A Parallel Reaction Monitoring Mass Spectrometric Method for Analysis of Potential CSF Biomarkers for Alzheimer's Disease.

SCOPE: The aim of this study was to develop and evaluate a parallel reaction monitoring mass spectrometry (PRM-MS) assay consisting of a panel of potential protein biomarkers in cerebrospinal fluid (CSF). EXPERIMENTAL DESIGN: Thirteen proteins were selected based on their association with neurodegenerative diseases and involvement in synaptic function, secretory vesicle function, or innate immune system. CSF samples were digested and two to three peptides per protein were quantified using stable isotope-labeled peptide standards. RESULTS: Coefficients of variation were generally below 15%. Clinical evaluation was performed on a cohort of 10 patients with Alzheimer's disease (AD) and 15 healthy subjects. Investigated proteins of the granin family exhibited the largest difference between the patient groups. Secretogranin-2 (p<0.005) and neurosecretory protein VGF (p<0.001) concentrations were lowered in AD. For chromogranin A, two of three peptides had significantly lowered AD concentrations (p<0.01). The concentrations of the synaptic proteins neurexin-1 and neuronal pentraxin-1, as well as neurofascin were also significantly lowered in AD (p<0.05). The other investigated proteins, ß2-microglobulin, cystatin C, amyloid precursor protein, lysozyme C, neurexin-2, neurexin-3, and neurocan core protein, were not significantly altered. CONCLUSION AND CLINICAL RELEVANCE: PRM-MS of protein panels is a valuable tool to evaluate biomarker candidates for neurodegenerative disorders.

Increased blood-brain barrier permeability is associated with dementia and diabetes but not amyloid pathology or APOE genotype.

Blood-brain barrier (BBB) dysfunction might be an important component of many neurodegenerative disorders. In this study, we investigated its role in dementia using large clinical cohorts. The cerebrospinal fluid (CSF)/plasma albumin ratio (Qalb), an indicator of BBB (and blood-CSF barrier) permeability, was measured in a total of 1015 individuals. The ratio was increased in patients with Alzheimer's disease, dementia with Lewy bodies or Parkinson's disease dementia, subcortical vascular dementia, and frontotemporal dementia compared with controls. However, this measure was not changed during preclinical or prodromal Alzheimer's disease and was not associated with amyloid positron emission tomography or APOE genotype. The Qalb was increased in diabetes mellitus and correlated positively with CSF biomarkers of angiogenesis and endothelial dysfunction (vascular endothelial growth factor, intracellular adhesion molecule 1, and vascular cell adhesion molecule 1). In healthy elderly, high body mass index and waist-hip ratio predicted increased Qalb 20 years later. In summary, BBB permeability is increased in major dementia disorders but does not relate to amyloid pathology or APOE genotype. Instead, BBB impairment may be associated with diabetes and brain microvascular damage.

Characteristic Cytokine and Chemokine Profiles in Encephalitis of Infectious, Immune-Mediated, and Unknown Aetiology.

BACKGROUND: Encephalitis is parenchymal brain inflammation due to infectious or immune-mediated processes. However, in 15-60% the cause remains unknown. This study aimed to determine if the cytokine/chemokine-mediated host response can distinguish infectious from immune-mediated cases, and whether this may give a clue to aetiology in those of unknown cause. METHODS: We measured 38 mediators in serum and cerebrospinal fluid (CSF) of patients from the Health Protection Agency Encephalitis Study. Of serum from 78 patients, 38 had infectious, 20 immune-mediated, and 20 unknown aetiology. Of CSF from 37 patients, 20 had infectious, nine immune-mediated and eight unknown aetiology. RESULTS: Heat-map analysis of CSF mediator interactions was different for infectious and immune-mediated cases, and that of the unknown aetiology group was similar to the infectious pattern. Higher myeloperoxidase (MPO) concentrations were found in infectious than immune-mediated cases, in serum and CSF (p = 0.01 and p = 0.006). Serum MPO was also higher in unknown than immune-mediated cases (p = 0.03). Multivariate analysis selected serum MPO; classifying 31 (91%) as infectious (p = 0.008) and 17 (85%) as unknown (p = 0.009) as opposed to immune-mediated. CSF data also selected MPO classifying 11 (85%) as infectious as opposed to immune-mediated (p = 0.036). CSF neutrophils were detected in eight (62%) infective and one (14%) immune-mediated cases (p = 0.004); CSF MPO correlated with neutrophils (p<0.0001). CONCLUSIONS: Mediator profiles of infectious aetiology differed from immune-mediated encephalitis; and those of unknown cause were similar to infectious cases, raising the hypothesis of a possible undiagnosed infectious cause. Particularly, neutrophils and MPO merit further investigation.

Diagnostic and prognostic significance of flow cytometry immunophenotyping in patients with leptomeningeal carcinomatosis.

Some patients with epithelial-cell cancers develop leptomeningeal carcinomatosis (LC), a severe complication difficult to diagnose and with an adverse prognosis. This study explores the contribution of flow cytometry immunophenotyping (FCI) to the diagnosis and prognosis of LC. Cerebrospinal fluid (CSF) samples from patients diagnosed with LC were studied using FCI. Expression of the epithelial-cell adhesion molecule (EpCAM) was the criterion used to identify the epithelial cells. To test the diagnostic precision, 144 patients (94 diagnosed with LC) were included. The prognostic value of FCI was evaluated in 72 patients diagnosed with LC and eligible for therapy. Compared with cytology, FCI showed greater sensitivity and negative predictive value (79.79 vs. 50%; 68.85 vs. 51.55%, respectively), but lower specificity and positive predictive value (84 vs. 100%; 90.36 vs. 100%, respectively). The multivariate analysis revealed that the percentage of CSF EpCAM+ cells predicted an increased risk of death (HR: 1.012, 95% CI 1.000-1.023; p=0.041). A cut-off value of 8% EpCAM+ cells in the CSF distinguished two groups of patients with statistically significant differences in overall survival (OS) (p=0.018). This cut-off value kept its statistical significance regardless of the absolute CSF cell-count. The FCI study of the CSF improved the sensitivity for diagnosing LC, but refinement of the technique is needed to improve specificity. Furthermore, quantification of CSF EpCAM+ cells was revealed to be an independent prognostic factor for OS in patients with LC eligible for therapy. An 8% cut-off value contributed to predicting clinical evolution before initiation of therapy.

Effectiveness of papaverine cisternal irrigation for cerebral vasospasm after aneurysmal subarachnoid hemorrhage and measurement of biomarkers.

Cisternal irrigation with thrombolytic agents was used to prevent post-SAH vasospasm, but its role remained inconclusive. To verify effectiveness of papaverine (PPV) in preventing vasospasm, we studied relationship between inflammatory biologic markers and vasospasm. This prospective study included 121 patients with clipped anterior circulation aneurysms that had ruptured, and 372 control patients. Patients were divided into three groups according to cisternal irrigation method: simple drain, papaverine group, and urokinase (UK) group. Intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) were determined in CSF and serum on days 3 and 7 after SAH. The PPV group showed similar incidence of vasospasm with UK group, but lower incidence than the simple drain group. The levels of ICAM-1 and VCAM-1 were significantly higher in the SAH group than in the control group. CSF and serum levels were more elevated on day 7 than day 3, and the degree of elevation were more marked when measured in the CSF than in the serum. However, there was no statistical difference between measured levels of ICAM-1 and VCAM-1, and vasospasm development. PPV cisternal irrigation was similarly effective as UK at preventing vasospasm. Although neither PPV nor UK irrigation could reduce the concentration of adhesion molecules compared with simple drain, we found levels of ICAM-1 and VCAM-1 were specifically elevated in the CSF. Therefore, further research should focus on anti-inflammation as a therapeutic target against cerebral vasospasm and on the CSF as the optimum place where such inflammatory action practically brought about.

Cytokines, cytokine antagonists, and soluble adhesion molecules in pediatric OMS and other neuroinflammatory disorders.

OBJECTIVE: To test for hypothesized disease- and treatment-induced changes in cytokines and adhesion molecules in children with opsoclonus-myoclonus syndrome (OMS). METHODS: Multiplex bead assay technology was used for simultaneous measurement of 34 soluble cytokines in cerebrospinal fluid (CSF) and serum. Soluble intercellular adhesion molecule-1 (sICAM-1) and vascular cell adhesion molecule-1 (sVCAM-1) were measured by ELISA. In total, there were 388 children (239 OMS, 114 controls, and 35 other inflammatory neurological disorders (OIND)). RESULTS: In untreated OMS, mean CSF IL-6 was elevated 2.3-fold, but 67-fold in OIND, without significant differences in other CSF cytokines. Mean serum concentrations of sIL-2Ra (+50%) and CXCL1 (+70%) (p<0.0001) were also raised. CSF CCL5 was more often detected in untreated OMS than controls (p=0.005), as was serum CCL11 and IL-13 in treated OMS. Mean CSF CCL4 and IL-1Ra were selectively higher in IVIg-treated OMS (p≤0.0001). CSF sICAM-1 was elevated only in OIND (3.3-fold); serum sICAM-1 was higher in untreated OMS (+21%); and sVCAM-1 was not affected. No correlations with OMS severity or duration were identified. CONCLUSIONS: Novel cytokine, cytokine antagonist, and soluble adhesion molecule abnormalities due to OMS or treatment were found. However, the normality of much of the data strengthens previous findings implicating B cell mechanisms.

Role of flow cytometry immunophenotyping in the diagnosis of leptomeningeal carcinomatosis.

PURPOSE: To explore the contribution of flow cytometry immunophenotyping (FCI) in detecting leptomeningeal disease in patients with solid tumors. EXPERIMENTAL DESIGN: Cerebrospinal fluid (CSF) samples from 78 patients who received a diagnosis of epithelial-cell solid tumors and had clinical data suggestive of leptomeningeal carcinomatosis (LC) were studied. A novel FCI protocol was used to identify cells expressing the epithelial cell antigen EpCAM and their DNA content. Accompanying inflammatory cells were also described. FCI results (positive or negative for malignancy) were compared with those from CSF cytology and with the diagnosis established by the clinicians: patients with LC (n = 49), without LC (n = 26), and undetermined (n = 3). RESULTS: FCI described a wide range of EpCAM-positive cells with a hyperdiploid DNA content in the CSF of patients with LC. Compared with cytology, FCI showed higher sensitivity (75.5 vs 65.3) and negative predictive value (67.6 vs 60.5), and similar specificity (96.1 vs 100) and positive predictive value (97.4 vs 100). Concordance between cytology and FCI was high (Kp = 0.83), although misdiagnosis of LC did not show differences between evaluating the CSF with 1 or 2 techniques (P = .06). Receiver-operator characteristic curve analyses showed that lymphocytes and monocytes had a different distribution between patients with and without LC. CONCLUSION: FCI seems to be a promising new tool for improving the diagnostic examination of patients with suspicion of LC. Detection of epithelial cells with a higher DNA content is highly specific of LC, but evaluation of the nonepithelial cell compartment of the CSF might also be useful for supporting this diagnosis.

Correlation of CSF neuroinflammatory molecules with leptomeningeal cortical subcortical white matter fractional anisotropy in neonatal meningitis.

It has been previously hypothesized that the high fractional anisotropy (FA) values in leptomeningeal cortical subcortical white matter (LCSWM) regions of neonatal brain with bacterial meningitis is due to the presence of adhesion molecules in the subarachnoid space, which are responsible for adherence of inflammatory cells over the subarachnoid membrane. The aim of this study was to look for any relationship between FA values in LCSWM regions and various neuroinflammatory molecules (NMs) in cerebrospinal fluid (CSF) measured in neonates with bacterial meningitis. Diffusion tensor imaging was performed on 18 term neonates (median age, 10.5 days) having bacterial meningitis and 10 age-/sex-matched healthy controls. CSF enzyme-linked immunosorbent assay was performed to quantify NMs [soluble intracellular adhesion molecules (sICAM), tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta)]. Significantly increased FA values were observed in LCSWM regions of the patients compared to controls. A significant positive correlation was observed between FA values in LCSWM regions and NMs [sICAM (r=0.67, P=.006), TNF-alpha (r=0.69, P=.005) and IL-1beta (r=0.82, P=.000)] in CSF of these patients. No difference in FA values (P=.99) in LCSWM regions was observed between patients with sterile (0.12+/-0.02) and culture-positive CSF study (0.12+/-0.02). FA may be used as noninvasive surrogate marker of NMs in neonatal meningitis in assessing therapeutic response in future.

Separation and determination of peptide hormones by capillary electrophoresis with laser-induced fluorescence coupled with transient pseudo-isotachophoresis preconcentration.

A new method for the determination of the peptide hormones and their fragments by capillary electrophoresis (CE) with laser-induced fluorescence (LIF) detection and transient pseudo-isotachophoresis (pseudo-tITP) preconcentration was established in this study. The LIF detector used an argon ion laser with excitation wavelength at 488 nm and emission wavelength at 535 nm. Fluorescein isothiocyanate (FITC) was used as precolumn derivatization reagent to label cholecystokinin tetrapeptide (CCK-4), neurotensin (NT), neurotensin hexapeptide (NT(8-13)), and neurokinin B (NKB). Borate (10 mmol/L, pH 9.0) was selected as derivatization medium to get the high efficiency. When the addition of 70% (v/v) methanol and 1% (m/v) sodium chloride (NaCl) to the sample matrix, and with borate buffer (110 mM, pH 9.5) and 20% (v/v) methanol as running buffer, a preconcentration based on the pseudo-tITP afforded 100-fold improvement in peak heights compared with the traditional hydrodynamic injection (2.3% capillary volume). The detection limits (signal/noise=3) based on peak height were found to be 0.04, 0.1, 0.2, and 0.08 nmol/L for NT(8-13), NT, NKB, and CCK-4, respectively. The method was validated and applied to qualitative analysis of NT and NT(8-13) in human cerebrospinal fluid sample.

Increased diffusion of soluble adhesion molecules in meningitis, severe sepsis and systemic inflammatory response without neurological infection is associated with intrathecal shedding in cases of meningitis.

OBJECTIVE: Sepsis and systemic inflammatory response syndrome (SIRS) result in the release in plasma of inflammatory cytokines and soluble forms of adhesion molecules in relation to endothelial activation. This study was designed to compare cerebrospinal fluid (CSF) concentrations of adhesion molecules in meningitis and SIRS without neurological infection and to evaluate in meningitis whether they originate from passive diffusion through damaged blood-CSF barrier or from local production. DESIGN: Prospective observational study. SETTING: University hospital medical intensive care unit. PATIENTS: Nineteen patients with meningitis and 41 patients with sepsis or SIRS without cerebrospinal infection consecutively admitted to the critical care unit over an 18-month period. INTERVENTIONS: Soluble forms of adhesion molecules (ICAM-1, VCAM-1, E-selectin) and cytokines (interleukin (IL)-1beta and TNF-alpha) were measured in paired CSF and blood samples. RESULTS: Serum concentrations of soluble adhesion molecules and cytokines were increased in the two groups, without significant differences. The CSF concentrations were elevated in both cases, whereas patients with meningitis demonstrated significantly higher CSF concentrations of soluble ICAM-1, VCAM-1, E-selectin, and TNF-alpha ( p<0.001), with higher corresponding CSF/serum ratios. Correlations between CSF and serum concentrations were found only in meningitis. These correlations were strong for soluble ICAM-1 (r(2)=0.7, p<0.001) and E-selectin (r(2)=0.9, p<0.001), but weaker for VCAM-1. VCAM-1 CSF/serum ratios were increased, in comparison with ICAM-1 and E-selectin CSF/serum ratios, despite similar molecular weights. Serum and CSF levels of cytokines and adhesion molecules were not predictive of death for the whole population, except concentrations of ICAM-1 significantly increased in non-surviving patients ( p<0.05). CONCLUSIONS: The CSF soluble adhesion molecules are increased in sepsis, SIRS and meningitis. In meningitis, the correlation between CSF and serum concentrations of adhesion molecules and the presence of a discrepancy of CSF/serum ratios for molecules of the same molecular weight may suggest intrathecal shedding in addition to diffusion through blood-CSF barrier.

Cell surface bound and soluble adhesion molecules in CSF and blood in multiple sclerosis: correlation with MRI-measures of subclinical disease severity and activity.

BACKGROUND: The expression of soluble cell adhesion molecules (AM) in cerebrospinal fluid (CSF) and blood and their significance as measures of disease activity has been extensively studied in patients with multiple sclerosis (MS). In previous studies, we found that cell surface bound AM on mononuclear cells (MNC) in CSF and blood might be useful markers of clinical disease activity in MS patients. OBJECTIVE: To analyze the correlation of cell surface bound and soluble AM in CSF and blood with magnetic resonance imaging (MRI) markers of subclinical disease severity and activity in patients with MS. METHODS: Expression levels of cell surface bound AM on peripheral blood and CSF MNC were determined by flow cytometry analysis in 77 (CSF: 33) MS patients. Concentration levels of the soluble forms of AM were measured by enzyme-linked immunosorbent assay (ELISA). In corresponding cerebral gadolinium (Gd)-enhanced MRI scans, we determined both measures of subclinical disease severity and subclinical disease activity. RESULTS: The expression levels of cell surface bound AM in peripheral blood correlated inversely with parameters for subclinical disease severity and activity on cerebral MRI scans as well as with the disease duration. Furthermore, we found significant correlations between serum levels of soluble AM and patient age but not with disease duration. CONCLUSIONS: Our results suggest that subclinical disease progression may be associated with a decrease of the expression of cell surface bound AM on peripheral blood MNC. This might be a result of activated MNC migration into the CNS.

CD45RA+ ICAM-3+ lymphocytes in cerebrospinal fluid and blood as markers of disease activity in patients with multiple sclerosis.

OBJECTIVES: Autoreactive T cells targeted against antigens of the myelin sheath are suggested to play an important role in the pathogenesis of multiple sclerosis (MS). Naive (CD45RA+) T cells and intercellular adhesion molecule-3 (ICAM-3) are markers for un-activated lymphocytes. This study was performed to investigate, whether the expression levels of these antigens both on cerebrospinal fluid (CSF) and peripheral blood lymphocytes can be used as activity markers in MS. MATERIALS AND METHODS: Corresponding blood and CSF samples were obtained from 31 patients with relapsing-remitting MS. Of the 31 MS patients 23 were suffering from acute relapses at the time of examination and all of them were treated with high-dose methylprednisolone (MP). Blood was collected again on the 10th day of therapy and after 3 months. The control group consisted of 12 healthy persons. Two-color flow cytometry was performed to evaluate the percentage of both CD45RA+ and ICAM-3+ cells within the lymphocyte population. RESULTS: The percentage of CD45RA+ ICAM-3+ cells in the CSF of MS patients with relapses was significantly increased compared to patients in remission (P<0.05). In blood, a significantly lower percentage of CD45RA+ ICAM-3+ lymphocytes was found in both patient groups compared to healthy controls (Relapse: P<0.05, Remission: P<0.10). Additionally, we found a significant increase (P < 0.01) in the percentage of CD45RA+ ICAM-3+ lymphocytes in blood of MS patients suffering from acute relapse on the 10th day of high-dose MP treatment. CONCLUSION: Our data suggest that the percentage of CD45RA+ ICAM-3+ lymphocytes in CSF can be used as marker of disease activity in MS patients.

Blood-brain barrier function in cerebral malaria and CNS infections in Vietnam.

BACKGROUND: The intraerythrocytic parasite Plasmodium falciparum induces the life-threatening neurologic syndrome of cerebral malaria (CM) from within cerebral blood vessels, without entering the brain parenchyma. OBJECTIVES: 1) To assess the use of CSF as an indicator of specific pathologic processes occurring in the brain during CM; 2) to compare this with other neurologic and infectious diseases to understand the distinct pathogenic features of CM; 3) to test the hypothesis that CM involves a specific functional breakdown of the blood-brain barrier (BBB). METHODS: 1) Radial immunodiffusion assays to detect albumin and IgG in matched plasma and CSF samples as indicators of BBB integrity and intrathecal IgG production; and 2) ELISA for soluble intracellular adhesion molecule-1 and sE-selectin, the cytokines tumor necrosis factor-alpha and transforming growth factor-beta1, and the matrix metalloproteinase MMP-9, to detect cellular activation and inflammatory responses within the brain. RESULTS: Albumin and IgG indices implied only minimal degree of BBB breakdown in a few cases of CM, with most remaining within the normal range. In contrast, cryptococcal, tubercular, and acute bacterial meningitis produced detectable changes in the composition of the CSF and evidence of BBB breakdown. CONCLUSIONS: CM appears to involve only subtle functional changes in BBB integrity with minimal intraparenchymal inflammatory responses compared with other neurologic infections. This focuses attention on local events within and around the cerebral microvasculature in CM, rather than indicating widespread parenchymal disease.

Soluble and cell surface ICAM-3 in blood and cerebrospinal fluid of patients with multiple sclerosis: influence of methylprednisolone treatment and relevance as markers for disease activity.

OBJECTIVE: The expression of intercellular adhesion molecule-3 (ICAM-3), a member of the Ig supergene family, is restricted to immune competent cells. Expression of soluble and cell surface ICAM-3 (s- and c-ICAM-3) is preferentially seen in the state of low activation of the immune system. We studied the relevance of the expression levels of s- and c-ICAM-3 in cerebrospinal fluid (CSF) and blood as markers for disease activity as well as the influence of high-dose methylprednisolone (MP) treatment upon the expression of s- and c-ICAM-3 in blood of patients with multiple sclerosis (MS). MATERIALS AND METHODS: A total of 33 patients (relapses n = 25, remission n = 8) with relapsing-remitting MS were included into the study. CSF and blood were acquired from all of them. Of the patients 24 were treated with high-dose MP. In those, blood was additionally collected at the 10th day of the therapy and after 3 months. Expression of c-ICAM-3 was determined by two colour FACS analysis, whereas the concentration levels of s-ICAM-3 were measured by ELISA. RESULTS: In CSF we detected a significant decrease of the expression levels of c-ICAM-3 on CD3+ T cells in 25 patients suffering from an acute relapse in contrast to 8 patients with remission (P= 0.04). In comparison to the levels before treatment and after 3 months, at the 10th day of MP treatment we obtained highly significant changes of the expression values of c-ICAM-3 both on CD3+ T cells (P = 0.0004; P= 0.005) and CD14+ monocytes/macrophages (P =0.0006; P=0.008) on the 10th day of high-dose MP treatment from 24 MS patients. CONCLUSION: The increase of ICAM-3 levels might indicate the anti-inflammatory effect of the MP treatment. It could be interesting to search for similar effects investigating the new immune modulatoring therapy forms of MS.

Cleaved L-selectin concentrations in meningeal leukaemia.

Involvement of the central nervous system has important therapeutic implications in acute leukaemia. Because the identification of blast cells in cerebrospinal fluid (CSF) is often difficult, there is a need for sensitive markers of leukaemic infiltration. Since the shed form of L-selectin (sL-selectin) is frequently increased in acute leukaemia (sL-selectin+ leukaemia), we examined whether assay of sL-selectin in CSF could improve our ability to detect such meningeal involvement. CSF sL-selectin was significantly (p < 0.001) higher in 15 patients with sL-selectin+ meningeal leukaemia (median 60 ng/mL, range 34-150) than in 20 patients with acute leukaemia without meningeal involvement (12 ng/mL, 1-39) or 88 control patients (14 ng/mL, 0-37). Serial measurements of sL-selectin in patients with sL-selectin+ leukaemic meningitis showed increased CSF concentrations of the cleaved receptor in 4 patients with therapy-resistant meningeal leukaemia and sustained normal concentrations in 9 patients in remission. Our results suggest that CSF sL-selectin may be a useful marker in the detection of meningeal involvement by blast cells in patients with sL-selectin+ leukaemia.

Increased levels of intercellular adhesion molecule-1 (ICAM-1) and tumor necrosis factor receptor in the cerebrospinal fluid of patients with multiple sclerosis.

We investigated the presence of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble tumor necrosis factor receptor (sTNF-R) antigens in the CSF of patients with multiple sclerosis (MS) using a double-determinant ELISA. Patients with acute relapsing MS during an exacerbation (p < 0.001) and those with chronic progressive MS (p < 0.001) had significantly increased CSF levels of sICAM-1 compared with subjects with other neurologic diseases. CSF levels of sTNF-R were also significantly increased in patients with acute relapsing MS during an exacerbation (p < 0.001) and chronic progressive MS (p < 0.001) compared with subjects with other neurologic diseases. CSF levels of sICAM-1 and sTNF-R were positively correlated in patients with acute relapsing MS during an exacerbation (r = 0.81, p < 0.01) and chronic progressive MS (r = 0.86, p < 0.001). These results suggest that active immune reactions involving ICAM-1 and TNF-R production are present within the CNS and that both sICAM-1 and sTNF-R are important immunologic markers of the clinical activity of MS.

Soluble intercellular adhesion molecule-1 in cerebrospinal fluid: an indicator for the inflammatory impairment of the blood-cerebrospinal fluid barrier.

A soluble form of the intercellular adhesion molecule-1 (sICAM-1) was measured in paired cerebrospinal fluid (CSF)/blood samples from 123 patients with different neurological diseases. Mean levels of circulating ICAM-1 in the blood were mean +/- SD = 423 +/- 184.6 ng ml-1 (range 44-1115 ng ml-1). Considerable differences of sICAM-1 in the CSF of patients were observed between disease groups. In acute bacterial meningitis, sICAM-1 levels as high as 1/5 of the serum concentration were detected in the CSF (n = 24; mean +/- SD = 33.0 +/- 23.7 ng ml-1; range: 4.8-93.9 ng ml-1). These changes coincided with a severe blood-CSF barrier dysfunction as indicated by a high CSF/blood ratio for albumin (mean +/- SD = 46.7 +/- 52.2; range: 16.8-249.3). In patients with polyradiculitis (n = 9; mean +/- SD = 14.5 +/- 11.9 ng ml-1; range: 2.6-43.7 ng ml-1) a similar covariation between the albumin and sICAM CSF/blood ratios was detected. In patients with multiple sclerosis (n = 9; mean +/- SD = 5 +/- 4.3; range: 0-12.7 ng ml-1) or HIV infection with neurological symptoms (n = 18; mean +/- SD = 4.9 +/- 3.2; range; 1-11.9 ng ml-1) low levels of sICAM-1 were detected in the CSF associated with intact blood-CSF barrier function in most patients. Among 13 patients with viral meningitis, only four had detectable levels of sICAM-1 in their CSF (mean +/- SD = 1.0 +/- 1.5 ng ml-1; range: 0-3.7).(ABSTRACT TRUNCATED AT 250 WORDS)

Adhesion molecule expression on cerebrospinal fluid T lymphocytes: evidence for common recruitment mechanisms in multiple sclerosis, aseptic meningitis, and normal controls.

The expression of T-cell surface antigens was investigated in the cerebrospinal fluid (CSF) and peripheral blood of 11 patients with multiple sclerosis, 6 patients with aseptic meningitis, and 16 healthy subjects. A panel of monoclonal antibodies to adhesion and activation proteins was used in combination with an anti-CD3 antibody in dual-color flow cytometry. The problem of low cell numbers in the CSF from normal individuals was overcome by use of a modified staining procedure in microtiter plates, enabling analysis of as few as 5,000 cells. The majority of T cells in the CSF of the three patient groups exhibited the phenotype of memory cells (CD45RO+). CSF T cells also expressed significantly higher levels of several adhesion and activation molecules, including very late activation (VLA) antigens 3 through 6, lymphocyte function-associated (LFA) antigen 1, LFA-3, CD2, CD26, and CD44. Comparison between the different categories revealed that peripheral blood T cells from patients with multiple sclerosis expressed significantly lower amounts of the VLA integrins 4 and 5 as well as their common beta subunit CD29, compared with normal control subjects. No differences between patients with multiple sclerosis and control subjects could, however, be seen regarding the distribution of memory/naive cells or CD4+/CD8+ cells in peripheral blood. Our data support a hypothesis that memory T cells with a high expression of several adhesion molecules are selectively recruited to the central nervous system compartment, under both pathological and normal conditions.(ABSTRACT TRUNCATED AT 250 WORDS)

Increased levels of circulating ICAM-1 in serum and cerebrospinal fluid of patients with active multiple sclerosis. Correlation with TNF-alpha and blood-brain barrier damage.

The mechanism for the initiation of blood-brain barrier damage and intrathecal inflammation in multiple sclerosis (MS) is poorly understood. We have recently reported that levels of tumor necrosis factor-alpha (TNF-alpha) correlate with blood-brain barrier damage in patients with active MS. Stimulation of endothelial cells by TNF-alpha induces the expression of intercellular adhesion molecule-1 (ICAM-1), which is an important early marker of immune activation and response. We report herein for the first time the detection of high levels of free circulating ICAM-1 in serum and cerebrospinal fluid of patients with active MS. Levels of circulating ICAM-1 in these patients correlated with CSF pleocytosis, TNF-alpha levels and blood-brain barrier damage. These findings have important implications for the understanding and investigation of the intrathecal inflammatory response in active MS.