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Blood-brain barrier (BBB) permeability can be measured by the ratio of albumin in cerebrospinal fluid (CSF) and blood and by dynamic contrast-enhanced MRI (DCEMRI). Albumin is a large molecule measured in CSF and blood to form the albumin index (Q alb ), which is a global measure of BBB permeability, while the smaller Gadolinium molecule measures regional transfer (K trans ); few studies have directly compared them in the same patients. We used both methods as part of a study of mechanisms of white matter injury in patients with different forms of dementia. In addition, we also measured biomarkers for inflammation, including proteases, angiogenic growth factors, and cytokines, and correlated them with the BBB results. We found that there was no correlation between Q alb and K trans . The Q alb was associated with the matrix metalloproteinases (MMP-2, MMP-3, and MMP-10), the angiogenic factors (VEGF-C and PlGF), and the cytokines (IL-6, IL-8 and TNF-α). On the other hand, K trans was associated with the diffusion measures, mean free water and PSMD, which indicate white matter injury. Our results show that the Q alb and K trans measure different aspects of BBB permeability, with albumin being a measure of inflammatory BBB opening and K trans indicating white matter injury.

Background: Increased cerebrospinal fluid (CSF) protein concentration is a common finding in neurological diseases of dogs. Distinguishing between intrathecally-produced proteins and proteins that have passed the blood-CSF barrier because of barrier disruption facilitates diagnosis. Albumin is a microprotein mainly produced extrathecally that can be used as a reference marker for blood-CSF barrier dysfunction., Objectives: Develop a quotient graph based on the CSF/serum quotient of albumin and immunoglobulin A (IgA; Reibergram) to visualize intrathecal IgA synthesis and blood-CSF barrier dysfunction., Animals and Methods: Retrospective single-center cohort study. A hyperbolic function was developed using data from 6 healthy Beagles and 38 dogs with neurological diseases in which an isolated blood-CSF barrier dysfunction was expected. The function was validated using data from 10 dogs with expected intrathecal IgA synthesis and was visualized as a quotient graph. Finally, the graph was used to evaluate data of 118 dogs with various neurological diseases., Results: Within the Reibergram, the function QLim IgA = 0.13 QAlb 2 + 11.9 · 10 - 6 - 1.01 · 10 - 3 describes the upper values of physiological IgA quotients. It detects diseases with expected intrathecal IgA synthesis with higher sensitivity (85%) and specificity (89%) than the IgA index. The upper value of the physiological albumin quotient is 2.22 and detects diseases with expected blood-CSF barrier dysfunction (sensitivity: 81%; specificity: 88%)., Conclusion and Clinical Importance: The canine Reibergram can detect blood-CSF barrier dysfunction and intrathecal IgA synthesis in the majority of cases. The graphical visualization simplifies data evaluation and makes it a feasible tool in routine CSF diagnostic testing., (© 2022 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Objective: CNS damage can increase the susceptibility of the blood-brain barrier (BBB) to changes induced by systemic inflammation. The aim of this study is to better understand BBB permeability in patients with MS and to examine whether compromised BBB integrity in some of these patients is associated with CNS damage and systemic inflammation., Methods: Routine CSF measurements of 121 patients with MS were analyzed including number and type of infiltrating cells, total protein, lactate, and oligoclonal bands, as well as intrathecal production of immunoglobulins and CSF/serum quotients for albumin, immunoglobulins, and glucose. In addition, in a subcohort of these patients, we performed ex vivo immunophenotyping of CSF-infiltrating and paired circulating lymphocytes using a panel of 13 monoclonal antibodies, we quantified intrathecal neurofilament light chain (NF-L) and chitinase 3-like 1 (CHI3L1), and we performed intrathecal lipidomic analysis., Results: Patients with MS with abnormal high levels of albumin in the CSF showed a distinct CSF cell infiltrate and markers of CNS damage such as increased intrathecal levels of NF-L and CHI3L1 as well as a distinct CSF lipidomic profile. In addition, these patients showed higher numbers of circulating proinflammatory Th1 and Th1* cells compatible with systemic inflammation. Of interest, the abnormally high levels of albumin in the CSF of those patients were preserved over time., Conclusions: Our results support the hypothesis that CNS damage may increase BBB vulnerability to systemic inflammation in a subset of patients and thus contribute to disease heterogeneity., (Copyright © 2021 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Background: The importance of cerebrospinal fluid (CSF) diagnostics for psychiatry is growing. The CSF/blood albumin quotient (Q Alb ) is considered to be a measure of the blood-CSF barrier function. Recently, systematically higher Q Alb in males than in females was described in neurological patients. The aim of this study was to investigate whether a sex difference could also be detected in a well-characterized psychiatric cohort., Methods: The patient cohort comprised 989 patients, including 545 females and 444 males with schizophreniform and affective syndromes who underwent CSF diagnostics, including Q Alb measurement. The basic CSF findings and antineuronal autoantibody data of this cohort have already been published. This re-analysis employed analysis of covariance with age correction for Q Alb mean values and chi 2 -testing for the number of increased age-corrected Q Alb levels to investigate sex differences in Q Alb ., Results: The Q Alb levels were elevated above reference levels by 18% across all patients, and a comparison between male and female patients revealed a statistically significant sex difference, with increased values in 26% of male patients and a corresponding rate of only 10% in female patients (chi 2  = 42.625, p < 0.001). The mean Q Alb values were also significantly higher in males (6.52 ± 3.69 × 10 -3 ) than in females (5.23 ± 2.56 × 10 -3 ; F = 52.837, p < 0.001)., Discussion: The main finding of this study was a significantly higher Q Alb level in male compared to female patients with psychiatric disorders, complementing previously described sex differences in neurological patient cohorts. This result indicates bias from some general factors associated with sex and could be partly explained by sex differences in body height, which is associated with spine length and thus a longer distance for CSF flow within the subarachnoid space down the spine from the occipital area to the lumbar puncture site in males compared to females. Hormonal influences caused by different estrogen levels and other sex-specific factors could also play a relevant role. The significance of the study is limited by its retrospective design, absence of a healthy control group, and unavailability of exact measures of spine length.

Context: Spondylodiscitis, or vertebral osteomyelitis, is an unusual infection of the vertebral bodies and intervertebral discs that can occasionally present with neurological signs., Findings: We present a patient with subacute flaccid paraparesis with associated albuminocytologic dissociation who was eventually diagnosed with spondylodiscitis., Conclusion: The case presented depicts a diagnostic difficulty encountered in clinical practice: Albuminocytologic dissociation in CSF is not always attributed to Guillain-Barre syndrome and other possible causes such as obstructive spinal cord lesions must always be considered.

Background: We aimed to assess the relationship between levels of a cerebrospinal fluid (CSF) marker of pericyte damage, soluble platelet-derived growth factor receptor β (sPDGFRβ) and CSF markers of blood-brain barrier (BBB) integrity (CSF albumin and CSF/serum albumin ratio) and disease pathology (reduced CSF Aβ42 and elevated CSF total and phosphorylated tau) in Alzheimer's disease (AD)., Methods: sPDGFRβ and albumin were measured by sandwich ELISA in ante-mortem CSF from 39 AD and 39 age-matched controls that were grouped according to their biomarker profile (i.e. AD cases t-tau > 400 pg/mL, p-tau > 60 pg/mL and Aβ42 < 550 pg/mL). sPDGFRβ was also measured in matched serum and CSF samples (n = 23) in a separate neurologically normal group for which the CSF/serum albumin ratio had been determined., Results: CSF sPDGFRβ level was significantly increased in AD (p = 0.0038) and correlated positively with albumin (r = 0.45, p = 0.007), total tau (r = 0.50, p = 0.0017) and phosphorylated tau (r = 0.41, p = 0.013) in AD but not in controls. CSF sPDGFRβ did not correlate with Aβ42. Serum and CSF sPDGFRβ were positively correlated (r = 0.547, p = 0.0085) in the independent neurologically normal CSF/serum matched samples., Conclusions: We provide further evidence of an association between pericyte injury and BBB breakdown in AD and novel evidence that a CSF marker of pericyte injury is related to the severity of AD pathology.

Blast-induced traumatic brain injury (bTBI) has been recognized as the common mode of neurotrauma amongst military and civilian personnel due to an increased insurgent activity domestically and abroad. Previous studies from our laboratory have identified enhanced blood-brain barrier (BBB) permeability as a significant, sub-acute (four hours post-blast) pathological change in bTBI. We also found that NADPH oxidase (NOX)-mediated oxidative stress occurs at the same time post-blast when the BBB permeability changes. We therefore hypothesized that oxidative stress is a major causative factor in the BBB breakdown in the sub-acute stages. This work therefore examined the role of NOX1 and its downstream effects on BBB permeability in the frontal cortex (a region previously shown to be the most vulnerable) immediately and four hours post-blast exposure. Rats were injured by primary blast waves in a compressed gas-driven shock tube at 180 kPa and the BBB integrity was assessed by extravasation of Evans blue and changes in tight junction proteins (TJPs) as well as translocation of macromolecules from blood to brain and vice versa. NOX1 abundance was also assessed in neurovascular endothelial cells. Blast injury resulted in increased extravasation and reduced levels of TJPs in tissues consistent with our previous observations. NOX1 levels were significantly increased in endothelial cells followed by increased superoxide production within 4 hours of blast. Blast injury also increased the levels/activation of matrix metalloproteinase 3 and 9. To test the role of oxidative stress, rats were administered apocynin, which is known to inhibit the assembly of NOX subunits and arrests its function. We found apocynin completely inhibited dye extravasation as well as restored TJP levels to that of controls and reduced matrix metalloproteinase activation in the sub-acute stages following blast. Together these data strongly suggest that NOX-mediated oxidative stress contributes to enhanced BBB permeability in bTBI through a pathway involving increased matrix metalloproteinase activation.

Objective: Dogs with spontaneous or acquired epilepsy exhibit resemblance in etiology and disease course to humans, potentially offering a translational model of the human disease. Blood-brain barrier dysfunction (BBBD) has been shown to partake in epileptogenesis in experimental models of epilepsy. To test the hypothesis that BBBD can be detected in dogs with naturally occurring seizures, we developed a linear dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis algorithm that was validated in clinical cases of seizing dogs and experimental epileptic rats., Methods: Forty-six dogs with naturally occurring seizures of different etiologies and 12 induced epilepsy rats were imaged using DCE-MRI. Six healthy dogs and 12 naive rats served as control. DCE-MRI was analyzed by linear-dynamic method. BBBD scores were calculated in whole brain and in specific brain regions. Immunofluorescence analysis for transforming growth factor beta (TGF-β) pathway proteins was performed on the piriform cortex of epileptic dogs., Results: We found BBBD in 37% of dogs with seizures. A significantly higher cerebrospinal fluid to serum albumin ratio was found in dogs with BBBD relative to dogs with intact blood-brain barrier (BBB). A significant difference was found between epileptic and control rats when BBBD scores were calculated for the piriform cortex at 48 hours and 1 month after status epilepticus. Mean BBBD score of the piriform lobe in idiopathic epilepsy (IE) dogs was significantly higher compared to control. Immunohistochemistry results suggested active TGF-β signaling and neuroinflammation in the piriform cortex of dogs with IE, showing increased levels of serum albumin colocalized with glial acidic fibrillary protein and pSMAD2 in an area where BBBD had been detected by linear DCE-MRI., Significance: Detection of BBBD in dogs with naturally occurring epilepsy provides the ground for future studies for evaluation of novel treatment targeting the disrupted BBB. The involvement of the piriform lobe seen using our linear DCE-MRI protocol and algorithm emphasizes the possibility of using dogs as a translational model for the human disease., (Wiley Periodicals, Inc. © 2019 International League Against Epilepsy.)

Objective: We sought to develop molecular biomarkers of intrathecal inflammation to assist neurologists in identifying patients most likely to benefit from a range of immune therapies., Methods: We used Luminex technology and index determination to search for an inflammatory activity molecular signature (IAMS) in patients with inflammatory demyelinating disease (IDD), other neuroinflammatory diagnoses, and noninflammatory controls. We then followed the clinical characteristics of these patients to find how the presence of the signature might assist in diagnosis and prognosis., Results: A CSF molecular signature consisting of elevated CXCL13, elevated immunoglobulins, normal albumin CSF/serum ratio (Q albumin ), and minimal elevation of cytokines other than CXCL13 provided diagnostic and prognostic value; absence of the signature in IDD predicted lack of subsequent inflammatory events. The signature outperformed oligoclonal bands, which were frequently false positive for active neuroinflammation., Conclusions: A CSF IAMS may prove useful in the diagnosis and management of patients with IDD and other neuroinflammatory syndromes., Classification of Evidence: This study provides Class IV evidence that a CSF IAMS identifies patients with IDD.

Guillain-Barré syndrome (GBS) is an immune-mediated polyneuropathy, often preceded by an illness. It is a self-limiting illness in most of the cases, but recurrence is rare and can be seen in about 1%-6% of patients. GBS is characterised by progressive, symmetrical, proximal and distal weakness. Areflexia and sensory disturbances are also common. Patients with GBS usually have albuminocytological dissociation on cerebrospinal fluid (CSF) analysis. This is a case of a 69-year-old woman with recurrent GBS and normal CSF findings., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2018. No commercial re-use. See rights and permissions. Published by BMJ.)

Given sex-related differences in brain disorders, it is of interest to study if there is a sex difference in the permeability of the blood-cerebrospinal fluid barrier (BCSFB) and the blood-brain barrier (BBB). The CSF/serum albumin ratio (Q A lb ) is a standardized biomarker that evaluates the function of these barriers. In previous studies, contradictory results have been reported with respect to sex difference using this quotient, possibly because of small population sizes and heterogeneity with respect to ages. Q A lb measurements in more than 20 000 patients between 1 and 90 years visiting our hospitals revealed a significant sex difference in all age groups also when excluding patients with pathologically high CSF albumin > 400 mg/L. Similar pattern was found in 335 healthy volunteers in similar age intervals. Although also other factors are likely important, our observation is consistent with lower integrity of the brain barriers in males. If the difference in Q A lb is caused mainly by a difference in barrier function, this may require different drug doses and strategies for efficient central nervous system (CNS) delivery in males and females, as well as it may indicate differences in brain metabolism. Moreover, our study emphasizes that different reference values should be used both for different ages and sexes., (© 2018 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.)

Background: In this study, we tested to which extent possible between-center differences in standardized operating procedures (SOPs) for biobanking of cerebrospinal fluid (CSF) samples influence the homogeneity of the resulting aliquots and, consequently, the concentrations of the centrally analyzed selected Alzheimer's disease biomarkers., Methods: Proficiency processing samples (PPSs), prepared by pooling of four individual CSF samples, were sent to 10 participating centers, which were asked to perform aliquoting of the PPSs into two secondary aliquots (SAs) under their local SOPs. The resulting SAs were shipped to the central laboratory, where the concentrations of amyloid beta (Aβ) 1-42, pTau181, and albumin were measured in one run with validated routine analytical methods. Total variability of the concentrations, and its within-center and between-center components, were analyzed with hierarchical regression models., Results: We observed neglectable variability in the concentrations of pTau181 and albumin across the centers and the aliquots. In contrast, the variability of the Aβ1-42 concentrations was much larger (overall coefficient of variation 31%), with 28% of the between-laboratory component and 10% of the within-laboratory (i.e., between-aliquot) component. We identified duration of the preparation of the aliquots and the centrifugation force as two potential confounders influencing within-center variability and biomarker concentrations, respectively., Conclusions: Proficiency processing schemes provide objective evidence for the most critical preanalytical variables. Standardization of these variables may significantly enhance the quality of the collected biospecimens. Studies utilizing retrospective samples collected under different local SOPs need to consider such differences in the statistical evaluations of the data.

Rationale: Ulcerative colitis is a chronic and recurrent inflammatory disease involving the intestine. It is reported that about 40% of patients with ulcerative colitis have extraintestinal manifestations, where as the literature on neurological involvement as extraintestinal manifestation is rather limited. Guillain-Barré syndrome is an abnormal immune-mediated and acute-acquired demyelinating disease that mainly affects the peripheral nervous system and often has a phenomenon of protein-cell separation of cerebrospinal fluid. Here, we report a rare case of ulcerative colitis with Guillain-Barré Syndrome., Patient Concerns: We described a patient with Guillain-Barré syndrome during the remission period of ulcerative colitis. Clinical manifestations are the numbness of the upper extremities, weakness in the limbs and the inability of the fingers companion. Cerebrospinal fluid (CSF) showed albuminocytological dissociation and electromyography suggested neurogenic lesion., Diagnoses: Ulcerative colitis with Guillain-Barré syndrome was diagnosed based on the history of ulcerative colitis, related symptoms, typical cerebrospinal fluid albuminocytological dissociation and evidence of neurogenic injury through electromyography., Interventions: The patient was treated with intravenous (IV) methylprednisolone., Outcomes: After the treatment of glucocorticoid, the symptoms of the nervous system were disappeared., Lessons: Neurological involvement of extraintestinal manifestation during the remission period of ulcerative colitis also exists in the clinic. This case highlights the need for diagnostic vigilance in cases of ulcerative colitis involving the peripheral nerves during the remission period. We recommend cerebrospinal fluid examination and electromyography in view of rare but serious possibility of Guillain-Barré syndrome.

Mild traumatic brain injury (mTBI) is a common occurrence, with over 3 million cases reported every year in the United States. While research into the underlying pathophysiology is ongoing, there is an urgent need for better clinical guidelines that allow more consistent diagnosis of mTBI and ensure safe return-to-play timelines for athletes, nonathletes, and military personnel. The development of a suite of biomarkers that indicate the pathogenicity of mTBI could lead to clinically useful tools for establishing both diagnosis and prognosis. Here, we review the current evidence for mTBI biomarkers derived from investigations of the multifactorial pathology of mTBI. While the current literature lacks the scope and size for clarification of these biomarkers' clinical utility, early studies have identified some promising candidates.

Brain capillary endothelial cells form the blood-brain barrier (BBB), which is covered with basement membranes and is also surrounded by pericytes and astrocyte end-feet in the neurovascular unit. The BBB tightly regulates the molecular exchange between the blood flow and brain parenchyma, thereby regulating the homeostasis of the central nervous system (CNS). Thus, dysfunction of the BBB is likely involved in the pathogenesis of several neurological diseases, including Alzheimer's disease (AD). While amyloid-β (Aβ) deposition and neurofibrillary tangle formation in the brain are central pathological hallmarks in AD, cerebrovascular lesions and BBB alteration have also been shown to frequently coexist. Although further clinical studies should clarify whether BBB disruption is a specific feature of AD pathogenesis, increasing evidence indicates that each component of the neurovascular unit is significantly affected in the presence of AD-related pathologies in animal models and human patients. Conversely, since some portions of Aβ are eliminated along the neurovascular unit and across the BBB, disturbing the pathways may result in exacerbated Aβ accumulation in the brain. Thus, current evidence suggests that BBB dysfunction may causatively and consequently contribute to AD pathogenesis, forming a vicious cycle between brain Aβ accumulation and neurovascular unit impairments during disease progression., Competing Interests: The authors declare no conflict of interest.

Background: Cerebrospinal fluid (CSF) protein analysis is an important element in the diagnostic chain for various central nervous system (CNS) pathologies. Among multiple existing approaches to interpreting measured protein levels, the Reiber diagram is particularly robust with respect to physiologic inter-individual variability, as it uses multiple subject-specific anchoring values. Beyond reliable identification of abnormal protein levels, the Reiber diagram has the potential to elucidate their pathophysiologic origin. In particular, both reduction of CSF drainage from the cranio-spinal space as well as blood-CNS barrier dysfunction have been suggested ρas possible causes of increased concentration of blood-derived proteins. However, there is disagreement on which of the two is the true cause., Methods: We designed two computational models to investigate the mechanisms governing protein distribution in the spinal CSF. With a one-dimensional model, we evaluated the distribution of albumin and immunoglobulin G (IgG), accounting for protein transport rates across blood-CNS barriers, CSF dynamics (including both dispersion induced by CSF pulsations and advection by mean CSF flow) and CSF drainage. Dispersion coefficients were determined a priori by computing the axisymmetric three-dimensional CSF dynamics and solute transport in a representative segment of the spinal canal., Results: Our models reproduce the empirically determined hyperbolic relation between albumin and IgG quotients. They indicate that variation in CSF drainage would yield a linear rather than the expected hyperbolic profile. In contrast, modelled barrier dysfunction reproduces the experimentally observed relation., Conclusions: High levels of albumin identified in the Reiber diagram are more likely to originate from a barrier dysfunction than from a reduction in CSF drainage. Our in silico experiments further support the hypothesis of decreasing spinal CSF drainage in rostro-caudal direction and emphasize the physiological importance of pulsation-driven dispersion for the transport of large molecules in the CSF.

Background: Meningeosis neoplastica is a diffuse metastatic spread of tumor cells in the subarachnoid space. Although first recognized in 1870, systematic investigations regarding cerebrospinal fluid (CSF) constituents in this condition are scarce., Methods: Routine CSF samples analyzed from 2001 to 2012 at the Laboratory of Clinical Neurochemistry, University of Göttingen, were re-evaluated. Patients, whose CSF contained malignant cells were included in this study., Results: Patients (n = 132, age 59.1 ± 29.1, 58% women) were identified, whose CSF contained malignant cells. The most frequent primary tumor was breast cancer (32.6%), followed by lung cancer (25.0%) and hematologic malignancies (21.2%). The most frequent clinical symptoms were affections of cranial nerves (41.7%), psychiatric abmormalities (32.6%) and radicular lesions of the lower extremities (20.5%). CSF cell counts ranged from 0 to 4692 cells/μl (median 4 cells/μl) and were elevated in 50%. The CSF-to-serum albumin ratio was abnormal in 69.4%. It ranged from 1.8 to 330 x 10 -3 (median 17.5 x 10 -3 ). Total CSF protein ranged from 166 to 15,840 mg/l (median 1012 mg/l). CSF lactate was elevated (>2.4 mmol/l) in 65.2% [3.6 mmol/l (1.3/15.6 mmol/l); median (minimum/maximum)]. In 50% of all patients CSF lactate was ≥3.5 mmol/l. The CSF cell counts correlated significantly with the CSF lactate levels and the CSF protein contents. In 56 of 118 CSF samples (47.5%) ferritin was elevated, and in 25 of 65 carcinoma patients (38.5%) an intrathecal production of carcinoembryonic antigen (CEA) was detected. Granulocytes were found in 52.7% of the CSF samples. The percentages of granulocytes and lymphocytes were higher in samples with an elevated cell count., Conclusion: In approximately 50% of CSF samples with meningeosis neoplastica the CSF cell count is not elevated. Diagnosis may be missed when only CSF samples with elevated cell counts are subjected to cytological analysis. CSF lactate and protein and the CSF-to-serum albumin ratio are frequently increased in meningeosis neoplastica. The differential diagnosis between meningeosis neoplastica and central nervous infections, in particular tuberculous or fungal meningitis, can be difficult.

We confirmed previous findings by a Japanese group that there is an accumulation of 7α-hydroxy-3-oxo-4-cholestenoic acid (7-Hoca) in human subdural hematomas. The accumulation correlated with the time from the bleeding to the sample collection. We present evidence that these accumulations are likely to be caused by the strong affinity of 7-Hoca to albumin and the marked difference between plasma and brain with respect to levels of albumin. In the circulation, 80-90% of 7-Hoca is bound to albumin with a ratio between the steroid acid and albumin of ∼1.4 ng/mg. In cerebrospinal fluid (CSF), the ratio between 7-Hoca and albumin is ∼30 ng/mg. When albumin or hemolyzed blood in a dialysis bag was exposed to CSF, there was a flux of 7-Hoca from CSF to the albumin. We suggest that the major explanation for accumulation of 7-Hoca in subdural hematoma is a flux from the brain into the hematoma due to the high affinity to albumin and the high capacity of 7-Hoca to pass biomembranes. We discuss the possibility that the markedly different ratios between 7-Hoca and albumin in circulation and brain can explain the flux of 7-Hoca from the brain into circulation against a concentration gradient., (Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.)

Purpose: The cytosolic enzyme N-glycanase 1, encoded by NGLY1, catalyzes cleavage of the β-aspartyl glycosylamine bond of N-linked glycoproteins, releasing intact N-glycans from proteins bound for degradation. In this study, we describe the clinical spectrum of NGLY1 deficiency (NGLY1-CDDG)., Methods: Prospective natural history protocol., Results: In 12 individuals ages 2 to 21 years with confirmed, biallelic, pathogenic NGLY1 mutations, we identified previously unreported clinical features, including optic atrophy and retinal pigmentary changes/cone dystrophy, delayed bone age, joint hypermobility, and lower than predicted resting energy expenditure. Novel laboratory findings include low cerebral spinal fluid (CSF) total protein and albumin and unusually high antibody titers toward rubella and/or rubeola following vaccination. We also confirmed and further quantified previously reported findings noting that decreased tear production, transient transaminitis, small feet, a complex hyperkinetic movement disorder, and varying degrees of global developmental delay with relatively preserved socialization are the most consistent features., Conclusion: Our prospective phenotyping expands the clinical spectrum of NGLY1-CDDG, offers prognostic information, and provides baseline data for evaluating therapeutic interventions.Genet Med 19 2, 160-168.

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.

Blood brain barrier impairment occurs early in the course of infection by HIV and it may persist in a subset of patients despite effective antiretroviral treatment. We tested the hypothesis that HIV-positive patients with dysfunctional blood brain barrier may have altered biomarkers of neuronal damage. In adult HIV-positive highly active antiretroviral treatment (HAART)-treated patients (without central nervous system infections and undergoing lumbar punctures for clinical reasons) cerebrospinal fluid albumin to serum ratios (CSAR), total tau, phosphorylated tau, 1-42 beta amyloid, and neopterin were measured. In 101 adult patients, cerebrospinal fluid-to-serum albumin ratios were 4.8 (3.7-6.1) with 12 patients (11.9%) presenting age-defined impaired blood brain barrier. A significant correlation was observed between CSAR and total tau (p = 0.005), phosphorylated tau (p = 0.008), and 1-42 beta amyloid (p = 0.040). Patients with impaired blood brain barrier showed significantly higher total tau (201.6 vs. 87.3 pg/mL, p = 0.010), phosphorylated tau (35.3 vs. 32.1 ng/mL, p = 0.035), and 1-42 beta amyloid (1134 vs. 830 pg/mL, p = 0.045). Despite effective antiretroviral treatment, blood brain barrier impairment persists in some HIV-positive patients: it is associated with markers of neuronal damage and it was not associated with CSF neopterin concentrations.

Objectives: It is a matter of debate whether impaired insulin action originates from a defect at the neural level or impaired transport of the hormone into the brain. In this study, we aimed to investigate the effect of aging on insulin concentrations in the periphery and the central nervous system as well as its impact on insulin-dependent brain activity., Methods: Insulin, glucose and albumin concentrations were determined in 160 paired human serum and cerebrospinal fluid (CSF) samples. Additionally, insulin was applied in young and aged mice by subcutaneous injection or intracerebroventricularly to circumvent the blood-brain barrier. Insulin action and cortical activity were assessed by Western blotting and electrocorticography radiotelemetric measurements., Results: In humans, CSF glucose and insulin concentrations were tightly correlated with the respective serum/plasma concentrations. The CSF/serum ratio for insulin was reduced in older subjects while the CSF/serum ratio for albumin increased with age like for most other proteins. Western blot analysis in murine whole brain lysates revealed impaired phosphorylation of AKT (P-AKT) in aged mice following peripheral insulin stimulation whereas P-AKT was comparable to levels in young mice after intracerebroventricular insulin application. As readout for insulin action in the brain, insulin-mediated cortical brain activity instantly increased in young mice subcutaneously injected with insulin but was significantly reduced and delayed in aged mice during the treatment period. When insulin was applied intracerebroventricularly into aged animals, brain activity was readily improved., Conclusions: This study discloses age-dependent changes in insulin CSF/serum ratios in humans. In the elderly, cerebral insulin resistance might be partially attributed to an impaired transport of insulin into the central nervous system.

The blood-brain barrier (BBB) limits entry of blood-derived products, pathogens, and cells into the brain that is essential for normal neuronal functioning and information processing. Post-mortem tissue analysis indicates BBB damage in Alzheimer's disease (AD). The timing of BBB breakdown remains, however, elusive. Using an advanced dynamic contrast-enhanced MRI protocol with high spatial and temporal resolutions to quantify regional BBB permeability in the living human brain, we show an age-dependent BBB breakdown in the hippocampus, a region critical for learning and memory that is affected early in AD. The BBB breakdown in the hippocampus and its CA1 and dentate gyrus subdivisions worsened with mild cognitive impairment that correlated with injury to BBB-associated pericytes, as shown by the cerebrospinal fluid analysis. Our data suggest that BBB breakdown is an early event in the aging human brain that begins in the hippocampus and may contribute to cognitive impairment., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Alterations in blood-brain barrier permeability have been proposed to represent a relevant factor contributing to Parkinson's disease progression. However, few studies have addressed this issue in patients at different stages of disease., Methods: Albumin was measured in cerebrospinal fluid and serum samples obtained from 73 non-demented subjects with idiopathic Parkinson's disease and 47 age-matched control subjects. The albumin ratio (AR) was calculated to assess blood-cerebrospinal fluid and blood-brain barrier function. The group of patients with Parkinson's disease included 46 subjects with Hoehn-Yahr staging between 1 and 2 and 27, with a score ranging from 2.5 to 4., Results: Statistically significant differences in albumin ratio were found between patients with advanced disease, and both early-stage and unaffected groups. Conversely, early-phase patients did not differ from healthy subjects. Additionally, dopaminergic treatment seems to exert a possible effect on AR values., Conclusions: Our study demonstrates that possible dysfunction of the blood-cerebrospinal fluid barrier, blood-brain barrier, or both, characterize Parkinson's disease progression. The associations between clinical scores, treatments and biochemical findings suggest a progressive impairment of barrier integrity during the course of the disease.

Background: Rabies is known to be lethal in human. Treatment with passive immunity for the rabies is effective only when the patients have not shown the central nerve system (CNS) signs. The blood-brain barrier (BBB) is a complex functional barrier that may compromise the therapeutic development in neurological diseases. The goal of this study is to determine the change of BBB integrity and to assess the therapeutic possibility of enhancing BBB permeability combined with passive immunity in the late stage of rabies virus infection., Methods: The integrity of BBB permeability in rats was measured by quantitative ELISA for total IgG and albumin levels in the cerebrospinal fluid (CSF) and by exogenously applying Evans blue as a tracer. Western blotting of occludin and ZO-1, two tight junction proteins, was used to assess the molecular change of BBB structure.The breakdown of BBB with hypertonic arabinose, recombinant tumor necrosis factor-alpha (rTNF-γ), and focused ultrasound (FUS) were used to compare the extent of BBB disruption with rabies virus infection. Specific humoral immunity was analyzed by immunofluorescent assay and rapid fluorescent focus inhibition test. Virus-neutralizing monoclonal antibody (mAb) 8-10E was administered to rats with hypertonic breakdown of BBB as a passive immunotherapy to prevent the death from rabies., Results: The BBB permeability was altered on day 7 post-infection. Increased BBB permeability induced by rabies virus infection was observed primarily in the cerebellum and spinal cord. Occludin was significantly decreased in both the cerebral cortex and cerebellum. The rabies virus-specific antibody was not strongly elicited even in the presence of clinical signs. Disruption of BBB had no direct association with the lethal outcome of rabies. Passive immunotherapy with virus-neutralizing mAb 8-10E with the hypertonic breakdown of BBB prolonged the survival of rabies virus-infected rats., Conclusions: We demonstrated that the BBB permeability was altered in a rat model with rabies virus inoculation. Delivery of neutralizing mAb to the infected site in brain combined with effective breakdown of BBB could be an aggressive but feasible therapeutic mode in rabies when the CNS infection has been established.

Background and Purpose: Subcortical ischemic vascular disease (SIVD) is a major form of vascular cognitive impairment (VCI) due to small vessel disease. Matrix metalloproteinases (MMPs) are neutral proteases that disrupt the blood-brain barrier and degrade myelin basic protein under conditions of neuroinflammation. Brain tissues and cerebrospinal fluid (CSF) of patients with VCI have increased levels of MMPs. We hypothesized that patients with SIVD have increased MMPs in the CSF, which are associated with increased CSF albumin., Methods: We studied 60 patients with suspected VCI. Twenty-five were classified as SIVD, whereas other groups included mixed Alzheimer disease and VCI, multiple strokes, and leukoaraiosis when white matter lesions were present and the diagnosis of VCI was uncertain. MMP-2 and MMP-9 in CSF and plasma were measured by gel zymography and indexed to CSF and plasma albumin. MMP-3 activity was measured by fluorescent assay., Results: We found reduced MMP-2 index (P<0.001) in the CSF for the full group of patients (SIVD, multiple strokes, mixed Alzheimer disease and VCI, and leukoaraiosis) compared with control subjects, whose CSF was obtained during spinal anesthesia. MMP-3 activity was increased in VCI compared with control subjects (P<0.01). In SIVD, MMP-2 index showed a negative correlation with albumin index, which was absent with the MMP-9 index. Combining MMP-2 index and MMP-3 activity separated the patients with SIVD from the control subjects with high specificity (P<0.0005)., Conclusions: Our results support the hypothesis that MMPs are associated with increased CSF albumin and suggest that they may contribute to the pathophysiology of SIVD.

Background: Antiretroviral treatment (ART) significantly reduces cerebrospinal fluid (CSF) HIV-1 RNA levels and residual viremia is less frequently found in CSF than in blood. However, persistent intrathecal immunoactivation is common, even after several years of ART. To investigate whether low-level CSF viremia and residual immunoactivation within the central nervous system (CNS) derive from ongoing local viral replication, we conducted a study of treatment intensification in patients on effective ART., Methods: Ten patients on ART with plasma HIV RNA <50 copies per milliliter for >18 months were included. Intensification was given for in total 8 weeks: 4 weeks with maraviroc or lopinavir/ritonavir (good CNS penetration), and 4 weeks with enfuvirtide (poor CNS penetration). Lumbar punctures were performed 4 weeks before, at intensification commencement, at switchover after 4 weeks, at the conclusion of, and 4 weeks after the intensification period., Results: No significant changes in HIV RNA, neopterin, β2-microglobulin, immunoglobulin G index, albumin ratio, and CD4(+) T-cell count were observed, either in CSF or blood, neither before, during, nor after the intensification periods., Conclusions: ART intensification did not reduce residual CSF HIV RNA levels or intrathecal immunoactivation in patients on ART. These findings do not support an ongoing viral replication in CNS.

Introduction: Raltegravir is an HIV-1 integrase inhibitor currently used in treatment-experienced HIV-1-infected patients resistant to other drug classes. In order to assess its central nervous system penetration, we measured raltegravir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing this drug., Methods: Raltegravir concentrations were determined by liquid chromatography tandem mass spectrometry in 25 paired CSF and plasma samples from 16 HIV-1-infected individuals. The lower limit of quantitation was 2.0 ng/ml for CSF and 10 ng/ml for plasma., Results: Twenty-four of the 25 CSF samples had detectable raltegravir concentrations with a median raltegravir concentration of 18.4 ng/ml (range, <2.0-126.0). The median plasma raltegravir concentration was 448 ng/ml (range, 37-5180). CSF raltegravir concentrations correlated with CSF:plasma albumin ratios and CSF albumin concentrations., Conclusions: Approximately 50% of the CSF specimens exceeded the IC(95) levels reported to inhibit HIV-1 strains without resistance to integrase inhibitors. In addition to contributing to control of systemic HIV-1 infection, raltegravir achieves local inhibitory concentrations in CSF in most, but not all, patients. Blood-brain and blood-CSF barriers likely restrict drug entry, while enhanced permeability of these barriers enhances drug entry.

Objective: We explored the relationship between adiposity factors measured during mid-life and blood-brain barrier (BBB) integrity measured via the cerebrospinal fluid/serum (CSF/S) albumin ratio in late life. Adiposity factors included body mass index and blood levels of sex hormone binding globulin (SHBG) and leptin. Design. Retrospective analyses over 24 years within a longitudinal study., Setting: Population-based sample. Subjects. Eighty-one women., Main Outcome Measures: CSF/S albumin ratio., Results: The CSF/S albumin ratio measured at age 70-84 years was higher amongst women who were overweight or obese (6.50 +/- 2.79 vs. 5.23 +/- 1.61, age-adjusted P = 0.012), and was inversely correlated with SHBG (age-adjusted r = -0.321, P < 0.005) at age 46-60 years. In stepwise regression models, SHBG predicted the CSF/S albumin ratio (beta = -0.017, R2 = 0.107, P = 0.007). The best model (R2 = 0.187) predicting CSF/S albumin ratio included SHBG, age group (age 46 years versus >46), overweight or obesity, and an age group by SHBG interaction., Conclusions: Lower levels of SHBG in mid-life were related to worse BBB integrity in women after 24 years in late life, even considering other adiposity factors. SHBG may be important for understanding sex hormone-mediated mechanisms in brain health or as an independent marker of adipose tissue, the largest endocrine organ.

Purpose: To report a patient with optic nerve (ON) sheath meningioma, unilateral optic disc swelling, and inhomogeneous cerebrospinal fluid (CSF) composition between lumbar CSF and CSF from the subarachnoid space (SAS) of the affected ON., Methods: A 39-year-old woman presented with unilateral optic disc swelling and slight deterioration of visual function in the left eye. Extensive laboratory workup and magnetic resonance imaging (MRI) of the brain and orbits were performed. As radiotherapy was refused by the patient, ON sheath fenestration (ONSF) was offered and performed in order to stop deterioration. CSF from the SAS of the ON was sampled., Results: Laboratory workup was within normal limits. MRI of the left orbit demonstrated enhancement of the dura in the precanalicular portion of the ON and distension of the SAS, most prominent in the bulbar portion of the ON. On lumbar puncture the opening pressure measured 19 (cm H2O). Compared to the lumbar CSF the CSF of the affected ON SAS showed markedly elevated measurements for albumin, IgG, and beta-trace protein. Visual function remained stable over a follow-up time of 18 months., Conclusions: Composition of CSF is considered to be homogenous throughout all CSF spaces. In this patient the authors found a marked concentration-gradient of albumin, IgG, and beta-trace protein between the CSF in the spinal canal and the CSF in the SAS of the affected ON. Based on the radiologic features of the left ON and the dissociated beta-trace protein concentrations in the CSF of the SAS of the ON and the lumbar CSF, the diagnosis of an ON sheath compartment syndrome due to an ON sheath meningioma was made.

The measurement of albumin concentrations in cerebrospinal fluid (CSF) and serum for albumin quotient (AQ) calculations in normal horses was performed by 2 methods: 1) total protein measurement, followed by electrophoresis of the samples to obtain an albumin percentage; and 2) albumin immunoprecipitation quantitated by nephelometry. The results of both methods correlated well, and nephelometry was chosen to determine the albumin concentrations in CSF samples obtained from an indwelling subarachnoidal catheter for daily sampling. Because the use of an indwelling catheter to collect repetitive CSF samples is a novel technique, routine cytological CSF analysis was performed along with daily clinical evaluation to ascertain the well-being of the horses. The catheters were placed in 2 horses for periods of 14 and 17 days. One horse exhibited pleocytosis on cytological evaluation of CSF on 2 occasions for a 1-2-day duration; however, the AQ showed a significant increase on only 1 occasion. The other horse had a normal cell count in CSF but showed 2 sudden changes in the AQ value; however, these values remained within the 95% confidence interval for AQ in horses. Albumin quotient values of the second horse were consistently below the lower range of the confidence interval. Results from this study indicate that nephelometry can be used for albumin determination in serum and CSF samples from horses. Furthermore, an indwelling subarachnoidal catheter system can provide serial CSF samples in horses, thus obviating the need for repetitive centesis for serial CSF sampling.

Blood-central nervous system (blood-CNS) barrier breakdown, an important pathophysiological event in meningitis, results in extravasation of leucocytes into subarachnoid space. The blood-CNS barrier disruption is mediated by primarily two enzyme systems, the plasminogen activators (PAs) and matrix metalloproteinases (MMPs). The present study showed that the activities of tissue-type PA (tPA), urokinase-type activator (uPA) and MMP-9 in cerebrospinal-like fluid (CSF-like fluid) were significantly increased in mice with eosinophilic meningitis compared with uninfected mice. Eosinophilia significantly correlated with tPA, uPA and MMP-9 activities, and albumin concentration. In addition, when GM6001, a specific matrix metalloproteinase blocker, was injected into infected mice, MMP-9 activity and total protein concentrations declined from their preinjection highs. These results suggest that the PAs and MMP-9 proteolytic cascade may be associated with blood-CNS barrier disruption in eosinophilic meningitis caused by Angiostrongylus cantonensis.

This study examined children with an acute encephalopathy illness for evidence of viral infection, disordered blood-brain barrier function, intrathecal immunoglobulin synthesis, and interferon (IFN) production, and related their temporal occurrence to outcome. A prospective study of 22 children (13 males, 9 females; age range 1mo to 13y, median 2y 4mo), recorded clinical details, with serum and cerebrospinal fluid (CSF) analysis near presentation and then on convalescent specimens taken up to day 39 of the neurological illness. Outcome was assessed with standard scales between 18 months and 3 years after presentation. A history consistent with viral infection was given in 17 children but laboratory evidence of viral infection was found in only 7 (7/17). In 18 out of 21 children, an elevated CSF:serum albumin ratio indicative of impairment of the blood-CSF and blood-brain barriers was detected at some stage of the illness. In 14 of the 15 children with a raised immunoglobulin G index, and in 12 of the 14 children where the CSF was positive for oligoclonal bands, this was preceded by, or was observed at the same time as, an abnormal albumin ratio. Sixteen children (16/18) had elevated IFN-alpha levels in serum, or CSF, or in both. We conclude that these findings indicate an initial disruption of the blood-brain barrier followed by intrathecal antibody production by activated lymphocytes, clonally restricted to a few antigens. This is the first in vivo study to show this as an important pathogenetic mechanism of encephalitis in children. Poor outcome was associated with young age, a deteriorating electroencephalogram pattern from grade 1 to grade 2, and the degree of blood-brain barrier impairment, particularly when prolonged, but not with Glasgow Coma Scale score. The persistence of IFN-alpha was associated with a good prognosis.

The aim of this study was to validate an automated immunoturbidimetric assay used to quantify human albumin in urine and to accurately measure canine albumin concentrations in both urine and cerebrospinal fluid. The partial homology existing between human and canine albumin limited the accuracy of the human assays in measuring canine albumin without method modifications. Thus, the assay was modified by calibrating the analyzer with calibrators made in the laboratory containing known concentrations of canine albumin. To prepare the set of calibrators, the albumin concentration of pooled sera of healthy dogs was assessed in 5 replicates using the BromocresolGreen assay. Pooled samples were aliquoted and serially diluted to obtain the expected concentrations of albumin (0.5, 1, 5, 13, and 30 mg/dl) for establishing the canine calibration curve. Thereafter, the performance was assessed by analyzing canine urine and CSF The modified assay accurately quantified canine albumin in both specimens, as indicated by the following. Intra- and interassay variability was 0.92% and 2.74%, respectively; recovery was 99.66% and 99.07% in urine and 105.02% in CSF No interference was detected when hemolysate and glucose were added to urine. The test was linear within the verified range (0-225 mg/dl). These results demonstrate that the modified human albumin immunoturbidimetric assay can be a useful tool in the veterinary diagnostic laboratory. It is accurate and tends itself to automatization on chemistry analyzers.

The APOE epsilon4 allele has been associated with unfavorable outcome after several types of acute brain injury, yet the biological mechanisms underlying this observation are poorly understood. Postmortem and experimental brain injury studies suggest the presence of increased amounts of apolipoprotein E (apoE) within the neuropil after acute brain injury. We assayed the concentration of apolipoprotein E in the cerebrospinal fluid (CSF) of non-injured controls and patients with traumatic brain injury (TBI) to determine whether differences exist, and if these differences correlate with injury severity and clinical outcome. CSF apoE and S100B, a marker of injury severity, were measured by enzyme linked immunosorbant assay. CSF was sampled from 27 traumatic brain injury patients (mean age 32, median 25, range 16-65 years) within 3 days of injury, and 28 controls (mean age 40, median 37, range 19-73 years). The TBI patients all had a Glasgow Coma Score (GCS) of less than eight (i.e., severe head injury). Clinical outcome was determined using the Glasgow Outcome Score (GOS). The average concentration of apoE in the CSF of controls was 12.4 mg/L (95% CI: 10.5-14.3 mg/L) and in TBI patients was 3.7 mg/L (95% CI: 2.1-4.1 mg/L; Mann-Whitney: p < 0.0001). In contrast, the concentration of S100B in the CSF of TBI patients was significantly higher than that of controls (Mann-Whitney: p < 0.0001). We speculate that apoE is retained within the parenchyma of the central nervous system in response to injury where in view of previous data, it may have a protective role.

Two hundred and ten patients with meningismus and the infections of the central nervous system (CNS) with the clinical symptoms and signs of the acute serous meningitis syndrome, were divided in to groups according to etiology (enterovirus meningitis-ENTERO, serous meningitis various etiology-SM and tuberculous meningitis-TBC). Intrathecal synthesis (ITS) of C3c and C4 complement components and IgG were determined by the method of cerebrospinal indexes (I), to examine their role in differential diagnosis of this syndrome. Correlative study between the CSF/serum ratio (Q) for albumin (Alb) and QC3c and QC4 in patients with no proven ITS of this two complement proteins, and the comparative study of the increased value of C3cI and C4I (and IgGI) between the examined groups of the patients was done. Highly significant correlations were found between QAlb and QC3c (r = 0.89, p < 0.001) and QC4 (r = 0.85, p < 0.001). In 22.4% of the examined patients ITS of C3c and C4 were found. There was no difference in frequency of ITS of the two complement proteins between the examined groups, nor inside any particular group. TBC group had significantly lower (p < 0.05) intensity of ITS of C3c and C4 than MNG and ENTERO, and significantly higher intensity of ITS of IgG (p < 0.05) than the other tested groups. CSF index was confirmed as a valid method to detect intrathecal C3c and C4 production. Determination of ITS C3c and C4 could not be of great help in differential diagnosis in the acute serous meningitis syndrome. The intensity of ITS of C3c and C4, related to the intensity of ITS of IgG, could be of help in the determination of the duration of the disease.

Caveolae are plasma membrane invaginations that may play an important role in numerous cellular processes including transport, signaling, and tumor suppression. By targeted disruption of caveolin-1, the main protein component of caveolae, we generated mice that lacked caveolae. The absence of this organelle impaired nitric oxide and calcium signaling in the cardiovascular system, causing aberrations in endothelium-dependent relaxation, contractility, and maintenance of myogenic tone. In addition, the lungs of knockout animals displayed thickening of alveolar septa caused by uncontrolled endothelial cell proliferation and fibrosis, resulting in severe physical limitations in caveolin-1-disrupted mice. Thus, caveolin-1 and caveolae play a fundamental role in organizing multiple signaling pathways in the cell.

A biuret automated colorimetric assay for total protein in urine and cerebrospinal fluids was established. The procedures were as follows. Acidify all urine sample before analysis. Add precipitant Na(2)WO(4) to urine samples. After 10 min, centrifuge, decant the supernatant fluid, drain the inverted tubes on absorbent tissue, dissolve the precipitation with 0.1 mol/L NaOH, and finally adapt the reconstituted urine to the Hitachi 7170 analyzer. A cell-free cerebrospinal fluid sample produced by centrifugation can be inserted in an auto-analyzer for protein measurement directly. The program: mix 35 microl sample (CSF or reconstituted urine) and standard with 0.2 mol/L NaOH; incurable at 37 degrees C for 5 min, and real A1. Add concentrated biuret reagent, and 10 min later measure absorbance A2 at 546 nm vs. reagent blank. Secondary wavelength was 700 nm. The test results were calculated against a one-point standard. This biuret colorimetric method was relatively simple, fast, and accurate for the determination of protein in urine and cerebrospinal fluid, with a wide linearity extending from 0.125 g/L up to 6 g/L, had a good correlation with Benzethonium chloride turbidimetry technique, and was a practical routine method., (Copyright 2001 Wiley-Liss, Inc.)

Introduction: The aim of the study was to find out, if there was a difference in function of the blood/cerebrospinal fluid barrier (BCSFB) in females and males, and if those differences intensify with age., Material and Methods: 120 patients of both sexes who underwent subarachnoideal anesthesia were divided into 6 groups, 20 patients each, considering sex and age criteria. Samples of venous blood (5 ml) and cerebrospinal fluid (1 ml) were collected from every patient simultaneously; then albumin permeability indexes (Qalb) were counted. The achieved results were compared using the t-Student test at the significance level of P < or = 0.05., Results: The mean value of Qalb in patients aged 20-50 was significantly lower than in the group of patients aged 51-70, as well as in the group of patients over 71. The difference between mean Qalb values in patients aged 51-70 and those aged over 71 was also statistically significant. No statistically significant difference between mean Qalb values in females and in males in the corresponding age groups was found. In every age group the value of albumin permeability index was lower in females., Conclusions: 1) The permeability of BCSFB increases with age. 2) There was no statistically significant difference between the values of albumin permeability index in females and males in the corresponding age groups. The function of BCSFB in the corresponding age groups of males and females was the same.

An IgG subclass deficiency is often associated with bacterial infections. We studied four pediatric patients suffering from meningoencephalitis, two of them due to Streptococcus pneumoniae and two due to Haemophilus influenzae type b. Simultaneous diagnostic serum and cerebrospinal fluid samples were taken during income. The four subclasses of IgG and albumin were quantified in both biologic fluids by radial immunodiffusion. Very low levels of seric IgG2 with non detectable cerebrospinal fluid IgG2 were found in the patients. No intrathecal IgG subclass synthesis was found in two patients. One patient with S. pneumoniae had IgG3 intrathecal synthesis. Intrathecal IgG1, IgG3 and IgG4 synthesis was found in one patient suffering from H. influenzae according with reibergrams. Substitutive therapy with intravenous gammaglobulin was given to the patients as part of the treatment.

Objective: To determine effects of blood contamination on western blot (WB) analysis of CSF samples for detection of anti-Sarcocystis neurona antibodies, and on CSF albumin and IgG concentrations, albumin quotient (AQ), and IgG index in horses., Design: Prospective in vitro study., Samples: Blood with various degrees of immunoreactivity against S neurona was collected from 12 healthy horses. Cerebrospinal fluid without immunoreactivity against S neurona was harvested from 4 recently euthanatized horses., Procedure: Blood was serially diluted with pooled nonimmunoreactive CSF so that final dilutions corresponded to 10(-3) to 100 microliters of blood/ml CSF, and WB analysis was performed on contaminated CSF samples. Number of RBC, albumin and IgG concentrations, AQ, and IgG index were also determined., Results: Antibodies against S neurona were detected in CSF contaminated with 10(-3) microliters of strongly immunoreactive blood/ml. In CSF samples contaminated with 10 microliters of blood/ml, AQ remained within reference range. Volume of blood required to increase IgG index varied among blood samples and was primarily influenced by serum IgG concentrations. Number of RBC in contaminated samples was correlated with volume of blood added, but not with degree of immunoreactivity detected in contaminated CSF samples., Conclusions and Clinical Relevance: During collection of CSF from horses, contamination with blood may introduce serum antibodies against S neurona at concentrations sufficient for detection by WB analysis, thus yielding false-positive results. When blood is moderately or strongly immunoreactive, the amount of contaminating albumin may be small enough as to not increase AQ above reference range. In these cases, AQ and IgG index should be interpreted with caution.

Blood-brain barrier (BBB) permeability in the demented elderly was investigated by use of the ratio of cerebrospinal fluid (CSF) albumin (Alb) to serum Alb (Q-Alb). Subjects with Alzheimer type dementia (AD), vascular dementia (VD), and controls without dementia (C) were investigated. Patients with AD were divided into mild AD (mAD) and severe AD (sAD) by the use of Hasegawa's dementia scale. The Q-Alb and the ratio of CSF alpha1-antichymotrypsin (ACT) to serum ACT (Q-ACT) were evaluated. Correlations between Q-Alb and Q-ACT were compared among the groups (mAD, sAD, VD, C). Correlations between Q-Alb and major monoaminergic neurochemicals were also analyzed. It was suggested that BBB permeability was preserved in C group, while it was impaired in the patients with VD. In AD group it appeared to be rather well preserved in mAD, while it seemed to be disturbed in a graded manner according to the progression of dementia.

Background: Serial cerebral angiograms, computed tomography, and magnetic resonance imaging are among the proposed methods for monitoring disease activity and response to therapy in isolated angiitis of the central nervous system. Cerebrospinal fluid has not proved to be useful in monitoring clinical course., Case Description: We describe a 45-year-old man with histological diagnosis of isolated angiitis of the central nervous system that was treated with prednisone plus azathioprine and monitored for 2 years. Samples of the cerebrospinal fluid were obtained for cytological and routine chemical examination, as well as albumin and immunoglobulin content. Before treatment, cerebrospinal fluid showed marked plasmatic transudation of albumin and intrathecal synthesis of immunoglobulins. During the first year of immunosuppression no events were noticed, and the previously abnormal aspects of the cerebrospinal fluid showed improvement. During the weaning of azathioprine, a new stroke occurred in conjunction with a marked deterioration of cerebrospinal fluid parameters. Immunosuppression was resumed at previous levels, and during the following year no further events occurred. Once again, abnormal cerebrospinal fluid values improved significantly., Conclusions: We report a case of isolated angiitis of the central nervous system in which the serial cerebrospinal fluid examinations (albumin and immunoglobulin content) showed a close correlation with clinical course. This method may be useful in monitoring response to therapy.

We analyzed matched cerebrospinal fluid and blood samples from 139 subjects enrolled in a study of the effects of human immunodeficiency virus type 1 (HIV-1) on the nervous system. Mean total intrathecal IgG synthesis rate was significantly higher in subjects with HIV-1-related neurologic disease (NeuroPos) than in HIV-1-seropositive (HIV+) subjects without neurologic disease (NeuroNeg) or at-risk seronegative controls (SNC). Mean trans-blood-brain barrier (BBB) albumin leakage (AL) rate increased significantly across groups (SNC < NeuroNeg < NeuroPos). AL was significantly higher in subjects with absolute CD4 counts < 100/mm3 versus those with > or = 100 cells/mm3 and significantly higher in AIDS compared with asymptomatic HIV+. Elevated total intrathecal IgG synthesis rate could not be accounted for solely by the presence of a damaged BBB, because 79% of subjects with elevated IgG synthesis rates had a normal BBB as assessed by the AL formula. Furthermore, the Tourtellotte formula inherently corrects for BBB leakage. We confirmed, using state-of-the-art albumin and IgG determinations, that intrathecal IgG synthesis is prevalent in all stages of HIV-1 disease. In the absence of a CNS opportunistic infection or tumor, mean total intrathecal IgG synthesis rate and trans-BBB AL are significantly higher in subjects with clinical HIV-1 CNS disease than in neurologically normally HIV+ subjects.

The diagnosis of neurosyphilis in patients infected with the human immunodeficiency virus (HIV) remains problematic. We examined the use of the Treponema pallidum hemagglutination (TPHA) index and quantitative tests of CSF by means of microhemagglutination-T. pallidum for diagnosis of neurosyphilis in 58 HIV-infected persons with latent syphilis who had not recently received therapy for syphilis. Five patients (9%) had reactive CSF VDRL tests and thus had proven neurosyphilis. For 13 patients (22%), CSF findings were normal and revealed no evidence of neurosyphilis. For 40 patients (69%), abnormal CSF findings were characteristic of neurosyphilis, but their CSF VDRL tests were nonreactive. Twenty-five of the 40 patients with possible neurosyphilis had pleocytosis and elevated CSF levels of protein and/or IgG. Five (12.5%) of these 40 patients had positive TPHA indices that indicated intrathecal antitreponemal antibody production, a finding that provided greater support for the diagnosis of active neurosyphilis. With use of the TPHA index, patients with CSF abnormalities can be better classified in regard to their need for therapy for neurosyphilis.

Brain damage after meningeal infection could result from impairment of cerebral endothelial cell functions and disruption of blood-brain barriers. Tumor necrosis factor-alpha (TNF alpha) and interleukin-1 beta (IL-1 beta) produce many of their effects by acting on endothelial cells. This study correlates levels of TNF alpha and IL-1 beta in paired cerebrospinal fluid (CSF) and serum samples with the degree of blood-brain barrier damage, as manifested by CSF to serum albumin quotient, in 48 patients with bacterial meningitis and 66 controls. CSF levels of TNF alpha and IL-1 beta in bacterial meningitis were significantly higher than in controls. Intrathecal levels of TNF alpha, but not IL-1 beta, correlated with albumin quotient (P less than .001), with degree of blood-brain barrier disruption (P less than .001), and with disease severity and indices of meningeal inflammation. Sequential CSF samples demonstrated that IL-1 beta and TNF alpha disappear from the CSF within 24 h of antibiotic treatment. Data presented here suggest that TNF alpha is related to blood-brain barrier damage in bacterial meningitis and that its effect could be dissociated from that of IL-1 beta.

Beta 2-microglobulin levels were measured in the cerebrospinal fluid (CSF) and serum of 163 human immunodeficiency virus-positive (HIV+) persons with normal neurologic physical examinations. None were on antiretroviral therapy. Only 3% had a positive CSF HIV p24 antigen test. The CSF beta 2-microglobulin levels increased as the CD4+ T cell count decreased. Intrathecal production of beta 2-microglobulin was suggested by finding CSF concentrations greater than serum concentrations in 15% of patients. The CSF beta 2-microglobulin levels rose as in vitro T helper cell function deteriorated, independent of CD4+ T cell count. CSF beta 2-microglobulin levels paralleled CSF IgG, IgG index, and IgG synthesis. Higher CSF beta 2-microglobulin levels were found in persons with positive CSF oligoclonal bands. CSF beta 2-microglobulin concentration may serve as a marker for subclinical neurologic damage due to HIV. If this is established, defining the effect of anti-HIV interventions on CSF beta 2-microglobulin would be warranted.

The concentrations of protein, albumin, IgG, and free amino acids in the cerebrospinal fluid of 16 patients with chronic toxic encephalopathy due to organic solvents were measured. The patient group consisted of all patients with this diagnosis in a neurological department in 1985. The diagnosis was based on neuraesthenic symptoms, pathological psychometric performance, and verified exposure to neurotoxic organic solvents. A control group of 16 patients with myalgias or backache, or both, and no signs of disease was used for comparison. The purpose was to study possible changes in the cerebrospinal fluid that might contribute to understanding the aetiology of solvent induced chronic toxic encephalopathy. A rise in protein, albumin, and IgG was found in the patient group compared with the control group, as well as reduced concentrations of phosphoethanolamine, taurine, homocarnosine, ethanolamine, alpha-aminobutyric acid, and leucine. Using a stepwise multiple regression analysis, taurine was negatively correlated to exposure to solvents. These findings may indicate membrane alterations in the central nervous system related to exposure to organic solvents.