06, respectively), accuracy (98.25%), and AUC (0.97). CSF CRP is excellent for screening BM and VM, as its best feature is its specificity (100%). CSF LDH is not recommended for screening or case-finding. LDH levels were higher in Gram-negative diplococcus than in Gram-positive diplococcus. Other biomarkers were not different between Gram-positive and negative bacteria. The highest level of agreement between the CSF biomarkers was between CSF lactate and CRP [kappa coefficient, 0.91 (0.79; 1.00)].

CONCLUSIONS

All markers showed significant differences between the studied groups and were increased in acute BM. CSF lactate is better than the other biomarkers studied for screening acute BM due to its high specificity.

Cerebrospinal fluid lactate as a predictive biomarker for tuberculous meningitis diagnosis

Objectives

The definitive diagnosis of tuberculous meningitis (TBM) is achieved by identifying Mycobacterium tuberculosis (MTb) in cerebrospinal fluid (CSF); however, diagnostic confirmation is difficult due to the inability of current tests for an effective diagnosis. Our objective was to retrospectively assess the characteristics of CSF lactate (CSF-LA) as an adjunct biomarker in the diagnosis of TBM.

Methods

608 CSF laboratory reports were assessed. Of these, 560 had clinically suspected TBM. These were classified as definite (n=36), probable (23), possible (278), or non-TBM (223) according to the international consensus TBM case definitions. An additional 48 CSF samples were negative controls with normal CSF.

Results

Against a reference standard of definite TBM, the cut-off value for CSF-LA was 4.0 mmol/L, the area under the ROC curve was 0.88 (95% CI, 0.82–0.94; p=0.0001), sensitivity was 69%, specificity 90%, negative predictive value 98%. These diagnostic parameters decreased when calculated against those of the other categories of TBM. CSF-LA exhibited high specificity, efficiency, negative predictive value, and clinical utility index in all the groups studied.

Conclusions

CSF-LA is a useful diagnostic marker to rule out TBM when associated with conventional microbiology tests, nucleic acid amplification assays, and clinical algorithms, particularly in endemic areas.

Spinal cord injury target-immunotherapy with TNF-α autoregulated and feedback-controlled human umbilical cord mesenchymal stem cell derived exosomes remodelled by CRISPR/Cas9 plasmid

Human umbilical cord mesenchymal stem cell (hucMSC) derived exosomes (EXOs) have been investigated as a new treatment for spinal cord injury (SCI) because of their anti-inflammatory, anti-apoptotic, angiogenesis-promoting, and axonal regeneration properties. The CAQK peptide found in the brains of mice and humans after trauma has recently been found to specifically bind to the injured site after SCI. Thus, we developed a nanocarrier system called EXO-C@P based on hucMSC exosomes remodelled by the CRISPR/Cas9 plasmid to control inflammation and modified by the CAQK peptide. EXO-C@P was shown to effectively accumulate at the injury site and saturate the macrophages to significantly reduce the expression of inflammatory cytokines in a mouse model of SCI. Moreover, EXO-C@P treatment improved the performance of mice in behavioural assessments and upregulated soluble tumour necrosis factor receptor-1 (sTNFR1) in serum and at the trauma site after SCI surgery, but lowered the proportion of iNOS⁺ cells and the concentration of proinflammatory factors. In conclusion, EXO-C@P provides an effective alternative to multiple topical administration and drug delivery approaches for the treatment of SCI. STATEMENT OF SIGNIFICANCE: SCI is a serious disease characterised by a high incidence, high disability rate, and high medical costs, and has become a global medical problem. Several studies have shown that the inflammatory response is the critical inducer of secondary injury after SCI. The inflammatory cytokine TNF-α is considered to be one of the most significant therapeutic targets for autoimmune diseases. Antibodies targeting TNF-α and sTNFR1 are capable of neutralising free TNF-α. In this study, exosomes in the CRISPR/Cas9 system were used to establish stem cells with an autoregulated and feedback-controlled TNF-α response, with these cells secreting sTNFR1, which neutralised TNF-α and antagonised the inflammation stimulated by TNF-α. Moreover, the plasmid was combined with CAQK, which targeted the injury site and promoted the recovery of SCI function.

Atezolizumab-associated encephalitis in metastatic lung adenocarcinoma: a case report

BACKGROUND

In recent years, immune checkpoint inhibitors have been widely used as a crucial therapy in malignant tumors. Immune checkpoint inhibitors can cause various autoimmune side effects called immune-related adverse events because they generate an exaggerated inflammatory response. Encephalitis associated with atezolizumab has rarely been reported as an immune-related adverse event. A case of encephalitis caused by treatment with atezolizumab is presented.

CASE PRESENTATION

A 56-year-old Japanese man with lung cancer previously treated with surgery and chemotherapy was admitted with high fever, consciousness disorder, and motor aphasia. His first atezolizumab treatment was 17 days earlier. Admission brain magnetic resonance imaging with gadolinium enhancement showed no abnormalities. Cerebrospinal fluid showed cell count 20/l, protein 166 mg/dl, glucose 73 mg/dl, and interleukin 6 82.9 pg/ml (normal< 8.7 pg/ml). Atezolizumab-induced encephalitis was diagnosed. His symptoms improved the day after steroid pulse therapy was started. Following steroid pulse therapy, oral prednisolone 30 mg was started and tapered. The cerebrospinal fluid findings normalized on day 14. He was discharged on day 16 without neurological sequelae.

CONCLUSION

In this case of encephalitis associated with atezolizumab, prompt steroid pulse therapy led to a successful response, and the outcome was good. The cerebrospinal fluid level of interleukin 6 reflected the severity of the encephalitis well. Clinicians should be aware of the possibility of encephalitis after initiation of immune checkpoint inhibitors.

Predictors of infectious meningitis or encephalitis: the yield of cerebrospinal fluid in a cross-sectional study

Background

Cerebrospinal fluid (CSF) analyses are recommended in patients with meningitis and/or encephalitis, but evidence regarding its diagnostic yield is low. We aimed to determine predictors of infectious pathogens in the CSF of adult patients presenting with meningitis, and/or encephalitis.

Methods

Consecutive patients with meningitis and/or encephalitis form 2011–17 at a Swiss academic medical care center were included in this cross-sectional study. Clinical, neuroradiologic, and laboratory data were collected as exposure variables. Infectious meningitis and/or encephalitis were defined as the composite outcome.

For diagnosis of bacterial meningitis the recommendations of the European Society of Clinical Microbiology and Infectious Diseases were followed. Viral meningitis was diagnosed by detection of viral ribonucleic or deoxyribonucleic acid in the CSF. Infectious encephalitis was defined according to the International Encephalitis Consortium (IEC). Meningoencephalitis was diagnosed if the criteria for meningitis and encephalitis were fulfilled. Multinomial logistic regression was performed to identify predictors of the composite outcome. To quantify discriminative power, the c statistic analogous the area under the receiver-operating curve (AUROC) was calculated. An AUROC between 0.7–0.8 was defined as “good”, 08–0.9 as “excellent”, and > 0.9 as “outstanding”. Calibration was defined as “good” if the goodness of fit tests revealed insignificant p-values.

Results

Among 372 patients, infections were diagnosed in 42.7% presenting as meningitis (51%), encephalitis (32%), and meningoencephalitis (17%). Most frequent infectious pathogens were Streptococcus pneumoniae, Varicella zoster, and Herpes simplex 1&2. While in multivariable analysis lactate concentrations and decreased glucose ratios were the only independent predictors of bacterial infection (AUROCs 0.780, 0.870, and 0.834 respectively), increased CSF mononuclear cells were the only predictors of viral infections (AUROC 0.669). All predictors revealed good calibration.

Conclusions

Prior to microbiologic workup, CSF data may guide clinicians when infection is suspected while other laboratory and neuroradiologic characteristics seem less useful. While increased CSF lactate and decreased glucose ratio are is the most reliable predictors of bacterial infections in patients with meningitis and/or encephalitis, only mononuclear cell counts predicted viral infections.

Trial registration

ClinicalTrials.gov identifier NCT03856528. Registered on February 26th 2019.

S1 guidelines "lumbar puncture and cerebrospinal fluid analysis" (abridged and translated version)

Introduction

Cerebrospinal fluid (CSF) analysis is important for detecting inflammation of the nervous system and the meninges, bleeding in the area of the subarachnoid space that may not be visualized by imaging, and the spread of malignant diseases to the CSF space. In the diagnosis and differential diagnosis of neurodegenerative diseases, the importance of CSF analysis is increasing. Measuring the opening pressure of CSF in idiopathic intracranial hypertension and at spinal tap in normal pressure hydrocephalus constitute diagnostic examination procedures with therapeutic benefits.Recommendations (most important 3-5 recommendations on a glimpse): The indications and contraindications must be checked before lumbar puncture (LP) is performed, and sampling CSF requires the consent of the patient.Puncture with an atraumatic needle is associated with a lower incidence of postpuncture discomfort. The frequency of postpuncture syndrome correlates inversely with age and body mass index, and it is more common in women and patients with a history of headache. The sharp needle is preferably used in older or obese patients, also in punctures expected to be difficult.In order to avoid repeating LP, a sufficient quantity of CSF (at least 10 ml) should be collected. The CSF sample and the serum sample taken at the same time should be sent to a specialized laboratory immediately so that the emergency and basic CSF analysis program can be carried out within 2 h.The indication for LP in anticoagulant therapy should always be decided on an individual basis. The risk of interrupting anticoagulant therapy must be weighed against the increased bleeding risk of LP with anticoagulant therapy.As a quality assurance measure in CSF analysis, it is recommended that all cytological, clinical-chemical, and microbiological findings are combined in an integrated summary report and evaluated by an expert in CSF analysis.

Conclusions

In view of the importance and developments in CSF analysis, the S1 guideline "Lumbar puncture and cerebrospinal fluid analysis" was recently prepared by the German Society for CSF analysis and clinical neurochemistry (DGLN) and published in German in accordance with the guidelines of the AWMF (https://www.awmf.org). /uploads/tx_szleitlinien/030-141l_S1_Lumbalpunktion_und_Liquordiagnostik_2019-08.pdf). The present article is an abridged translation of the above cited guideline. The guideline has been jointly edited by the DGLN and DGN.

Eosinopenia as a marker of diagnosis and prognostic to distinguish bacterial from aseptic meningitis in pediatrics

Procalcitonin (PCT) has proven its efficacy to distinguish bacterial from aseptic meningitis in children. Nevertheless, its use in routine is limited by its cost and availability, especially in low- and middle-income countries. It is now acknowledged that eosinopenia is a marker of infection and/or severity of the systemic inflammatory response. Although no study ever demonstrated that eosinopenia could differentiate bacterial from viral infection, we decided to conduct a study concerning meningitis in children. This bicentric and retrospective study was conducted between January 2012 and October 2018, in children hospitalized for meningitis. The white blood cell was systematically gathered at the admission to evaluate the eosinophil count. Characteristic data were compared between 2 groups: documented bacterial meningitis (DBP) and aseptic meningitis which includes documented viral meningitis (DVM) and non-documented meningitis (ND). Among 190 patients admitted for meningitis, 151 were analyzed, including DBM (n = 45), DVM (n = 73), and ND (n = 33) meningitis. Groups were comparable. Mean age was 33 ± 48 months with a sex ratio of 1.6. Mean of eosinophil count was 15 ± 34/mm³ in the DBM group versus 132 ± 167/mm³ for the aseptic meningitis group (p < 0.0001). Best threshold for the diagnosis of bacterial meningitis was an eosinophil count < 5/mm³ with a sensitivity of 80% and specificity of 73% and a likelihood ratio of 2.9. Eosinopenia seems to be a reliable and non-invasive marker of bacterial meningitis in pediatrics. The absence of extra cost makes it very interesting in low- and middle-income countries or when usual biomarkers such as PCT are unavailable.

Cerebrospinal fluid monocytes in bacterial meningitis, viral meningitis, and neuroborreliosis

OBJECTIVE

Cerebrospinal fluid (CSF) leukocytes analysis is commonly used to diagnose meningitis and to differentiate bacterial from viral meningitis. Interpreting CSF monocytes can be difficult for physicians, especially in France where lymphocytes and monocytes results are sometimes pooled.

PATIENTS AND METHODS

We assessed SF monocytes in patients presenting with microbiologically confirmed meningitis (CSF leukocyte count>10/mm³ for adults or >30/mm³ for children<2 months), i.e. bacterial meningitis (BM), viral meningitis (VM), and neuroborreliosis (NB).

RESULTS

Two-hundred patients (82 BM, 86 VM, and 32 NB) were included. The proportions of monocytes were higher in VM (median 8%; range 0-57%) than in BM (median 5%; range 0-60%, P=0.03) or NB (median 5%; range 0-53%, P=0.46), with a high value overlap between conditions.

CONCLUSION

CSF monocytes should not be used to discriminate BM from VM and NB because of value overlaps.

Mass-spectrometric profiling of cerebrospinal fluid reveals metabolite biomarkers for CNS involvement in varicella zoster virus reactivation

Background

Varicella zoster virus (VZV) reactivation spans the spectrum from uncomplicated segmental herpes zoster to life-threatening disseminated CNS infection. Moreover, in the absence of a small animal model for this human pathogen, studies of pathogenesis at the organismal level depend on analysis of human biosamples. Changes in cerebrospinal fluid (CSF) metabolites may reflect critical aspects of host responses and end-organ damage in neuroinfection and neuroinflammation. We therefore applied a targeted metabolomics screen of CSF to three clinically distinct forms of VZV reactivation and infectious and non-infectious disease controls in order to identify biomarkers for CNS involvement in VZV reactivation.

Methods

Metabolite profiles were determined by targeted liquid chromatography-mass spectrometry in CSF from patients with segmental zoster (shingles, n = 14), facial nerve zoster (n = 16), VZV meningitis/encephalitis (n = 15), enteroviral meningitis (n = 10), idiopathic Bell’s palsy (n = 11), and normal pressure hydrocephalus (n = 15).

Results

Concentrations of 88 metabolites passing quality assessment clearly separated the three VZV reactivation forms from each other and from the non-infected samples. Internal cross-validation identified four metabolites (SM C16:1, glycine, lysoPC a C26:1, PC ae C34:0) that were particularly associated with VZV meningoencephalitis. SM(OH) C14:1 accurately distinguished facial nerve zoster from Bell’s palsy. Random forest construction revealed even more accurate classifiers (signatures comprising 2–4 metabolites) for most comparisons. Some of the most accurate biomarkers correlated only weakly with CSF leukocyte count, indicating that they do not merely reflect recruitment of inflammatory cells but, rather, specific pathophysiological mechanisms. Across all samples, only the sum of hexoses and the amino acids arginine, serine, and tryptophan correlated negatively with leukocyte count. Increased expression of the metabolites associated with VZV meningoencephalitis could be linked to processes relating to neuroinflammation/immune activation, neuronal signaling, and cell stress, turnover, and death (e.g., autophagy and apoptosis), suggesting that these metabolites might sense processes relating to end-organ damage.

Conclusions

The results provide proof-of-concept for the value of CSF metabolites as (1) disease-associated signatures suggesting pathophysiological mechanisms, (2) degree and nature of neuroinflammation, and (3) biomarkers for diagnosis and risk stratification of VZV reactivation and, likely, neuroinfections due to other pathogens.

Trial registration

Not applicable (non-interventional study).

Electronic supplementary material

The online version of this article (10.1186/s12974-017-1041-0) contains supplementary material, which is available to authorized users.

Vascular diseases and bleedings

Diseases of the central nervous system that are caused by an underlying vascular pathology typically result in either hemorrhage or ischemia. Most prominent entities include spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. For anatomic reasons, cerebrospinal fluid (CSF) qualifies as body fluid for the exploration of biomarkers in these disorders. Even though in subarachnoid hemorrhage a few CSF parameters have been established for routine diagnostic purposes, there is still an unmet need and broad interest in the identification of molecules that would allow further insight into disease mechanisms and supplement patients' medical care. This chapter provides an overview on what is presently known about CSF biomarkers in spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. We recapitulate current evidence on established diagnostic tests, discuss the role of various CSF molecules in the pathophysiology of these diseases, and illuminate their potential use in future clinical practice. Furthermore, we address methodologic aspects as well as shortcomings of research in this field.

Cerebrospinal fluid lactate: a differential biomarker for bacterial and viral meningitis in children

OBJECTIVE

To assess the performance of cerebrospinal fluid (CSF) lactate as a biomarker to differentiate bacterial meningitis from viral meningitis in children, and to define an optimal CSF lactate concentration that can be called significant for the differentiation.

METHODS

Children with clinical findings compatible with meningitis were studied. CSF lactate and other conventional CSF parameters were recorded.

RESULTS

At a cut-off value of 3mmol/L, CSF lactate had a sensitivity of 0.90, specificity of 1.0, positive predictive value of 1.0, and negative predictive value of 0.963, with an accuracy of 0.972. The positive and negative likelihood ratios were 23.6 and 0.1, respectively. When comparing between bacterial and viral meningitis, the area under the curve for CSF lactate was 0.979.

CONCLUSIONS

The authors concluded that CSF lactate has high sensitivity and specificity in differentiating bacterial from viral meningitis. While at a cut-off value of 3mmol/L, CSF lactate has high diagnostic accuracy for bacterial meningitis, mean levels in viral meningitis remain essentially below 2mmol/L.

γδ T cells provide the early source of IFN-γ to aggravate lesions in spinal cord injury

Immune responses and neuroinflammation are critically involved in spinal cord injury (SCI). γδ T cells, a small subset of T cells, regulate the inflammation process in many diseases, yet their function in SCI is still poorly understood. In this paper, we demonstrate that mice deficient in γδ T cells (TCRδ^-/- ) showed improved functional recovery after SCI. γδ T cells are detected at the lesion sites within 24 hours after injury and are predominantly of the Vγ4 subtype and express the inflammatory cytokine IFN-γ. Inactivating IFN-γ signaling in macrophages results in a significantly reduced production of proinflammatory cytokines in the cerebrospinal fluid (CSF) of mice with SCIs and improves functional recovery. Furthermore, treatment of SCI with anti-Vγ4 antibodies has a beneficial effect, similar to that obtained with anti-TNF-α. In SCI patients, γδ T cells are detected in the CSF, and most of them are IFN-γ positive. In conclusion, manipulation of γδ T cell functions may be a potential approach for future SCI treatment.

Effects of propofol on myocardial ischemia-reperfusion injury in rats with type-2 diabetes mellitus

The current study aimed to examine the effects of propofol on myocardial ischemia-reperfusion injury (MIRI) in rats with type-2 diabetes mellitus (T2DM) and to assess the role of inflammatory mediators. Fifty healthy male adult Sprague-Dawley rats were randomly divided into the sham, ischemia-reperfusion (IR), IR plus low, middle and high-dose (6, 12 and 24 mg/kg/h, intravenous) propofol groups. The rats of all the groups were fed a high-sugar and high-fat diet for 8 weeks and streptozotocin (30 mg/kg, intraperitoneally) was used to establish the T2DM model. Apart from the sham group rats, MIRI was induced by ligating the left anterior descending coronary artery for 30 min, followed by reperfusion for 2 h. Heart rate (HR), left ventricular systolic pressure (LVSP), and the rate of left ventricular pressure increase in early systole (± dp/dt_max) were recorded. Levels of cardiac troponin T (cTnT), nitric oxide (NO), endothelin-1 (ET-1), interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α were also measured. Myocardial lesions were observed under light microscopy and scanning electron microscopy. Compared with levels prior to arterial occlusion, HR, LVSP, and ± dp/dt_max were significantly reduced (P<0.05) following occlusion for 30 min and reperfusion for 2 h. The administration of propofol ameliorated the cardiac function of rats as reflected by the increase in HR, LVSP and ± dp/dt_max. In addition, the administration of propofol increased the serum NO concentration, and reduced ET-1 and cTnT levels, as well as levels of inflammatory mediators including IL-1β, IL-6 and TNF-α. Thus, propofol exerts protective effects against MIRI in T2DM rats by increasing NO and reducing ET-1 and the inflammatory mediators.

Diagnostic accuracy of tumor necrosis factor-alpha assay for tuberculous pleurisy: A PRISMA-compliant meta-analysis

BACKGROUND

The diagnosis of tuberculous pleurisy is difficult and traditional methods are not always helpful. Many studies have focused on the tumor necrosis factor-alpha (TNF-α) assay in pleural effusion for the diagnosis of tuberculous pleurisy, but the results remain controversial. This meta-analysis was conducted to determine the overall diagnostic accuracy of TNF-α.

METHODS

Relevant studies were searched from PubMed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), Wangfang, and Weipu. We pooled the published results and computed the accuracy measures, including sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), and diagnostic odds ratio (DOR). Receiver operating characteristic curves (SROC) and the area under the curve (AUC) were used to summarize the overall test performance.

RESULTS

Twelve studies with 1022 patients met the inclusion criteria. The pooled sensitivity and specificity were 0.85 (95%CI, 0.81-0.89) and 0.80 (95% CI, 0.77-0.83) respectively. The area under the SROC curve was 0.89.

CONCLUSIONS

The results of meta-analysis suggested that the TNF-α assay plays a vital role in the diagnosis of tuberculous pleurisy, whereas other test results or clinical findings should be interpreted together with the TNF-α assay to improve the overall diagnostic accuracy.

Clinical decision rules for acute bacterial meningitis: current insights

Acute community-acquired bacterial meningitis (BM) requires rapid diagnosis so that suitable treatment can be instituted within 60 minutes of admitting the patient. The cornerstone of diagnostic examination is lumbar puncture, which enables microbiological analysis and determination of the cerebrospinal fluid (CSF) cytochemical characteristics. However, microbiological testing is not sufficiently sensitive to rule out this diagnosis. With regard to the analysis of standard CSF cytochemical characteristics (polymorphonuclear count, CSF glucose and protein concentration, and CSF:serum glucose), this is often misleading. Indeed, the relatively imprecise nature of the cutoff values for these BM diagnosis markers can make their interpretation difficult. However, there are two markers that appear to be more efficient than the standard ones: CSF lactate and serum procalcitonin levels. Scores and predictive models are also available; however, they only define a clinical probability, and in addition, their use calls for prior validation on the population in which they are used. In this article, we review current methods of BM diagnosis.

Comparative proteomics of cerebrospinal fluid reveals a predictive model for differential diagnosis of pneumococcal, meningococcal, and enteroviral meningitis, and novel putative therapeutic targets

BACKGROUND

Meningitis is the inflammation of the meninges in response to infection or chemical agents. While aseptic meningitis, most frequently caused by enteroviruses, is usually benign with a self-limiting course, bacterial meningitis remains associated with high morbidity and mortality rates, despite advances in antimicrobial therapy and intensive care. Fast and accurate differential diagnosis is crucial for assertive choice of the appropriate therapeutic approach for each form of meningitis.

METHODS

We used 2D-PAGE and mass spectrometry to identify the cerebrospinal fluid proteome specifically related to the host response to pneumococcal, meningococcal, and enteroviral meningitis. The disease-specific proteome signatures were inspected by pathway analysis.

RESULTS

Unique cerebrospinal fluid proteome signatures were found to the three aetiological forms of meningitis investigated, and a qualitative predictive model with four protein markers was developed for the differential diagnosis of these diseases. Nevertheless, pathway analysis of the disease-specific proteomes unveiled that Kallikrein-kinin system may play a crucial role in the pathophysiological mechanisms leading to brain damage in bacterial meningitis. Proteins taking part in this cellular process are proposed as putative targets to novel adjunctive therapies.

CONCLUSIONS

Comparative proteomics of cerebrospinal fluid disclosed candidate biomarkers, which were combined in a qualitative and sequential predictive model with potential to improve the differential diagnosis of pneumococcal, meningococcal and enteroviral meningitis. Moreover, we present the first evidence of the possible implication of Kallikrein-kinin system in the pathophysiology of bacterial meningitis.

Infection surveillance in transsphenoidal pituitary surgery - comparison of lipopolysaccharide-binding-protein, interleukin 6, C-reactive protein, white blood cell count, erythrocyte sedimentation rate and body temperature

BACKGROUND

One of the major concerns in transsphenoidal surgery are infections because the approach to the pituitary includes a route of microbial colonization. To minimize the associated morbidity and mortality, a surveillance program is crucial to monitor for perioperative infections.

METHODS

For 1 year, we analysed body temperature (BT), erythrocyte sedimentation rate (ESR), white blood cell count (WBC), C-reactive protein (CRP), interleukin 6 (IL-6) and lipopolysaccharide-binding-protein (LBP) following elective transsphenoidal pituitary surgery. Samples were collected on admission, day 1, 3 and 7 as well as 3 months postoperatively.

RESULTS

In 116 patients, all data were available. No postoperative infections occurred within the first postoperative week. BT (37.6 ± 0.6, baseline 37.0 ± 0.5 °C), WBC (11,366 ± 2,541, baseline 6,861 ± 2,123/μl), CRP (25.3 ± 22.6, baseline 3.1 ± 6 mg/l), IL-6 (12 ± 13, baseline 2.7 ± 2.6 pg/ml), and LBP (11.3 ± 4.9, baseline 5.7 ± 2.7 μg/ml) peaked on day 1 postoperatively (each p = 0.001), while ESR peaked on day 3 (25 ± 16, baseline 13 ± 11 mm/h, p = 0.001). BT and IL-6 normalized by day 3 and CRP by day 7, while ESR (23 ± 16 mm/h, p = 0.001), WBC (7,807 ± 2,750/μl, p = 0.001) and LBP (7.3 ± 2.6 μg/ml, p = 0.028) were still increased by day 7.

CONCLUSION

The present study establishes normative values for an infection surveillance following transsphenoidal pituitary surgery. CRP, a convenient and reasonable priced parameter, is affected by the procedure for the first postoperative week. IL-6 is more robust and allows a close monitoring on the expense of additional pricing. ESR, WBC and LBP are sustained affected by surgery, and do not offer any advantage. Since no infections were observed, we were unable to calculate the respective sensitivity and specificity.

Immediate diagnosis of ventriculits: evaluation of parameters independent of microbiological culture

BACKGROUND

Generally accepted reference values in CSF diagnostics are not valid in cerebrospinal fluid (CSF) containing large amounts of blood. Residual blood may obscure ventriculitis as diagnostics largely depend on parameters such as cell count, lactic acid and total protein measurement. We sought to improve the diagnostics by evaluating a cytokine panel and soluble CD62L as markers of ventriculitis. In addition, we tested an algorithm of established parameters to predict ventriculitis in a specific patient collective.

METHODS

Analysis was performed on ventricular CSF samples from 50 consecutive patients. Gram staining, microbiological culture, total cell count, total protein and CD62L expression on neutrophil granulocytes were analysed immediately. Cytokines and soluble CD62L were measured by flow cytometry.

FINDINGS

Positive culture was detected in ten patients. Of all parameters tested only IL1-beta, IL8 and CD62L on neutrophils were significantly different between culture-positive and -negative patients. The highest predictive value was obtained when analysing IL1-beta. The predictive value of a parameter combination (IL6 in CSF, C-reactive protein and leukocytes in periphereal blood) was comparable to IL1-beta. Half of the patients in this analysis were identified as culture positive because of the lack of inflammatory response.

CONCLUSIONS

IL1-beta and perhaps also IL8 provide very good analytical performance when looking for ventriculitis in patients with residual blood in CSF. Turn-around time is short, and results could be reported within 1 h for 24 h a day. In some patients application of glucocorticoids may result in restricted inflammatory response. Even in these patients IL1-beta provides a reliable parameter for the immediate diagnosis of ventriculitis.

Meningitis in adult patients with a negative direct cerebrospinal fluid examination: value of cytochemical markers for differential diagnosis

INTRODUCTION

The objective of this study was to determine the ability of various parameters commonly used for the diagnosis of acute meningitis to differentiate between bacterial and viral meningitis, in adult patients with a negative direct cerebrospinal fluid (CSF) examination.

METHODS

This was a prospective study, started in 1997, including all patients admitted to the emergency unit with acute meningitis and a negative direct CSF examination. Serum and CSF samples were taken immediately on admission. The patients were divided into two groups according to the type of meningitis: bacterial (BM; group I) or viral (VM; group II). The CSF parameters investigated were cytology, protein, glucose, and lactate; the serum parameters evaluated were C-reactive protein and procalcitonin. CSF/serum glucose and lactate ratios were also assessed.

RESULTS

Of the 254 patients with meningitis with a negative direct CSF examination, 35 had BM and 181, VM. The most highly discriminative parameters for the differential diagnosis of BM proved to be CSF lactate, with a sensitivity of 94%, a specificity of 92%, a negative predictive value of 99%, a positive predictive value of 82% at a diagnostic cut-off level of 3.8 mmol/L (area under the curve (AUC), 0.96; 95% confidence interval (CI), 0.95 to 1), and serum procalcitonin, with a sensitivity of 95%, a specificity of 100%, a negative predictive value of 100%, and a positive predictive value of 97% at a diagnostic cut-off level of 0.28 ng/ml (AUC, 0.99; 95% CI, 0.99 to 1).

CONCLUSIONS

Serum procalcitonin and CSF lactate concentrations appear to be the most highly discriminative parameters for the differential diagnosis of BM and VM.

Quantification of cerebrospinal fluid lactic acid in the differential diagnosis between HIV chronic meningitis and opportunistic meningitis

BACKGROUND

Approximately 40% of HIV infected patients have chronic meningitis at various stages during the infection, 59% are asymptomatic. This is a diagnosis of exclusion and a confounding factor in cerebrospinal fluid (CSF) analysis, any other causes of chronic meningitis by opportunistic or co-infection must be ruled out. The aim of this study was to analyze CSF lactic acid (LA) as an adjuvant biomarker in chronic meningitis due to HIV.

METHODS

CSF LA was quantified in 223 CSF samples by the Dimension AR (Dade Behring, Deerfield, IL, USA), distributed into nine groups: 1) HIV positive with an increase in CSF WBCs (n=17); 2) HIV positive with normal CSF (n=20); 3) enterovirus meningitis (n=33); 4) Herpesviridae meningoencephalitis (n=30); 5) fungal meningitis (n=25); 6) tuberculosis (TB) meningitis (n=17); 7) toxoplasmosis (n=18); 8) neurosyphilis (n=6); 9) control group (n=57).

RESULTS

CSF LA (median; IQR) was higher in samples with TB meningitis (5.5; 2.9-7.5 mmol/L) and Cryptococcus neoformans meningitis (3.9; 2.7-5.8 mmol/L) compated with samples with HIV chronic meningitis (1.7; 1.4-1.9 mmol/L) and other groups (p ≤ 0.0001). For the diagnosis of HIV chronic meningitis, using a cut-off of 3.5 mmol/L, CSF LA showed high sensitivity and negative predictive value, although low specificity.

CONCLUSIONS

CSF LA helps to discriminate between C. neoformans or TB meningitis and HIV chronic meningitis: CSF LA can be included with the methods currently used to identify these specific pathogens, though it does not replace them. It is rapid, inexpensive and easy to perform, and can be used in developing countries.

Cerebrospinal fluid lactate concentration to distinguish bacterial from aseptic meningitis: a systemic review and meta-analysis

Introduction

Making a differential diagnosis between bacterial meningitis and aseptic meningitis is a critical clinical problem. The utility of a cerebrospinal fluid (CSF) lactate assay for this purpose has been debated and is not yet routinely clinically performed. To adequately evaluate this assay, a systematic review and meta-analysis of studies of the CSF lactate concentration as a marker for both bacterial meningitis and aseptic meningitis was performed.

Methods

Electronic searches in PubMed, Scopus, the MEDION database and the Cochrane Library were conducted to identify relevant articles published before March 2009. A manual search of reference lists from selected articles was also conducted. Two reviewers independently selected relevant articles and extracted data on study characteristics, quality and accuracy.

Results

Twenty-five articles were identified that met the eligibility criteria. Diagnostic odds ratios were considerably homogenous (Chi-square P = 0.1009, I² = 27.6%), and the homogeneity was further confirmed by a Galbraith plot and meta-regression analysis using several covariates. The symmetrical summary receiver-operator characteristic curve (SROC), fitted using the Moses-Shapiro-Littenberg method, was positioned near the upper left corner of the SROC curve. The Q value and area under the curve were 0.9451 and 0.9840, respectively, indicating excellent accuracy. The diagnostic accuracy of the CSF lactate concentration was higher than those of other four conventional markers (CSF glucose, CSF/plasma glucose quotient, CSF protein, and CSF total number of leukocytes) using a head to head meta-analysis of the 25 included studies.

Conclusions

To distinguish bacterial meningitis from aseptic meningitis, CSF lactate is a good single indicator and a better marker compared to other conventional markers.

Dexamethasone prevents LPS-induced microglial activation and astroglial impairment in an experimental bacterial meningitis co-culture model

We analyzed the effect of dexamethasone on gram-negative bacteria derived lipopolysaccharide (LPS) induced inflammation in astroglial/microglial co-cultures. At the cellular level the microglial phenotype converted to an activated type after LPS incubation. Furthermore, LPS compromised functional astroglial properties like membrane resting potential, intracellular coupling and connexin 43 (Cx43) expression. This change in Cx43 expression was not due to a downregulation of Cx43 mRNA expression. Morphological and functional changes were accompanied by a time-dependent release of inflammation related cytokines. Co-incubation of dexamethasone with LPS prevented these LPS-induced changes within our glial co-culture model. The ability of dexamethasone to reconstitute astrocytic properties and to decrease microglial activation in vitro could be one possible explanation for the beneficial effects of dexamethasone in the treatment of acute bacterial meningitis in vivo.

Quantitation of cerebrospinal fluid lactic acid in infectious and non-infectious neurological diseases

BACKGROUND

The differential diagnosis between bacterial and viral meningitis is not easy in some cases. Cerebrospinal fluid (CSF) analysis is essential for establishing this diagnosis. The objectives were to quantitate lactic acid (LA) concentrations in bacterial and viral meningitis, and other central nervous system (CNS) diseases in order to evaluate the diagnostic utility of CSF LA for discriminating bacterial from viral meningitis.

METHODS

CSF LA was measured in 139 CSF samples from seven groups: viral meningitis with classic CSF; suspicion of viral meningitis with neutrophils in CSF; bacterial meningitis; non-infectious neurological diseases; chronic meningitis; traumatic lumbar puncture (LP) and normal CSF.

RESULTS

CSF LA was higher in bacterial meningitis 8.7 + 5.4 mmol/L compared with viral meningitis (1.9 + 0.6) and the other groups (p < 0.0001). CSF LA in the groups with viral meningitis was not different compared to groups with non-infectious CNS diseases and chronic meningitis. The ability of CSF LA to discriminate bacterial from viral meningitis showed a sensitivity of 80% and specificity of 97%, positive predictive value (PPV) of 94%, and negative predictive value (NPV) of 89%.

CONCLUSIONS

CSF LA is a powerful test to discriminate bacterial from viral meningitis with high sensitivity, specificity and predictive values. CSF LA can help in the cases with diagnostic uncertainty.

Sequential analysis of biomarkers in cerebrospinal fluid and serum during invasive meningococcal disease

The aim of the present study was to determine the profile of different inflammatory molecules in serum and cerebrospinal fluid (CSF) during invasive meningococcal disease (IMD). Their relationship with IMD severity was also assessed. A cohort of 12 patients with IMD was investigated. Paired serum and CSF samples were obtained at the time of diagnostic and follow-up lumbar puncture and were examined using Luminex analysis. IMD severity correlated with serum interleukin-6 (IL-6) and interleukin-1 receptor antagonist (IL-1 ra) on admission. Furthermore, the CSF levels of IL-1 beta, IL-1 ra, IL-6, IL-8, macrophage inflammatory protein-1 beta (MIP-1 beta), and monocyte chemoattractant protein-1 (MCP-1) were significantly higher than their respective serum levels. The strongest correlations were found between serum concentrations of IL-1 beta and IL-1 ra, IL-6, IL-8, and MIP-1 beta, whereas the strongest correlations in CSF were found between endotoxin and IL-8, IL-17, MIP-1 beta, and MCP-1. As was expected, the concentrations of inflammatory molecules in both serum and CSF significantly decreased after antibiotic treatment. With regard to kinetics, a severe course of IMD correlated positively with rapid declines of CSF IL-6 and cortisol levels. Sequential multiple analyses revealed patterns of inflammatory responses that were associated with the severity of IMD, as well as with the compartmentalization and kinetics of the immune reaction.

Cortisol levels in cerebrospinal fluid correlate with severity and bacterial origin of meningitis

Introduction

Outcomes following bacterial meningitis are significantly improved by adjunctive treatment with corticosteroids. However, little is known about the levels and significance of intrathecal endogenous cortisol. The aim of this study was to assess cortisol as a biological and diagnostic marker in patients with bacterial meningitis.

Methods

Forty-seven consecutive patients with bacterial meningitis and no prior treatment were evaluated. For comparison, a group of 37 patients with aseptic meningitis and a group of 13 healthy control individuals were included.

Results

The mean age of the bacterial meningitis patients was 42 years, and the mean Glasgow Coma Scale, Acute Physiology and Chronic Health Evaluation II, and Sequential Organ Failure Assessment scores on admission were 12, 13 and 4, respectively. Altogether, 40 patients (85%) were admitted to the intensive care unit, with a median (interquartile range) length of stay of 8 (4 to 15) days. A bacterial etiology was confirmed in 35 patients (74%). The median (interquartile range) cortisol concentration in cerebrospinal fluid (CSF) was 133 (59 to 278) nmol/l. CSF cortisol concentrations were positively correlated with serum cortisol levels (r = 0.587, P < 0.001). Furthermore, CSF cortisol levels correlated with Acute Physiology and Chronic Health Evaluation II score (r = 0.763, P < 0.001), Sequential Organ Failure Assessment score (r = 0.650, P < 0.001), Glasgow Coma Scale score (r = -0.547, P < 0.001) and CSF lactate levels (r = 0.734, P < 0.001). CSF cortisol was only weakly associated with intrathecal levels of IL-6 (r = 0.331, P = 0.02) and IL-8 (r = 0.296, P < 0.05). CSF cortisol levels in bacterial and aseptic meningitis significantly differed (P < 0.001). The CSF cortisol concentration of 46.1 nmol/l was found to be the optimal cutoff value for diagnosis of bacterial meningitis.

Conclusion

CSF cortisol levels in patients with bacterial meningitis are highly elevated and correlate with disease severity. Moreover, our findings also suggest that intrathecal cortisol may serve as a valuable marker in discriminating between bacterial and aseptic meningitis.

Cytokine expression in pediatric subperiosteal orbital abscesses

BACKGROUND

Cytokines have been shown to play a key role in infectious and inflammatory processes. The purpose of the study was to characterize the pattern of cytokine expression in subperiosteal orbital abscesses associated with pediatric orbital cellulitis.

METHODS

All pediatric patients over a 5-month period who had orbital cellulitis and a subperiosteal abscess with an adjacent sinusitis requiring surgical drainage of the orbital abscess were given the opportunity to enroll in the study. A protein array membrane and a chemiluminescent detection system were used to identify the presence of 45 cytokines in the subperiosteal abscess fluid.

RESULTS

Four abscesses were analyzed with the protein array membrane. Of the 45 cytokines studied for this report, interleukin (IL)-1alpha, IL-1beta, IL-1 receptor antagonist (ra), IL-6, tumor necrosis factor (TNF)-alpha, and TNF-beta were detected in all specimens. Additionally, IL-16, epidermal growth factor related protein, and soluble TNF receptor II were detected in 3 of the 4 specimens.

INTERPRETATION

Pediatric orbital cellulitis with subperiosteal abscess is an inflammatory condition with a distinct pattern of cytokine expression. The detection of IL-1, IL-1 ra, IL-6, and TNF suggests that in the future these cytokines may play a role in monitoring disease activity or as potential targets for immunotherapy.

Cerebrospinal fluid cytological and biochemical characteristics in the presence of CNS neoplasia

Central nervous system (CNS) infiltration must be ruled out in patients with known neoplastic diseases and neurological symptoms. It was done a retrospective analysis of 1,948 CSF samples from patients with suspected malignant infiltration in the CNS, in order to evaluate the positivity rate of malignant cells in cerebrospinal fluid (CSF) samples and correlate with cytochemical characteristics. Sixty-two percent of subjects had acute lymphocytic leukemia. Malignant cells were found in 24% of all CSF samples. Subjects with positive malignant cells had predominance of increased levels of CSF total protein (TP), glucose and total cytology (p<0.05). Mean total cell count in this group was 232 (SD 933) cells/mm³, compared to 9 (SD 93) cells/mm³ in the group without neoplasic cells (p=0.029). CSF TP specificity was 87% and negative predictive value (NPV) 96%. CSF total cell count specificity 86% and NPV 97%. Although sensitivity and positive predictive value were low. The presence of inflammatory cells and elevated TP found in patients with malignant cells in the CSF can aid in diagnosing CNS neoplasms.

Analysis of Intrathecal Interleukin-6 As a Potential Predictive Factor for Vasospasm in Subarachnoid Hemorrhage

OBJECTIVE

Inflammatory response seems to be one of the relevant pathophysiological aspects for developing vasospasm in subarachnoid hemorrhage. The probable diagnostic value of intrathecal proinflammatory markers is still unclear and is assessed in this study.

METHODS

We analyzed daily clinical data and laboratory tests of the cerebrospinal fluid (CSF) of 64 patients with mostly poor-grade subarachnoid hemorrhage during a period of 14 days. Special attention was given to the relationship between the development of vasospasm and the time course of the intrathecal interleukin (IL)-6 concentrations in CSF (IL-6CSF). The potential power of IL-6CSF for predicting vasospasm was studied.

RESULTS

Vasospasm developed in 28.1% of the patients, with a mean onset of 6.4 days after bleeding, and was detected by conventional methods. Patients with vasospasm demonstrated statistically significant higher median values of IL-6CSF on Days 4 and 5 (P < 0.05). Most importantly, the increase of IL-6CSF preceded the conventional signs of vasospasm. A cut-off value of IL-6CSF of at least 2000 pg/ml on Day 4 yielded an 11.72-fold higher relative risk (95% confidence interval, 2.93-46.60) of developing vasospasm, predicting vasospasm with a sensitivity of 88.9% and a specificity of 78.3%. We found a statistically significant correlation between IL-6CSF and delayed cerebral ischemia for Day 7 (P = 0.03). However, there was no correlation with IL-6CSF on any other day and outcome.

CONCLUSION

IL-6CSF seems to be a reliable early marker for predicting vasospasm after subarachnoid hemorrhage on Days 4 and 5 before clinical onset.

Role of tumor necrosis factor-α in acute gastric mucosal injury in rats after acute brain trauma

AIM: To detect the content of tumor necrosis factor-α (TNF-α) in acute gastric mucosal injury in rats after acute brain trauma and explore its significance.

METHODS: Modified Allen's method was used to induce the rat model of acute gastric mucosal injury after acute brain trauma. Meanwhile, the sham operation group was also designed. The content of TNF-α and ulcer index of gastric mucosa were determined at different time points (1, 3, 6, 24 h), and the pathological changes were also observed under light microscope.

RESULTS: The content of TNF-α in model group was significantly higher than that in control group at the 1^st, 3^rd, 6^th and 24^th hour (t = 16.45, P = 0.000; t = 5.252, P = 0.000; t = 9.099, P = 0.000; t = 12.028, P = 0.000). More severe injury occurred in model group and the ulcer index of gastric mucosa was markedly higher than that in control group at the 6th and 24^th hour (t = 7.275, P = 0.000; t = 10.579, P = 0.000). TNF-α content was positively correlated with the ulcer index of gastric mucosa (r = 0.68, P = 0.004).

CONCLUSION: TNF-α plays a certen role in acute gastric mucosal injury after acute brain trauma.

Accuracy of the cerebrospinal fluid results to differentiate bacterial from non bacterial meningitis, in case of negative gram-stained smear

OBJECTIVE

The aim of this study was to evaluate the usefulness of various laboratory results for differential diagnosis of bacterial (BM) and nonbacterial meningitis (NBM) with negative initial Gram stain.

DESIGN AND SETTING

A prospective multicenter study was conducted in the emergency departments of 3 teaching hospitals.

PARTICIPANTS AND METHODS

Consecutive adult patients with a diagnosis of meningitis based on compatible clinical features and cerebrospinal fluid (CSF) culture findings with a CSF leukocyte count greater than 5/mm(3) were included in the study. Symptoms, examination findings, data from laboratory results, including CSF results and serum C-reactive protein (CRP) levels, and clinical outcome were assessed.

RESULTS

One hundred fifty-one patients (age, 35 +/- 15 years) with confirmed meningitis were admitted: 133 with NBM and 18 with BM. CRP and procalcitonin (PCT) levels, CSF white cell and absolute neutrophil counts, and CSF glucose/blood glucose and CSF protein levels were significantly higher in the BM group. However, as diagnostic indicators of BM, none of these variables except PCT was more efficient than that of the emergency physician. Values of the area under the receiver operating characteristic curve were 0.59 (95% confidence interval [CI], 0.21-0.82), 0.79 (95% CI, 0.47-0.92), 0.18 (95% CI, 0.0-0.43), 0.70 (95%CI, 0.30-0.89), 0.81 (95% CI, 0.58-0.92), and 0.98 (95% CI, 0.83-1.0) for CSF leukocyte count, percentage of CSF leukocyte, CSF/blood glucose ratio, CSF protein level, serum CRP, and serum PCT (P < .05 vs CRP), respectively.

CONCLUSION

CSF results have a modest role in distinguishing BM from NBM in a negative Gram stain for bacteria. PCT serum levels seem to be an excellent predictor of BM.

Lipopolysaccharide binding protein is a potential marker for invasive bacterial infections in children

BACKGROUND

The aim of this study was to test the hypothesis that elevated lipopolysaccharide binding protein (LBP) serum concentration is a useful marker in the early diagnosis of invasive bacterial infection in children. We measured LBP in serum and cerebrospinal fluid (CSF) of children with proven invasive infection caused by Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis.

PATIENTS AND METHODS

Samples were collected from 39 children (aged 2 months to 17 years) with bacterial sepsis (n = 19) or meningitis (n = 20). Bacterial infection was diagnosed when a blood or CSF culture was positive and clinical signs of invasive infection were present. The control group consisted of serum (n = 60) and CSF (n = 19) samples from children with neurologic disease, juvenile idiopathic arthritis or viral infection. In 10 patients with bacterial infection, follow-up samples (24 and 48 hours) were available. LBP values were measured by an immunochemiluminescence analyzer (IMMULITE; DPC Biermann, Bad Nauheim, Germany) and compared with tumor necrosis factor-alpha and interleukin-8 concentrations.

RESULTS

The median LBP serum concentrations in patients with bacterial infection were markedly elevated compared with the control groups (45.0 [33.1-55.2] versus 8.3 [6.8-10.1] microg/mL [median and 5-95% confidence interval]; P < 0.0001). Follow-up serum values of LBP were persistently elevated despite adequate antibiotic treatment, whereas tumor necrosis factor-alpha and interleukin-8 concentrations decreased. In contrast, LBP concentrations in the CSF were below the detection limit of 0.5 microg/mL in 67% of patients with bacterial meningitis (median <0.5 microg/mL), whereas tumor necrosis factor-alpha and interleukin-8 levels were highly elevated.

CONCLUSION

LBP serum concentration is elevated in serum of children with invasive bacterial infection and could be a promising diagnostic marker.

Serum procalcitonin and other biologic markers to distinguish between bacterial and aseptic meningitis

OBJECTIVE

To identify the biologic tests that best distinguish between bacterial and aseptic meningitis in an emergency department (ED).

STUDY DESIGN

All children hospitalized for bacterial meningitis between 1995 and 2004 or for aseptic meningitis between 2000 and 2004 were included in a retrospective cohort study. Predictive values of blood (C-reactive protein, procalcitonin [PCT], white blood cell [WBC] count, neutrophil count) and cerebrospinal fluid (CSF) findings (protein, glucose, WBC count, neutrophil count) available in the ED were determined. Tests with the best predictive value were identified by using univariate and multivariate analyses and ROC curves comparison.

RESULTS

Among the 167 patients included, 21 had bacterial meningitis. The CSF gram-stain and bacterial antigen test had 86% and 60% sensitivity rates, respectively. PCT (>/=0.5 ng/mL) and CSF protein (>/=0.5 g/L) were the best biologic tests, with 89% and 86% sensitivity rates, 89% and 78% specificity rates, adjusted odds ratios of 108 (95% CI, 15-772) and 34 (95% CI, 5-217), and areas under the ROC curves of 0.95 and 0.93, respectively.

CONCLUSION

PCT and CSF protein had the best predictive value to distinguish between bacterial and aseptic meningitis in children.

Elevation of ST2 protein levels in cerebrospinal fluid following subarachnoid hemorrhage

OBJECTIVE

To study the mode of appearance of ST2 in cerebrospinal fluid (CSF) after subarachnoid hemorrhage (SAH).

MATERIALS AND METHODS

Immunoprecipitation and subsequent immunoblotting were performed to reveal the existence of ST2 in CSF after SAH. CSF samples from 21 patients were analyzed for ST2 using an enzyme-linked immunosorbent assay system. The ST2 levels were compared between serum and CSF after SAH. The ST2 levels in CSF were measured in six patients operated with other than SAH.

RESULTS

ST2 was secreted into CSF after SAH. The concentration of ST2 was the highest in the samples of the first post-operative day and declined thereafter. The patients operated with other than SAH did not show the elevation of ST2 in CSF.

CONCLUSIONS

This study revealed the presence of ST2 in CSF for the first time and suggested a possibility that ST2 is related to the inflammatory reaction in the central nervous system after SAH.

TNF-alpha and IL-6 in the diagnosis of bacterial and aseptic meningitis in children

The objective of this study was to analyze the usefulness of tumor necrosis factor-alpha and interleukin-6 cerebrospinal fluid concentrations for the differential diagnosis between bacterial and aseptic meningitis in children and in the prognostic evaluation. A cross-sectional study was performed on 35 children between 1 month and 12 years of age with suspected meningitis. Cytokines determination was performed by enzyme-linked immunosorbent assay technique. The Mann-Whitney test and Spearman's correlation coefficients were used for statistical analysis. Six children presented bacterial meningitis, 13 aseptic, and 16 had no meningitis. The tumor necrosis factor-alpha concentrations were significantly higher in the bacterial meningitis group as compared with the aseptic group (P = 0.001) and among groups with and without meningitis (P = 0.000). There was correlation between tumor necrosis factor-alpha and cerebrospinal fluid leukocytes (P = 0.019), protein (P = 0.000), and glucose (P = 0.038). There was no association between cytokines and complications of the meningitis. The tumor necrosis factor-alpha concentrations in the cerebrospinal fluid were useful markers for distinguishing bacterial from aseptic meningitis and were demonstrated to be useful in evaluating the intensity of the inflammatory process in the central nervous system.

Accuracy of clinical presentation for differentiating bacterial from viral meningitis in adults: a multivariate approach

OBJECTIVE

To determine whether bacterial (BM) and viral (VM) meningitis can be differentiated based on initial clinical presentation.

DESIGN AND SETTING

Retrospective cohort study in a medical emergency department and intensive care unit in a university hospital.

PATIENTS

144 adults, including 90 with confirmed BM and 54 unpretreated VM.

MEASUREMENTS AND RESULTS

Symptoms, examination findings, paraclinical data, and clinical outcome were assessed. Severity was defined by the presence at referral of one of the following criteria: altered consciousness, seizures, focal neurological findings, and shock. After univariate analyses we performed stepwise logistic regression to determine predictors for BM available at referral (except for CSF Gram stain) and logistic regression using previously validated CSF cutoffs. Univariate methods identified the presence of one sign of severity as the most important predictor for BM (sensitivity 0.989, specificity 0.981, positive predictive value 0.989, negative predictive value 0.981, odds ratio 4,770) and showed that CSF results differ in BM and in VM (except for CSF glucose). Logistic regression analysis revealed severity and CSF absolute neutrophil count as the two predictors of BM (R2=0.876). Logistic analysis showed that BM was related to severity (beta=6.46+/-1.27) and a CSF absolute neutrophil count above 1,000/mm3 whereas CSF glucose below 2 mmol/l and CSF protein higher than 2 g/l were not predictive.

CONCLUSIONS

The presence of at least one sign of severity at referral and a CSF absolute neutrophil count above 1,000/mm3 mm are predictive of BM.

Physiological Levels of Pro- and Anti-Inflammatory Mediators in Cerebrospinal Fluid and Plasma: A Normative Study

Numerous recent studies have reported a significant inflammatory reaction in the brain and the systemic circulation following traumatic brain injury (TBI), infection, or neoplasm of the brain with a sequential release of pro- and anti-inflammatory mediators. Although there is growing knowledge and understanding of the mechanisms leading to the often poor outcome of these patients, only a limited database exists on the physiological expression of pro- and anti-inflammatory cytokines and molecules in plasma and particularly in cerebrospinal fluid (CSF). Therefore, we analyzed paired plasma/CSF samples of healthy human volunteers for the physiological concentrations of Interleukin (IL)-6, IL-8, IL-10, soluble TNF-receptors (sTNF-R) p55 and p75, soluble ICAM (sICAM), and soluble E-selectin (sE-selectin). A physiological release of IL-6, IL-8, IL-10, and sTNF-R p55 and p75 was detected in plasma and CSF. In contrast, sICAM and sE-selectin were only detectable in plasma. Pro- and anti-inflammatory mediators exhibited different concentration patterns in plasma and CSF, suggesting a pro-inflammatory predisposition in the central nervous system.