Lumbar and ventricular CSF protein, leukocytes, and lactate in suspected bacterial CNS infections

Comprehensive Therapeutic Approaches to Tuberculous Meningitis: Pharmacokinetics, Combined Dosing, and Advanced Intrathecal Therapies

Tuberculous meningitis (TBM) presents a critical neurologic emergency characterized by high mortality and morbidity rates, necessitating immediate therapeutic intervention, often ahead of definitive microbiological and molecular diagnoses. The primary hurdle in effective TBM treatment is the blood-brain barrier (BBB), which significantly restricts the delivery of anti-tuberculous medications to the central nervous system (CNS), leading to subtherapeutic drug levels and poor treatment outcomes. The standard regimen for initial TBM treatment frequently falls short, followed by adverse side effects, vasculitis, and hydrocephalus, driving the condition toward a refractory state. To overcome this obstacle, intrathecal (IT) sustained release of anti-TB medication emerges as a promising approach. This method enables a steady, uninterrupted, and prolonged release of medication directly into the cerebrospinal fluid (CSF), thus preventing systemic side effects by limiting drug exposure to the rest of the body. Our review diligently investigates the existing literature and treatment methodologies, aiming to highlight their shortcomings. As part of our enhanced strategy for sustained IT anti-TB delivery, we particularly seek to explore the utilization of nanoparticle-infused hydrogels containing isoniazid (INH) and rifampicin (RIF), alongside osmotic pump usage, as innovative treatments for TBM. This comprehensive review delineates an optimized framework for the management of TBM, including an integrated approach that combines pharmacokinetic insights, concomitant drug administration strategies, and the latest advancements in IT and intraventricular (IVT) therapy for CNS infections. By proposing a multifaceted treatment strategy, this analysis aims to enhance the clinical outcomes for TBM patients, highlighting the critical role of targeted drug delivery in overcoming the formidable challenges presented by the blood-brain barrier and the complex pathophysiology of TBM.

Cerebrospinal fluid analysis of metabolites is not correlated to microdialysis measurements in acute brain injured patients

BACKGROUND

Cerebral microdialysis (CMD) has become an established bedside monitoring modality but its implementation remains complex and costly and is therefore performed only in a few well-trained academic centers. This study investigated the relationship between cerebrospinal fluid (CSF) and CMD glucose and lactate concentrations.

METHODS

Two centers retrospective study of prospectively collected data. Consecutive adult (>18 years) acutely brain injured patients admitted to the Intensive Care Unit between 2010 and 2021 were eligible if CSF and CMD glucose and lactate concentrations were concomitantly measured at least once.

RESULTS

Of 113 patients being monitored with an external ventricular drainage and CMD, 49 patients (25 from Innsbruck and 24 from Brussels) were eligible for the final analysis, including a total of 96 measurements. Median CMD glucose and lactate concentrations were 1.15 (0.51-1.57) mmol/L and 3.44 (2.24-5.37) mmol/L, respectively; median CSF glucose and lactate concentrations were 4.67 (4.03-5.34) mmol/L and 3.40 (2.85-4.10) mmol/L, respectively. For the first measurements, no correlation between CSF and CMD glucose concentrations (R2 <0.01; p = 0.95) and CSF and CMD lactate concentrations (R2 =0.16; p = 0.09) was found. Considering all measurements, the repeated measure correlation analysis also showed no correlation for glucose (rrm = -0.01; 95% Confidence Intervals -0.306 to 0.281; p = 0.93) and lactate (rrm = -0.11; 95% Confidence Intervals -0.424 to 0.236; p = 0.55).

CONCLUSIONS

In this study including acute brain injured patients, no correlation between CSF and brain tissue measurements of glucose and lactate was observed. As such, CSF measurements of such metabolites cannot replace CMD findings.

Clinical Experience with Off-Label Intrathecal Administration of Selected Antibiotics in Adults: An Overview with Pharmacometric Considerations

Drain-associated intracerebral infections are life-threatening emergencies. Their treatment is challenging due to the limited penetration of antibiotics to the site of infection, resulting in potentially inadequate exposure. The emergence of multidrug-resistant pathogens might force the use of off-label intrathecal (IT) doses of antibiotics. We reviewed the literature on general aspects determining intrathecal dosing regimen, using pharmacometric knowledge. We summarised clinical experience with IT doses of antibiotics that are usually not used intrathecally, as well as the outcome of the cases and concentrations reached in the cerebrospinal fluid (CSF). Factors determining the IT regimen are the size of the ventricle system and the CSF drainage volume. With regard to pharmacometrics, pharmacokinetic/pharmacodynamic indices are likely similar to those in non-cerebral infections. The following number (N) of cases were described: benzylpenicillin (>50), ampicillin (1), ceftazidime (2), cephaloridine (56), ceftriaxone (1), cefotiam (1), meropenem (57), linezolid (1), tigecycline (15), rifampicin (3), levofloxacin (2), chloramphenicol (3) and daptomycin (8). Many side effects were reported for benzylpenicillin in the 1940-50s, but for the other antibiotics, when administered correctly, all side effects were minor and reversible. These data might help when choosing an IT dosing regimen in case there is no alternative option due to antimicrobial resistance.

Spatial and temporal variation of routine parameters: pitfalls in the cerebrospinal fluid analysis in central nervous system infections

The cerebrospinal fluid (CSF) space is convoluted. CSF flow oscillates with a net flow from the ventricles towards the cerebral and spinal subarachnoid space. This flow is influenced by heartbeats, breath, head or body movements as well as the activity of the ciliated epithelium of the plexus and ventricular ependyma. The shape of the CSF space and the CSF flow preclude rapid equilibration of cells, proteins and smaller compounds between the different parts of the compartment. In this review including reinterpretation of previously published data we illustrate, how anatomical and (patho)physiological conditions can influence routine CSF analysis. Equilibration of the components of the CSF depends on the size of the molecule or particle, e.g., lactate is distributed in the CSF more homogeneously than proteins or cells. The concentrations of blood-derived compounds usually increase from the ventricles to the lumbar CSF space, whereas the concentrations of brain-derived compounds usually decrease. Under special conditions, in particular when distribution is impaired, the rostro-caudal gradient of blood-derived compounds can be reversed. In the last century, several researchers attempted to define typical CSF findings for the diagnosis of several inflammatory diseases based on routine parameters. Because of the high spatial and temporal variations, findings considered typical of certain CNS diseases often are absent in parts of or even in the entire CSF compartment. In CNS infections, identification of the pathogen by culture, antigen detection or molecular methods is essential for diagnosis.

The Influence of the Ventricular-Lumbar Gradient on Cerebrospinal Fluid Analysis in Serial Samples

Background: Cerebrospinal fluid (CSF) samples from patients with non-inflammatory neurological diseases are used for control groups in biomarker studies. Since large amounts of CSF are withdrawn, patients with idiopathic intracranial hypertension (IIH) or normal pressure hydrocephalus (NPH) are especially suitable. The serially taken CSF portions are usually collected in different tubes. We aimed to investigate whether the later random choice of one of these tubes for CSF investigations might harbor the risk of different CSF protein findings due to the so-called ventriculo-lumbar CSF gradient. Methods: Patients with IIH (9) and NPH (7) were included. CSF was serially taken and collected in six tubes of 5 mL each. Concentrations and CSF-serum quotients of immunoglobulins, albumin and the virus-specific antibody index (AI) were determined in the first, fourth and sixth CSF fraction. Results: CSF immunoglobulin and albumin concentrations and CSF-serum protein quotients were significantly lower in the fourth and sixth CSF fraction compared with the first CSF fraction. Virus-specific AI did not significantly differ in the different CSF fractions. Conclusions: CSF protein analytics should be performed in the first CSF fraction in order to avoid different measurement results and achieve comparability within a control group and between different control and patient groups.

Extracellular vesicles: the key for precision medicine in glioblastoma

Glioblastoma (GBM) represents the most aggressive and lethal disease of the central nervous system. Diagnosis is delayed following the occurrence of symptoms, and treatment is based on standardized approaches that are unable to cope with its heterogeneity, mutability, and invasiveness. The follow-up of patients relies on burdensome schedules for magnetic resonance imaging (MRI). However, to personalize treatment, biomarkers and liquid biopsy still represent unmet clinical needs. Extracellular vesicles (EVs) may be the key to revolutionize the entire process of care for patients with GBM. EVs can be collected noninvasively (eg, blood) and impressively possess multilayered information, which is constituted by their concentration and molecular cargo. EV-based liquid biopsy may facilitate GBM diagnosis and enable the implementation of personalized treatment, resulting in customized care for each patient and for each analyzed time point of the disease, thereby tackling the distinctive heterogeneity and mutability of GBM that confounds effective treatment. Herein, we discuss the limitations of current GBM treatment options and the rationale behind the need for personalized care. We also review the evidence supporting GBM-associated EVs as a promising tool capable of fulfilling the still unmet clinical need for effective and timely personalized care of patients with GBM.

Cerebrospinal fluid cell count variability is a major confounding factor in external ventricular drain-associated infection surveillance diagnostics: a prospective observational study

Background

External ventricular drain (EVD)-related infections (EVDIs) are feared complications that are difficult to rapidly and correctly diagnose, which can lead to unnecessary treatment with broad-spectrum antibiotics. No readily available diagnostic parameters have been identified to reliably predict or identify EVDIs. Moreover, intraventricular hemorrhage is common and affect cerebrospinal fluid (CSF) cellularity. The relationship between leukocytes and erythrocytes is often used to identify suspected infection and triggers the use of antibiotics pending results of cultures, which may take days. Cell count based surveillance diagnostics assumes a homogeneous distribution of cells in the CSF. Given the intraventricular sedimentation of erythrocytes on computed tomography scans this assumption may be erroneous and could affect diagnostics.

Aims

To evaluate the consistency of cell counts in serially sampled CSF from EVDs, with and without patient repositioning, to assess the effect on infection diagnostics.

Methods

We performed a prospective single-center study where routine CSF sampling was followed by a second sample after 10 min, allocated around a standard patient repositioning, or not. Changes in absolute and pairwise cell counts and ratios were analyzed, including mixed regression models.

Results

Data from 51 patients and 162 paired samples were analyzed. We observed substantial changes in CSF cellularity as the result of both resampling and repositioning, with repositioning found to be an independent predictor of bidirectional cellular change. Glucose and lactate levels were affected, however clinically non-significant. No positive CSF cultures were seen during the study. Thirty percent (30%) of patients changed suspected EVDI status, as defined by the cell component of local and national guidelines, when resampling after repositioning.

Conclusions

CSF cell counts are not consistent and are affected by patient movement suggesting a heterogeneity in the intraventricular space. The relationship between leukocytes and erythrocytes was less affected than absolute changes. Importantly, cell changes are found to increase with increased cellularity, often leading to changes in suspected EVDI status. Faster and more precise diagnostics are needed, and methods such as emerging next generation sequencing techniques my provide tools to more timely and accurately guide antibiotic treatment.

Trial Registration NCT04736407, Clinicaltrials.gov, retrospectively registered 2nd February 2021.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03715-1.

Association of cerebrospinal fluid protein biomarkers with outcomes in patients with traumatic and non-traumatic acute brain injury: systematic review of the literature

BACKGROUND

Acute brain injuries are associated with high mortality rates and poor long-term functional outcomes. Measurement of cerebrospinal fluid (CSF) biomarkers in patients with acute brain injuries may help elucidate some of the pathophysiological pathways involved in the prognosis of these patients.

METHODS

We performed a systematic search and descriptive review using the MEDLINE database and the PubMed interface from inception up to June 29, 2021, to retrieve observational studies in which the relationship between CSF concentrations of protein biomarkers and neurological outcomes was reported in patients with acute brain injury [traumatic brain injury, subarachnoid hemorrhage, acute ischemic stroke, status epilepticus or post-cardiac arrest]. We classified the studies according to whether or not biomarker concentrations were associated with neurological outcomes. The methodological quality of the studies was evaluated using the Newcastle-Ottawa quality assessment scale.

RESULTS

Of the 39 studies that met our criteria, 30 reported that the biomarker concentration was associated with neurological outcome and 9 reported no association. In TBI, increased extracellular concentrations of biomarkers related to neuronal cytoskeletal disruption, apoptosis and inflammation were associated with the severity of acute brain injury, early mortality and worse long-term functional outcome. Reduced concentrations of protein biomarkers related to impaired redox function were associated with increased risk of neurological deficit. In non-traumatic acute brain injury, concentrations of CSF protein biomarkers related to dysregulated inflammation and apoptosis were associated with a greater risk of vasospasm and a larger volume of brain ischemia. There was a high risk of bias across the studies.

CONCLUSION

In patients with acute brain injury, altered CSF concentrations of protein biomarkers related to cytoskeletal damage, inflammation, apoptosis and oxidative stress may be predictive of worse neurological outcomes.

Central nervous system infections and antimicrobial resistance: an evolving challenge

PURPOSE OF REVIEW

Antimicrobial resistance is an increasing threat to patients also in nosocomial central nervous system (CNS) infections. The present review focusses on optimizing intravenous treatment in order to achieve sufficient concentrations of antibiotics in the different compartments of the CNS when the causative pathogens have reduced sensitivity to antibiotics or/and the impairment of the blood-cerebrospinal fluid (CSF) and blood-brain barrier is mild.

RECENT FINDINGS

Experience has been gathered with treatment protocols for several established antibiotics using increased doses or continuous instead of intermittent intravenous therapy. Continuous infusion in general does not increase the average CSF concentrations (or the area under the concentration-time curve in CSF) compared to equal daily doses administered by short-term infusion. In some cases, it is postulated that it can reduce toxicity caused by high peak plasma concentrations. In case reports, new β-lactam/β-lactamase inhibitor combinations were shown to be effective treatments of CNS infections.

SUMMARY

Several antibiotics with a low to moderate toxicity (in particular, β-lactam antibiotics, fosfomycin, trimethoprim-sulfamethoxazole, rifampicin, vancomycin) can be administered at increased doses compared to traditional dosing with low or tolerable adverse effects. Intrathecal administration of antibiotics is only indicated, when multiresistant pathogens cannot be eliminated by systemic therapy. Intravenous should always accompany intrathecal treatment.

Population pharmacokinetics of vancomycin in patients with external ventricular drain-associated ventriculitis

BACKGROUND

To determine the distribution of vancomycin into the cerebrospinal fluid (CSF) in patients with external ventricular drain (EVD)-associated ventriculitis, the pharmacokinetics of vancomycin were evaluated and covariate relationships explored.

METHODS

For the population pharmacokinetic model patients were recruited in a neurocritical care unit at the University Hospital of Muenster in the period between January 2014 and June 2015. All patients had a clinical evidence of EVD-associated ventriculitis. Population pharmacokinetic analysis of vancomycin was performed using NONMEM.

RESULTS

A total of 184 blood and 133 CSF samples were collected from 29 patients. The final population pharmacokinetic model is a three-compartment model with linear elimination. Creatinine clearance (Cl_Cr ) and CSF-lactate were detected as significant covariates, showing that the total vancomycin plasma clearance (Cl) depends on Cl_Cr and furthermore the clearance (Cl_dif ) between the central and CSF compartment correlates with CSF lactate concentration. Based on the final model, the following values were estimated by NONMEM: Cl = 5.15 L/h, Q (intercompartmental clearance) = 3.31 L/h, Cl_dif  = 0.0031 L/h, V_central  = 42.1 L, V_CSF  = 0.32 L and the value of V_peripheral was fixed to 86.2 L. With the developed pharmacokinetic model, area under the curve (AUC) values as well as CSF trough levels were simulated.

CONCLUSION

Based on our analysis, the dosing of vancomycin should be referred to the degree of inflammation (derived from the CSF lactate concentration) and renal function (derived from Cl_Cr ).

Powassan Virus Neuropathology and Genomic Diversity in Patients With Fatal Encephalitis

Background

Powassan virus (POWV) is an emerging cause of severe encephalitis; very little is known about human pathogenicity due to challenges in diagnosis and viral RNA recovery. We present 3 patients with fatal encephalitis due to POWV lineage II (deer tick virus).

Methods

We obtained 27 unique samples, including from brain biopsy and autopsy, and used metagenomic sequencing, quantitative reverse transcriptase polymerase chain reaction, and a newly developed CRISPR-based diagnostic assay to perform the first detailed characterization of POWV compartmentalization and genomics between and within human subjects.

Results

In all 3 patients, imaging and histopathology findings were notable for profound cerebellar involvement. All patients were initially diagnosed with POWV by metagenomic sequencing, and 2 of the 3 had negative clinical testing by serology. We detected POWV RNA in 13 clinical samples; levels were highest in the cerebellum, and there was very little involvement of peripheral tissue. We assembled complete POWV genomes from 8 samples, providing unique information about the strains of POWV lineage II (deer tick virus) that infect humans.

Conclusions

We demonstrate the utility of molecular assays for detecting POWV infection, including in seronegative patients, and nominate viral genomic features that may relate to human infection and neuropathogenicity. The cerebellum was identified as a key target POWV in fatal infection, by radiological and histopathological findings as well as molecular testing.

Discrepancy between ventricular and lumbar CSF in chronic meningitis

Meningitis patient can present with various manifestation including hydrocephalus due to multiple reason. Diagnosis of meningitis mainly rely on CSF analysis which is usually obtained from lumbar puncture. In case of hydrocephalus CSF can be obtain from ventricles during VP shunt operation. Sometimes ventricular CSF can be normal in meningitis patient while lumbar CSF shows abnormality. Possible mechanisms behind this phenomenon are discussed here. Patients who present with hydrocephalus and have normal Ventricular CSF should investigated with lumbar CSF analysis in a view of delay in diagnosis and treatment.

Intrathecal Antibacterial and Antifungal Therapies

Intrathecal administration of anti-infectives is indicated in central nervous system infections by multiresistant pathogens when drugs that can reach adequate cerebrospinal fluid (CSF) concentrations by systemic therapy are not available. Antibiotics that readily pass the blood-brain and blood-CSF barriers and/or that have low toxicity allowing an increase in the daily dosage should not be used for intrathecal therapy. Intrathecal therapy is accompanied by systemic treatment. Antibacterials indispensable for intrathecal therapy include aminoglycosides, colistin, daptomycin, tigecycline, and vancomycin. Limited experience suggests the utility of the antifungals amphotericin B and caspofungin. Intraventricular administration ensures distribution throughout the CSF compartment, whereas intralumbar dosing often fails to attain adequate antibiotic concentrations in the ventricles. The individual dose is determined by the estimated size of the CSF space and by the estimated clearance from CSF. For moderately lipophilic anti-infectives with a molecular weight above approximately 1,000 g/mol, as well as for hydrophilic drugs with a molecular weight above approximately 400 g/mol, one daily dose is normally adequate. The ventricular drain should be clamped for 15 to 120 min to facilitate the distribution of the anti-infective in the CSF space. Therapeutic drug monitoring of the trough levels is necessary only in cases of therapeutic failure.

Cerebrospinal Fluid Collected by Lumbar Puncture Has a Higher Diagnostic Accuracy than Collected by Ventriculostomy

BACKGROUND

Patients harboring an external ventricular drain (EVD) who develop signs of infection require screening for infection in the central nervous system (CNS). The cerebrospinal fluid (CSF) can be collected by the EVD or by lumbar puncture (LP). If only one sample is analyzed, the diagnosis might be dubious or false-negative. The objective of this study was to compare the diagnosis accuracy of CNS infection of CSF samples collected from EVD and LP.

METHODS

We conducted a transversal study where data were prospectively collected from 2016 to 2019. Patients harboring EVD with signs of infection were submitted to the CSF analysis collected by LP and EVD. Diagnosis sensibility and results correlation were analyzed using the kappa index.

RESULTS

The 141 samples from LP and 141 samples from EVD were collected from 108 patients. Among the 282 samples, a total of 77 had infection. Seventy CSF samples from LP fulfilled infection criteria. However, only 32 EVD samples demonstrated infection. Among the 70 cases of infection based on the LP sample, 25 CSF samples collected from the EVD were also suggestive of infection; but in 45 patients only the CSF samples from LP met infection criteria. Seven patients had diagnosis of infection only in the EVD sample. The kappa correlation index of the results obtained from LP and EVD was 0.260 and the McNemar χ² test was <0.01.

CONCLUSIONS

The CSF analysis exclusive from the EVD has a low sensibility and negative predictive value. CSF collected from LP has a sensibility 2.18 times higher than EVD.

Outcomes of Pediatric Central Nervous System Tuberculosis in California, 1993-2011

BACKGROUND

Our goal was to describe the characteristics and posttreatment outcomes of pediatric patients with central nervous system (CNS) tuberculosis (TB) and to identify factors associated with poor outcome.

METHODS

We included children aged 0 to 18 years with CNS TB reported to the California TB registry between 1993 and 2011. Demographics, clinical characteristics, severity of disease at presentation (Modified Medical Research Council stage I, II, or III [III is most severe]), treatment, and outcomes during the year after treatment completion were abstracted systematically from the medical and public health records. Patient outcomes were categorized as good or poor on the basis of disability in hearing, vision, language, ambulation, and development and other neurologic deficits.

RESULTS

Among 151 pediatric CNS TB cases reported between 1993 and 2011 in California for which records were available, 92 (61%) cases included sufficient information to determine outcome. Overall, 55 (60%) children had a poor outcome. After we adjusted for age (0 to 4 years), children with stage III severity (vs I or II; prevalence rate ratio [PRR], 1.4 [95% confidence interval (CI), 1.1-1.9]), a protein concentration of >100 mg/dL on initial lumbar puncture (PRR, 1.2 [95% CI, 1.03-1.4]), or infarct on neuroimaging (PRR, 1.2 [95% CI, 1.04-1.3]) were at increased risk for a poor outcome. In multivariate analysis, an age of 0 to 4 years (vs >4 years; PRR, 1.4 [95% CI, 1.2-1.7]) and a stage II or III Modified Medical Research Council score (vs stage I; PRR, 1.2 [95% CI, 1.03-1.5]) remained significantly associated with poor outcome.

CONCLUSIONS

Pediatric patients with CNS TB in California are left with high rates of disabling clinical sequelae after treatment. The identification of modifiable factors is critical for improving outcomes.

When Ventricular Cerebrospinal Fluid Assessment Misleads: Basal Meningitis and the Importance of Lumbar Puncture Sampling

The diagnosis of central nervous system (CNS) infection relies upon analysis of cerebrospinal fluid (CSF). We present 4 cases of CNS infections associated with basal meningitis and hydrocephalus with normal ventricular CSF but grossly abnormal lumbar CSF. We discuss CSF ventricular-lumbar composition gradients and putative pathophysiological mechanisms and highlight clinical clues for clinicians.

Cell-free mitochondrial DNA in progressive multiple sclerosis

Recent studies have linked cell-free mitochondrial DNA (ccf-mtDNA) to neurodegeneration in both Alzheimer's and Parkinson's disease, raising the possibility that the same phenomenon could be seen in other diseases which manifest a neurodegenerative component. Here, we assessed the role of circulating cell-free mitochondrial DNA (ccf-mtDNA) in end-stage progressive multiple sclerosis (PMS), where neurodegeneration is evident, contrasting both ventricular cerebral spinal fluid ccf-mtDNA abundance and integrity between PMS cases and controls, and correlating ccf-mtDNA levels to known protein markers of neurodegeneration and PMS. Our data indicate that reduced ccf-mtDNA is a component of PMS, concluding that it may indeed be a hallmark of broader neurodegeneration.

Cisterno-lumbar gradient of complement fractions in geriatric patients with suspected normal pressure hydrocephalus

BACKGROUND

The complement system is a functional link between the innate and adaptive immune system and present in all compartments of the body. The composition of the cerebrospinal fluid (CSF) differs between the ventricular, cisternal and lumbar space. Usually, concentrations of blood-derived CSF proteins increase from ventricular to lumbar fractions.

METHODS

In 20 geriatric patients with suspected normal pressure hydrocephalus (NPH) [13 women, 7 men, age 80.5 (75/85) years; median (25th/75th percentile)] a lumbar spinal tap of 40 ml was performed, and 10 ml of serum was drawn. CSF, sequentially collected in 8 fractions of 5 ml (1st fraction: lumbar CSF; 8th fraction: cisterna magna-near CSF), was analyzed for complement protein C3, and the activation products C3a and sC5b-9 by enzyme immunoassay.

RESULTS

The concentrations of the complement factors measured in fractions 1 and 8 of each individual patient were strongly correlated: C3 (Spearman's rank correlation coefficient r_S = 0.75, p = 0.0002); C3a (r_S = 0.93, p < 0.0001); sC5b-9 (r_S = 0.64, p = 0.002). CSF complement concentrations were lower in the cistern-near fraction 8 than in the lumbar fraction 1 (C3: p = 0.005; C3a: p = 0.0009; sC5b-9: p = 0.0003, Wilcoxon signed rank test). The concentrations of complement factors in CSF were two orders of magnitude lower than those in serum. C3 levels in the lumbar CSF strongly correlated with the lumbar CSF/serum albumin concentration quotient (Q_Alb) as a measure of the functionability of the blood-CSF barrier and the velocity of CSF flow (r_S = 0.84, p < 0.0001) suggesting diffusion of C3 from blood to CSF. The lumbar and cistern-near concentrations of C3a did not significantly correlate with Q_Alb (r_S = 0.26) pointing to a local conversion of C3 to C3a. The lumbar concentrations of sC5b-9 moderately correlated with Q_Alb (r_S = 0.62, p = 0.004). Plotting the CSF/serum quotient of C3 and sC5b-9 versus the Q_Alb revealed an approx. 50% local synthesis of C3, but a strong production of sC5b-9 in the CNS.

CONCLUSIONS

The increase of the complement concentrations from cisternal to lumbar CSF and the strong correlation of C3 with Q_Alb suggest that (1) a substantial portion of complement C3 in CSF originates from blood and (2) the complement system is mildly activated in the CSF of NPH patients.

The cerebrospinal fluid and barriers - anatomic and physiologic considerations

The cerebrospinal fluid (CSF) space consists of the intracerebral ventricles, subarachnoid spaces of the spine and brain (e.g., cisterns and sulci), and the central spinal cord canal. The CSF protects the central nervous system (CNS) in different ways involving metabolic homeostasis, supply of nutrients, functioning as lymphatic system, and regulation of intracranial pressure. CSF is produced by the choroid plexus, brain interstitium, and meninges, and it circulates in a craniocaudal direction from ventricles to spinal subarachnoid space from where it is removed via craniocaudal lymphatic routes and the venous system. The CSF is renewed 3-5 times daily and its molecular constituents are mainly blood-derived (80%), while the remainder consists of brain-derived and intrathecally produced molecules (20%). The CSF space is separated from the vascular system by the blood-CSF barrier (BCB), whereas the blood-brain barrier (BBB), responsible for maintaining the homeostasis of the brain, is located between brain parenchyma and vascular system. Although both barriers have similar functions, they differ with regard to their morphologic and functional properties. Both barrier systems are permeable not only for small molecules, but also for macromolecules and circulating cells. The transport of molecules across the BBB and BCB is regulated by passive diffusion (e.g., albumin, immunoglobulins) and facilitated or active transport (e.g., glucose). The extracellular space volume, potassium buffering, CSF circulation, and interstitial fluid absorption are mainly regulated by aquaporin-4 channels, which are abundantly located at the blood-brain and brain-CSF interfaces. The composition of CSF shows a high dynamic range, and the levels of distinct proteins vary due to several influencing factors, such as site of production (brain or blood-derived), site of sampling (ventricular or lumbar), CSF flow rate (BCB function), diurnal fluctuations of CSF production rate, and finally, molecular size of blood-derived proteins (IgM vs. albumin) and circadian rhythm (glucose, prostaglandin D synthase). Alterations of lumbar CSF are mainly influenced by processes of the CNS located adjacent to the ventricular and spinal CSF space and less by pathologies in cortical areas remote from the ventricles.

Clusterin, a New Cerebrospinal Fluid Biomarker in Severe Subarachnoid Hemorrhage: A Pilot Study

BACKGROUND

Inflammation following subarachnoid hemorrhage (SAH) involves numerous mediators with biomarker properties. Preliminary studies indicated that clusterin, a multifunctional chaperon protein, was a potential biomarker in SAH. We aimed to clarify the status of clusterin in SAH.

METHODS

From 27 patients with severe SAH, 47 cerebrospinal fluid (CSF) samples were collected 0-3, 5-7, and 10-14 days after SAH. Control CSF was collected from 25 age- and sex-matched healthy control subjects undergoing spinal anesthesia for minor surgery. Clusterin concentrations were assayed using enzyme-linked immunosorbent assay and compared with inflammatory markers, imaging findings, and treatment outcome.

RESULTS

In healthy control subjects, mean CSF clusterin level (1908.5 ng/mL ± 36.0) was significantly higher than in the patient group (P < 0.001). In the patient group, mean clusterin level was 741.1 ng/mL ± 759.2 0-3 days, 601.6 ng/mL ± 507.2 5-7 days, and 639.2 ng/mL ± 446.8 10-14 days after SAH. Clusterin level failed to differentiate between good (Glasgow Outcome Scale 4-5) and poor (Glasgow Outcome Scale 1-3) outcomes 0-3 days and 10-14 days after SAH (P = 0.238 and P = 0.225), but significantly higher levels of CSF clusterin were found 5-7 days after SAH in patients with good outcome (P = 0.017). There was a significant correlation between CSF clusterin level 5-7 days after SAH and Glasgow Outcome Scale at 3 months (correlation coefficient = 0.633). The best correlation was found for World Federation of Neurological Societies scale (correlation coefficient = -0.741).

CONCLUSIONS

SAH is associated with immediate decrease in CSF clusterin concentrations. Clusterin level at one point was a good predictor of outcome, and it may serve as a biomarker.

Small cisterno-lumbar gradient of phosphorylated Tau protein in geriatric patients with suspected normal pressure hydrocephalus

Background

The composition of the cerebrospinal fluid (CSF) is not homogeneous, and concentrations of proteins from different origins diverge among ventricular, cisternal and lumbar CSF fractions. Concentrations of blood-derived proteins increase and of brain-derived proteins decrease from ventricular to lumbar fractions. We studied whether the origin of the CSF portion analysed may affect results in CSF analysis for dementia.

Methods

In 16 geriatric patients with suspected normal pressure hydrocephalus [age 82.5 (76/87) years; median (25th/75th percentile)] a lumbar spinal tap of 40 ml was performed. The CSF was sequentially collected in 8 fractions of 5 ml with the 1st fraction corresponding to lumbar CSF, the 8th to cisterna magna-near CSF. Fractions were analysed for total protein, albumin, Tau protein (Tau), phosphorylated Tau (pTau), Amyloid beta 1–42 (Aβ1–42), Amyloid beta 1–40 (Aβ1–40), and the Aβ1–42/Aβ1–40 ratio.

Results

The concentrations of total protein and albumin increased from cisternal to lumbar fractions due to diffusion-related accumulation from blood to CSF with significantly higher concentrations in fraction 1 compared to fraction 8. The concentrations of Tau showed a non-significant trend towards decreased values in lumbar samples, and pTau was slightly, but significantly decreased in the lumbar fraction 1 [26.5 (22.5/35.0) pg/ml] compared to the cistern-near fraction 8 [27.0 (24.2/36.3) pg/ml] (p = 0.02, Wilcoxon signed rank test). Aβ1-42, Aβ1-40, and the Aβ1-42/Aβ1-40 ratio remained almost constant.

Conclusions

According to the flow-related diverging dynamics of blood-derived and brain-derived proteins in CSF, the concentrations of Tau and pTau tended to be lower in lumbar compared to cisternal CSF fractions after a spinal tap of 40 ml. The differences reached statistical significance for pTau only. The small differences will not affect clinical interpretation of markers of dementia in the vast majority of cases.

Electronic supplementary material

The online version of this article (doi:10.1186/s12987-016-0039-9) contains supplementary material, which is available to authorized users.

Fingerprint changes in CSF composition associated with different aetiologies in human neonatal hydrocephalus: inflammatory cytokines

PURPOSE

Hydrocephalus (HC) has a multifactorial and complex picture of pathophysiology due to aetiology, age at and duration since onset. We have previously identified distinctions in markers of cell death associated with different aetiologies. Here, we examined cerebrospinal fluid (CSF) from human HC neonates for cytokines to identify further distinguishing features of different aetiologies.

METHODS

CSF was collected during routine lumbar puncture or ventricular tap from neonates with hydrocephalus, or with no neurological condition (normal controls). Total protein, Fas receptor, Fas ligand, stem cell factor (SCF), hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), insulin growth factor-1 (IGF-1), tumour necrosis factor alpha (TNF-α) and interleukin 6 (IL-6) were measured and compared between 8 unaffected and 28 HC neonatal CSF samples.

RESULTS

Total protein was significantly (P < 0.05) raised in late-onset hydrocephalus (LOH). Fas receptor was raised (P < 0.05) in post-haemorrhagic hydrocephalus (PHH) and spina bifida with hydrocephalus (SB/HC), but no difference in Fas ligand was found. SCF was raised (P < 0.05) in SB/HC. HGF was found in all HC and was increased (P < 0.01) in PHH. Increased VEGF was found in PHH (P < 0.01) and SB/HC (P < 0.05). Variable levels of IL-6, TNF-α and IGF-1 were found in all HC groups compared with none in normal.

CONCLUSIONS

LOH was unusual with significantly raised total protein indicating an inflammatory state. Increased Fas receptor, VEGF, IGF-1 and HGF suggest anti-apoptotic and repair mechanism activation. By contrast, elevated TNF-α and IL-6 indicate inflammatory processes in these neonatal brains. Taken with our previous study, these data indicate that different pathophysiology, inflammation and repair are occurring in HC of different aetiologies and that additional treatment strategies may benefit these infants in addition to fluid diversion.

Metabolomics of human cerebrospinal fluid identifies signatures of malignant glioma

Cerebrospinal fluid is routinely collected for the diagnosis and monitoring of patients with neurological malignancies. However, little is known as to how its constituents may change in a patient when presented with a malignant glioma. Here, we used a targeted mass-spectrometry based metabolomics platform using selected reaction monitoring with positive/negative switching and profiled the relative levels of over 124 polar metabolites present in patient cerebrospinal fluid. We analyzed the metabolic profiles from 10 patients presenting malignant gliomas and seven control patients that did not present malignancy to test whether a small sample size could provide statistically significant signatures. We carried out multiple unbiased forms of classification using a series of unsupervised techniques and identified metabolic signatures that distinguish malignant glioma patients from the control patients. One subtype identified contained metabolites enriched in citric acid cycle components. Newly diagnosed patients segregated into a different subtype and exhibited low levels of metabolites involved in tryptophan metabolism, which may indicate the absence of an inflammatory signature. Together our results provide the first global assessment of the polar metabolic composition in cerebrospinal fluid that accompanies malignancy, and demonstrate that data obtained from high throughput mass spectrometry technology may have suitable predictive capabilities for the identification of biomarkers and classification of neurological diseases.

Normal ventricular-CSF may comfound the diagnosis of tuberculous meningitis hydrocephalus

BACKGROUND

The standard procedure for the diagnosis of central nervous system (CNS) infections consists of cerebrospinal fluid (CSF) sampling, which is usually accomplished by a lumbar puncture. However, in some patients presenting with acute hydrocephalus submitted to immediate CSF drainage, the fluid is customarily obtained from the placed draining system. In addition, the CSF obtained from the ventricular and lumbar spaces in some cases may show unusual differences, both in physiological and pathological conditions.

ILLUSTRATIVE CASES

We report two children who presented with confounding results in the initial studies of their ventricular and lumbar CSF who were subsequently diagnosed with tuberculous meningitis, causing delay in diagnosis and treatment. AIM. By reporting these cases, we wanted to alert the treating physician about the possibility of this discrepancy to avoid the delayed diagnosis and management of the affected patients.

DISCUSSION

We comment on the possible pathophysiological mechanisms that may result in this dissociation in ventricular and lumbar CSF composition. CONCLUSIONS; Normal results in CSF studies, especially those of the ventricular fluid, do not always rule out the presence of tuberculous meningitis. We suggest obtaining a CSF sample from the lumbar subarachnoid space in doubtful, or suspicious, cases of CNS infection even in the presence of a normal ventricular CSF.

Lumbar puncture and brain herniation in acute bacterial meningitis: a review

There has been controversy regarding the risk of cerebral herniation caused by a lumbar puncture (LP) in acute bacterial meningitis (ABM). This review discusses in detail the issues involved in this controversy. Cerebral herniation occurs in about 5% of patients with ABM, accounting for about 30% of the mortality. In many reports, LP is temporally strongly associated with this event of herniation and is most likely causative based on pathophysiologic arguments. Although a computed tomography (CT) scan of the head is useful to find contraindications to an LP, a normal CT scan in ABM does not mean that an LP is safe. Clinical signs of "impending" herniation are the best predictors of when to delay an LP because of the risk of precipitating herniation, even with a normal CT scan. Some of these clinical signs to be considered are deteriorating level of consciousness (particularly to a Glasgow Coma Scale of <or= 11), brainstem signs (including pupillary changes, posturing, or irregular respirations), and a very recent seizure. The risk of not doing an LP when it is contraindicated because of concern of the risk of herniation is extremely small. In those considered high risk for herniation, interventions to control intracranial pressure, such as attention to airway, breathing, and circulation, with a mannitol infusion and antibiotics started, should be the priorities, followed by an urgent CT scan and not an LP.

[Location of the lesion and the cerebrospinal fluid findings in tuberculous meningitis: differences in the lumbar, cisternal and ventricular compartments]

Tuberculosis remains one of the most prevalent infectious diseases worldwide. In the present study, we describe a case of tuberculous meningitis that caused cerebrospinal fluid (CSF) flow block, leading to difficulties in the diagnosis. The importance of the lesion site and its influence on CSF analysis as a support for the diagnosis of tuberculous meningitis is discussed. In this case, the search for acid-fast bacilii was positive in the cisternal CSF, but not in the ventricular and lumbar CSF, demonstrating the relationship between the accuracy of the test and the location of the inflamatory lesion disease.

Comparison of ventricular and lumbar cerebrospinal fluid T cells in non-inflammatory neurological disorder (NIND) patients

The aim of the present study was to define the cellular composition of ventricular, as compared with lumbar, cerebrospinal fluid (CSF) in patients with non-inflammatory neurological disorders (NIND). We addressed this issue by determining the cellular composition of lumbar CSF from patients with normal pressure hydrocephalus (NPH) who were undergoing lumbar CSF drainage during evaluation for shunting procedures, and evaluating ventricular CSF from a subset of these who underwent subsequent placement of ventriculoperitoneal shunts. We determined the cellular composition of lumbar CSF from 18 patients with NPH, and found that the leukocyte differentials, and relative proportions of CD4+ and CD8+ central memory (TCM), effector memory (TEM) and naive cell (TNaive) populations, were equivalent to those found previously in studies of CSF from patients with NIND. We further evaluated cells in the ventricular CSF of five patients who had previously undergone lumbar drainage. Leukocyte differential counts, as well as CD4+ and CD8+ TCM, TEM, and TNaive proportions, were equivalent in matched ventricular and lumbar CSF samples. These observations support the hypothesis that leukocytes enter the CSF in a selective fashion, at its site of formation in the choroid plexus. The results implicate CSF T cells in the immune surveillance of the central nervous system.

Case report: greater meningeal inflammation in lumbar than in ventricular region in human bacterial meningitis

Differences in the composition of ventricular and lumbar cerebrospinal fluid (CSF) based on single pairs of samples have previously been described. We describe a patient that developed post-surgical recurrent meningitis monitored by daily biochemical and bacteriological CSF analysis, simultaneously withdrawn from lumbar space and ventricles. A 20-year-old Caucasian man was admitted to the ICU after a resection of a chordoma that extended from the sphenoidal sinus to the anterior face of C2. CSF was continuously leaking into the pharyngeal cavity after surgery, and three episodes of recurrent meningitis, all due to Pseudomonas aeruginosa O12, occurred. Our case showed permanent ventricular-to-lumbar CSF gradients of leukocytes, protein and glucose that were increased during the acute phase of meningitis, with the greatest amplitude being observed when bacteria were present in both ventricular and lumbar CSF. This might suggest a greater extent of meningeal inflammation in the lumbar than in the ventricular region. Our case also showed that the increase in intravenous antibiotics (cefepim from 8 to 12 g/day and ciprofloxacine from 1.2 to 2.4 g/day) led to an increase in concentration in plasma but not in CSF.

Proteome Study of Human Cerebrospinal Fluid following Traumatic Brain Injury Indicates Fibrin(ogen) Degradation Products as Trauma-Associated Markers

Traumatic brain injury (TBI), like other central nervous system pathologies, causes changes in the composition of cerebrospinal fluid (CSF). Consequently analysis of the CSF components is important to better understand the pathological processes involved in such diseases. The aim of this work was to identify specific markers of severe TBI. Proteomic analysis including two-dimensional gel electrophoresis combined with mass spectrometry analysis was used to compare the CSF protein profile of severe TBI patients and controls. Proteins (alpha 1 antitrypsin, haptoglobin 1 alpha1, alpha2, and beta) belonging to the acute phase response showed an increased expression in severe TBI patients. Two other proteins, identified as proteolytic degradation products of the carboxyl-terminal portion of the fibrinogen beta, were present only in TBI patients. The presence of these markers could correlate with a post-traumatic local increase in fibrinolysis as well as to an inflammatory event following CNS tissue injury.

D- and L-lactate in rabbit and human bacterial meningitis

Increased total CSF lactate is an important indicator differentiating bacterial from aseptic meningitis. Bacteria can produce D- and L-lactate; mammalian cells produce only L-lactate. We measured D- and L-lactate production of Streptococcus pneumoniae, Staphylococcus aureus, Neisseria meningitidis and Escherichia coli in vitro, of S. pneumoniae and E. coli in rabbit experimental meningitis and of various common pathogens in CSF from patients with bacterial meningitis. Despite marked in vitro production of D-lactate by S. aureus (maximum: 4.59 mmol/l; i.e. 34.9% of total lactate), N. meningitidis (4.62 mmol/l; i.e. 98.1%) and E. coli (3.14 mmol/l; i.e. 97.2%), minimal amounts were measured in human S. aureus (0.38 mmol/l; i.e. 1.3% of total lactate) or N. meningitidis (0.28 mmol/l; i.e. 3.9%) and experimental E. coli meningitis (0.75 mmol/l; i.e. 4.4%). In only 9 of 54 human CSF samples did D-lactate exceed 0.15 mmol/l. S. pneumoniae did not produce significant amounts of D-lactate in vitro (maximum: 0.55 mmol/l; i.e. 2.7% of total lactate), in experimental meningitis (0.18 mmol/l; i.e. 3%) or in human cases of meningitis (0.28 mmol/l; i.e. 1.9%). In conclusion, increased total CSF lactate in meningitis consists mainly of L-lactate and originates predominantly from host cells. CSF D-lactate is of limited diagnostic value.

Neuron-specific enolase and S100B in cerebrospinal fluid after severe traumatic brain injury in infants and children

BACKGROUND

Traumatic brain injury (TBI) is a leading cause of death and disability in children. Considerable insight into the mechanisms involved in secondary injury after TBI has resulted from analysis of ventricular cerebrospinal fluid (CSF) obtained in children with severe noninflicted and inflicted TBI (nTBI and iTBI, respectively). Neuron-specific enolase (NSE) is a glycolytic enzyme that is localized primarily to the neuronal cytoplasm. S100B is a calcium-binding protein localized to astroglial cells. In adults, CSF and serum concentrations of NSE and S100B have served as markers of neuronal damage after TBI. Neither NSE nor S100B has previously been studied in CSF after TBI in infants or children.

OBJECTIVE

To compare the time course and magnitude of neuronal and astroglial death after nTBI and iTBI by measuring CSF concentrations of NSE and S100B using a rapid enzyme-linked immunosorbent assay.

METHODS

Severe nTBI and iTBI were defined by strict clinical criteria. Serial ventricular CSF samples (n = 35) were obtained from children 1.5 to 9 years with severe nTBI (n = 5) and children 0.2 to 1.5 years (n = 5) with severe iTBI. Lumbar CSF samples from 5 children 0.1 to 2.3 years evaluated for meningitis were used as a comparison group. CSF NSE and S100B concentrations were quantified by an enzyme-linked immunosorbent assay (SynX Pharma Inc, Ontario, Canada).

RESULTS

There was no difference in age between patients with iTBI (median [range]: 0.2 years [0.2-1.8]), nTBI (2.0 years [1.5-9]), and the comparison group (0.2 years [0.2-1.8]). The initial Glasgow Coma Scale score was higher in the iTBI group (9 [4-14]) versus the nTBI group (3 [3-7]). NSE was increased in TBI versus the comparison group in 34 of 35 samples. Mean NSE was markedly increased (mean +/- SEM, 117.1 +/- 12.0 ng/mL vs 3.5 +/- 1.4 ng/mL). After nTBI, a transient peak in NSE was seen at a median of 11 hours after injury (range: 5-20 hours). After iTBI, an increase in admission NSE was followed by a sustained and delayed peak at a median of 63 hours after injury (range: 7-94). The magnitude of peak NSE was similar in nTBI and iTBI. S100B was increased versus the comparison group in 35 of 35 samples. Mean S100B was markedly increased in TBI versus the comparison group (1.67 +/- 0.2 ng/mL vs 0.02 +/- 0.0 ng/mL). S100B showed a single peak at 27 hours (range: 5-63 hours) after both nTBI and iTBI. The mean S100B concentration, peak S100B concentration, and the time to peak were not associated with mechanism of injury.

CONCLUSIONS

Markers of neuronal and astroglial death are markedly increased in CSF after severe nTBI and iTBI. ITBI produces a unique time course of NSE, characterized by both an early and late peak, presumably representing 2 waves of neuronal death, the second of which may represent apoptosis. Delayed neuronal death may represent an important therapeutic target in iTBI. NSE and S100B may also be useful as markers to identify occult iTBI, help differentiate nTBI and iTBI, and assist in determining the time of injury in cases of iTBI.

Dosage of lactate in the cerebrospinal fluid in infectious diseases of the central nervous system

This paper analyzes the diagnosis aid of the dosage of lactate in the cerebrospinal fluid (CSF) in infectious diseases of the central nervous system (CNS). We analyzed prospectively 130 samples of CSF of 116 patients with diagnoses of infectious processes in the CNS. The 130 samples of CSF were divided into five groups: 28 samples of the control group, 40 of bacterial meningitis, 22 of viral meningitis, 16 of fungal meningitis and 24 of patients presenting acquired immune deficiency syndrome (AIDS). The concentration of lactate in the CSF was elevated in the group of patients with bacterial meningitis (average = 46.2 mg/dL), fungal meningitis (average = 27.3 mg/dL) and in the AIDS group (average = 23.5 mg/dL). In the control group and viral meningitis group the lactate content in the CSF presented the reference rates according to the employed method. The lactate dosage in the CSF presented a negative correlation with glycorrhachia and positive correlation with the cellularity and total proteins of the CSF. We conclude that the lactate dosage in the CSF, although unspecific, helps to distinguish the infectious processes of the CNS.

Elevated nerve growth factor and neurotrophin-3 levels in cerebrospinal fluid of children with hydrocephalus

BACKGROUND

Elevated intracranial pressure (ICP) resulting from impaired drainage of cerebrospinal fluid (CSF) causes hydrocephalus with damage to the central nervous system. Clinical symptoms of elevated intracranial pressure (ICP) in infants may be difficult to diagnose, leading to delayed treatment by shunt placement. Until now, no biochemical marker of elevated ICP has been available for clinical diagnosis and monitoring. In experimental animal models, nerve growth factor (NGF) and neurotrophin-3 (NT-3) have been shown to be produced by glial cells as an adaptive response to hypoxia. We investigated whether concentrations of NGF and NT-3 are increased in the CSF of children with hydrocephalus.

METHODS

NGF was determined in CSF samples collected from 42 hydrocephalic children on 65 occasions (taps or shunt placement surgery). CSF samples obtained by lumbar puncture from 22 children with suspected, but unconfirmed bacterial infection served as controls. Analysis was performed using ELISA techniques.

RESULTS

NGF concentrations in hydrocephalic children were over 50-fold increased compared to controls (median 225 vs 4 pg/mL, p < 0.0001). NT-3 was detectable (> 1 pg/mL) in 14/31 hydrocephalus samples at 2-51 pg/mL but in none of 11 control samples (p = 0.007).

CONCLUSION

NGF and NT-3 concentrations are increased in children with hydrocephalus. This may represent an adaptive response of the brain to elevated ICP.

Migration of human granulocytes through reconstituted basement membrane is not dependent on matrix metalloproteinase-9 (MMP-9)

Transmigration of human granulocytes across a basal lamina equivalent was studied in vitro. Transwell inserts were coated with Matrigel, a reconstituted basement membrane. Granulocytes (2x10(6)) were applied to the upper chamber. As chemoattractant interleukin-8 (IL-8; 25 ng/ml) was added to the lower chamber. After 1 h of migration, cells were counted in the lower chamber. Specific hydroxamate inhibitors of MMPs (BB-3103, Ro 31-9790) or of serine proteases (Pefabloc, leupeptin) were added at various concentrations to both chambers before the start of migration. Additional experiments were performed with alpha(2)-macroglobulin, a natural inhibitor of MMPs and a monoclonal antibody which specifically blocks the activity of MMP-9. Migration of granulocytes through Matrigel could not be reduced significantly by any of the MMP inhibitors. A dose-dependent impairment of transmigration was only found with Pefabloc, however, this substance also induced severe morphological changes of the cells. The other inhibitor of serine proteases, leupeptin, did not influence migration at all.

Increased cerebrospinal fluid concentrations of soluble Fas (CD95/Apo-1) in hydrocephalus

BACKGROUND AND AIMS

The ventricular enlargement observed in children with chronically raised intracranial pressure (ICP) causes a secondary loss of brain tissue. In animal studies of hydrocephalus, programmed cell death (apoptosis) has been found as a major mechanism of neuronal injury. One of the regulators of the apoptotic cell death programme is the receptor mediated Fas/Fas ligand interaction.

METHODS

The apoptosis regulating cytokines soluble Fas (sFas) and soluble Fas ligand (sFasL) were studied in the cerebrospinal fluid (CSF) of 31 hydrocephalic children undergoing shunt surgery for symptomatic hydrocephalus and 18 controls.

RESULTS

High concentrations of sFas were observed in children with hydrocephalus (median 252 ng/ml); in controls sFas was below the detection limit (0.5 ng/ml). sFasL was undetectable in all but one sample.

CONCLUSION

High concentrations of sFas in the CSF of children with hydrocephalus suggest intrinsic sFas production, potentially antagonising pressure mediated Fas activation.