Neurofilament Heavy Chain Levels Research Articles

Serum spectrin breakdown product and neurofilament heavy in predicting outcome after cardiac arrest: A diagnostic accuracy study

ObjectivesSpectrin breakdown products 145 kDa (SBDP145) and neurofilament heavy chain (Nf-H) have been identified as potential biomarkers of neuronal injury. However, their ability to predict hypoxic-ischemic brain injury following cardiac arrest in humans is not well understood. This study aimed to investigate whether SBDP145 and Nf-H could be used as biomarkers to predict neurological outcomes after cardiac arrest. MethodsThis prospective study was conducted at two academic hospitals and included adults who survived after cardiac arrest. Blood samples were collected at 0, 24, and 48 h after the return of spontaneous circulation, and biomarker analyses were performed to measure SBDP145 and Nf-H. Poor neurological outcome was defined as a modified Rankin Score of 4–6, and diagnostic performance was determined by receiver-operating characteristics analysis. ResultsA total of 56 patients were included in this study. There were no significant differences in levels of SBDP145 or Nf-H between the poor and good outcome groups at any time point. Areas under the receiver-operating characteristics curve of SBDP145 and Nf-H were small, ranging from 0.51 to 0.7. At 0, 24, and 48 h, SBDP145 showed very low sensitivity (18.61 %, 13.89 %, and 13.79 %, respectively) and accuracy (33.93 %, 36.74 %, and 39.02 %, respectively) at a cut-off value for 100 % specificity. Nf-H also showed very low sensitivity (9.30 %, 16.67 %, and 0 %, respectively) and accuracy (29.09 %, 36.74 %, and 30.95 %, respectively). ConclusionsSBDP145 and Nf-H were found to be poor predictors of poor neurological outcomes six months after cardiac arrest.

Remodeling of the neuromuscular junction in myasthenia gravis increases serum neurofilament heavy chain levels.

In myasthenia gravis, prolonged muscle denervation causes muscle atrophy. We re-visited this observation using a biomarker hypothesis. We tested if serum neurofilament heavy chain levels, a biomarker for axonal degeneration, were elevated in myasthenia gravis. We enrolled 70 patients with isolated ocular myasthenia gravis and 74 controls recruited from patients in the emergency department. Demographic data were collected alongside serum samples. Serum samples were analyzed by enzyme-linked immunosorbent assay (ELISA) for the neurofilament heavy chain (NfH-SMI35). The statistical analyses included group comparisons, receiver operator characteristic (ROC) curves, area under the curve (AUC), sensitivity, specificity, and positive and negative predictive values. Serum neurofilament heavy chain levels were significantly (p < 0.0001) higher in individuals with myasthenia gravis (0.19 ng/mL) than in healthy control subjects (0.07 ng/mL). A ROC AUC optimized cutoff level of 0.06 ng/mL gave a diagnostic sensitivity of 82%, specificity of 76%, positive predictive value of 0.77 and a negative predictive value of 0.81. The increase of serum neurofilament heavy chain levels in myasthenia gravis is consistent with observations of muscle denervation. We suggest that there is ongoing remodeling of the neuromuscular junction in myasthenia gravis. Longitudinal quantification of neurofilament isoform levels will be needed to investigate the prognostic value and potentially guide treatment decisions.

Clinical and genetic features of amyotrophic lateral sclerosis patients with C9orf72 mutations.

An expansion of the GGGGCC hexanucleotide in the non-coding region of C9orf72 represents the most common cause of familial amyotrophic lateral sclerosis. The objective was to describe and analyse the clinical and genetic features of amyotrophic lateral sclerosis patients with C9orf72 mutations in a large population. Between November 2011 and December 2020, clinical and genetic characteristics of n = 248 patients with amyotrophic lateral sclerosis carrying C9orf72 mutations were collected from the clinical and scientific network of German motoneuron disease centres. Clinical parameters included age of onset, diagnostic delay, family history, neuropsychological examination, progression rate, phosphorylated neurofilament heavy chain levels in CSF and survival. The number of repeats was correlated with the clinical phenotype. The clinical phenotype was compared to n = 84 patients with SOD1 mutations and n = 2178 sporadic patients without any known disease-related mutations. Patients with C9orf72 featured an almost balanced sex ratio with 48.4% (n = 120) women and 51.6% (n = 128) men. The rate of 33.9% patients (n = 63) with bulbar onset was significantly higher compared to sporadic (23.4%, P = 0.002) and SOD1 patients (3.1%, P < 0.001). Of note, 56.3% (n = 138) of C9orf72, but only 16.1% of SOD1 patients reported a negative family history (P < 0.001). The GGGGCC hexanucleotide repeat length did not influence the clinical phenotypes. Age of onset (58.0, interquartile range 52.0-63.8) was later compared to SOD1 (50.0, interquartile range 41.0-58.0; P < 0.001), but earlier compared to sporadic patients (61.0, interquartile range 52.0-69.0; P = 0.01). Median survival was shorter (38.0 months) compared to SOD1 (198.0 months, hazard ratio 1.97, 95% confidence interval 1.34-2.88; P < 0.001) and sporadic patients (76.0 months, hazard ratio 2.34, 95% confidence interval 1.64-3.34; P < 0.001). Phosphorylated neurofilament heavy chain levels in CSF (2880, interquartile range 1632-4638 pg/ml) were higher compared to sporadic patients (1382, interquartile range 458-2839 pg/ml; P < 0.001). In neuropsychological screening, C9orf72 patients displayed abnormal results in memory, verbal fluency and executive functions, showing generally worse performances compared to SOD1 and sporadic patients and a higher share with suspected frontotemporal dementia. In summary, clinical features of patients with C9orf72 mutations differ significantly from SOD1 and sporadic patients. Specifically, they feature a more frequent bulbar onset, a higher share of female patients and shorter survival. Interestingly, we found a high proportion of patients with negative family history and no evidence of a relationship between repeat lengths and disease severity.

Heroin Addiction Induces Axonal Transport Dysfunction in the Brain Detected by In Vivo MRI.

Heroin is a highly addictive drug that causes axonal damage. Here, manganese-enhanced magnetic resonance imaging (MEMRI) was used to dynamically monitor axonal transport at different stages of heroin addiction. Rat models of heroin addiction (HA) and prolonged heroin addiction (PHA) were established by injecting rats with heroin at different stages. Heroin-induced learning and memory deficits were evaluated in the Morris water maze (MWM), and MEMRI was used to dynamically evaluate axonal transport in the olfactory pathway. The expression of proteins related to axonal structure and function was also assessed by Western blotting. Transmission electron microscopy (TEM) was used to observe ultrastructural changes, and protein levels of neurofilament heavy chain (NF-H) were analyzed by immunofluorescence staining. HA rats, especially PHA rats, exhibited worse spatial learning and memory than control rats. Compared with HA rats and control rats, PHA rats exhibited significantly longer escape latencies, significantly fewer platform-location crossings, and significantly more time in the target quadrant during the MWM test. Mn2+ transport was accelerated in HA rats. PHA rats exhibited severely reduced Mn2+ transport, and the axonal transport rate (ATR) was significantly lower in these rats than in control rats (P < 0.001). The levels of cytoplasmic dynein and kinesin-1 were significantly decreased in the PHA group than in the control group (P < 0.001); additionally, the levels of energy-related proteins, including cytochrome c oxidase (COX) IV and ATP synthase subunit beta (ATPB), were lower in the PHA group (P < 0.001). The brains of heroin-exposed rats displayed an abnormal ultrastructure, with neuronal apoptosis and mitochondrial dysfunction. Heroin exposure decreased the expression of NF-H, as indicated by significantly reduced staining intensities in tissues from HA and PHA rats (P < 0.05). MEMRI detected axonal transport dysfunction caused by long-term repeated exposure to heroin. The main causes of axonal transport impairment may be decreases in the levels of motor proteins and mitochondrial dysfunction. This study shows that MEMRI is a potential tool for visualizing axonal transport in individuals with drug addictions, providing a new way to evaluate addictive encephalopathy.

Teaching an old dog new tricks: serum troponin T as a biomarker in amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis is a devastating neurodegenerative disease characterized by progressive loss of upper and lower motor neurons. Diagnosis, management and therapeutic trials are hampered by a lack of informative biomarkers. Troponins are components of skeletal and cardiac muscles. Acute elevation of cardiac isoforms of troponin I and T in serum indicates myocardial injury. Case reports suggested that serum levels of cardiac troponin T, but not cardiac troponin I are chronically elevated in myotrophic lateral sclerosis and other neuromuscular disorders. Using standard clinical laboratory methodologies, we studied serum troponin levels in a multicentric cross-sectional cohort of 75 amyotrophic lateral sclerosis patients and 30 Alzheimer’s disease controls and 29 healthy controls (DESCRIBE-ALS cohort) and in a real-world cohort of 179 consecutive patients from our amyotrophic lateral sclerosis clinic at the University Hospital Bonn. We found that serum cardiac troponin T is elevated in >60% of amyotrophic lateral sclerosis patients, while cardiac troponin I is always normal. Serum cardiac troponin T levels increase over time and correlate with disease severity as measured with the revised Amyotrophic Lateral Sclerosis Functional Rating Scale score. There was no correlation with the phosphorylated neurofilament heavy chain levels in the cerebrospinal fluid. We propose that cardiac troponin T elevations in amyotrophic lateral sclerosis are of non-cardiac origin and may serve as a proxy of lower motor neuron or skeletal muscle involvement. They potentially help to stratify patients according to lower motoneuron involvement. Further research will determine the biological origin of the cardiac troponin T elevation and its validity as a diagnostic and/or prognostic marker. Our finding also serves as a reminder to interpret cardiac troponin T elevations in patients with neuromuscular diseases with caution.

SMA - TREATMENT: EP.286 Phosphorylated neurofilament heavy chain level is associated with future motor function in nusinersen-treated individuals with infantile-onset SMA

Neurofilament (NF) isoforms are major structural proteins of the neuronal cytoskeleton and are released into interstitial fluid following axonal damage or neuronal degeneration. Elevated NF levels have been detected in neurodegenerative disorders, including spinal muscular atrophy (SMA). Given that individuals with infantile-onset SMA in the Endear/Shine studies improved following nusinersen treatment, we evaluated the association between baseline (pretreatment) plasma phosphorylated neurofilament heavy chain (pNF-H) levels and the magnitude of improvement from baseline in clinical motor function endpoints.

Current application of neurofilaments in amyotrophic lateral sclerosis and future perspectives.

Motor neuron disease includes a heterogeneous group of relentless progressive neurological disorders defined and characterized by the degeneration of motor neurons. Amyotrophic lateral sclerosis is the most common and aggressive form of motor neuron disease with no effective treatment so far. Unfortunately, diagnostic and prognostic biomarkers are lacking in clinical practice. Neurofilaments are fundamental structural components of the axons and neurofilament light chain and phosphorylated neurofilament heavy chain can be measured in both cerebrospinal fluid and serum. Neurofilament light chain and phosphorylated neurofilament heavy chain levels are elevated in amyotrophic lateral sclerosis, reflecting the extensive damage of motor neurons and axons. Hence, neurofilaments are now increasingly recognized as the most promising candidate biomarker in amyotrophic lateral sclerosis. The potential usefulness of neurofilaments regards various aspects, including diagnosis, prognosis, patient stratification in clinical trials and evaluation of treatment response. In this review paper, we review the body of literature about neurofilaments measurement in amyotrophic lateral sclerosis. We also discuss the open issues concerning the use of neurofilaments clinical practice, as no overall guideline exists to date; finally, we address the most recent evidence and future perspectives.

Neurofilament heavy chain gene polymorphism and risk of multiple sclerosis

Multiple sclerosis (MS) is a chronic disease characterized by degeneration of the central nervous system (CNS). High levels of Neurofilament heavy chain (NEFH) in cerebrospinal fluid (CSF) is associated with MS. 40 MS patients and 40 controls genotyped by polymerase chain reaction (PCR) and Sanger sequencing. Genotypic and allelic distributions were compared between cases and controls. Fisher test was used to estimate the risk of MS associated with genotypes. We showed that NEFH, 1084-244G&gt;A gene polymorphism, has no significant association with the susceptibility or severity of MS in Iranian patients (P = 0.737). Further prospective studies are required for confirmation.

Cross-sectional and longitudinal measures of chitinase proteins in amyotrophic lateral sclerosis and expression of CHI3L1 in activated astrocytes

ObjectiveAmyotrophic lateral sclerosis (ALS) is a complex disease with numerous pathological mechanisms resulting in a heterogeneous patient population. Using biomarkers for particular disease mechanisms may enrich a homogeneous subset of...

Retinal Nerve Fiber Layer Thickness Correlates with Serum and Cerebrospinal Fluid Neurofilament Levels and is Associated with Current Disability in Multiple Sclerosis.

The main purpose of the present study is to confirm Peripapillary Retinal Nerve Fiber Layer (pRNFL) thickness is a biomarker of axonal degeneration in patients with Multiple Sclerosis (MS) and to evaluate its relationship with Neurofilament heavy chain (NfH) and Nitrotyrosine (NT). We quantified serum (s) and/or cerebrospinal fluid (CSF) NfH and NT levels in 30 relapsing-remitting MS patients (RRMS), 16 secondary progressive MS (SPMS) patients and in 29 control subjects matched for age and gender. Optical coherence tomography (OCT) measurements of pRNFL were performed in all subjects. Clinical outcomes were tested by Multiple Sclerosis Functional Composite (MSFC) and Expanded Disability Status Scale (EDSS). RRMS patients exhibited significantly higher NfH/NT levels (99 pg/mL, 107.52 nM respectively) than controls (74 pg/mL, 48.72 nM) in CSF (p<0.0001), but not in sera. SPMS patients had significantly higher s NfH/NT values (111.25 pg/mL, 1251.77 nM respectively) and lower mean pRNFL thickness (79 µm) than patients with RRMS (98.50 µm) and controls (108 µm) (p<0.0001). pRNFL thickness was significantly correlated with all clinical disability measurements (EDSS, Trail Making test, 9-Hole Peg Test, and PASAT) in both RRMS and SPMS (p<0.001, p=0.02, p=0.03, p=0.02 respectively). A positive correlation was also found between serum and/or CSF NfH levels and EDSS scores in RRMS and SPMS (p<0.001, p=0.02 respectively). The pRNFL thickness was also correlated significantly with serum and/or CSF NfH levels but not with s/CSF NT levels in both clinical forms of MS (p<0.01, p<0.001 respectively). The current study demonstrated that both pRNFL and s/CSF NfH are reliable and quantitative biomarkers that correlate with current disease course and cross-sectional measure of disability in patients with MS.

Neurofilament Heavy Chain and Tau Protein Are Not Elevated in Cerebrospinal Fluid of Adult Patients with Spinal Muscular Atrophy during Loading with Nusinersen.

Nusinersen is the first approved drug for the treatment of spinal muscular atrophy (SMA). Treatment of SMA with nusinersen is based on a fixed dosing regimen. For other motoneuron diseases, such as amyotrophic lateral sclerosis (ALS), biomarkers are available for clinical diagnostics; however, no such biomarkers have yet been found for SMA. Serum and cerebrospinal fluid (CSF) samples of 11 patients with adult SMA type 3 were prospectively collected and analyzed during loading with nusinersen. Neurofilament heavy chain, tau protein, S100B protein, and neuron-specific enolase were investigated as potential biomarkers of motor neuron destruction. No significant pathological alterations in levels of neurofilament heavy chain, tau protein, or S100B protein were detected in the CSF or blood samples under baseline conditions or during loading with nusinersen. Neuron-specific enolase was marginally elevated in CSF and blood samples without significant alteration during treatment. In a mixed cohort of adult patients with SMA type 3, neurofilament heavy chain, tau protein, S100B protein, and neuron-specific enolase do not serve as potential biomarkers during the loading phase of nusinersen. The slow progression rate of SMA type 3 may not lead to detectable elevation of levels of these common markers of axonal degradation.

Nusinersen in infants who initiate treatment in a presymptomatic stage of spinal muscular atrophy (SMA): Interim results from the phase 2 nurture study

Nusinersen is the first approved treatment for SMA. We present interim results from the ongoing NURTURE study (NCT02386553) examining efficacy/safety of intrathecal nusinersen, initiated prior to symptom onset, in infants with 2 or 3 SMN2 copies. Enrolled infants were age ≤ 6 weeks at first dose, clinically presymptomatic, and genetically diagnosed with SMA. Primary endpoint is time to death or respiratory intervention (≥6 h/day continuously for ≥7 days or tracheostomy). Patient consent/IRB approval were obtained. As of 15 May 2018, 25 infants (2 copies SMN2 [n = 15]; 3 copies [n = 10]) were enrolled. Median age at last visit was 26.0 (range:14.0–34.3) months. All infants were alive and none required permanent ventilation. Median time to death or respiratory intervention could not be estimated because of too few events. Four infants (all 2 SMN2 copies) required respiratory intervention for ≥6 h/day continuously for ≥7 days, with all cases initiated during acute, reversible illness. All infants achieved the WHO motor milestone sitting without support and 22/25 (88%) achieved walking with assistance; 17/22 (77%) were walking alone. Phosphorylated neurofilament heavy chain levels rapidly declined during the nusinersen loading phase and then stabilized. AEs occurred in all infants; 20/25 had mild/moderate AEs; 9 had SAEs. No new safety concerns were identified. Results from a new, Spring 2019 interim analysis, including additional assessments, will be presented. There was continued benefit to infants who initiated nusinersen before symptom onset, emphasizing the value of early treatment and newborn screening. Updated analyses will provide further information. Originally presented at CureSMA 2019.

Phosphorylated neurofilament heavy chain levels in paired plasma and CSF of amyotrophic lateral sclerosis

Background and objectiveAmyotrophic lateral sclerosis (ALS) is a fatal disease characterized by degeneration of both upper and lower motor neurons. In this study, we aimed to measure both plasma and cerebrospinal fluid (CSF) phosphorylated neurofilament heavy chain (pNF-H) levels in patients with ALS, and determine if there is a correlation. We also evaluated plasma and CSF pNF-H levels to investigate if this biomarker could predict the time to generalization (TTG) in ALS better. MethodsPaired plasma and CSF pNF-H levels of patients with ALS (n=51), multiple system atrophy (n=12) and controls (n=30) were measured by monoclonal sandwich ELISA. TTG, which also indicates the time of symptoms spreading from spinal or bulbar localization to both, was evaluated in all ALS patients. ResultsWe found a strong correlation between plasma and CSF pNF-H levels within individual patients (r=0.712, p<0.001). The mean TTG in ALS patients was 22.9months (range 1–84months), and there was an inverse correlation between plasma (r=−0.661; p<0.001)/CSF (r=−0.869; p<0.001) pNF-H levels and TTG. ConclusionThe correlation of plasma and CSF pNF-H levels would bring insight into the pathogenesis of ALS. TTG might play an important role in the future study of ALS, as an early indicator of survival.

Plasma neurofilament heavy chain is not a useful biomarker in Charcot-Marie-Tooth disease.

The negative results in trials of vitamin C in Charcot-Marie-Tooth disease (CMT) type 1A have highlighted the lack of sensitive outcome measures. Neurofilaments are abundant neuronal cytoskeletal proteins, and their concentration in blood is likely to reflect axonal breakdown. We therefore examined plasma neurofilament heavy-chain (NfH) concentration as a potential biomarker in CMT. Blood samples were collected from healthy controls and patients with CMT over a 2-year period. Disease severity was measured using the CMT Examination Score. An in-house enzyme-linked immunoabsorbent assay was used to measure plasma NfH levels. There was no significant difference in plasma NfH concentrations between CMT patients and controls (P = 0.449). There was also no significant difference in plasma NfH levels in the CMT group over 1 year (mean difference = -0.02, SEM = 4.44, P = 0.98). Plasma NfH levels are not altered in patients with CMT and are not a suitable biomarker of disease activity. Muscle Nerve 53: 972-975, 2016.

High-Fidelity Simulation of Primary Blast: Direct Effects on the Head.

The role of primary blast in blast-induced traumatic brain injury (bTBI) is controversial in part due to the technical difficulties of generating free-field blast conditions in the laboratory. The use of traditional shock tubes often results in artifacts, particularly of dynamic pressure, whereas the forces affecting the head are dependent on where the animal is placed relative to the tube, whether the exposure is whole-body or head-only, and on how the head is actually exposed to the insult (restrained or not). An advanced blast simulator (ABS) has been developed that enables high-fidelity simulation of free-field blastwaves, including sharply defined static and dynamic overpressure rise times, underpressures, and secondary shockwaves. Rats were exposed in head-only fashion to single-pulse blastwaves of 15 to 30 psi static overpressure. Head restraints were configured so as to eliminate concussive and minimize whiplash forces exerted on the head, as shown by kinematic analysis. No overt signs of trauma were present in the animals post-exposure. However, significant changes in brain 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNPase) and neurofilament heavy chain levels were evident by 7 days. In contrast to most studies of primary blast-induced TBI (PbTBI), no elevation of glial fibrillary acidic protein (GFAP) levels was noted when head movement was minimized. The ABS described in this article enables the generation of shockwaves highly representative of free-field blast. The use of this technology, in concert with head-only exposure, minimized head movement, and the kinematic analysis of the forces exerted on the head provide convincing evidence that primary blast directly causes changes in brain function and that GFAP may not be an appropriate biomarker of PbTBI.

Plasma neurofilament heavy chain levels and disease progression in amyotrophic lateral sclerosis: insights from a longitudinal study

ObjectiveTo investigate the role of longitudinal plasma neurofilament heavy chain protein (NfH) levels as an indicator of clinical progression and survival in amyotrophic lateral sclerosis (ALS).MethodsA cross-sectional study involving 136...

Neurofilament heavy chain as a marker of neuroaxonal pathology and prognosis in acute encephalitis

The neurological outcome of acute encephalitis can be devastating and early prognosis remains difficult. Biomarkers that quantify the extent of early brain injury are needed to improve the prognostic accuracy and aid patient management. Our objective was to assess whether cerebrospinal fluid (CSF) protein biomarkers of neuroaxonal and glial cell injury are elevated in distinct forms of acute encephalitis and predictive of poor outcome. This was a prospective study of patients presenting with acute encephalitis to three teaching hospitals in London, UK. Levels of neurofilament heavy chain (NfH, SMI35) and S100B were quantified in CSF using enzyme-linked immunosorbent assay. The outcome was assessed by the Glasgow Outcome Scale (GOS). Fifty-six patients with acute encephalitis were recruited and classified into the following diagnostic categories: infectious (n=20), inflammatory (n=14) and unknown etiology (n=22). Pathological levels of NfH and S100B were observed in 24/56 (43%) and 54/56 (96%), respectively. Patients with infectious encephalitis had significantly higher NfH levels compared with the other two groups (P<0.05). A poor outcome (GOS <5) was associated with significantly higher CSF NfH levels within samples taken 2weeks after symptom onset. This study suggests that longitudinal CSF NfH levels are of superior prognostic value compared with CSF S100B levels. Prolonged release of NfH, a marker of neuroaxonal damage, was associated with poor outcome. Potentially there is a window of opportunity for future neuroprotective treatment strategies in encephalitis.

Serial cerebrospinal fluid neurofilament heavy chain levels in severe Guillain‐Barré syndrome

Proximal axonotmesis results in the release of neurofilament (Nf) proteins into the cerebrospinal fluid (CSF) in patients with Guillain-Barré syndrome (GBS). High CSF levels of the phosphorylated form of Nf-heavy chain (NfH(SMI35) ) at GBS onset have been reported to be a poor prognostic marker, but routine measurement of CSF NfH(SMI35) levels has not been done and the longitudinal profile of CSF NfH(SMI35) levels in GBS is not known. This prospective case series describes the clinical, neurophysiological, and biomarker characteristics of 3 patients with severe GBS. High and increasing levels of CSF NfH(SMI35) in serial CSF samples were associated with poor clinical and electrophysiological outcome. These data further suggest that CSF NfH(SMI35) could be a prognostic biomarker which might indicate the development of retrograde axonal degeneration or additional proximal axonal damage during the course of GBS.

Plasma Neurofilament Heavy Chain Levels Correlate to Markers of Late Stage Disease Progression and Treatment Response in SOD1G93A Mice that Model ALS

BackgroundAmyotrophic lateral sclerosis (ALS) is an incurable neurodegenerative disorder characterised by progressive degeneration of motor neurons leading to death, typically within 3–5 years of symptom onset. The diagnosis of ALS is largely reliant on clinical assessment and electrophysiological findings. Neither specific investigative tools nor reliable biomarkers are currently available to enable an early diagnosis or monitoring of disease progression, hindering the design of treatment trials.Methodology/Principal FindingsIn this study, using the well-established SOD1G93A mouse model of ALS and a new in-house ELISA method, we have validated that plasma neurofilament heavy chain protein (NfH) levels correlate with both functional markers of late stage disease progression and treatment response. We detected a significant increase in plasma levels of phosphorylated NfH during disease progression in SOD1G93A mice from 105 days onwards. Moreover, increased plasma NfH levels correlated with the decline in muscle force, motor unit survival and, more significantly, with the loss of spinal motor neurons in SOD1 mice during this critical period of decline. Importantly, mice treated with the disease modifying compound arimoclomol had lower plasma NfH levels, suggesting plasma NfH levels could be validated as an outcome measure for treatment trials.Conclusions/SignificanceThese results show that plasma NfH levels closely reflect later stages of disease progression and therapeutic response in the SOD1G93A mouse model of ALS and may potentially be a valuable biomarker of later disease progression in ALS.

A Model for Mild Traumatic Brain Injury that Induces Limited Transient Memory Impairment and Increased Levels of Axon Related Serum Biomarkers

Mild traumatic brain injury (mTBI) is one of the most common neuronal insults and can lead to long-term disabilities. mTBI occurs when the head is exposed to a rapid acceleration-deceleration movement triggering axonal injuries. Our limited understanding of the underlying pathological changes makes it difficult to predict the outcome of mTBI. In this study we used a scalable rat model for rotational acceleration TBI, previously characterized for the threshold of axonal pathology. We have analyzed whether a TBI just above the defined threshold would induce any detectable behavioral changes and/or changes in serum biomarkers. The effect of injury on sensory motor functions, memory and anxiety were assessed by beam walking, radial arms maze and elevated plus maze at 3–7 days following TBI. The only behavioral deficits found were transient impairments in working and reference memory. Blood serum was analyzed at 1, 3, and 14 days after injury for changes in selected protein biomarkers. Serum levels of neurofilament heavy chain and Tau, as well as S100B and myelin basic protein showed significant increases in the injured animals at all time points. No signs of macroscopic injuries such as intracerebral hematomas or contusions were found. Amyloid precursor protein immunostaining indicated axonal injuries at all time points analyzed. In summary, this model mimics some of the key symptoms of mTBI, such as transient memory impairment, which is paralleled by an increase in serum biomarkers. Our findings suggest that serum biomarkers may be used to detect mTBI. The model provides a suitable foundation for further investigation of the underlying pathology of mTBI.