Alzheimer's LINX™ – Alzheimer's-Associated Immune Reactivity
Performed by: Cyrex Laboratories
What Is Alzheimer's-Associated Immune Reactivity?
Alzheimer's-Associated Immune Reactivity refers to a group of biomarkers that evaluate whether the immune system is producing antibodies against brain proteins, infections, environmental chemicals, and other substances that have been studied in relation to neuroinflammation, cognitive decline, and neurological health.
This category is best known through Alzheimer's LINX™, a specialized blood test panel developed by Cyrex Laboratories. The panel measures immune reactivity to dozens of targets associated with brain function, blood-brain barrier integrity, microbial exposures, environmental factors, and dietary proteins.
Importantly, a positive result does not diagnose Alzheimer's disease, dementia, or memory loss. Likewise, a normal result does not guarantee protection from future cognitive decline. These biomarkers measure immune responses, not the presence or absence of a neurological disease.
Instead, the panel is designed to identify patterns of immune reactivity that may provide additional insight into factors that could influence brain health and cognitive function.
What Alzheimer's LINX Does — and Does Not Measure
One of the most common misconceptions about Alzheimer's-associated immune testing is that it functions as a diagnostic test for Alzheimer's disease.
It does not.
Alzheimer's disease is currently diagnosed using a combination of clinical evaluation, cognitive testing, imaging studies, cerebrospinal fluid biomarkers, and increasingly blood-based biomarkers such as phosphorylated tau and amyloid-related markers.
Alzheimer's LINX evaluates whether the immune system is reacting to specific proteins, pathogens, environmental chemicals, or dietary antigens that researchers have investigated in connection with neuroinflammation and neurodegenerative processes.
A positive result may indicate immune recognition of a target. It does not prove that the target is causing symptoms, nor does it establish that a person has Alzheimer's disease.
Results should always be interpreted alongside medical history, symptoms, cognitive assessments, imaging findings, and other laboratory data.
Why Immune Reactivity Matters in Brain Health
Research increasingly suggests that Alzheimer's disease and other neurodegenerative disorders involve more than the accumulation of amyloid-beta plaques and tau tangles.
Scientists are actively studying the roles of:
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Chronic inflammation
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Immune system activation
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Blood-brain barrier dysfunction
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Metabolic disease
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Environmental exposures
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Infections and microbial triggers
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Oxidative stress
These factors may influence neurological health years before significant cognitive symptoms appear.
The immune system plays a central role in many of these processes. When immune responses become chronic or dysregulated, they may contribute to inflammation within the nervous system and potentially affect neuronal function.
Alzheimer's-associated immune reactivity testing is intended to explore whether immune responses against specific targets are present and whether they may warrant further investigation.
What Does This Category Measure?
The biomarkers in this category generally fall into several major groups.
Brain Proteins Associated With Neurodegeneration
These biomarkers assess immune reactivity to proteins that play important roles in brain structure and neurological function, including:
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Tau Protein
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Amyloid-Beta Peptide
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Alpha-Synuclein
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Rabaptin-5 + Presenilin
These proteins have been extensively studied in Alzheimer's disease and other neurodegenerative conditions.
Growth Factors and Neuroregeneration Markers
This group evaluates immune responses directed against molecules involved in neuronal growth, repair, and maintenance, including:
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Brain-Derived Neurotrophic Factor (BDNF)
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Nerve Growth Factor (NGF)
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Neurotrophins
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Somatotropin
These molecules help support neuronal survival, communication, and adaptability throughout life.
Blood-Brain Barrier and Neural Integrity Markers
The blood-brain barrier (BBB) serves as a protective interface between the bloodstream and the brain.
Biomarkers in this category evaluate immune reactivity to proteins involved in maintaining BBB integrity and neural structure, including:
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Blood-Brain Barrier Protein + Claudin-5
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Neurofilament Proteins
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Aquaporins
Abnormal immune reactivity to these targets may suggest increased immune recognition of structures that normally help protect and support the nervous system.
Pathogens and Microbial Triggers
Researchers continue to investigate whether chronic infections and microbial exposures may contribute to neuroinflammation or cognitive decline in susceptible individuals.
This category includes immune-reactivity markers associated with:
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Herpes Simplex Virus Type 1 (HSV-1)
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Oral pathogens
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Enterococcus faecalis
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Campylobacter jejuni
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Escherichia coli toxins
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Salmonella toxins
The presence of antibodies reflects immune recognition and should not be interpreted as proof of active infection.
Environmental Chemicals and Heavy Metals
Environmental exposures may influence oxidative stress, inflammation, and immune activation.
Biomarkers in this category evaluate immune reactivity to substances such as:
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Aluminum
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Mercury compounds
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Phthalates
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Dinitrophenyl-related compounds
These tests do not directly measure toxic burden. Instead, they assess whether the immune system has developed antibodies against compounds associated with environmental exposure.
Food Cross-Reactivity Markers
Some biomarkers evaluate foods that have been studied for potential immune cross-reactivity with neurological proteins and amyloid-related targets.
Examples include:
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Caseins
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Gliadin-related proteins
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Egg yolk proteins
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Lentil and pea lectins
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Selected seafood proteins
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Tree nut proteins
Importantly, positive food-reactivity findings do not prove that a food is causing neurological symptoms, cognitive decline, or Alzheimer's disease. These results are best viewed as hypothesis-generating markers that may warrant further discussion with a qualified healthcare professional.
Who May Consider Alzheimer's-Associated Immune Reactivity Testing?
Healthcare professionals may consider this type of testing for individuals who:
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Have a family history of Alzheimer's disease or dementia
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Are experiencing memory concerns or cognitive changes
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Have autoimmune or chronic inflammatory conditions
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Have a history of traumatic brain injury or repeated head trauma
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Have gastrointestinal disorders associated with immune dysregulation
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Are interested in exploring potential contributors to neuroinflammation
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Are following a preventive or functional medicine approach to cognitive health
Testing is generally intended to provide additional information rather than establish a diagnosis.
How Are Results Typically Used?
Results may help identify areas for further investigation, including:
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Immune responses to neurological proteins
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Blood-brain barrier integrity concerns
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Chronic inflammatory patterns
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Environmental exposure considerations
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Dietary immune-reactivity patterns
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Potential microbial triggers
Healthcare professionals may integrate these findings with other laboratory results, imaging studies, cognitive assessments, and clinical history to develop a broader understanding of an individual's neurological health profile.
Bottom Line
Alzheimer's-Associated Immune Reactivity testing evaluates immune responses directed against brain proteins, blood-brain barrier structures, pathogens, environmental chemicals, and dietary antigens that have been studied in relation to neuroinflammation and cognitive health.
These biomarkers do not diagnose Alzheimer's disease, dementia, or memory loss. Instead, they provide information about immune-reactivity patterns that may help identify potential contributors to neurological health concerns and guide further clinical investigation.
For individuals exploring potential contributors to cognitive health, Alzheimer's LINX™ and related biomarkers provide one additional lens—alongside established neurological assessment, imaging, and validated biomarkers—for understanding immune-reactivity patterns that may be relevant to brain health.
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Biomarkers included in this panel:
Alpha-Synuclein
Aluminums
Aquaporins
Beta Nerve Growth Factor
Beta Nerve Growth Factor (β-NGF) is a neurotrophic protein that supports the growth, survival, maintenance, and repair of neurons throughout the nervous system. In the Alzheimer's LINX™ panel, this marker measures immune reactivity to
Learn moreBeta Nerve Growth Factor (β-NGF) is a neurotrophic protein that supports the growth, survival, maintenance, and repair of neurons throughout the nervous system. In the Alzheimer's LINX™ panel, this marker measures immune reactivity to
Learn moreCaseins
Dinitrophenyl
Herpes Type 1
Lentil Lectin + Pea Lectin measures immune reactivity to lectins, naturally occurring proteins found in lentils, peas, and other legumes. In the Alzheimer's LINX™ panel, this marker evaluates whether the immune system has developed antibodi
Learn moreNeurotrophins
Non-Gluten Wheat Proteins measures immune reactivity to proteins found in wheat that are not part of the gluten complex. In the Alzheimer's LINX™ panel, this marker evaluates whether the immune system has developed antibodies against these
Learn moreOral Pathogens
Phthalates
Scallops + Squid
Somatotropin
Tau Protein
Tau Protein is a structural protein found inside neurons, where it helps stabilize microtubules that support normal nerve cell function. In the Alzheimer's LINX™ panel, this marker measures immune reactivity to tau protein rather than tau l
Learn more