Serum Of Amyotrophic Lateral Sclerosis Patients Research Articles

Elevated serum circulating cell-free mitochondrial DNA in amyotrophic lateral sclerosis.

The substantial role of inflammation in amyotrophic lateral sclerosis (ALS) is gaining support from recent research. Studies indicate that circulating cell-free mitochondrial DNA (ccf-mtDNA) can activate the immune system and is associated with neurodegenerative diseases. This research was designed to quantify ccf-mtDNA levels in the serum of ALS patients. The medical records of ALS patients were reviewed. Serum ccf-mtDNA levels of patients with ALS (n = 62) and age-matched healthy controls (n = 46) were measured and compared. Additionally, serum interleukin-6 (IL-6) levels were measured using an enzyme-linked immunosorbent assay in 26 ALS patients. Correlations between variables were analyzed. Serum ccf-mtDNA was notably higher in the patients with ALS. When stratified by genotype, the superoxide dismutase 1 (SOD1) mutation group showed the greatest increase in ccf-mtDNA levels relative to other ALS patients. Among all 108 individuals, a cut-off set at 1.1 × 105 mtDNA copies on a receiver-operating characteristic curve identified patients with ALS with 80.7% sensitivity and 50.0% specificity; the area under the curve was 0.69 (p < 0.001). Furthermore, serum ccf-mtDNA levels correlated negatively with the progression rate of ALS (ΔFS; rs = -0.26, p = 0.044), but not the ALSFRS-R score (rs = 0.06, p = 0.625). Importantly, the correlation between ccf-mtDNA and ΔFS was more pronounced in the SOD1 mutation group (rs = -0.62, p = 0.018). Lastly, a significant positive association was observed between serum ccf-mtDNA levels and IL-6 levels in ALS (r s= 0.41, p = 0.038). Our study found increased serum ccf-mtDNA in ALS patients, suggesting a link to inflammatory processes and disease mechanism. Moreover, ccf-mtDNA could be an indicator for ALS progression, especially in those with the SOD1 mutation.

Advancing amyotrophic lateral sclerosis disease diagnosis: A lab-on-chip electrochemical immunosensor for ultra-sensitive TDP-43 protein detection and monitoring in serum patients’

The global increase in population aging has led to a rise in neurodegenerative diseases (NDs), posing significant challenges to public health. Developing selective and specific biomarkers for early diagnosis and drug development is crucial addressing the growing burden of NDs. In this context, the RNA-binding protein TDP-43 has emerged as a promising biomarker for amyotrophic lateral sclerosis (ALS), frontotemporal lobar degeneration (FTLD), and TDP-43-associated proteinopathies. However, existing detection methods suffer from limitations such as cost, complexity, and operator dependence. Here, we present a novel electrochemical biosensor integrated into a lab-on-chip (LoC) platform to detect TDP-43. The sensor utilizes electrosynthesized polypyrrole derivatives with carboxylic groups for transducer functionalization, enabling targeted immobilization of TDP-43 antibodies. Differential pulsed voltammetry (DPV) is used for the indirect detection and quantification of TDP-43. The chip exhibits rapid response, good reproducibility, a linear detection range, and sensitivity from 0.01 ng/mL to 25 ng/mL of TDP-43 protein concentration with a LOD = 10 pg/mL. Furthermore, successful TDP-43 detection in complex matrices like serum of ALS patients and healthy individuals demonstrates its potential as a point-of-care diagnostic device. This electrochemical biosensor integrated into a chip offers good sensitivity, rapid response, and robust performance, providing a promising avenue for advancing neurodegenerative disease diagnostics and therapeutic development.

SerpinA1 levels in amyotrophic lateral sclerosis patients: An exploratory study.

SerpinA1, a serine protease inhibitor, is involved in the modulation of microglial-mediated inflammation in neurodegenerative diseases. We explored SerpinA1 levels in cerebrospinal fluid (CSF) and serum of amyotrophic lateral sclerosis (ALS) patients to understand its potential role in the pathogenesis of the disease. SerpinA1, neurofilament light (NfL) and heavy (NfH) chain, and chitinase-3-like protein-1 (CHI3L1) were determined in CSF and serum of ALS patients (n = 110) and healthy controls (n = 10) (automated next-generation ELISA), and correlated with clinical parameters, after identifying three classes of progressors (fast, intermediate, slow). Biomarker levels were analyzed for diagnostic power and association with progression and survival. SerpinA1serum was significantly decreased in ALS (median: 1032 μg/mL) compared with controls (1343 μg/mL) (p = 0.02). SerpinA1CSF was elevated only in fast progressors (8.6 μg/mL) compared with slow (4.43 μg/mL, p = 0.01) and intermediate (4.42 μg/mL, p = 0.03) progressors. Moreover, SerpinA1CSF correlated with neurofilament and CHI3L1 levels in CSF. Contrarily to SerpinA1CSF , neurofilament and CHI3L1 concentrations in CSF correlated with measures of disease progression in ALS, while SerpinA1serum mildly related with time to generalization (rho = 0.20, p = 0.04). In multivariate analysis, the ratio between serum and CSF SerpinA1 (SerpinA1 ratio) and NfHCSF were independently associated with survival. Higher SerpinA1CSF levels are found in fast progressors, suggesting SerpinA1 is a component of the neuroinflammatory mechanisms acting upon fast-progressing forms of ALS. Both neurofilaments or CHI3L1CSF levels outperformed SerpinA1 at predicting disease progression rate in our cohort, and so the prognostic value of SerpinA1 alone as a measure remains inconclusive.

Metabolic Profile and Pathological Alterations in the Muscle of Patients with Early-Stage Amyotrophic Lateral Sclerosis.

Diverse biomarkers and pathological alterations have been found in muscle of patients with Amyotrophic lateral sclerosis (ALS), but the relation between such alterations and dysfunction in energetic metabolism remains to be investigated. We established the metabolome of muscle and serum of ALS patients and correlated these findings with the clinical status and pathological alterations observed in the muscle. We obtained data from 20 controls and 17 ALS patients (disease duration: 9.4 ± 6.8 months). Multivariate metabolomics analysis identified a distinct serum metabolome for ALS compared to controls (p-CV-ANOVA < 0.035) and revealed an excellent discriminant profile for muscle metabolome (p-CV-ANOVA < 0.0012). Citramalate was discriminant for both muscle and serum. High lauroylcarnitine levels in muscle were associated with low Forced Vital Capacity. Transcriptomics analysis of key antioxidant enzymes showed an upregulation of SOD3 (p = 0.0017) and GLRX2(1) (p = 0.0022) in ALS muscle. Analysis of mitochondrial enzymatic activity in muscle revealed higher complex II/CS (p = 0.04) and lower LDH (p = 0.03) activity in ALS than in controls. Our study showed, for the first time, a global dysfunction in the muscle of early-stage ALS patients. Furthermore, we identified novel metabolites to be employed as biomarkers for diagnosis and prognosis of ALS patients.

Novel serum autoantibodies against ß-actin (ACTB) in amyotrophic lateral sclerosis

To identify novel biomarkers using the serological analysis of recombinant cDNA expression libraries (SEREX) method and to evaluate their clinical significance in amyotrophic lateral sclerosis (ALS). Serum of ALS patients were screened for autoantibodies using the SEREX method. The identified autoantibodies were validated by measuring their serum levels in 70 ALS patients, 60 normal controls (NC), and 62 Parkinson disease (PD) patients using the amplified luminescent proximity homogeneous assay-linked immunosorbent assay (AlphaLISA). The clinical relevance of these autoantibodies was investigated in ALS patients. SEREX identified 16 candidate antigens including β-actin (ACTB) in addition to proteasome subunit alpha type 7 (PSMA7) that we previously reported, and serum levels of antibodies against ACTB, were significantly higher in ALS patients than in NC (p < 0.001) and PD patients (p = 0.001). Moreover, serum levels of anti-ACTB antibody were higher in advanced stage ALS patients (Stage 4 on the King’s ALS clinical staging) and in those with more severe disability (ALS Functional Rating Scale revised [ALSFRS-R] score < 40.5) compared to early stage (Stage 2 [2nd region involved)]) patients and those with less severe disability (ALSFRS-R score ≥ 40.5) (p = 0.003, p = 0.014). Anti-ACTB antibody levels were also negatively correlated with ALSFRS-R score (ρ = −0.409, p = 0.001), but positively correlated with clinical disease stage (ρ = 0.355, p = 0.003), and showed a weak positive correlation with disease duration (ρ = 0.294, p = 0.014). Anti-ACTB antibodies may be a potential biomarker of ALS could indicate disease severity.

CXCL13/CXCR5 signalling is pivotal to preserve motor neurons in amyotrophic lateral sclerosis.

BackgroundCXCL13 is a B and T lymphocyte chemokine that mediates neuroinflammation through its receptor CXCR5. This chemokine is highly expressed by motoneurons (MNs) in Amyotrophic Lateral Sclerosis (ALS) SOD1G93A (mSOD1) mice during the disease, particularly in fast-progressing mice. Accordingly, in this study, we investigated the role of this chemokine in ALS.MethodsWe used in vitro and in vivo experimental paradigms derived from ALS mice and patients to investigate the expression level and distribution of CXCL13/CXCR5 axis and its role in MN death and disease progression. Moreover, we compared the levels of CXCL13 in the CSF and serum of ALS patients and controls.FindingsCXCL13 and CXCR5 are overexpressed in the spinal MNs and peripheral axons in mSOD1 mice. CXCL13 inhibition in the CNS of ALS mice resulted in the exacerbation of motor impairment (n = 4/group;Mean_Diff.=27.81) and decrease survival (n = 14_Treated:19.2 ± 1.05wks, n = 17_Controls:20.2 ± 0.6wks; 95% CI: 0.4687–1.929). This was corroborated by evidence from primary spinal cultures where the inhibition or activation of CXCL13 exacerbated or prevented the MN loss. Besides, we found that CXCL13/CXCR5 axis is overexpressed in the spinal cord MNs of ALS patients, and CXCL13 levels in the CSF discriminate ALS (n = 30) from Multiple Sclerosis (n = 16) patients with a sensitivity of 97.56%.InterpretationWe hypothesise that MNs activate CXCL13 signalling to attenuate CNS inflammation and prevent the neuromuscular denervation. The low levels of CXCL13 in the CSF of ALS patients might reflect the MN dysfunction, suggesting this chemokine as a potential clinical adjunct to discriminate ALS from other neurological diseases.FundingVaccinex, Inc.; Regione Lombardia (TRANS-ALS)

25-Hydroxycholesterol is involved in the pathogenesis of amyotrophic lateral sclerosis.

This study aimed to evaluate the levels of three major hydroxycholesterols (24-, 25-, and 27-hydroxycholesterols) in the serum and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS), as well as to show their role in the pathogenesis of ALS experimental models. The level of 25-hydroxycholesterol were higher in untreated ALS patients (n = 30) than in controls without ALS (n = 33) and ALS patients treated with riluzole (n = 9) both in their serum and CSF. The level of 25-hydroxycholesterol in the serum of ALS patients were significantly associated with their disease severity and rate of progression. In the motor neuron-like cell line (NSC34) with the human mutant G93A superoxide dismutase 1 gene (mSOD1-G93A), 25-hydroxycholesterol induced motor neuronal death/ apoptosis via glycogen synthase kinase-3β and liver X receptor pathways; riluzole treatment attenuated these effects. The expressions of enzymes that synthesize 25-hydroxycholesterol were significantly increased in the brains of early symptomatic mSOD1G93A mice. Our data, obtained from patients with ALS, a cellular model of ALS, and an animal model of ALS, suggests that 25-hydroxycholesterol could be actively involved in the pathogenesis of ALS, mostly in the early symptomatic disease stage, by mediating neuronal apoptosis.

Anti-Sulfoglucuronosyl Paragloboside Antibody: A Potential Serologic Marker of Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by progressive degeneration of upper and lower motor neurons. Although the etiology of ALS is obscure, genetic studies of familiar ALS suggest a multifactorial etiology for this condition. Similarly, there probably are multiple causes for sporadic ALS. Autoimmune-mediated motor neuron dysfunction is one proposed etiology for sporadic ALS. In the present study, anti-glycolipid antibodies including GM1, GD1b, GD3, and sulfoglucuronosyl paragloboside (SGPG) were investigated in the sera of a large number of patient samples, including 113 ALS patients and 50 healthy controls, by means of enzyme-linked immunosorbent assay with affinity parametric complex criterion evaluation and thin-layer chromatography immunooverlay (immuno-TLC). Anti-SGPG antibodies were found in the sera of 13.3% ALS patients (15 out of 113). The highest titer reached 1:1600. The presence of anti-SGPG antibodies in the serum samples was also confirmed by immuno-TLC. Importantly, a multiple logistic regression analysis showed that the presence of anti-SGPG antibody was positively correlated with age (p < .01) and negatively correlated with ALS Functional Rating Scale score (p < .05). Moreover, the localization of SGPG-immunoreactivity on the motor neurons of rat spinal cord and a mouse motor neuronal cell line, NSC-34 was observed by an immunofluorescence method. These data suggest that SGPG could represent a specific pathogenic antigen in those ALS patients. The presence of anti-SGPG antibodies in the serum of ALS patients should represent a diagnostic biomarker of ALS, and it could reflect the severity of the disease.

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Immunological disturbances have been implicated in the pathogenesis of some neurodegenerative disorders like Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). Adhesion molecules are markers of activated endothelial cells upregulated by action of cytokinesTo investigate the activation or not of the vascular cells in AD and ALS, serum soluble intercellular adhesion molecule-1 (ICAM-1) and soluble E-selectin were evaluated (enzyme-like immunosorbent assay, ELISA) in 22 patients with Alzheimer's disease (AD), 20 patients with amyotrophic lateral sclerosis (ALS), 34 patients with non-inflammatory neurological diseases (NIND) and 15 control subjects.Patients with AD had higher s-ICAM-1 levels compared to NIND patients and control subjects (p<0.0027 and p<0.04, respectively). Patients with ALS had not higher s-ICAM-1 levels compared to NIND patients and control subjects (p<0.21 and p<0.31, respectively). Soluble-E-selectin levels in AD and ALS patients were not statistically different compared to NIND patients and controls (p<0.4, p<0.9 and p<0.3, p<0.19, respectively).The presence of high s-ICAM values may be related to immunological processes involved in pathogenetic mechanisms of AD. The not statistically significant values of s-E selectin, a glycoprotein considered an exclusive marker of endothelial activation, seem to suggest the neural rather than the endothelial s-ICAM origin in patients with AD. The low values of s-ICAM-1 and sE-selectin in the serum of ALS patients do not exclude the presence of an unconventional immunological abnormality in this disorder.

Identification of active loci of a human endogenous retrovirus in neurons of patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is characterized by the progressive loss of motor neurons, of unknown etiology. Previous studies showed reverse transcriptase in serum of ALS patients at levels comparable to human immunodeficiency virus-infected patients; however, the source and significance of the retroviral elements is uncertain. Expression of a human endogenous retrovirus (HERV-K) was determined in autopsy brain tissue of patients with ALS and compared to control populations by real-time polymerase chain reaction followed by sequencing of the amplified genes and confirmed by immunostaining. HERV-K pol transcripts were increased in patients with ALS compared to those with chronic systemic illness, but could not be detected in Parkinson disease or in the accidental death controls. Sequencing revealed several actively transcribed loci in the HML-2 and 3 subfamilies of HERV-K, with a specific pattern of expression including intact open reading frames and the transcription of a unique locus in ALS. The frequency of intact pol transcripts was highest in the motor cortex, and the reverse transcriptase protein was localized to cortical neurons of ALS patients. HERV-K expression strongly correlated with TDP-43, a multifunctional protein known to be dysregulated in ALS. We have identified a specific pattern of HERV-K expression in ALS, which may potentially define the pathophysiology of ALS. Targeting of activated genome-encoded retroviral elements may open new prospects for the treatment of ALS.

The Kynurenine Pathway and Inflammation in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor neuron disease of unknown pathogenesis. The kynurenine pathway (KP), activated during neuroinflammation, is emerging as a possible contributory factor in ALS. The KP is the major route for tryptophan (TRP) catabolism. The intermediates generated can be either neurotoxic, such as quinolinic acid (QUIN), or neuroprotective, such as picolinic acid (PIC), an important endogenous chelator. The first and inducible enzyme of the pathway is indoleamine 2,3-dioxygenase (IDO). The present study aimed to characterize the expression of the KP in cerebrospinal fluid (CSF), serum and central nervous system (CNS) tissue of ALS patients. Using high performance liquid chromatography, we analysed the levels of TRP and kynurenine (KYN), and, with gas chromatography/mass spectrometry, the levels of PIC and QUIN, in the CSF and serum of ALS patients and control subjects. Immunohistochemistry was employed to determine the expression of QUIN, IDO and human leukocyte antigen-DR (HLA-DR) in sections of brain and spinal cord from ALS patients. There were significantly increased levels of CSF and serum TRP (P < 0.0001), KYN (P < 0.0001) and QUIN (P < 0.05) and decreased levels of serum PIC (P < 0.05) in ALS samples. There was a significant increase in activated microglia expressing HLA-DR (P < 0.0001) and increased neuronal and microglial expression of IDO and QUIN in ALS motor cortex and spinal cord. We show the presence of neuroinflammation in ALS and provide the first strong evidence for the involvement of the KP in ALS. These data point to an inflammation-driven excitotoxic-chelation defective mechanism in ALS, which may be amenable to inhibitors of the KP.

Serum Nogo-A levels are not elevated in amyotrophic lateral sclerosis patients

Improved biomarkers would facilitate the diagnosis and treatment of amyotrophic lateral sclerosis (ALS). Muscle content of the neuritic outgrowth inhibitor Nogo-A is increased in patients with ALS and other denervating conditions. Seeking a less invasive diagnostic method, we sought to determine whether or not Nogo increases in the serum of ALS patients. We developed a dissociation-enhanced lanthanide fluorescent immunoassay (DELFIA) protocol to screen serum samples from 172 ALS patients and 172 healthy controls for Nogo-A immunoreactivity. Unexpectedly, there was a trend toward decreased levels of serum Nogo-A in ALS. Mean serum Nogo-A level in ALS patients was 0.71 nM (95% confidence interval (CI) 0.42–1.00), as opposed to 1.15 nM (95% CI 0.72–1.59) in healthy controls. A significantly larger percentage of healthy control sera (11.0% vs 4.7%) displayed markedly elevated levels of Nogo-A. Additional study is required to determine the factors that lead to elevated Nogo-A levels in a subset of both ALS patients and healthy controls.

Activity and expression of glutathione S-transferase pi in patients with amyotrophic lateral sclerosis

Glutathione S-transferase (GST, EC 2.5.1.18) is an enzyme responsible for inactivation of a large variety of toxic, electrophilic compounds and organic peroxides. GST activity and GST pi expression were studied in patients with amyotrophic lateral sclerosis (ALS). Studies were conducted on cerebrospinal fluid (CSF), blood serum and peripheral blood mononuclear cells (PBMC) obtained from 40 ALS patients. CSF from 30 subjects without neurological diseases and blood from 40 healthy blood donors were used as controls. GST activity assayed with 1-chloro-2,4-dinitrobenzene (substrate for transferase activity) and cumene peroxide (substrate for peroxidase activity) was significantly decreased in PBMC of ALS patients, as well as the GST pi expression on both mRNA and protein level. The mean peroxidase activity was however significantly increased in CSF and serum of ALS patients with the specificity of 80% and 73%, and the sensitivity of 78% and 85%, respectively. It can thus be concluded that the protective barrier formed by GST is originally affected in peripheral blood of ALS patients, and may increase their vulnerability to toxic effects of electrophilic compounds and organic peroxides. Studies on a larger group are needed to answer the question whether GSH-Px determination may be implicated in the diagnosis of ALS.

Serum levels of soluble intercellular adhesion molecule-1 (s-ICAM-1) and soluble endothelial leukocyte adhesion molecule-1(s-ELAM-1) in amyotrophic lateral sclerosis

Immunological disturbances have been implicated in the pathogenesis of amyotrophic lateral sclerosis (ALS). Adhesion molecules are markers of activated endothelial cells up-regulated by action of cytokines. To investigate the activation or inactivation of the vascular cells in ALS, serum soluble intercellular adhesion molecule-1 (s-ICAM-1) and soluble E-selectin (s-ELAM-1) were evaluated (ELISA) in 16 patients with ALS, 30 patients with non-inflammatory neurological diseases (NINDS) and 15 healthy control subjects. Patients with ALS had no higher s-ICAM-1 levels compared with the NINDS patients and the control subjects (pv0.31 and pv0.21, respectively). s-ELAM levels were not statistically significant compared with the NINDS patients and healthy subjects (pv0.21 and pv0.24, respectively). We conclude that the low values of s-ICAM-1 and s-ELAM-1 in the serum of ALS patients do not exclude the presence of immunological abnormality in this disorder. Soluble E-selectin is a glycoprotein which is considered an exclusive marker of endothelial activation. Its low level in our study may suggest a neural rather than an endothelial s-ICAM origin in patients with ALS.

The role of soluble intercellular adhesion molecules in neurodegenerative disorders

Immunological disturbances have been implicated in the pathogenesis of some neurodegenerative disorders like Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS). Adhesion molecules are markers of activated endothelial cells upregulated by action of cytokines Materials and methods To investigate the activation or not of the vascular cells in AD and ALS, serum soluble intercellular adhesion molecule-1 (ICAM-1) and soluble E-selectin were evaluated (enzyme-like immunosorbent assay, ELISA) in 22 patients with Alzheimer's disease (AD), 20 patients with amyotrophic lateral sclerosis (ALS), 34 patients with non-inflammatory neurological diseases (NIND) and 15 control subjects. Results Patients with AD had higher s-ICAM-1 levels compared to NIND patients and control subjects ( p<0.0027 and p<0.04, respectively). Patients with ALS had not higher s-ICAM-1 levels compared to NIND patients and control subjects ( p<0.21 and p<0.31, respectively). Soluble-E-selectin levels in AD and ALS patients were not statistically different compared to NIND patients and controls ( p<0.4, p<0.9 and p<0.3, p<0.19, respectively). Conclusions The presence of high s-ICAM values may be related to immunological processes involved in pathogenetic mechanisms of AD. The not statistically significant values of s-E selectin, a glycoprotein considered an exclusive marker of endothelial activation, seem to suggest the neural rather than the endothelial s-ICAM origin in patients with AD. The low values of s-ICAM-1 and sE-selectin in the serum of ALS patients do not exclude the presence of an unconventional immunological abnormality in this disorder.

Survival of 793 patients with amyotrophic lateral sclerosis diagnosed over a 28-year period

We reviewed retrospectively 793 consecutive patients discharged with ALS diagnosis between 1971 and 1998 to identify survival predictors. Vital status in July 2001 was known for all patients. Mean age at onset was 56 (SD 11.7) years and mean age at diagnosis was 57.4 (SD 11.5) years. Onset symptoms were bulbar in 20.8% of patients. The median survival time from symptoms onset was 2.9 years (95% CI 2.7-3.1). Survival from onset was 93% after one, 48% after three and 24% after five years. Median survival was shorter in patients with time between onset and diagnosis <12 months than in those diagnosed> 23 months; (2.1 years vs. 5.9 years; P<0.001). Patients with onset after age 65 had a 4.2 times greater risk of death than patients less than 40 years. Bulbar onset was associated with 1.4 times greater risk of death than spinal onset. Patients diagnosed after 1990 had longer median survival (3.3 years) than those diagnosed in 1971-1979 (2.4 years) (P<0.001). As expected, age, bulbar onset and short time from onset to diagnosis were independent predictors of survival. We also found a significant increase in survival over time, probably due to improved comprehensive treatment of ALS patients in Italy.

Matrix metalloproteinase-9 is elevated in serum of patients with amyotrophic lateral sclerosis.

Matrix metalloproteinase-9 (MMP-9) and its specific inhibitor, tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), were analysed by enzyme-linked immunosorbent assay (ELISA) and by zymography in serum and cerebrospinal fluid (CSF) of patients with amyotrophic lateral sclerosis (ALS). In contrast to patients with inflammatory diseases, MMP-9 levels were not elevated in CSF of ALS patients. In serum, however, compared to healthy donors, MMP-9 was significantly (p = 0.0003) increased up to levels as high as those of viral meningoencephalitis (VM) or bacterial meningitis (BM) patients. MMP-9 levels remained elevated during long-term observation of ALS patients. In the absence of an inflammatory response, the results indicate that the increase of MMP-9 in serum of ALS patients might be caused by upregulation of MMP-9 in denervated muscles or in degenerating peripheral nerves following motor neurone loss.