NfL Levels Research Articles

Assessment of axonal injury in multiple sclerosis: combined analysis of serum light-chain neurofilaments and diffusion tensor imaging

BackgroundMultiple sclerosis (MS) is a chronic neuroinflammatory condition characterised by demyelination and axonal damage in the central nervous system. Diffusion tensor imaging (DTI) enables non-invasive investigation of microstructural white matter...

CK1δ/ε-mediated TDP-43 phosphorylation contributes to early motor neuron disease toxicity in amyotrophic lateral sclerosis

Hyperphosphorylated TDP-43 aggregates in the cytoplasm of motor neurons is a neuropathological signature of amyotrophic lateral sclerosis (ALS). These aggregates have been proposed to possess a toxic disease driving role in ALS pathogenesis and progression, however, the contribution of phosphorylation to TDP-43 aggregation and ALS disease mechanisms remains poorly understood. We’ve previously shown that CK1δ and CK1ε phosphorylate TDP-43 at disease relevant sites, and that genetic reduction and chemical inhibition could reduce phosphorylated TDP-43 (pTDP-43) levels in cellular models. In this study, we advanced our findings into the hTDP-43-ΔNLS in vivo mouse model of ALS and TDP-43 proteinopathy. This mouse model possesses robust disease-relevant features of ALS, including TDP-43 nuclear depletion, cytoplasmic pTDP-43 accumulation, motor behavior deficits, and shortened survival. We tested the effect of homozygous genetic deletion of Csnk1e in the hTDP-43-ΔNLS mouse model and observed a delay in the formation of pTDP-43 without significant ultimate rescue of TDP-43 proteinopathy or disease progression. Homozygous genetic deletion of Csnk1d is lethal in mice, and we were unable to test the role of CK1δ alone. We then targeted both CK1δ and CK1ε kinases by way of CK1δ/ε-selective PF-05236216 inhibitor in the hTDP-43-ΔNLS mouse model, reasoning that inhibiting CK1ε alone would be insufficient as shown by our Csnk1e knockout mouse model study. Treated mice demonstrated reduced TDP-43 phosphorylation, lowered Nf-L levels, and improved survival in the intermediate stages. The soluble TDP-43 may have been more amenable to the inhibitor treatment than insoluble TDP-43. However, the treatments did not result in improved functional measurements or in overall survival. Our results demonstrate that phosphorylation contributes to neuronal toxicity and suggest CK1δ/ε inhibition in combination with other therapies targeting TDP-43 pathology could potentially provide therapeutic benefit in ALS.

Plasma extracellular vesicle neurofilament light chain as the biomarkers of the progression of Parkinson's disease.

Parkinson's disease (PD) is a common neurodegenerative disorder characterized by progressive symptoms, underscoring the urgent need for predictive blood biomarkers. Plasma extracellular vesicles (EVs) offer a promising platform for biomarker development, with neurofilament light chain (NfL) emerging as a potential candidate for neurological diseases. This study evaluated plasma EV NfL as a biomarker for disease progression in a PD cohort.A total of 55 patients with PD (PwP) and 58 healthy controls (HCs) were followed, with PwP completing an average of 3.96 visits and HCs 2.25 visits. Plasma EVs were isolated and validated, and EV NfL levels were measured using an immunomagnetic reduction assay. Generalized estimating equations and Spearman correlations assessed relationships between clinical symptom progression and biomarkers. Although no significant differences in plasma EV NfL levels were observed between PwP and HCs over time, changes in plasma EV NfL significantly correlated with motor symptom progression, specifically with adjusted-total and akinetic-rigidity subscores of the Unified PD Rating Scale (UPDRS) Part III. Additionally, changes in UPDRS Part II scores were significantly associated with plasma EV NfL levels. These findings suggest that plasma EV NfL reflects motor symptom progression in PwP, highlighting its potential as a valuable biomarker for monitoring disease progression and guiding clinical trials in PD.

Population-Based Evidence for the Use of Serum Neurofilaments as Individual Diagnostic and Prognostic Biomarkers in Amyotrophic Lateral Sclerosis.

Neurofilament light chains (NfL) and phosphorylated neurofilament heavy chains (pNfH), established as diagnostic and prognostic biomarkers in hospital-based amyotrophic lateral sclerosis (ALS) cohorts, are now surrogate markers in clinical trials. This study extends their evaluation to a population level, with the aim of advancing their full establishment and assessing the transferability of biomarker findings from controlled cohorts to real-world ALS populations. We measured serum NfL and pNfH levels in all ALS patients (n = 790) and general population controls (n = 570) with available baseline samples participating in the epidemiological ALS Registry Swabia, providing platform-specific (ELLA™) reference data and Z-scores for controls, as well as reference data, disease-specific Z-scores and longitudinal data in ALS. We evaluated the diagnostic and prognostic utility of neurofilaments and quantified the impact of ALS-related factors and non-ALS confounders. Neurofilaments showed high diagnostic and prognostic utility at the population level, with NfL superior to pNfH. The novel concept of a population-based ALS Z-score significantly improved the prognostic utility compared to absolute raw values. Both biomarkers increased more strongly with age in controls than in ALS, and age adjustment improved diagnostic accuracy. Our data show that disease progression rates, ALS phenotype, body mass index (BMI), and renal function need to be considered when interpreting neurofilament levels; longitudinal neurofilament levels were generally stable in individual patients, especially when adjusted for age and baseline levels. Population-based assessment enhances the utility of particularly serum NfL as a diagnostic and prognostic biomarker in ALS and improves the translation of findings from controlled cohorts to real-world populations. ANN NEUROL 2024;96:1040-1057.

Disease Severity Staging System for NOTCH3-Associated Small Vessel Disease, Including CADASIL

Typical cysteine-altering NOTCH3 (NOTCH3cys) variants are highly prevalent (approximately 1 in 300 individuals) and are associated with a broad spectrum of small vessel disease (SVD), ranging from early-onset stroke and dementia (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy [CADASIL]) to nonpenetrance. A staging system that captures the full NOTCH3-SVD severity spectrum is needed and currently lacking. To design a simple disease severity staging system that captures the broad clinicoradiological NOTCH3-SVD severity spectrum. A cohort study was performed in which the NOTCH3-SVD severity staging system was developed using a discovery cohort (2019-2020) and validated in independent international CADASIL cohorts (1999-2023) and the UK Biobank. Clinical and imaging data were collected from participants originating from 23 international CADASIL cohorts and from the UK Biobank. Eligibility criteria were presence of a NOTCH3cys variant, availability of brain magnetic resonance imaging, and modified Rankin Scale score. The discovery cohort consisted of 195 NOTCH3cys-positive cases from families with CADASIL; the validation set included 1713 NOTCH3cys-positive cases from 15 countries. The UK Biobank cohort consisted of 101 NOTCH3cys-positive individuals. Data from 2-year (2019-2023) and 18-year (1999-2017) follow-up studies were also analyzed. Data analysis was performed from July 2023 to August 2024. Percentage of cases following the sequence of events of the NOTCH3-SVD stages, and the association between the stages and ischemic stroke, intracerebral hemorrhage, global cognition, processing speed, brain volume, brain microstructural damage, and serum neurofilament light chain (NfL) level. The NOTCH3-SVD staging system encompasses 9 disease stages or substages, ranging from stage 0 (premanifest stage) to stage 4B (end stage). Of all 1908 cases, which included 195 in the discovery cohort (mean [SD] age, 52.4 [12.2] years) and 1713 in the validation cohorts (mean [SD] age, 53.1 [13.0] years), 1789 (94%) followed the sequence of events defined by the NOTCH3-SVD staging system. The NOTCH3-SVD stages were associated with neuroimaging outcomes in the NOTCH3cys-positive cases in the CADASIL cohorts and in the UK Biobank and with cognitive outcomes and serum NfL level in cases from the CADASIL cohorts. The NOTCH3-SVD staging system captured disease progression and was associated with 18-year survival. The NOTCH3-SVD staging system captures the full disease spectrum, from asymptomatic individuals with a NOTCH3cys variant to patients with end-stage disease. The NOTCH3-SVD staging system is a simple but effective tool for uniform disease staging in the clinic and in research.

Human Leukocyte Antigen Polymorphism and Blood Biomarker Profiles in Parkinson’s Disease: A Pilot Study in a Latvian Cohort

Background: Parkinson’s disease (PD) is a neurodegenerative disorder characterised by a high prevalence of sporadic cases. Various molecular mechanisms are involved in its pathogenesis. This pilot study aimed to identify potential risk and protective human leukocyte antigen (HLA) alleles in PD, discover candidate alleles for further research, and evaluate potential blood biomarkers. Methods: A total of 43 PD patients and 79 unrelated sex-matched controls were enrolled in this study. We analysed the polymorphism of HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the blood levels of biomarkers such as S100 calcium-binding protein A9 (S1000A9), kynurenic acid (KYNA), neurofilament light chain (NfL), and glutamate decarboxylase (GAD1). Results: We found that the frequencies of the HLA-DRB1*04, -DQA1*02:01, and -DQA1*03:01 alleles were significantly higher in the PD patients than in the controls, suggesting that these alleles are potential risk factors. Furthermore, the HLA-DQA1*02:01 allele was detected more frequently in the PD group when the disease onset was at 60 years or older. On the contrary, the HLA-DRB1*01 and HLA-DQA1*05:01 alleles were less common in the PD patients, indicating a possible protective effect. Regarding biomarkers, the blood levels of S100 calcium-binding protein A9 were significantly higher, and the kynurenic acid levels were significantly lower in the PD group. The NfL levels were also higher in the PD group but did not reach statistical significance, possibly due to the sensitivity limitations of the ELISA method used. The GAD1 levels showed no significant differences between the two groups. Conclusions: Our findings indicate that the HLA-DRB1*01 and -DRB1*04 alleles and the HLA-DQA1*02:01, -DQA1*03:01, and -DQA1*05:01 alleles are associated with PD. Moreover, S100 calcium-binding protein A9 and kynurenic acid can be considered potential blood biomarkers for PD. These findings contribute to the growing body of knowledge on PD and offer new directions for further research in Latvian cohorts.

The polygenic hazard score mediates the association between plasma neurofilament light chain and brain morphometry in dementia spectrum

IntroductionBlood-based biomarkers such as plasma neurofilament light chain (pNfL) are crucial biomarkers for Alzheimer's disease (AD). Additionally, neuroimaging techniques such as tensor-based morphometry (TBM), which identify structural changes in the brain, can provide valuable insights into AD pathophysiology. However, the role of genetics in linking the blood based biomarkers and imaging findings has not been well understood. Therefore, we aimed to investigate whether the polygenic hazard score (PHS), affects the association between neurofibrillary tangles and neuritis plaques and brain imaging findings. MethodsUsing the Alzheimer's Disease Neuroimaging Initiative (ADNI) database, we enrolled all participants for whom a complete dataset of pNfL, PHS, and TBM was available. Using Python, we analyzed the associations between pNfL levels and the TBM data of 567 participants incluidng 152 cognitively normal individuals, 309 participants with mild cognitive impairment (MCI), and 106 patients with AD. We used a mediation analysis to identify the effect of PHS in how pNfL is associated with TBM measures. ResultsWe found a negative correlation between the accelerated TBM measure and NfL levels in both the MCI and AD groups. The pNfL concentration predicted both accelerated statistical and anatomical TMB measures in patients with MCI. Furthermore, PHS mediatedthe association between statistical TBM measures and NfL levels in AD patients, to the extent that the significant association between NfL and TBM measures disappeared after accounting for PHS. ConclusionWe showed that although pNfL can predict the cognitiee decline and imaging findings in AD, this effect is mediated by the PHS. Therefore, PHS should be considered when investigating AD biomarkers and their corresponding imaging findings.

Association between serum neurofilament light chain levels and chronic kidney disease: a cross-sectional population-based study from the National Health and Nutrition Examination Survey (2013–2014 cycle)

Background The relationships of serum neurofilament light chain (NfL) levels with chronic kidney disease (CKD) and renal function indicators remain controversial, and comprehensive studies with large sample sizes are lacking. Methods In total, 2,051 participants aged 20 to 75 years were identified from the National Health and Nutrition Examination Survey (2013-2014 cycle). Logistic regression models were used to assess the associations between serum NfL levels and CKD, whereas multivariate linear models were used to investigate the relationships between serum NfL levels and two kidney function indicators, namely, estimated glomerular filtration rate (eGFR) and urinary albumin–creatinine ratio (UACR). Adjustments were made to account for potential confounding variables in the analysis. Subgroup analyses stratified by age and sex were conducted. When sNfL is incorporated into the model as continuous variables, a log transformation is applied. Results The present study included a cohort of 2,051 individuals ranging in age from 20 to 75 years. After covariate adjustment, multivariable logistic regression revealed a significant association between high serum NfL levels and an increased prevalence of CKD (OR 1.60; 95% CI 1.40–1.82; p < 0.0001), which remained significant when analyzed by quartiles (p for trend <0.0001). There was a statistically significant inverse correlation between the serum NfL level and the eGFR (β=-6.34; 95% CI −8.32 to −4.37; p < 0.0001), as well as a positive correlation between the serum NfL level and the UACR (β = 84.67; 95% CI 19.52-149.83; p < 0.0001). Furthermore, when stratified by age, there were significant interactions of serum NfL levels with CKD, the eGFR, and the UACR (p for interaction = 0.008, 0.016, and 0.020, respectively). Conclusion Serum NfL levels are positively associated with the prevalence of CKD and the UACR but negatively correlated with the eGFR, particularly in older patients.

Cerebrospinal fluid levels of NfM in relation to NfL and pNfH as prognostic markers in amyotrophic lateral sclerosis

Objective: To evaluate the prognostic potential of neurofilament medium chain (NfM) in CSF from patients with ALS and explore its relationship with the extensively studied neurofilament light chain (NfL) and phosphorylated heavy chain (pNfH). Method: CSF levels of NfL, NfM, and pNfH were analyzed in 235 samples from patients with ALS, ALS mimics, and healthy controls in a well-characterized cohort from Karolinska ALS Clinical Research Center in Stockholm, Sweden. NfM levels were analyzed using an antibody-based suspension bead-array and NfL and pNfH levels were measured using ELISA. Clinical data, including ALS Revised Functional Rating Scale (ALSFRS-R), and survival outcomes were utilized for disease progression estimations. Result: Increased NfM levels were observed in patients with ALS compared with mimics and healthy controls. Similarly, higher NfM levels were found in fast compared with slow progressing patients for baseline and longitudinal progression when evaluating both total and subscores of ALSFRS-R. These findings were consistent with the results observed for NfL and pNfH. All three proteins, used individually as well as in combination, showed comparable performance when classifying fast vs slow progressing patients (AUCs 0.78–0.85). For all neurofilaments, higher survival probability was observed for patients with low CSF levels. Conclusion: Based on this cross-sectional study, the prognostic value provided by NfM aligns with the more established markers, NfL and pNfH. Additional investigations with independent cohorts and longitudinal studies are needed to further assess the potential added value of NfM.

Phenotypic and oncological insights in ANNA1 autoimmunity: Age stratification and biomarker analysis.

To describe the phenotypes, oncological associations, biomarker profiles, and outcomes across different age groups in patients with ANNA1 (anti-Hu) autoimmunity. A retrospective review of patients with ANNA1-IgG in serum/CSF between January 1, 2001, and December 31,2019 was performed. Patients were classified into three groups based on the age of symptom onset. Phage immunoprecipitation sequencing (PhIP-Seq) and neurofilament light chain (NfL) measurements were done in patient sera/CSF with archived samples. Of 122 patients, 81 (66%), 20 (16%), and 21 (17%) patients belonged to older adults, young adults, and pediatric groups, respectively. Lung cancer and neuromuscular presentations were more common in older adults (p < 0.001), while limbic encephalitis and neuroblastoma were more common in pediatric patients (p < 0.005). Most young adults (75%) did not have cancer identified. Proportions of patients with a favorable response to immunotherapy were 20%, 30%, and 52% among older adults, young adults, and pediatric groups, respectively. PhIP-Seq demonstrated significant enrichment for ELAVL4 peptides especially for amino acids 240-289, in the majority of samples evaluated (36/67, 54%). ZIC and SOX2 peptides were significantly enriched in those with central nervous system presentations. Serum NfL levels were elevated in patients with cancer and those with poor long-term outcomes. Young adults with ANNA1 autoimmunity phenotypically resembled older adults but rarely had an underlying cancer. Pediatric patients frequently presented with limbic encephalitis and neuroblastoma and often responded favorably to immunotherapy. Distinct antigenic signatures may underlie differences in clinical presentations. Serum NfL levels may be a biomarker of poor long-term outcomes in ANNA1 autoimmunity.

The challenge to identify sensitive safety biomarkers of peripheral neurotoxicity in the rat: A collaborative effort across industry and academia (IMI NeuroDeRisk project)

Peripheral nervous system (PNS) toxicity assessment in non-clinical safety studies is challenging and relies mostly on histopathological assessment. The present work aims to identify blood-based biomarkers that could detect peripheral neuropathy in rats upon exposure to neurotoxic compounds. Three anticancer agents (oxaliplatin, cisplatin, paclitaxel) and a developmental compound (NVS-1) were assessed in male rats (Wistar Han). Clinical and/or functional endpoints (i.e., electronic Von Frey, Cold Plate, and Paw Pressure tests) and blood biomarkers (i.e., neurofilament light chain (NfL), neurofilament heavy chain (NF-H), microtubule-associated protein Tau (Tau), neuron specific enolase (NSE), vascular endothelial growth factor A (VEGFA), and glial fibrillary acidic protein (GFAP)) were assessed. Drug exposure and histopathological evaluations were conducted on selected nervous tissues. Oxaliplatin, cisplatin and paclitaxel treatment resulted in a significant decrease of nociceptive thresholds. Clinical signs suggestive of PNS toxicity were observed with NVS-1. NfL was consistently increased in the NVS-1 study and correlated with moderate microscopic findings in dorsal root ganglia (DRG). Only minimal microscopic findings were observed in oxaliplatin-treated animals, whereas no treatment-related microscopic findings were observed in animals treated with cisplatin and paclitaxel. For all compounds, exposure was confirmed in the PNS tissues. Clinical and functional changes were observed with all the compounds evaluated. NfL levels in plasma proved to be the most sensitive indicator of PNS toxicities, capturing moderate nervous degeneration in DRG. A combined approach that includes both functional assessments and biomarker measurements offers a more comprehensive evaluation than histopathological analysis alone when monitoring drug-induced neurotoxicity in rat models.

Neurofilament light chain: a biomarker at the crossroads of clarity and confusion for gene-directed therapies.

Neurofilament light chain (NfL) is a promising biomarker for neurodegenerative diseases, measurable in both CSF and blood upon neuroaxonal damage. While CSF analysis was traditionally used, blood-based assays now offer a less invasive alternative. NfL levels correlate with disease severity and progression in conditions like Alzheimer's disease, amyotrophic lateral sclerosis, multiple sclerosis and Huntington's disease. Clinical trials demonstrate its utility as a pharmacodynamic biomarker in MS and ALS. The FDA's approval of Tofersen for SOD1-ALS based on NfL reduction underscores its growing acceptance as surrogate marker. However, challenges remain in standardizing assays, interpreting clinical correlations, low specificity and understanding the dynamics between CSF and blood NfL levels. Addressing these issues is crucial for maximizing NfL's potential in neurodegenerative disease management.

Identifying amyotrophic lateral sclerosis using diffusion tensor imaging, and correlation with neurofilament markers

To determine diagnostic value of diffusion tensor imaging (DTI) in amyotrophic lateral sclerosis (ALS) patients and investigate the association between DTI and neurofilaments (NFs), including serum and cerebrospinal fluid (CSF) levels of neurofilament light chain (NFL) and phosphorylated neurofilament heavy chain (pNFH). Forty-three clinically diagnosed ALS patients and 32 control subjects without neurological disorders underwent routine MRI (magnetic resonance imaging) and DTI scans. DTI parameters (mean diffusivity [MD] and fractional anisotropy [FA]) at axial levels of internal capsules and cerebral peduncles along the corticospinal tract (CST) were measured. The study compared the differences of DTI parameters between ALS patients and controls using the Mann-Whitney U test. Diagnostic efficacy of each DTI metric was evaluated using the receiver operating characteristic (ROC) curve. NFs (NFL and pNFH levels in serum and CSF) were measured by enzyme-linked immunosorbent assay. Correlation analyses were conducted between DTI parameters and NFs. Capsule-MD and Peduncle-MD in ALS patients were higher than those in controls; whereas Capsule-FA and Peduncle-FA in ALS patients were lower than those in controls (all, p < 0.05). The area under curve (AUC) was 0.730 for Capsule-FA, 0.828 for Capsule-MD, 0.890 for Peduncle-FA, and 0.896 for Peduncle-MD. Capsule-FA was negatively correlated with CSF-NFL (r = − 0.813, p < 0.001), Serum-NFL (r = − 0.493, p = 0.001), CSF-pNFH (r = − 0.637, p < 0.001), and Serum-pNFH (r = − 0.672, p < 0.001); Peduncle-FA negatively with CSF-NFL (r = − 0.562, p < 0.001), CSF-pNFH (r = − 0.506, p = 0.001), and Serum-pNFH (r = − 0.488, p = 0.001); Peduncle-MD positively with CSF-NFL (r = 0.516, p < 0.001), CSF-pNFH (r = 0.494, p = 0.001). DTI had superior performance in identifying ALS patients and could serve as a reliable predictor. DTI parameters related to neurofilament markers, and Capsule-FA may become a robust surrogate biomarker indicating disease severity and progression rate for ALS patients.

Abstract 4138781: Neuro-specific biomarkers for risk assessment of ischemic stroke and death in patients with atrial fibrillation not receiving oral anticoagulation

Background: Biomarkers measured in plasma reflecting cardiorenal dysfunction and inflammation are associated with clinical outcomes in atrial fibrillation (AF). We recently showed an association between the plasma level of the neuronal biomarker neurofilament light chain (NFL) and subsequent stroke and death in patients with AF not receiving oral anticoagulation (OAC). Purpose: We aimed to compare NFL with other circulating neuro-specific biomarkers, specifically glial fibrillary acidic protein (GFAP), tau, and ubiquitin carboxy-terminal hydrolase L1 (UCHL1), concerning associations with the risk of stroke and other outcomes in patients with AF. Methods: Concentrations of NFL, GFAP, tau, and UCHL1 were determined with Single Molecule Array (Simoa®) in plasma samples obtained at baseline from 967 patients with AF randomized to aspirin in the ACTIVE A trial. Median follow-up was 3.6 years. Associations between baseline biomarker concentrations, clinical variables (age, sex, body mass index, smoking, alcohol consumption, type of AF, cardiac rhythm at baseline, heart failure, hypertension, diabetes, prior stroke/transient ischemic attack, peripheral arterial disease, and myocardial infarction), and outcomes (ischemic stroke, cardiovascular and all-cause death) were analysed with Cox regression, adjusting for clinical variables and other biomarkers. Results: Increasing age and female sex were associated with elevated levels of all four biomarkers. Plasma levels of NFL were positively correlated with those of GFAP (r=0.67, p&lt;0.001), tau (r=0.12, p&lt;0.001), and UCHL1 (r=0.37, p&lt;0.001). NFL was independently associated with subsequent ischemic stroke (HR 1.27, 95% CI 1.03–1.56 for a doubling of NFL), cardiovascular death (HR 1.37, 95% CI 1.13–1.64 for a doubling of NFL), and all-cause death (HR 1.46, 95% CI 1.25–1.70 for a doubling of NFL) after adjustment for clinical factors and other biomarkers. In unadjusted analyses, GFAP was associated with ischemic stroke and death; tau and UCHL1 with death only, however, these associations were not significant after adjusting for clinical variables (Table). Conclusions: In patients with AF not receiving OAC, NFL was independently associated with ischemic stroke and death. Further investigation of NFL and its association with clinical outcomes in patients with cardiovascular disease is therefore warranted.

Asymptomatic Cerebrospinal Fluid HIV-1 Escape: Incidence and Consequences.

The incidence and clinical relevance of asymptomatic cerebrospinal fluid escape (CSF-E) during antiretroviral therapy (ART) is uncertain. We examined the impact and incidence of asymptomatic CSF-E in a Swedish HIV cohort. Neuroasymptomatic people living with HIV (PLWH) who have been on ART for at least six months with suppressed plasma viral load were followed longitudinally. CSF-E was defined as either increased CSF HIV-1 RNA with concurrent plasma suppression or as CSF HIV-1 RNA exceeding that in plasma when both were quantifiable. Paired CSF and plasma were analyzed for HIV-1 RNA, neopterin, neurofilament light protein (NfL), white blood cell (WBC) count, and albumin ratio. Asymptomatic CSF-E (cut-off 50 copies/mL) was found in 4/173 PLWH (2%) and 5/449 samples (1%). The corresponding proportions were 8% of PLWH and 4% for samples using a 20 copies/mL cut-off for CSF HIV-1 RNA. CSF-E samples (cut-off 20 copies/mL) had a 25% higher geometric mean of CSF neopterin (P = .01) and 8% higher albumin ratio (P = .04) compared to samples without CSF-E. No differences were observed in CSF NfL levels (P = .8). The odds ratio for increased CSF WBC (≥ 3 cells/μL) in samples with CSF-E was 3.9 (P = .004), compared to samples without elevated CSF viral load. Asymptomatic CSF-E was identified in only four (2%) PLWH, with no cases of continuous CSF-E observed. Increased CSF HIV-1 RNA was associated with biomarkers of CNS immune activation and blood-brain-barrier impairment, but not with biomarkers of neuronal injury.

NCOG-27. HIGHER LEVELS OF SERUM ICAM-1 AND IL-10 ARE ASSOCIATED WITH COGNITIVE DYSFUNCTION IN BOTH IDH-WILDTYPE AND IDH-MUTANT GLIOMA

Abstract BACKGROUND Cognitive dysfunction is common among glioma patients, but the contribution of specific mechanisms to the development of cognitive symptoms is unclear. Circulating levels of proteins linked to neurodegeneration, inflammation, and vascular damage have been associated with cognitive symptoms in neurological diseases and aging, but their prognostic value in glioma is unknown. Here, we examined associations between cognitive symptoms and serum levels of protein biomarkers in glioma patients. METHODS Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA, scores ≤ 25 = cognitive dysfunction). Cytokines (interleukin-1β [IL-1β], IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, interferon-γ [IFN-γ], tumor necrosis factor-α [TNF-α]), and neurodegeneration (neurofilament light chain [NfL], tau, glial fibrillary acidic protein [GFAP]), and vascular damage markers (Serum amyloid A [SAA], C-reactive protein [CRP], vascular cell adhesion molecule 1 [VCAM-1], and intercellular adhesion molecule 1 [ICAM-1]) were measured using ultrasensitive assays (Meso Scale Discovery). RESULTS Patients (n=73) were predominantly male (58%), white (74%), with a median age of 44 (range=24,74). Cognitive dysfunction was found in 53% of the patients. Levels of NfL (p=0.035), IL-6 (p=0.006), IL-10 (p=0.007), TNF-α (p=0.035), IFN-γ (p=0.011), CRP (p=0.016), VCAM-1 (p=0.012), and ICAM-1 (p&amp;lt;0.001) were higher in patients with cognitive dysfunction when compared to those with normal cognition. After adjusting for isocitrate dehydrogenase (IDH) tumor mutation status, age, tumor grade, and number of surgeries, higher levels of ICAM-1 and IL-10, but not other markers, remained associated with cognitive dysfunction. MoCA scores were negatively correlated with GFAP (r=-0.24, p=0.038), IFN-γ (r=-0.31, p=0.008), IL-6 (r=-0.29, p=0.014), IL-10 (r=-0.24, p=0.039), and ICAM-1 (r=-0.39, p&amp;lt;0.001). CONCLUSIONS ICAM-1 and IL-10 levels were higher in patients with MOCA determined cognitive dysfunction, suggesting an association between cognitive symptoms and inflammation and vascular impairment in glioma patients. Future analyses in larger longitudinal cohorts are warranted to assess the predictive value of protein biomarkers.

BIOM-72. INTEGRATION OF ULTRASENSITIVE ELECTROLUMINESCENT IMMUNOASSAY AND CELL-FREE DNAMETHYLATION ANALYSIS FOR NON-INVASIVE MONITORING OF ADULT DIFFUSE GLIOMAS

Abstract Gliomas are highly aggressive brain tumors with nearly universal recurrence rate. Despite this, the ability to accurately predict and identify tumor recurrence relies solely on serial MRI imaging, which is marred by treatment effects such as radiation necrosis, and necessarily identifies progression retrospectively. It is believe that tumor undergo molecular changes upon tumor progression, however the resampling of tumors upon recurrence imposes significant risks. This highlights the need for novel non-invasive biomarkers capable of identifying tumor recurrence. Due to the low accuracies of individual biomarkers, we have proposed the use of an integrated, multi-platform approach to biomarker discovery. A cohort of 107 glioma plasma samples, including 30 pairs, underwent plasma proteomic analysis, consisting of a panel of serum proteins (FABP4, GFAP, NFL, Tau and MMP3,4 &amp;7) quantified through ultrasensitive electrochemiluminescence multiplexed immunoassays, and plasma DNA methylation analysis, captured through cell-free methylated DNA immunoprecipitation and high-throughput sequencing. Unsupervised hierarchal clustering revealed robust separation of primary and recurrent tumors through plasma proteomics, associated with a distinct plasma methylation signature. NFL, Tau and MMP3 levels differed between primary and recurrent samples; pair-wise analysis revealed increased in NFL and Tau concentrations upon recurrence. Tau levels predicted outcome independent of WHO Grade and IDH status. A predictive generalized linear regression model created through the integration of the proteomic and methylation signatures allowed for the discrimination of primary and recurrent samples in 83% of cases. This work suggests that the combination of DNA methylation and plasma proteomics may improve the ability of these techniques for the serial monitoring of gliomas patients.

NCOG-28. SERUM PROTEIN BIOMARKERS LINKED TO NEURODEGENERATIVE PROCESSES ARE ELEVATED IN GLIOMA PATIENTS AND ASSOCIATED WITH SEVERITY OF NEUROLOGIC SYMPTOMS

Abstract BACKGROUND Glioma patients frequently report neurologic symptoms, adding to the complexity of cancer management and negatively impacting quality of life. However, mechanisms associated with the development of neurologic symptoms in glioma patients remain unclear. Pathological changes in the brain of glioma patients might result in elevated peripheral blood levels of proteins previously linked to central nervous system (CNS) damage and neurodegeneration, including neurofilament light chain (NfL), tau, and glial fibrillary acidic protein (GFAP). Here, we tested the hypothesis that the circulating levels of these proteins in blood are elevated in glioma patients and associated with the severity of neurologic symptoms. METHODS Patients (n=73) were enrolled in a natural history study (NCT02851706, PI T. Armstrong). Healthy subjects (n=39) were recruited by the National Institutes of Health Clinical Center Blood Bank. Neurologic symptom severity and walking interference were assessed using MD Anderson Symptom Inventory-Brain Tumor (MDASI-BT). Serum proteins were analyzed using ultrasensitive assays (Meso Scale Discovery). RESULTS Participants were predominantly white (patients 74%, healthy subjects 67%) and male (patients 58%, healthy subjects 54%). The median age was 44 (range=24,74) for patients and 49 (range=19,78) for healthy volunteers. No significant differences in age, sex, or race were observed between patients and healthy subjects. Serum levels of NfL (p&amp;lt;0.0001), GFAP (p&amp;lt;0.0001), and tau (p&amp;lt;0.0001) were higher in glioma patients when compared to healthy subjects. Patients with walking interference had higher levels of GFAP (p=0.003), NfL (p=0.003), and tau (p=0.004), and those who reported numbness had higher levels of GFAP (p=0.012). CONCLUSIONS These findings suggest that serum levels of protein markers of neurodegeneration are elevated in glioma patients and associated with the presence of neurologic symptoms. Blood-based biomarkers have the potential to shed light on the mechanisms underlying symptoms and offer a non-invasive alternative for monitoring CNS damage that impact patient outcomes.

Sex differences in the association between repetitive negative thinking and neurofilament light

Emerging evidence suggests that repetitive negative thinking (RNT; i.e., worry and ruminative brooding) is associated with biomarkers of Alzheimer’s disease. Given that women have a greater risk of many neurodegenerative diseases, this study investigated whether worry and brooding are associated with general neurodegeneration and whether associations differ by sex. Exploratory analyses examined whether allostatic load, a marker of chronic stress, mediates any observed relationships. Baseline data from 134 cognitively healthy older adults in the Age-Well clinical trial were utilised. Worry and brooding were assessed using questionnaires. Plasma neurofilament light chain (NfL), a biomarker of neurodegeneration, was quantified using a Meso Scale Discovery assay. We found a positive interaction between brooding and sex on NfL, with higher brooding associated with greater NfL levels in women. No associations were observed between worry/ruminative brooding and allostatic load. These results offer preliminary support that RNT is associated with worse brain health, specifically in women.

Exploiting blood-based biomarkers to align preclinical models with human traumatic brain injury.

Rodent models are important research tools for studying the pathophysiology of traumatic brain injury (TBI) and developing new therapeutic interventions for this devastating neurological disorder. However, the failure rate for the translation of drugs from animal testing to human treatments for TBI is 100%. While there are several potential explanations for this, previous clinical trials have relied on extrapolation from preclinical studies for critical design considerations, including drug dose optimization, post-injury drug treatment initiation and duration. Incorporating clinically relevant biomarkers in preclinical studies may provide an opportunity to calibrate preclinical models to identical (or similar) measurements in humans, link to human TBI biomechanics and pathophysiology, and guide therapeutic decisions. To support this translational goal, we conducted a systematic literature review of preclinical TBI studies in rodents measuring blood levels of clinically used GFAP, UCH-L1, NfL, t-Tau, or p-Tau, published in PubMed/EMBASE up to April 10th, 2024. Although many factors influence clinical TBI outcomes, many of those cannot routinely be assessed in rodent studies (e.g., ICP monitoring), thus we focused on blood biomarkers' temporal trajectories and discuss our findings in the context of the latest clinical TBI biomarker data. Out of the 805 original preclinical studies, 74 met the inclusion criteria, with a median quality score of 5 (25th-75th percentiles: 4-7) on the CAMARADES checklist. GFAP was measured in 43 studies, UCH-L1 in 21, NfL in 20, t-Tau in 19, and p-Tau in seven. Data in rodent models indicate that all biomarkers exhibited injury severity-dependent elevations with distinct temporal profiles. GFAP and UCH-L1 peaked within the first day after TBI (30- and 4-fold increases, respectively, in moderate-to-severe TBI versus sham) with the highest levels observed in the contusion TBI model. NfL peaked within days (18-fold increase) and remained elevated up to 6 months post-injury. GFAP and NfL show a pharmacodynamic response in 64.7% and 60%, respectively, of studies evaluating neuroprotective therapies in preclinical models. However, GFAP's rapid decline post-injury may limit its utility for understanding the response to new therapeutics beyond the hyperacute phase after experimental TBI. Furthermore, as in humans, subacute NfL levels inform on chronic white matter loss after TBI. t-Tau and p-Tau levels increased over weeks after TBI (up to 6- and 16-fold, respectively); however, their relationship with underlying neurodegeneration has yet to be addressed. Further investigation into biomarker levels in the subacute and chronic phases after TBI will be needed to fully understand the pathomechanisms underpinning blood biomarkers' trajectories and select the most suitable experimental model to optimally relate preclinical mechanistic studies to clinical observations in humans. This new approach could accelerate the translation of neuroprotective treatments from laboratory experiments to real-world clinical practices.