Alzheimer’s LINX™ - Alzheimer’s-Associated Immune Reactivity (INCLUDES DOCTOR'S CONSULTATION ON ALL TEST RESULTS)

A SIMPLE BLOOD TEST THAT WILL IDENTIFY ALL THE TRIGGERS OF ALZHEIMER'S DISEASE

Cyrex’s Alzheimer’s LINX™ offers possibility of early intervention. Detection of antibodies against polyantigens originated from brain, blood-brain barriers, enteric nerve, food, pathogens and neoantigens (chemicals + tissue antigens) give a clear warning about epigenetic propensities and the need for clear intervention based on the individual’s personalized antibody immune print.

OVERVIEW

Neurons are the building blocks of the nervous system, which encompasses the brain, the spinal cord, and the enteric nerve network. Neurodegenerative disorders are a group of conditions that primarily affect the brain and cause a selective loss of neurons in the motor, sensory or cognitive systems. Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, Lewy body dementia, and amyotrophic lateral sclerosis are some examples of neurodegenerative disorders.

Dementia is a degenerative brain disease, in which damage to neurons in parts of the brain involved with cognitive function occurs. It is characterized by a decline in memory, language, problem-solving and other cognitive function of everyday life. The prevalence of dementia ranges from 6% to 10% in adults aged 65 and older; two-thirds of these cases are Alzheimer’s disease (AD).1 AD is characterized as the formation of amyloid plaque deposits in the brain.2 First identified more than 100 years ago, 70 years passed before AD was recognized as the most common cause of dementia, as well as a major cause of death.3 It is characterized by cognitive impairment, ß-amyloid deposition, neurofibrillary tangle formation, neuroinflammation, neurodegeneration and neurocognitive decline. In AD, the destruction of neurons eventually affects other parts of the brain, which control basic bodily functions such as walking and swallowing. Round-the-clock care is required for people in the final stages of the disease, as they are bed- bound. Alzheimer’s disease is ultimately fatal.

Statistically, deaths resulting from stroke, heart disease and prostate cancer decreased in the USA between 2000 and 2013 by 23%, 14% and 11% respectively, while deaths from AD increased 71%.4

Before AD takes its toll on the patient’s life, there are other tolls to pay. In 2015, an estimated 18.1 billion hours of unpaid, family-member care was given to people with AD and other dementias, which equals about $221 billion.4 No monetary value can be applied to the emotional cost of AD and other dementias. Paid services for health care, long-term care and hospice services for people aged = 65 years with dementia areestimated at $236 billion in 2016.4 Someone in the USA develops AD every 66 seconds, but by 2050, due to an aging baby-boomer population that is expected to increase to every 33 seconds, resulting in nearly 1 million new cases of AD per year.4

The monetary and emotional cost of AD and other dementias is skyrocketing. Thus, we need to gain control. When neurodegenerative diseases such as Alzheimer’s or Parkinson’s cause neurocognitive disorder, conditions often worsen as time progresses. It is therefore crucial to determine and deal with the underlying causes of these disorders at the earliest stages possible. Researchers believe that early detection of environmental factors that contribute to the pathogenesis of AD is the most crucial for developing interventional programs that will slow down or stop the progression of the disease.4-7 Bredesen introduced one such program that included the following: optimization of diet and sleep, reduction of stress, exercise, brain stimulation, prebiotics, probiotics, hormone balance, antioxidants, vitamins, healthy gut, optimization of mitochondrial function, and avoidance of toxic metals.8-9 This program of personalized protocols for metabolic enhancement showed reversal of cognitive decline in 9 out of 10 patients. These successes ofthe Bredesen program show that lifestyle changes can indeed ameliorate and even reverse cognitive decline. Despite this, many people still believe that AD is solely a genetic disorder and therefore there is no solution. This may be true for early-onset AD, but one thing should be clarified: early onset Alzheimer’s disease occurs between the ages of the 30s to mid-60s and accounts for much less than 10% of all individuals with AD [https://www.nia.nih.gov/health/alzheimers-disease-genetics-fact-sheet]. Most sufferers of AD have the late-onset form of the disease, which becomes fully active in the mid-60s and beyond. In contrast to early-onset AD, the causes of late-onset AD likely include a combination of genetics, environmental factors (including lifestyle factors), and the integrity of the protective blood-brain barrier (BBB) [https://www.nia.nih.gov/health/alzheimers-disease-genetics-fact-sheet]. 

MECHANISMS LEADING TO ALZHEIMER’S DISEASE, MILD COGNITIVE IMPAIRMENT AND DEMENTIA

The Role of Genetics in Alzheimer’s Disease

Researchers have found that the more prevalent form of AD, late-onset AD, is likely attributable to a combination of factors that includes genetics, environmental triggers, lifestyle, and BBB-permeability. As early as 2002, a team from the University of California Irvine proposed that environmental agents such as diet, aluminum and viruses are as important as genetic factors in the etiology of AD.10 Like other researchers, Grant et al. found commonality between the dietary risk factors for AD and those for heart disease; they also cited aluminum’s association with neurological damage and the link between apolipoprotein E (ApoE)-e4 and herpes virus-1 in the brain of AD patients but not in controls. The Pedersen Swedish twin study11 involving 662 pairs of twins aged 52 to 98 found that only 48% of the variation in liability to AD could be attributed to genetics. In 2006 Stewart et al. found strong evidence linking lead exposure to neurodegeneration in former lead workers.12 More recently, in September of 2018, a Finnish team led by Haapala concluded that genetic risk factors increase the risk of AD but do not actually cause it, citing instead the environmental factor of lifestyle, specifically metabolic syndrome.13 The Haapala study found that obese girls had a greater risk of developing AD. The BBB’s role in AD deserves special mention simply for the overabundance of the literature generated regarding it, more of which is found in a later section of this material. A review citing many of these publications was published by Montagne et al. in 2017.14

While researchers have not found a specific gene that directly causes the late-onset form of the disease, one of several forms of the ApoE on chromosome 19 has been recognized as increasing a person’s risk for AD. The ApoE-e4 genotype represents the most important genetic risk factor for Alzheimer’s disease. It may be useful to evaluate the genotype as part of prevention and early reversal of symptoms.8 However, some people with an ApoE-?4 allele never get the disease, and others who develop AD have no ApoE-e4 alleles at all, stressing the point that genetics is not the only contributor to Alzheimer’s disease.

One very obvious factor to examine as a harbinger of AD, Mild Cognitive Impairment (MCI) or dementia is, of course, an individual’s medical history. Medical history risk factors include:

• Family history of cognitive declinereviewed in 15-17
• Genetic susceptibilityreviewed in 15, 17
• Diabetesreviewed in 15-17
• Mid-life obesityreviewed in 15-16
• Mid-life hypertensionreviewed in 15-16
• History of depressionreviewed in 15
• Sleep disturbancereviewed in 15
• Hyperlipidemiareviewed in 15
• Traumatic brain injury in malesreviewed in 15
• Conjugated equine progesterone acetate usereviewed in 15
• Periodontitis18
• Blood-brain barrier breakdownreviewed in 19-23

The Role of Environmental Triggers in AD

Amyloid-ß (Aß) is a protein found in the brain, and tangled aggregates of Aß are the hallmark of Alzheimer’s disease. When highly purified Aß antigen was used in a study on the stages of AD, researchers found very high levels of Aß in serum in the mild to moderate AD group compared to healthy controls, and levels decreased in the moderate to severe AD group.24 Another study found that declining cognitive test scores correlated with increased levels of Aß-immunoglobulin G (IgG) immune complexes.25 Although the exact mechanisms for the development of AD are not definitively known, researchers are accumulating evidence that strongly indicates interaction between Aß and the triad of environmental triggers: infections, reactive foods, and toxic chemicals.

It may not be possible to control a person’s genetic makeup, but it is certainly possible for people to control their lifestyles and try to avoid harmful environmental factors. But it is only possible to avoid environmental triggers to the immune system if a patient knows exactly what specific factors personally affect his own unique immune system. The best way to find this out is to determine a patient’s antibody signature or immune print, which is a record of the factors to which an individual has reacted or is immunologically sensitive. This is the very reason Cyrex developed the Alzheimer’s LINXTM based on three recent research articles by Vojdani.5-7 

Infections and Their Cross-Reaction with Amyloid-ß in Alzheimer’s Disease

Infections have been suspected as early as the 1980s of having a role in neurodegenerative disorders.26Carter has posited that polymicrobial brain invasion may be a determinant factor in Alzheimer’s disease, citing the upregulation of bacterial, viral and fungal sensors/defenders found in the AD brain, blood or cerebrospinal fluid.27 Aß appears to be produced by the body as an antibiotic against these pathogenic invaders. Unfortunately, Aß shares sequence homology or molecular mimicry with the protein sequences of many pathogens, including Borellia burgdorferi, Cryptococcus neoformans, Chlamydia pHelicobacter pylori, Porphyromonas gingivalis, the herpes viruses, and herpes simplex virus-1 (HSV-1). Higher levels of autoantibodies against Aß are found in AD patients, suggesting that the immune system may have produced antibodies against both Aß and actual pathogens because of molecular mimicry. These Aß autoantibodies may weaken Aß’s antimicrobial effects, promoting pathogenic survival and cerebral pathogenic invasion, leading to the activation of neuro-destructive immune/inflammatory processes.27Vojdani’s study demonstrates, for the first time, direct support for Carter’s earlier hypothesis.5 The study used a specific monoclonal antibody made against amyloid-beta peptide 42 (Aß42), which not only reacted strongly with Aß42, tau protein, and a-synuclein, but also had weak to strong reactions with pathogens such as Enterococcus faecalis, Escherichia coli, Salmonella,. Campylobacter jejuni, herpes type-1, oral pathogens or their toxins, some of which have been associated with AD. The homology between peptide stretches of microbial origin and proteins involved in AD could be a mechanism by which antibodies to homologous peptides mount attacks against autoantigens in AD. Vojdani et al. concluded that bacterial molecules bind to Aß protein, forming small oligomers, then encasing pathogens and their molecules to form amyloid plaques, the tell-tale markers of AD. Conversely, these same Aß peptides induce the production of antibodies to both Aß42 and bacterial molecules, which may inhibit bacterial pathogenesis, but in the process may promote amyloid plaque formation (Figure 3). It should be noted that everyone has a unique personal microbiome and unique personal immune system with its own strengths and susceptibilities. Not everyone will be susceptible to, or react, to the same infections and pathogens. It is therefore reasonable to measure antibodies against these Aß42 cross-reactive pathogens (Figure 4) in both asymptomatic individuals and patients with AD in order to suggest treatment modalities tailored to the individuals that may help delay progression or even provide remission in patients with AD. This is where the Alzheimer’s LINXTM can be useful, as it can use a patient’s immune print to identify the culpable pathogens so that the appropriate treatment can be applied.

Figure 3. Amyloid plaque formation due to molecular mimicry between pathogenic antigens and Amyloid- Beta peptide (AßP). Bacteria release bacterial toxins and antigens, eliciting an immune response in the form of antibody production against them. These antibodies bind to AßP through the homology between them, contributing to amyloid plaque formation. It is also possible that these cross-reactive antibodies bind to pathogens and block further pathogenic invasion, or help prevent amyloidogenesis by attacking their corresponding pathogens and toxins.

Food Antigens and Their Cross-Reaction with Amyloid-ß in Alzheimer’s Disease

Carter found that Aß peptide also shares similarity with some food proteins.28 Vojdani’s study provided the first direct corroboration for Carter’s earlier work.7 Vojdani and Vojdani tested 208 food antigens and found that 19 of the foods reacted with Aß42. This is not surprising as earlier studies have already shown significant homology between food and brain antigens, such as wheat peptide with cerebellar, synapsin, casein, butyrophilin, myelin basic peptide, myelin oligodendrocyte glycoprotein, and plant aquaporins with human aquaporin.29-32 This is how it is believed that some of these foods may be involved in such diseases as gluten ataxia, multiple sclerosis, and neuromyelitis optica.33-35 The Vojdani study also showed a very strong reaction between Aß42 antibody and canned tuna, but not with raw tuna. Again, this is not to be unexpected, as earlier research by Vojdani has already shown that there can be vastly different reactivities between raw foods and cooked/processed foods, as the cooking/processing can affect the molecular structure of the food.36 Similar to infections and the immune system, everyone has a different composition and balance of digestive peptides and commensal bacteria within their gut. Different people will be sensitive or immune-reactive to different foods, so that one person can happily eat peanuts and another can actually die from the same thing. It is therefore reasonable to measure antibodies against these Aß42 cross-reactivefoods (Figure 5) in both asymptomatic individuals and patients with AD in order to remove the specific Aß42 cross-reactive foods from the individual’s diet, which may prevent, delay progression or even reverse the course of the disease in patients with AD. This is where the Alzheimer’s LINXTM can be useful, as it can use a patient’s immune print to identify the reactive foods.

Figure 5. Foods with which Aß42 shares homology or molecular mimicry. Not everyone will react to the same foods. This is where the Alzheimer’s LINXTM can be useful, as it can use a patient’s immune print to identify the culpable foods so that the appropriate treatment can be applied.

Chemicals and Their Effect on Protein Structures in Alzheimer’s Disease

In a recent study, Vojdani and Vojdani7 found that monoclonal anti-Aß42 has moderately to strong reactions with several chemicals bound to human serum albumin (HSA), but not to many other chemicals bound to HSA, or to HSA alone. Autoantibodies against amyloid-ß protein and peptides are commonly detected in AD and even in some non-demented members of the ageing population.37 The exact source of these anti-Aß antibodies is not clear, but they could be derived from immune response to aggregated forms of amyloid-ß, or from protein misfolding induced by aluminum, mercury, and plasticizers. Aluminum, phthalate and dinitrophenyl are three chemicals bound to HSA that reacted significantly with anti-Aß42. Toxic metals such as aluminum38-42 and mercury,43-45 are among the few that are known to cause toxicity to the brain and other organs and have been linked to numerous neurodegenerative disorders, including AD.

For many years, exposure to aluminum was suggested to favor an abnormal immune response in different diseases, including autoimmune conditions.46 Aluminum accumulates in the skeletal system and the brain, and a link with diseases such as osteomalacia, encephalopathy, Alzheimer’s and Parkinson’s diseases has been reported. Internal accumulation of aluminum may be particularly relevant to Crohn’s disease since it has been identified not only within macrophages of Peyer’s patches, but also around dilated submucosal lymphatics and in MLN. The low percentage of oral bioavailability of aluminum is actually misleading. In fact, after oral administration, 40% of the ingested aluminum accumulated within the intestinal mucosa, affecting barrier function.47

Moreover, aluminum is a well-established neurotoxin, and is suspected of being a factor in the development of neurodegenerative disorders. This is because aluminum accumulation in the brain affects the memory and cognition, alters synaptic activity, activates microglia, and promotes Aß and neurofilament aggregation, all of which are hallmarks of neurodegenerative disorders.48 Exposure to aluminum and such metals has been followed by aggregation of amyloid-ß protein on neuronal cells,49 as well as, AD-like pathologies, which have been shown in animals as well as in human subjects. Aluminum-induced neurotoxicity includes oxidative stress, mitochondrial dysfunction, inflammatory response, and neurofibrillary degeneration, possibly through amyloid-ß oligomerization.38,40 In vitro studies have shown that aluminum together with other metals is involved in the formation of Aß protein aggregation, which leads to amyloid fibrils and the formation of amyloid-like plaque structure.42

A review in 1998,50 showed that such accumulations of amyloid and extracellular tangles act as irritants, resulting in inflammatory reactions that lead to the production of potentially neurotoxic products that contribute to neuronal loss. And as recently as 2018, Yumoto et al. found that aluminum and iron had colocalized in the nuclei of nerve cells in the AD brain. They theorized that this colocalization might lead to neurodegeneration and the development of AD.51 Aluminum is one of the factors that accelerate Aß42monomer aggregation by cross-linking anionic amino acids contained in the Aß42 sequence to form Aß42aggregates.40,52 This may be one explanation as to why high levels of antibodies to Aß42 and other amyloid proteins are detected in patients with AD.53-54 Similar mechanisms of action may be applied to the aluminum binding to human albumin, where the aluminum may affect the functional properties of albumin or other proteins, leading to the formation first of dipoles and then of clusters that may mimic Aß42oligomerization or protein misfolding similarities.  Mercury has also been reported as a risk factor for AD due to its well-known neurotoxicity. Mercury ions bind to tubulin, inhibiting guanosine triphosphate (GTP) nucleotide binding capacity and reducing its biological activity, leading to microtubule degeneration.43 In vitro and animal studies have shown that mercury causes hyperphosphorylation of tau protein and increased formation of Aß protein aggregation.44

Phthalates and bisphenol A (BPA) are used as plasticizers in water bottles, food cans, and many other products. As such, they can leach or migrate into food and water, and hence through estrogenic activity or epigenetic modification may affect human health.56-57 If BPA crosses the blood-brain barrier, it can bind to a target enzyme called protein disulfide isomerase (PDI).

PDI is a stress protein found in the endoplasmic reticulum of many cells, including neural tissue, and is involved in protein folding. Normally this enzyme effectively inhibits a-synuclein fibril formation, but the S-nitrosylation of PDI by chemicals leads to a loss of enzymatic activity and the enhancement of proteinmisfolding and a-synuclein aggregation that are found in AD and Parkinson’s disease.58-59 This explanation is supported by the findings that numerous age-related disorders are now recognized to be related to the accumulation of different misfolded proteins that result in the production of autoantibodies called anti-oligomer antibodies.60

Not everyone will be susceptible to or react to the same toxic chemicals which, after binding to human protein, can cause misfolding similar to Aß protein. It is therefore reasonable to measure antibodies against these chemicals (Figure 7) in both asymptomatic individuals and patients with AD in order to suggest treatment modalities tailored to the individuals that may help delay progression or even provide remission in patients with AD. This is where the Alzheimer’s LINXTM can be useful, as it can use a patient’s immune print to identify the culpable toxins so that the appropriate treatment can be applied.

1. The Role of the Blood-Brain Barrier in Alzheimer’s Disease

The blood-brain barrier (BBB) acts as a gatekeeper, preventing neuroinvasion of autoreactive agents circulating in the bloodstream. For full details on the function of the BBB and its role in health and disease, please see our Clinical Application Guide for the Array 20 - Blood-Brain Barrier Permeability Screen. The basic concept of the BBB is that circulating autoreactive agents are relatively harmless unless they breach the BBB. If the BBB is broken, then the more autoreactive agents there are in the bloodstream, the greater the neuronal tissue damage.63

Some researchers are pointing to BBB breakdown as an early stage in the pathogenesis of mild cognitive

impairment (MCI) and AD.64, reviewed in 65-67 Indeed, cognitive decline was associated with stronger BBB

breakdown in both patients with MCI and with early AD.64 Using dynamic contrast-enhanced MR imaging

with dual-time resolution, the BBB leakage was shown to be via the tight junctions and was globally found

throughout the brain, rather than localized to a single tissue class.64 The breakdown of BBB tight junctions

can lead to the toxic accumulation of substances in the brain. These autoreactive agents can trigger

neuroautoimmunity. The BBB can become compromised as a person ages, and inflammatory agents in the

bloodstream, such as lipopolysaccharides (LPS) and other bacterial toxins can accelerate the BBB

breakdown allowing for the transport of Aß into the cerebrum leading to AD.reviewed in 67 The loss of BBB

tight junctions and BBB breakdown in patients who died with diagnosed AD has been confirmed by more

than 20 independent postmortem human studies showing brain capillary leakages and perivascular

accumulation of blood-derived autoreactive agents such as fibrinogen, thrombin, albumin and IgG.reviewed in14,66

Protecting the BBBs in patients with a family history of AD, MCI or dementia should be incorporated into a therapy for the prevention of neurodegeneration in healthy individuals. Assessing and addressing BBB breakdown in patients already exhibiting early signs of cognitive decline should be a first-line step in recovering the patient. BBB protocols can be implemented in patients already in later stages of cognitive decline as a means to slow down the pathogenesis.