Elevation of MCP-1 and MCP-1/VEGF ratio in cerebrospinal fluid of amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with progressive cell death of upper and lower motor neurons. In this study, we measured monocyte chemotactic protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) levels in cerebrospinal fluid (CSF) and serum by enzyme-linked immunosorbent assay (ELISA) in 42 ALS patients, and compared these levels with those of control subjects with other neurodegenerative disorders or with those of normal controls. MCP-1 levels in CSF were significantly higher in ALS patients than in the control group. VEGF levels in CSF tended to be lower in ALS patients than in the control group, but not significantly. A positive correlation was found between MCP-1 levels in CSF of ALS patients and the total Norris scale. The elevation of MCP-1/VEGF ratio in CSF was more specific to ALS patients compared to other neurological diseases such as Parkinson's disease (PD) and spinocerebellar ataxia (SCA) and to controls. Our data suggested that both MCP-1 levels and MCP-1/VEGF ratio in CSF may be useful markers for the clinical diagnosis of ALS.     

Elevation of MCP-1 and MCP-1/VEGF ratio in cerebrospinal fluid of amyotrophic lateral sclerosis patients

Abstract

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease with progressive cell death of upper and lower motor neurons. In this study, we measured monocyte chemotactic protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) levels in cerebrospinal fluid (CSF) and serum by enzyme-linked immunosorbent assay (ELISA) in 42 ALS patients, and compared these levels with those of control subjects with other neurodegenerative disorders or with those of normal controls. MCP-1 levels in CSF were significantly higher in ALS patients than in the control group. VEGF levels in CSF tended to be lower in ALS patients than in the control group, but not significantly. A positive correlation was found between MCP-1 levels in CSF of ALS patients and the total Norris scale. The elevation of MCP-1/VEGF ratio in CSF was more specific to ALS patients compared to other neurological diseases such as Parkinson's disease (PD) and spinocerebellar ataxia (SCA) and to controls. Our data suggested that both MCP-1 levels and MCP-1/VEGF ratio in CSF may be useful markers for the clinical diagnosis of ALS.     

Cerebrospinal fluid vascular endothelial growth factor in patients with amyotrophic lateral sclerosis

Oxidative stress and glutamate-mediated toxicity may play an important role in the etiopathogenesis of amyotrophic lateral sclerosis (ALS). The vascular endothelial growth factor (VEGF) is a neuroprotective cytokine activated by hypoxia. The aim of this study was to measure VEGF levels in the cerebrospinal fluid (CSF) of ALS patients. The study concerned 30 ALS patients and 30 control subjects. The VEGF was measured by the enzyme-linked immunosorbent assay. The results have shown that CSF VEGF levels are significantly increased in patients with long duration of ALS and in patients with limb-onset of the disease compared with controls (P<0.05). Moreover, the type of ALS patients’ subgroup significantly influences CSF VEGF levels (P=0.05). The CSF VEGF levels were significantly increased in patients with limb-onset compared to patients with bulbar-onset of ALS, and in patients with long duration of ALS compared to patients with its short duration (P<0.05). There was a significant correlation between CSF VEGF levels and duration of ALS (P<0.05). It seems that a significant increase in CSF VEGF levels in patients with limb-onset of ALS and in patients with long duration of the disease may have a protective role against glutamate-mediated toxicity and oxidative damage of motor neurons. However, the conclusions are limited due to relatively small subgroups of ALS patients and by lack of a control group consisting of healthy persons. Further investigations could help to confirm the results from this preliminary report.     

VEGF is increased in serum but not in spinal cord from patients with amyotrophic lateral sclerosis

Homogenates of postmortem spinal cord from seven patients with amyotrophic lateral sclerosis (ALS) and six controls together with serum from 13 patients with ALS and 13 controls were analysed for vascular endothelial growth factor (VEGF) using an immunoassay (ELISA). There was no significant difference in VEGF levels in the spinal cord between the ALS patients and the controls. In serum the VEGF levels were significantly higher in the ALS group than in the control group. There was a moderate inverse relation between the duration of the disorder and the serum VEGF levels. The findings indicate that the capacity to synthesize VEGF is preserved even in the late stages of ALS. The results might also be consistent with a transient hypoxic component during the course of ALS, but not with a persistant spinal hypoxia in the late stages of the disorder.     

Mécanismes de dérégulation de la réponse à l’hypoxie dans la sclérose latérale amyotrophique

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder of upper and lower motorneurons, leading to death in 3 to 5 years. Respiratory insufficiency and hypoxemia are closely linked during the clinical course of ALS. Chronic respiratory insufficiency and hypoxemia generally occur late in the disease course but rapid episodes of intermittent hypoxemia followed by reoxygenation can occur early and insidiously. Two pathways are involved in the response to hypoxemia: (i) hypoxia inducible factor-1 (HIF-1) and VEGF/HIF-2 and an erythropoietin (EPO) mediated pathway, in response to prolonged hypoxemia; and (ii) nuclear factor κ-B (NFκ-B) during acute hypoxemia followed by reoxygenation episodes, inducing inflammatory mediators: interleukin-6 (IL-6), TNF-α, cyclo oxygenase-2 (COX-2) and prostaglandin E-2 (PGE-2). Our aim was to specify the role of the different functional pathways of response to hypoxemia in sporadic ALS patients, compared with neurological controls and according to the level of hypoxemia. We report the results of several studies of hypoxemic and/or inflammatory mediators in the cerebrospinal fluid (CSF) from ALS patients, according to their respiratory status, showing a selective defect of HIF-1 mediated angiogenic factors (VEGF and angiogenin [ANG]) during chronic hypoxia in sporadic ALS patients, compared to hypoxemic neurological controls; contrasting with an early activation of the NFκ-B pathway since the isolated desaturation stage (IL-6, TNF-α, PGE-2, angiopoietin-2) in the same cohort of sporadic ALS patients. All these results are consistent with a selective impairment of the HIF-1 pathway during chronic hypoxemia in ALS patients. Inflammatory mediators were strongly elevated, since the early stage of the disease until chronic hypoxemia, suggesting a compensatory mechanism.     

Increased cerebrospinal fluid levels of substance P in patients with amyotrophic lateral sclerosis

To clarify the mechanism of brain and spinal cord impairment in amyotrophic lateral sclerosis (ALS), we measured the cerebrospinal fluid (CSF) levels of substance P (SP) in 11 patients with sporadic ALS. Findings were compared with those obtained in controls and diseased controls. The CSF SP levels of patients with ALS, and particularly in patients with a disease duration of less than 2.5 years, were significantly higher than those in controls. These findings strongly suggested that SP may play an important role in the pathophysiology of ALS.     

GDNF but not BDNF is increased in cerebrospinal fluid in amyotrophic lateral sclerosis

Cerebrospinal fluid from 15 patients with ALS and 11 controls without neurological disease were analysed for levels of the neurotrophic factors BDNF and GDNF. Analyses were performed using a sensitive sandwich immunoassay (ELISA). There was no significant difference in BDNF levels between the ALS patients and the control subjects studied. Measurable levels of GDNF were found in 12 out of 15 ALS samples. GDNF was not detected in CSF from any of the control subjects. The finding of increased CSF levels of GDNF in ALS compared to controls, together with earlier findings of increased expression of GDNF mRNA in muscle in ALS, indicates that the capacity to synthesize GDNF is enhanced in this disorder.     

Elevated cerebrospinal fluid and plasma homocysteine levels in ALS

Background:  High cerebrospinal fluid (CSF) and plasma levels of homocysteine (HC) have been reported in certain neurodegenerative disorders, such as Alzheimer's, Parkinson's diseases and, recently, amyotrophic lateral sclerosis (ALS).
Objectives:  To assay the CSF and plasma levels of HC in ALS patients and controls, and to evaluate the relationship between HC levels and clinical variables of the disease.
Methods:  Cerebrospinal fluid from sixty-nine (M/F 1.87) and plasma from sixty-five ALS patients (M/F 1.83) were taken and stored at −80°C until use. Controls (CSF = 55; plasma = 67) were patients admitted to our hospital for neurological disorders with no known relationship to HC changes. CSF and plasma from ALS patients and controls were obtained as a necessary step of the diagnostic workup. HC levels in CSF and plasma were assayed using a high performance liquid chromatograph (HPLC) and a fluorimeter detector.
Results:  The median level of total HC in the CSF of ALS patients was 0.46 μM, significantly higher than that of the controls (0.24 μM, +91.6%, P  < 0.001). A similar trend was observed when HC was assayed in plasma (ALS, 12.4 μM vs. controls, 7.26 μM, +70.8%, P  < 0.001). The CSF and plasma HC levels showed no relationship with the disease progression, age at onset, and the site of onset.
Conclusions:  Homocysteine is a biochemical marker in ALS, and it might be related to the pathophysiology of the disease.     

Glutamate levels in cerebrospinal fluid in amyotrophic lateral sclerosis: a reappraisal using a new HPLC method with coulometric detection in a large cohort of patients.

Glutamate is involved in the degeneration of motor neurons in amyotrophic lateral sclerosis (ALS). However, the aetiology of ALS appears heterogeneous, leading to the possibility that patient subgroups with different pathophysiology may exist. The concentration of glutamate in cerebrospinal fluid (CSF) is measured using a new HPLC method with coulometric detection in a large cohort of ALS patients and controls: 377 ALS patients, 88 neurological patients and 18 normal controls. In ALS patients, and only in these subjects, the existence of two groups was observed, one with normal glutamate concentrations and one (40.8% of ALS patients) with high glutamate concentrations. High glutamate concentrations were correlated with a spinal onset of the disease, more impaired limb function and a higher rate of muscle deterioration. These results suggest that elevations of CSF glutamate concentrations could reflect the intensity of cell insult in the spinal cord. It remains to be determined if the group of patients with high CSF glutamate concentrations represents a specific subgroup of patients in terms of mechanism of disease, or only in terms of the spatial extent of motor neuron insult.     

Serum level of CNTF is elevated in patients with amyotrophic lateral sclerosis and correlates with site of disease onset

We measured serum levels of neurotrophic cytokines ciliary neurotrophic factor (CNTF) and leukaemia inhibiting factor (LIF) in 96 patients either with familial amyotrophic lateral sclerosis (FALS, n  = 18) or sporadic ALS (SALS, n  = 78) and in 27 inflammatory neurological controls (13 multiple sclerosis and 14 Guillain-Barré syndrome) and in 27 healthy controls. Serum level of CNTF was significantly higher in ALS patients than in inflammatory neurological controls or healthy controls, and significantly higher in patients with ALS onset from upper or lower extremities than in patients with a purely bulbar onset of the disease. Serum CNTF levels did not significantly differ between patients with FALS and SALS, and it did not correlate with the age of onset or duration of the disease. No detectable serum levels of LIF were observed in the patient groups or in the healthy controls.     

Increased TDP-43 protein in cerebrospinal fluid of patients with amyotrophic lateral sclerosis

There is mounting pathological, biochemical and genetic evidence that the metabolism and aggregation of the 43-kDa transactive response (TAR)-DNA-binding protein (TDP-43) play a crucial role in the pathogenesis of sporadic and some forms of familial amyotrophic lateral sclerosis (ALS). Recently, it was reported using an ELISA system that elevated levels of TDP-43 were detected in plasma samples from patients with Alzheimer’s disease and frontotemporal dementia, compared to healthy controls. To determine whether quantification of TDP-43 in cerebrospinal fluid (CSF) is potentially informative in the diagnosis of ALS, we measured the concentration, by a similar ELISA method, of TDP-43 in CSF from 30 patients with ALS (diagnosed according to the revised El Escorial criteria) and 29 age-matched control patients without any neurodegenerative disease. We found that, as a group, the ALS patients had significantly higher levels of TDP-43 in their CSF than the age-matched controls (6.92 ± 3.71 ng/ml in ALS versus 5.31 ± 0.94 ng/ml in controls, p < 0.05), with levels of TDP-43 in CSF elevated beyond 95% upper confidence level for the control group in six (20%) of the patients with sporadic ALS. All the six patients with higher levels of CSF TDP-43 were examined within 10 months of the onset of illness. The patients examined within 10 months of onset showed significantly higher levels of CSF TDP-43 (8.24 ± 4.72 ng/ml) than those examined after 11 months or more of onset (5.41 ± 0.66 ng/ml, p < 0.05). These results suggest that the levels of TDP-43 in CSF may increase in the early stage of ALS. We also confirmed the existence of the TDP-43 protein in CSF from some patients with ALS, and a control subject, by western blotting of proteins immunocaptured from the CSF samples. Raised TDP-43 levels in the CSF may preempt the formation of TDP-43 pathology in the central nervous system, or correlate with early-stage TDP-43 pathology, and accordingly be a biomarker for the early stage of ALS.     

Cerebrospinal fluid tau protein is not a biological marker in amyotrophic lateral sclerosis

Background:  Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disorder leading to progressive motor neuron cell death. Etiopathogenesis is still imperfectly known and much effort have been undertaken to find a biological marker that could help in the early diagnosis and in the monitoring of disease progression. Cerebrospinal fluid (CSF) concentrations of tau , an axonal microtubule-associated protein, have been measured in ALS with levels found increased in some studies and unchanged in others.
Methods:  Total CSF tau level was assayed in a population of ALS patients ( n =  57) and controls ( n =  110) using a specific ELISA method.
Results:  No significant differences in the median CSF tau levels between ALS cases and controls were found [ALS: 126 pg/ml (78–222); controls: 112 pg/ml (71–188), P =  ns]. In the ALS group, the bulbar-onset patients showed increased CSF tau levels as compared with the spinal-onset cases. These differences might be related to the higher age of the bulbar-onset patients. Further, no correlations were found between CSF tau concentrations and the rate of progression of the disease.
Conclusions:  These results do not support the hypothesis that total CSF tau protein is a reliable biological marker for ALS.     

Cerebrospinal fluid and serum vascular endothelial growth factor and nitric oxide levels in newborns with hypoxic ischemic encephalopathy

Excitatory amino acids, cytokines and nitric oxide (NO) have been studied in the etiology and pathogenesis of hypoxic ischemic encephalopathy (HIE) of the newborn. Vascular endothelial growth factor (VEGF) is a known mediator of angiogenesis and has been shown to induce vascular proliferation and permeability via NO-mediated mechanism during hypoxia. The objective of this study was to investigate the cerebrospinal fluid and serum VEGF and NO levels in different stages of HIE and the correlation between the two mediators. Cerebrospinal fluid (CSF) and serum samples of 19 newborns with HIE and 13 controls were obtained within the first 24 h of life and kept at -70 degrees C until the time of measurement. NO levels were determined by Sievers NOA by chemiluminescence method and VEGF levels were measured by the enzyme-linked immunosorbent assay double sandwich method. The NO levels in CSF were higher than the control and mild HIE group in newborns with moderate to severe HIE, and VEGF levels in CSF were higher in the mild HIE group compared to controls but similar in the moderate to severe HIE group compared to mild HIE and control patients. There was no difference between groups with regard to serum NO or VEGF levels, and no correlation was observed between NO and VEGF levels both in CSF and serum samples. Depending on the severity of the hypoxic insult the stimulus for NO production by VEGF may have variable effects on endothelial cells which may give rise to the current results.     

CSF neurofilament protein analysis in the differential diagnosis of ALS

Background

Cerebrospinal fluid (CSF) biomarkers have been studied to differentiate between patients with ALS and neurological controls, but not in comparison to clinically more relevant disorders mimicking ALS.

Methods

In this retrospective study, CSF concentrations of various brain-specific proteins were analyzed in patients with ALS (n = 32) and ALS-mimic disorders (n = 26).

Results

CSF concentrations of neurofilament light (NFL) and heavy chain (NFHp35), but not other brain-specific proteins, were significantly higher in patients with ALS than in patients with an ALS-mimic disorder, however with maximum sensitivity or specificity of 80 %. The mean CSF level of NFHp35 was 781 ng/L in the ALS group vs. 338 ng/L in the ALSmimic disorders group and for NFL the mean CSF levels were 62 ng/L vs. 24 ng/L.

Conclusion

Although CSF concentrations of NFL and NFHp35 are higher in patients with ALS, the diagnostic accuracy for differentiating ALS from ALS-mimic disorders seems insufficient. Our results suggest that, in the clinical work-up of patients suspected of ALS, application of CSF analysis alone is limited but may have potential in combination with other clinical and electrophysiological markers.     

CSF neurofilament proteins as diagnostic and prognostic biomarkers for amyotrophic lateral sclerosis

Elevated cerebrospinal fluid (CSF), Neurofilament Light (NF-L) and phosphorylated Heavy (pNF-H) chain levels have been found in Amyotrophic Lateral Sclerosis (ALS), with studies reporting a correlation of both neurofilaments (NFs) with the disease progression. Here, we measured NF-L and pNF-H concentrations in the CSF of ALS patients from a single tertiary Center and investigated their relationship with disease-related variables. A total of 190 ALS patients (Bulbar, 29.9%; Spinal, 70.1%; M/F = 1.53) and 130 controls with mixed neurological diseases were recruited. Demographic and clinical variables were recorded, and ΔFS was used to rate the disease progression. Controls were divided into two cohorts: (1) patients with non-inflammatory neurological diseases (CTL-1); (2) patients with acute/subacute inflammatory diseases and tumors, expected to lead to significant axonal and tissue damage (CTL-2). For each patient and control, CSF was taken at the time of the diagnostic work-up and stored following the published guidelines. CSF NF-L and pNF-H were assayed with commercially available ELISA-based methods. Standard curves (from independent ELISA kits) were highly reproducible for both NFs, with a coefficient of variation < 20%. We found that CSF NF-L and pNF-H levels in ALS were significantly increased when compared to CTL-1 (NF-L: ALS, 4.7 ng/ml vs CTL-1, 0.61 ng/ml, p < 0.001; pNF-H: ALS, 1.7 ng/ml vs CTL-1, 0.03 ng/ml, p < 0.0001), but not to CTL-2. Analysis of different clinical and prognostic variables disclosed meaningful correlations with both NF-L and pNF-H levels. Our results, from a relatively large ALS cohort, confirm that CSF NF-L and pNF-H represent valuable diagnostic and prognostic biomarkers in ALS.     

Cerebrospinal fluid neurofilament light levels in amyotrophic lateral sclerosis: impact of SOD1 genotype

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative syndrome with familial and sporadic forms. Most ALS-associated mutations are found in the superoxide dismutase 1 ( SOD1 ) gene. We conducted a study including 60 sporadic and 19 familial ALS patients, 206 reference patients with other neurological disorders and 40 age- and sex-matched healthy controls to test the hypothesis that cerebrospinal fluid (CSF) levels of neurofilament light (NF-L) protein, a marker of axonal degeneration, might provide diagnostic and prognostic information on the disease. All ALS patients were screened for SOD1 mutations. Ten of the familial and five of the sporadic cases carried SOD1 mutations. NF-L concentration [median (range)] was strongly elevated in ALS [2110 (255–10 800) ng/l] compared with reference patients and healthy controls [277 (<125–15 506) and 175 (<125–710) ng/l, respectively, P  < 0.001] and correlated inversely with disease duration (Spearman R  = −0.518, P  = 0.001). NF-L levels were lower in SOD1 mutation-associated ALS compared with SOD1 wild-type (wt) ALS ( P  = 0.03). In conclusion, CSF NF-L levels may provide both diagnostic and prognostic information, particularly in SOD1 wt ALS.     

Low levels of the vascular endothelial growth factor in CSF from early ALS patients

Deletion of the hypoxia-response element in the vascular endothelial growth factor (VEGF) promoter causes motor neuron degeneration in a mouse model. "At-risk" haplotypes with low circulating VEGF levels have been demonstrated in humans. Here the authors report low VEGF levels in the CSF of ALS patients during their first year of the disease, independently of VEGF promoter polymorphism. This finding early in ALS patients suggests a possible role for VEGF gene regulation in the pathogenesis of ALS.     

Production of monocyte chemoattractant protein-1 in amyotrophic lateral sclerosis

The presence of activated microglia in the spinal cord of amyotrophic lateral sclerosis (ALS) patients is usually accompanied by inflammatory biochemical changes, but these are largely unexplored. Monocyte chemoattractant protein-1 (MCP-1) is critical for recruitment of inflammatory cells of monocytic lineage after inflammation or injury to the central nervous system. MCP-1 concentrations were measured by an enzyme-linked immunosorbent assay in the cerebrospinal fluid (CSF) and the serum of 27 patients with ALS and 30 patients with noninflammatory neurological diseases. In ALS, circulating MCP-1 levels were significantly increased in the serum and particularly in the CSF. Immunoreactivity for MCP-1 in ALS spinal cord was detected mostly in astrocytes but also in microglia, neurons, and within the vasculature of the cord. Our findings suggest a role for MCP-1 as an important molecular mediator of the injury response in ALS.     

Decreased cerebrospinal fluid cGMP levels in patients with amyotrophic lateral sclerosis

Summary. The role of cyclic guanosine 5 monophosphate (cGMP) in neurodegeneration of motor neurons in amyotrophic lateral sclerosis (ALS) is still controversial. The aim of this study was to measure levels of cGMP in cerebrospinal fluid (CSF) of patients with ALS, and to investigate whether there is a relationship between CSF cGMP levels and clinical parameters of the disease. The study involved 30 ALS and 20 control group patients. The CSF cGMP was measured by the enzyme-linked immunosorbent assay. The results showed that levels of CSF cGMP were significantly decreased in the group of ALS patients compared to controls and did not depend on clinical state of ALS patients, type of ALS onset, or the duration of the disease. Decreased levels of CSF cGMP observed in this study may suggest the role of cGMP in neurodegeneration in ALS. The CSF cGMP cannot be a marker of the disease activity.