Blood-based biomarkers: The future of neurological diagnostics

• Blood-based biomarkers offer a less invasive, more accessible, and lower-cost alternative to PET scans and lumbar punctures for the investigation of neurological diseases

• pTau and NfL blood tests may enable earlier detection and more informed management of Alzheimer’s disease and multiple sclerosis

• By supporting efficient triage and scalable testing, blood-based biomarkers hold the potential to  improve patient care while helping healthcare systems operate more sustainably

Neurological diseases such as Alzheimer’s disease and multiple sclerosis (MS) pose increasingly difficult clinical and economic challenges for healthcare systems worldwide.^1,2 In the US alone, an estimated 6.5 million people were living with Alzheimer’s dementia in 2022, a figure projected to more than double by 2060.¹ Globally, the cost of dementia care is expected to rise from $USD 1.3 trillion in 2020 to over $USD 9 trillion by 2050, representing nearly 11% of worldwide healthcare spending.^1,3 MS, which affects approximately 2.9 million people worldwide, also carries a substantial economic burden of its own, with annual costs in the US estimated at $USD 85 billion in 2019 and projected to reach $USD 108 billion by 2039.^2,4 The economic burden of MS carries not only direct medical costs, but indirect costs as well, arising from lost productivity and informal caregiving.⁵

A substantial part of the soaring economic burden of these diseases is due to the inherent constraints of neuroimaging, and a lack of neuroradiologists to interpret results, which often delays timely diagnosis and treatment.^6-8 This is because, for decades, diagnosing neurological diseases has relied on specialized procedures such as magnetic resonance imaging (MRI), positron emission tomography (PET) computed tomography (CT) scans, or lumbar punctures for cerebrospinal fluid (CSF) analysis. While these approaches provide valuable clinical information, they tend to be costly, resource-intensive, invasive, and difficult to access outside major medical centers.⁹

With a growing recognition of the vital role accessible testing plays in managing complex neurodegenerative conditions, blood-based biomarkers are emerging as revolutionary tools in both AD and MS, though their likely clinical utility serves distinct strategic purposes. In AD, blood biomarkers (e.g. p-tau217) act as highly promising triage and diagnostic tools, enabling the early detection of cerebral amyloid pathology and accelerating disease diagnosis through a simple blood draw. Conversely, in MS management, peripheral neurofilament light chain (NfL) functions not as an initial diagnostic instrument, but as a sensitive monitor of ongoing neuroaxonal injury, capable of catching subclinical disease activity during intervals between routine MRI scans. Together, these blood-based biomarkers have the potential to expand access to precise neurological assessment, reduce reliance on, or intensity of, invasive or costly imaging procedures, and support more efficient, personalized care pathways across both specialized and decentralized healthcare settings.^9-11

Alzheimer’s disease is characterized by the accumulation of amyloid-beta (Aꞵ) plaques and tau pathology in the brain—biological changes that can begin years before significant cognitive decline becomes apparent. 

The recent introduction of amyloid-targeting disease-modifying therapies represents a significant milestone in the management of Alzheimer’s disease. To qualify for these treatments, patients must be in the early stages of cognitive decline—specifically mild cognitive impairment (MCI) or mild dementia—and have a positive medical test confirming amyloid buildup in the brain. Limited access to advanced diagnostics like amyloid-PET, combined with a shortage of neurologists, often leads to diagnostic delays that can prevent patients from receiving timely treatment. Blood-based biomarkers can potentially accelerate this diagnostic pathway, thereby optimizing patient management.^10,12

Recent advances in blood-based biomarkers for Alzheimer’s disease are helping meet this need. Blood tests measuring biomarkers such as pTau181 and pTau217 have demonstrated high accuracy in detecting  Alzheimer’s disease pathology and are increasingly evaluated for clinical use.¹² Analysis via a simple routine blood draw creates new opportunities to expand access to biomarker testing beyond specialized centers.

As the need for timely diagnosis continues to increase, blood-based biomarkers provide an opportunity to support more efficient patient triage—helping to identify individuals who may benefit from specialist evaluation, additional diagnostic assessment, or consideration for emerging disease-modifying therapies. Additionally, as a lower-cost alternative to neuroimaging and cerebrospinal fluid testing, blood-based biomarkers may help healthcare organizations manage increasing diagnostic demand more effectively while improving access to care.^10,12,13

Multiple sclerosis is characterised by immune-mediated neuroinflammation and subsequent neuroaxonal damage within the central nervous system—pathological processes that can cause subclinical injury long before a clinical relapse or permanent disability becomes visible.¹⁴

The widespread use of high-efficacy disease-modifying therapies has significantly altered the management of multiple sclerosis, enabling the opportunity to slow or even prevent irreversible neurological decline.¹⁵ To optimise these treatments, clinicians must actively monitor patients for disease activity and identify suboptimal treatment responders early enough to safely switch therapies.¹¹

Meeting this challenge, advances in blood-based biomarker technology are introducing powerful new tools to clinical practice alongside MRI. Among the growing number of MS biomarkers, neurofilament light chain (NfL) is gaining attention for its potential clinical utility.¹⁶ NfL is a protein released into the cerebrospinal fluid and bloodstream when neuroaxonal damage occurs.^17,18 Because NfL levels reflect neuroinflammation and ongoing neuronal injury, they provide valuable insights into disease activity that may not be fully captured through clinical assessment or MRI alone. 

Recent developments in highly sensitive testing technologies have made it possible to accurately measure NfL in blood. This opens the door to more accessible and routine monitoring of patients with MS and supports the growing role of blood-based biomarkers in routine clinical practice. Research has shown, for instance, that blood NfL levels correlate with clinical symptoms, MRI findings, and response to disease-modifying therapies.^16,19

For healthcare providers, blood-based NfL testing, one of the most promising multiple sclerosis biomarkers, offers an objective tool to potentially support treatment decisions and monitor disease progression over time. By providing a less invasive way to assess neuroaxonal injury, NfL testing may help to improve treatment efficiency and enable more personalized care for people living with MS. Routine blood-based monitoring may also reduce the need for some resource-intensive assessments, helping clinicians make more informed decisions while improving the patient experience.^17,18

Early diagnosis is critical for improving neurological care, yet significant delays remain common. An estimated 75% of people living with dementia (~70% due to Alzheimer’s disease) remain undiagnosed, with the average time between symptom onset and diagnosis reaching more than two years in some regions.²⁰ These delays can postpone specialist evaluation, additional diagnostic testing, access to clinical trials and the use of emerging treatment options. For patients already diagnosed with MS, significant gaps persist in tracking subclinical progression and detecting silent disease flares during routine monitoring. Because monitoring relies heavily on serial MRI scans, surveillance is frequently hindered by adverse social determinants of health (SDOH), including geographic disparities in specialised imaging centers, high costs, and lengthy wait times. These systemic and socioeconomic barriers frequently delay crucial neuroimaging and specialist evaluations, ultimately preventing the timely detection of active disease and the proactive optimisation of disease-modifying therapies.²¹

Recent advances in ultrasensitive biomarker detection technologies have made it possible to accurately measure brain-derived proteins in blood at concentrations that were previously undetectable, helping translate decades of research into practical clinical tools.²² Combined with the simplicity of a routine blood draw, these innovations are helping bring neurological diagnostics closer to where patients first seek care. Because blood collection is minimally invasive and easily performed across a range of healthcare settings, blood-based biomarkers can extend diagnostic testing to community clinics.²³

Ultimately, blood-based biomarkers can serve as objective triage tools in primary care and other decentralized settings, helping providers identify patients who may benefit from specialist referral, advanced imaging, additional diagnostic evaluation, or treatment.²³ By supporting earlier diagnosis, blood-based biomarkers may:^9,23,24

• Help patients enter appropriate care pathways sooner

• Support timely intervention, including lifestyle modifications and disease-modifying treatments where appropriate

• Access clinical trials

• Create opportunities to slow disease progression and preserve quality of life

• Give patients and their families greater insight into their condition

• Enable more active participation in care planning and health management

Patient experience may also reasonably stand to improve. Compared with advanced imaging and lumbar punctures, a blood draw is generally more familiar, convenient, and accessible for patients.²² This may reduce barriers to testing and support broader participation in diagnostic programs, particularly in community-based settings.

As healthcare systems prepare for growing demand for neurological assessments and disease-modifying therapies, making the best use of clinical resources is becoming increasingly important. 

Blood-based biomarkers can support more streamlined care pathways by identifying which patients are most likely to benefit from specialist evaluation, advanced imaging, or additional testing, while helping direct others toward more suitable diagnostic routes.²³ Research suggests that incorporating blood biomarkers into the diagnostic assessment of Alzheimer’s disease can improve the use of amyloid PET imaging, enhance cost-effectiveness, and support more targeted allocation of healthcare resources.^9,25 Similarly, it has been demonstrated that peripheral measurement of NfL in MS provides a minimally invasive method to monitor subclinical neuroaxonal injury, track treatment efficacy, and forecast long-term disability progression.²⁶ These benefits illustrate the broader potential of blood-based biomarkers to improve efficiency across neurological care pathways.

For healthcare providers, this approach offers several potential advantages:^9,23,24

• More efficient use of specialist consultations and imaging capacity

• Reduced reliance on costly and resource-intensive diagnostic procedures

• Reducing time from initial assessment to diagnosis and treatment

• Improved access to neurological diagnostics in community and rural settings

• Better allocation of healthcare resources across the patient journey

For healthcare executives, the value proposition extends beyond clinical performance. Compared with PET imaging and lumbar punctures, for instance, blood-based biomarkers can lower diagnostic costs, improve laboratory throughput, and help ensure that specialist resources are directed where they are needed most.^9,23 Together, these advantages can contribute to a more financially sustainable model of neurological care.

Importantly, many blood-based biomarkers are designed to run on fully automated immunoassay platforms already present in hospital and reference laboratories.^27-29 This allows organizations to integrate advanced neurological testing into existing workflows while minimizing operational complexity. By supporting scalable testing, blood-based biomarkers can improve efficiency across the care continuum while maintaining high standards of diagnostic quality.

Growing demand for neurological care requires diagnostic solutions that are clinically effective as well as scalable and accessible. Blood-based biomarkers, including biomarkers for Alzheimer’s disease and MS, represent an important step toward this future, enabling earlier detection and broader access to advanced neurological diagnostics through a simple blood draw.²²

For healthcare leaders, adopting these technologies is an opportunity to improve patient care while making better use of limited clinical resources. Organizations that invest in blood-based biomarker testing today can help build more resilient healthcare systems, accelerate access to emerging therapies, and position themselves at the forefront of innovation in neurological care.