2026
Biases and consistency of different assay methods for neurological biomarkers using Quanterix single-molecule-array technology: A comparative study of the secondary analysis method
Breakthrough technologies such as the Single molecule array (Simoa) technology developed by Quanterix provide higher sensitivity, enabling measurement of central nervous system-abundant proteins in blood. Neurofilament light chain (NfL) and glial fibrillary protein (GFAP) are two proteins that have attracted considerable attention as biomarkers for many neurological conditions. Due to their performance and utility, these biomarkers are available in different Quanterix assays, including singleplex and multiplex assay setups. Limited research has been conducted to evaluate how modifications in assay formulations may impact overall analytical performance and comparability. In this study, we established reference intervals (RI) for plasma NfL and GFAP measured in normative samples from the Canadian Health Measures Survey (CHMS) using the Quanterix Neurology 4-Plex E (N4PE) Advantage.
2025
Characterizing the physiology of circulatory arrest in humans
The dying process from circulatory arrest is an underexplored domain in humans and has transdisciplinary pertinence. Here we conducted a prospective, observational cohort study of the dying process in 39 adults, with a multimodal assessment of cerebrovascular and cardiovascular physiology. We found that cerebral blood velocities and brain tissue oxygen tensions ceased before systemic hemodynamics. The brain exhibited diffusion limitation of oxygen extraction during the dying process compared with extracranial tissues. Anterior and posterior brain circulations had differences in timing of cessation of circulation and physiologic responses during the dying process. Blood-based neurologic biomarkers from the brain did not change during the associated ischemia related to the dying process. Heart pathology was associated with the length of the dying process. This study provides proof-of-concept of an in vivo human model to comprehensively investigate severe cerebral ischemia and the human dying process. ClinicalTrials.gov registration: NCT06130033.
Advocates, Academics, Survivors and Clinicians to END Intimate Partner Violence (ASCEND-IPV) initiative: a prospective observational case–control study protocol to identify plasma biomarkers of intimate partner violence (IPV)-caused brain injury (BI)
Although as many as 92% of survivors of physical intimate partner violence (IPV) report impacts to the head and/or non-fatal strangulation (NFS) that raise clinical suspicion of brain injury (BI), there are no evidence-based methods to document and characterise BI in this vulnerable population, limited clinical practice guidelines and insufficient understanding about long-term risks for conditions including Alzheimer’s Disease and Related Dementias (ADRD). This leaves most survivors of IPV-caused BI (IPV-BI), overwhelmingly women, without adequate access to medical care and support, safe housing, back-to-school/work accommodations or follow-up care for long-term neurocognitive health. Although traumatic brain injury (TBI) is an established ADRD risk factor, little is known about the attributable risk of ADRD due to IPV-BI, particularly in women.
Molecular and imaging biomarker responses to brain mutant HTT lowering in a mouse model of Huntington disease
Therapies targeting mutant huntingtin (mHTT) reduction in the brain hold promise as disease-modifying treatments for Huntington disease (HD), necessitating biomarkers that accurately reflect treatment response. We evaluated candidate molecular and imaging biomarkers after mHTT reduction in YAC128 HD mice, with equal numbers of males and females per group. At 6 months of age, YAC128 mice received unilateral intracerebroventricular injections of saline or mHTT-lowering antisense oligonucleotide (HTT ASO). Plasma neurofilament light chain (NEFL) and glial fibrillary acidic protein (GFAP) were measured longitudinally from 6 to 12 months. Structural MRI was performed at 6, 9, and 12 months. At study endpoint, we quantified mHTT target engagement in the brain and performed striatal RNA sequencing.
ABO blood group and COVID-19 severity: Associations with endothelial and adipocyte activation in critically ill patients
ABO blood group has been implicated both in susceptibility to, and severity of, SARS-CoV-2 infection. The aim of this study was to explore a potential association between ABO blood group and severity of COVID-19 infection in critically ill patients and the following biological mechanisms: inflammatory cytokines, endothelial injury, and adipokines.
Prognostic value of plasma biomarkers for informing clinical trial design in mild-to-moderate Alzheimer’s disease
Emerging evidence supports the diagnostic and prognostic utility of plasma biomarkers in Alzheimer’s disease (AD), particularly in early disease stages. We sought to extend these findings by evaluating the prognostic value of plasma biomarkers in a clinical trial of mild-to-moderate AD. Elevated baseline plasma NfL predicted more rapid clinical decline and MRI volume loss. Furthermore, increasing plasma NfL concentration over time was associated with worsening on the CDR-SB. Plasma NfL is an easily accessible biomarker that may enhance the design of clinical trials in mild-to-moderate AD.
Ambroxol as a Treatment for Parkinson Disease Dementia
Carrying a variation in the gene for β-glucocerebrosidase is a major risk factor for Parkinson disease dementia (PDD), and raising β-glucocerebrosidase levels lowers α-synuclein in cell and animals. Ambroxol is a chaperone for β-glucocerebrosidase, which increases the levels of β-glucocerebrosidase. Results of this randomized clinical trial reveal that ambroxol was safe, well-tolerated, and demonstrated target engagement. However, the effect of ambroxol on cognition was not confirmed.
Plasma biomarkers distinguish Boston Criteria 2.0 cerebral amyloid angiopathy from healthy controls
Cerebral amyloid angiopathy (CAA) is characterized by the deposition of beta-amyloid (Aβ) in small vessels leading to hemorrhagic stroke and dementia. This study examined whether plasma Aβ42/40, phosphorylated-tau (p-tau), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) differ in CAA and their potential to discriminate Boston Criteria 2.0 probable CAA from healthy controls.
Pathophysiology, blood biomarkers, and functional deficits after intimate partner violence-related brain injury: Insights from emergency department patients and a new rat model
Intimate partner violence is a serious, but underappreciated, issue that predominantly affects women and often results in concussion (i.e., mild traumatic brain injury). However, concussion in intimate partner violence is unique because it often involves a concomitant strangulation which may exacerbate or alter the physiology and clinical presentation of the brain injury. Therefore, here we conducted human and rodent studies to provide insight into knowledge gaps related to the detection, pathophysiology, and functional consequences of intimate partner violence-related brain injury. We conducted the first study to analyze blood biomarkers and symptoms of brain injury in intimate partner violence patients presenting to an emergency department within 72 h of concussion.
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, total-Tau (t-Tau) or phosphorylated-Tau (p-Tau) published in PubMed/EMBASE up to 10 April 2024.
2024
The role of C-reactive protein and ferritin in the diagnosis of HLH, adult-onset still’s disease, and COVID-19 cytokine storm
Cytokine storm syndromes such as hemophagocytic lymphohistiocytosis (HLH), Adult-onset Still’s disease (AOSD), and COVID-19 cytokine storm (CCS) are characterized by markedly elevated inflammatory cytokines. However clinical measurement of serum cytokines is not widely available. This study examined the clinical utility of C-reactive protein (CRP) and ferritin, two inexpensive and widely available inflammatory markers, for distinguishing HLH from AOSD and CCS. This single centre retrospective study included 44 secondary HLH patients, 14 AOSD patients, and 13 CCS patients. Baseline CRP and ferritin measured within 72 h of diagnosis and before administration of corticosteroids or other anti-inflammatory therapies were analyzed. The median CRP in HLH patients was lower than AOSD (71 mg/L vs. 172 mg/L, p < 0.001) and CCS (71 mg/L vs. 121 mg/L, p = 0.0095) patients. Serum ferritin levels were lower in CCS compared to HLH (1,386 µg/L vs. 29,019 µg/L, p < 0.001) and AOSD (11,359 µg/L vs. 29,019 µg/L, p = 0.035). A CRP < 130 mg/L when combined with an HScore > 136 improves the specificity of HScore alone for HLH from 85.2 to 96.3%. Adding CRP < 130 mg/L to ferritin > 15,254 µg/L increases specificity for HLH from 88.9 to 100%. This study demonstrates that median CRP is lower in HLH than in AOSD and CCS, and median ferritin is lower in CCS than in HLH or AOSD. This study demonstrates the clinical utility of these widely available inflammatory markers for distinguishing between different cytokine storm syndromes.
Impact of a national dementia research consortium: The Canadian Consortium on Neurodegeneration in Aging (CCNA)
The Canadian Consortium on Neurodegeneration in Aging (CCNA) was created by the Canadian federal government through its health research funding agency, the Canadian Institutes for Health Research (CIHR), in 2014, as a response to the G7 initiative to fight dementia. Two five-year funding cycles (2014-2019; 2019-2024) have occurred following peer review, and a third cycle (Phase 3) has just begun. A unique construct was mandated, consisting of 20 national teams in Phase I and 19 teams in Phase II (with research topics spanning from basic to clinical science to health resource systems) along with cross-cutting programs to support them. Responding to the needs of researchers within the CCNA teams, a unique sample of 1173 deeply phenotyped patients with various forms of dementia was accrued and studied over eight years (COMPASS-ND). In the second phase of funding (2019-2024), a national dementia prevention program (CAN-THUMBS UP) was set up. In a short time, this prevention program became a member of the World Wide FINGERS prevention consortium. In this article, the challenges, successes, and impacts of CCNA in Canada and internationally are discussed. Short-term deliverables have occurred, along with considerable promise of impacts in the longer term. The creation of synergy, networking, capacity building, engagement of people with lived experience, and economies of scale have contributed to the considerable success of CCNA by all measures. CCNA is evidence that an organized “centrally-organized” approach to dementia research can catalyze important progress nationally and yield significant and measurable results.
Advancements in APOE and dementia research: Highlights from the 2023 AAIC Advancements: APOE conference
The apolipoprotein E gene (APOE) is an established central player in the pathogenesis of Alzheimer’s disease (AD), with distinct apoE isoforms exerting diverse effects. apoE influences not only amyloid-beta and tau pathologies but also lipid and energy metabolism, neuroinflammation, cerebral vascular health, and sex-dependent disease manifestations. Furthermore, ancestral background may significantly impact the link between APOE and AD, underscoring the need for more inclusive research.
Intimate Partner Violence-Related Brain Injury: Unmasking and Addressing the Gaps
Intimate partner violence (IPV) is a significant, global public health concern. Women, individuals with historically underrepresented identities, and disabilities are at high risk for IPV and tend to experience severe injuries. There has been growing concern about the risk of exposure to IPV-related head trauma, resulting in IPV-related brain injury (IPV-BI), and its health consequences. Past work suggests that a significant proportion of women exposed to IPV experience IPV-BI, likely representing a distinct phenotype compared with BI of other etiologies. An IPV-BI often co-occurs with psychological trauma and mental health complaints, leading to unique issues related to identifying, prognosticating, and managing IPV-BI outcomes. The goal of this review is to identify important gaps in research and clinical practice in IPV-BI and suggest potential solutions to address them. We summarize IPV research in five key priority areas: (1) unique considerations for IPV-BI study design; (2) understanding non-fatal strangulation as a form of BI; (3) identifying objective biomarkers of IPV-BI; (4) consideration of the chronicity, cumulative and late effects of IPV-BI; and (5) BI as a risk factor for IPV engagement. Our review concludes with a call to action to help investigators develop ecologically valid research studies addressing the identified clinical-research knowledge gaps and strategies to improve care in individuals exposed to IPV-BI. By reducing the current gaps and answering these calls to action, we will approach IPV-BI in a trauma-informed manner, ultimately improving outcomes and quality of life for those impacted by IPV-BI.
Characterizing the Relationship Between Arterial Carbon Dioxide Trajectory and Serial Brain Biomarkers with Central Nervous System Injury During Veno-Venous Extracorporeal Membrane Oxygenation: A Prospective Cohort Study
Central nervous system (CNS) injury following initiation of veno-venous extracorporeal membrane oxygenation (VV-ECMO) is common. An acute decrease in partial pressure of arterial carbon dioxide (PaCO2) following VV-ECMO initiation has been suggested as an etiological factor, but the challenges of diagnosing CNS injuries has made discerning a relationship between PaCO2 and CNS injury difficult. Although rapid decreases in PaCO2 following initiation of VV-ECMO were slightly greater in patients who had CNS injuries versus those without, data overlap and absence of relationships between PaCO2 and brain biomarkers suggests other pathophysiologic variables are likely at play.
Neuroinflammation and the immune system in hypoxic ischaemic brain injury pathophysiology after cardiac arrest
Hypoxic ischaemic brain injury after resuscitation from cardiac arrest is associated with dismal clinical outcomes. To date, most clinical interventions have been geared towards the restoration of cerebral oxygen delivery after resuscitation; however, outcomes in clinical trials are disappointing. Therefore, alternative disease mechanism(s) are likely to be at play, of which the response of the innate immune system to sterile injured tissue in vivo after reperfusion has garnered significant interest. The innate immune system is composed of three pillars: (i) cytokines and signalling molecules; (ii) leucocyte migration and activation; and (iii) the complement cascade. In animal models of hypoxic ischaemic brain injury, pro-inflammatory cytokines are central to propagation of the response of the innate immune system to cerebral ischaemia-reperfusion. In particular, interleukin-1 beta and downstream signalling can result in direct neural injury that culminates in cell death, termed pyroptosis. Leucocyte chemotaxis and activation are central to the in vivo response to cerebral ischaemia-reperfusion. Both parenchymal microglial activation and possible infiltration of peripherally circulating monocytes might account for exacerbation of an immunopathological response in humans. Finally, activation of the complement cascade intersects with multiple aspects of the innate immune response by facilitating leucocyte activation, further cytokine release and endothelial activation. To date, large studies of immunomodulatory therapies have not been conducted; however, lessons learned from historical studies using therapeutic hypothermia in humans suggest that quelling an immunopathological response might be efficacious. Future work should delineate the precise pathways involved in vivo in humans to target specific signalling molecules.
Detecting a hidden pandemic: The current state and future direction of screening and assessment tools for intimate partner violence-related brain injury
Intimate partner violence (IPV) is a major global concern, and IPV victim-survivors are at an increased risk of brain injury (BI) due to the physical assaults. IPV-BI can encompass both mild traumatic brain injury (mTBI) and non-fatal strangulation (NFS), but IPV-BI often goes undetected and untreated due to a number of complicating factors. Therefore, the clinical care and support of IPV victim-survivors could be enhanced by BI screening and assessment in various settings (e.g., first responders, emergency departments, primary care providers, rehabilitation, shelters, and research). Further, appropriate screening and assessment for IPV-BI will support more accurate identifications, and prevalence estimates, improve understanding of health implications, and have the potential to inform policy decisions. Here we overview the seven available tools that have been used for IPV-BI screening and assessment purposes, including the BISA, BISQ-IPV, BAT-L/IPV, OSU TBI-ID, the HELPS, and the CHATS, and outline the advantages and disadvantages of these screening tools in the clinical, community, and research settings. Recommendations for further research to enhance the validity and utility of these tools are also included.
Plasma Biomarkers of Traumatic Brain Injury in Adolescents With Sport-Related Concussion
Blood-based biomarkers may clarify underlying neuropathology and potentially assist in clinical management of adolescents with sport-related concussion (SRC). Plasma glial fibrillary acidic protein (GFAP), ubiquitin c-terminal hydrolase-L1 (UCH-L1), neurofilament light (NfL), and total tau (t-tau) were assayed. Group-level comparisons of biomarker levels were conducted between uninjured and post-SRC intervals (postinjury day [PID] 0-3, 4-10, 11-28, and >28) considering age and sex as modifiers. Secondary analyses explored associations between biomarker concentrations and clinical outcomes (Sport Concussion Assessment Tool, Fifth Edition [SCAT5] symptom scores and time to RTP).
APOE ε4 carrier status modifies plasma p-tau181 concentrations in cognitively healthy super-seniors
This study investigates the effect of apolipoprotein E (APOE) genotype on neurology plasma biomarkers in cognitively healthy Super-Seniors. Three hundred seventy plasma specimens from Super-Senior participants ≥ 85 years old, who have never been diagnosed with dementia, cancer, diabetes, cardiovascular, or major pulmonary disease, were analyzed on the Quanterix Simoa HD-X analyzer using commercial Neurology 4-plex E and phosphorylated tau (p-tau)181 assays.
