Phosphorylated neurofilament subunit levels in the serum of cervical compressive myelopathy patients

Cerebrospinal fluid biomarkers of white matter injury and astrogliosis are associated with the severity and surgical outcome of degenerative cervical spondylotic myelopathy

BACKGROUND CONTEXT

Degenerative cervical spondylotic myelopathy (DCM) is the commonest form of spinal cord injury in adults. However, a limited number of clinical reports have assessed the role of biomarkers in DCM.

PURPOSE

We evaluated cerebrospinal fluid (CSF) biomarkers in patients scheduled for DCM surgery and hypothesized that CSF biomarkers levels (1) would reflect the severity of preoperative neurological status; and (2) correlate with radiological appearance; and (3) correlate with clinical outcome.

STUDY DESIGN/SETTING

Prospective clinical and laboratory study.

PATIENT SAMPLE

Twenty-three DCM patients, aged 66.4±12.8 years and seven controls aged 45.4±5.3 years were included.

OUTCOME MEASURES

The American Spinal Injury Association Impairment Scale, the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire and EuroQol 5-dimensions were assessed preoperatively and at 3 months post-surgery.

METHODS

We measured preoperative biomarkers (glial fibrillary acidic protein [GFAP], neurofilament light [NFL], phosphorylated neurofilament-H [pNF-H] and Ubiquitin C-terminal hydrolase L1) in CSF samples collected from patients with progressive clinical DCM who underwent surgical treatment. Biomarker concentrations in DCM patients were compared with those of cervical radiculopathy controls.

RESULTS

The median symptom duration was 10 (interquartile range 6) months. The levels of GFAP, NFL, pNF-H, Ubiquitin C-terminal hydrolase L1 were significantly higher in the DCM group compared to controls (p=.044, p=.002, p=.016, and p=.006, respectively). Higher pNF-H levels were found in patients with low signal on T1 Magnetic Resonance Imaging sequence compared to those without (p=.022, area under the receiver operating characteristic curve [AUC] 0.780, 95% Confidence Interval: 0.59-0.98). Clinical improvement following surgery correlated mainly with NFL and GFAP levels (p<.05).

CONCLUSIONS

Our results suggest that CSF biomarkers of white matter injury and astrogliosis may be a useful tool to assess myelopathy severity and predict outcome after surgery, while providing valuable information on the underlying pathophysiology.

Serial changes in serum phosphorylated neurofilament and value for prediction of clinical outcome after traumatic brain injury

Background:

Phosphorylated neurofilament heavy subunit (pNF-H) is a constituent protein of the nerve axon, which leaks into the peripheral blood in various central nervous disorders. This study examined the time course of pNF-H value up to 1 month after injury and investigated the correlation with clinical outcome.

Methods:

Serum pNF-H concentration was measured on admission, and at 24 h, 72 h, 1 week, 2 weeks, and 1 month after injury in 20 patients, 15 males and 5 females aged 35–68 years (mean 52 years), with traumatic brain injury (TBI) transported to our hospital between April 2016 and March 2017. The clinical outcome at discharge was evaluated by Glasgow Outcome Scale.

Results:

The pNF-H value showed no increase in patients without brain parenchymal injury, but pNF-H value increased depending on the severity of brain damage. pNF-H value peaked at 2 weeks after injury. Two patients with peak value exceeding 10,000 unit had very severe injury and died during hospitalization. Peak pNF-H value was 3210 ± 1073 unit in 12 patients with good outcome and 9884 ± 2353 unit in 8 patients with poor outcome (P = 0.0119).

Conclusion:

Serum pNF-H level tended to increase and peak at 2 weeks after injury, and the peak pNF-H value was correlated with clinical outcome after TBI. The temporal profile of blood pNF-H seems to be useful to predict the clinical outcome after TBI.

Neural Cell Adhesion Molecule (NCAM) a Serum Biomarker Indicative for the Severity of Cervical Spondylotic Myelopathy

STUDY DESIGN

Peripheral blood samples were obtained from 25 patients with cervical spondylotic myelopathy (CSM) and 13 healthy volunteers.

OBJECTIVES

Our aim was to investigate the significance of neurodegenerative biomarkers in patients with CSM and correlate their expression with CSM severity.

SUMMARY OF BACKGROUND DATA

CSM is a common disorder involving chronic progressive compression of the cervical spinal resulting in progressive neurological impairment that ranges from mild tingling in the upper limbs to complete quadriplegia. However, the immunological background related to the neurodegenerative damage and its significance in CSM is still unclear.

METHODS

Protein expression profiles of 14 neurodegenerative biomarkers were measured by multiplex Luminex bead assay and further analyzed by group comparison statistics, correlation studies, and receiver-operating characteristic analysis.

RESULTS

Eleven of 14 biomarkers were significantly elevated in CSM patients as compared with healthy subjects (P<0.05). Specifically, the clinical severity of CSM on the scales of Nurick and modified Japanese Orthopedics Association scale (mJOA) was inversely related to neural cell adhesion molecule (NCAM) levels (r=-0.529, P=0.007; r=-0.519, P=0.001, respectively).

CONCLUSIONS

Serum level of neural cell adhesion molecule may serve as a diagnostic biomarker correlating with the severity of CSM.

Serum Phosphorylated Neurofilament Heavy Subunit-H, a Potential Predictive Biomarker for Postoperative Cognitive Dysfunction in Elderly Subjects Undergoing Hip Joint Arthroplasty

BACKGROUND

Postoperative cognitive dysfunction (POCD), which refers to a cognitive impairment subsequent to surgical procedures, is a common complication in the elderly subjects. This study aimed to investigate potential risk factors for POCD in elderly subjects undergoing hip joint arthroplasty.

METHODS

Consecutive elderly osteoarthritis patients who were scheduled to undergo hip arthroplasty under epidural anesthesia were enrolled into this single-center, prospective observational study. Serum phosphorylated neurofilament heavy subunit-H (pNF-H) was measured by the enzyme-linked immunosorbent assay method. A level of >70.5 pg/mL was accepted as pNF-H positivity. Neuropsychological assessment at baseline (1 day before the surgery) and postoperative day 7 was conducted. POCD was defined according to the calculated Z scores. Risk factors for POCD were evaluated by univariate and multivariate logistic regression analyses.

RESULTS

In final, 287 patients were enrolled, and 55 had suffered POCD within postoperative 7 days with an incidence of 19.2%. The final multiple logistic regression analysis revealed a higher pNF-H positivity was the only independent risk factor for POCD (odds ratio: 2.03, 95% confidence interval: 1.21-3.29, P = .012).

CONCLUSIONS

Our results revealed an increased preoperative serum pNF-H expression was an independent risk factor for POCD development in elderly subjects undergoing hip joint arthroplasty, suggesting the close association between anatomical damage in central nervous system and POCD.

Direct evidence of central nervous system axonal damage in patients with postoperative delirium: A preliminary study of pNF-H as a promising serum biomarker

INTRODUCTION

Approximately 50-80% patients experience postoperative delirium, an acute cognitive dysfunction associated with prolonged hospitalization, increased mortality, excess healthcare costs, and persistent cognitive impairment. Elucidation of the mechanism of delirium and associated diagnostic and therapeutic measures are urgently required. Here we investigated the role of phosphorylated neurofilament heavy subunit (pNF-H), a major structural protein in axons, as a predictive maker of postoperative delirium.

MATERIAL AND METHODS

Twenty-three patients who underwent surgery for abdominal cancer were screened for postoperative delirium, and they were assessed for its severity using the memorial delirium assessment scale (MDAS) at and 48h after delirium onset. Serum pNF-H levels were also measured at both time points. The patients were divided into two groups according to the presence or absence of pNF-H. Clinical variables were compared between groups using the Mann-Whitney U test, and the relationship between pNF-H levels and delirium severity was analyzed using the exponential curve fitting.

RESULTS

Fifteen of the 23 (65.2%) patients tested positive for pNF-H, and these patients exhibited significantly higher MDAS scores compared with the pNF-H-negative patients only at the onset of delirium. Although the MDAS score significantly improved over time in the positive group, pNF-H positivity persisted. There was a correlation between the maximum pNF-H level and maximum MDAS score (R²=0.31, p=0.013).

CONCLUSIONS

More severe postoperative delirium was directly related to higher serum pNF-H levels, suggesting the potential application of pNF-H as a quantitative biomarker of neural damage in postoperative delirium.

The Serum Phosphorylated Neurofilament Heavy Subunit as a Predictive Marker for Outcome in Adult Patients after Traumatic Brain Injury

The serum phosphorylated neurofilament heavy subunit (pNF-H) is a nervous system-specific protein that is released from damaged neural tissue after traumatic brain injury (TBI). The aim of this study was to elucidate the usefulness of serum pNF-H as a predictive marker for the outcome of patients after TBI. Patients with TBI (Glasgow Coma Scale score of 13 or less on admission) were included. Patients who were younger than age 18, dependent on others for daily activities before injury, pregnant, or who were not likely to survive for more than 24 h after injury were excluded. The outcome was assessed using the Glasgow Outcome Scale at 6 months after injury. Blood was collected from subjects (n = 32), and the serum pNF-H value was assessed at 24 and 72 h after TBI. The optimal cutoff value and usefulness of the serum pNF-H value for predicting the long-term outcome were investigated. We found that the serum pNF-H value at 24 h after injury was a good predictive marker of death at 6 months (p < 0.001) after injury. The optimal cutoff value was 240 pg/mL, and the area under the curve in the receiver operating characteristic analysis was 0.930. The serum pNF-H value at 72 h after injury was correlated with an unfavorable outcome (vegetative state or death) at 6 months (p < 0.01) with a cutoff value of 80 pg/mL. Collectively, the results of this study indicate that the serum pNF-H value is a useful predictive marker for patient outcome after TBI.