By Frank Amato, CEO and President, SYNAPS Dx
An early diagnosis of Alzheimer’s disease (AD) can help determine if the symptoms a patient is experiencing are genuinely due to AD or some other conditions that can be curable or managed with different interventions. Unfortunately, when it comes to the current diagnostic tests, there is considerable confusion in the marketplace, mainly because they measure proteins that are associated with but not necessarily causative of AD.
Living with the onset of dementia in a loved one is difficult. However, without a definitive diagnosis, it’s frustrating, expensive and overwhelming for patients and families, providers and payers to know how to proceed in the care journey. Physicians try and identify patients with AD but struggle especially in the first four years of this disease; they use invasive procedures such as amyloid PET, MRI, and CSF-based biomarker testing. After cognitive tests assess the degree of cognitive impairment and blood work rules out other, potentially treatable dementias, physicians may utilize additional diagnostic testing modalities. But payers often decline to cover as they perceive these tests as being fraught with error, costly, and largely invasive.
Today, the most promising breakthrough is the first accurate, minimally invasive test for the definitive diagnosis of AD versus other forms of dementia. This test is designed to accurately assess the loss of synaptic activity in the brain, where memories lie, due to AD. The loss of synaptic activity eventually leads to loss in memory, language, reasoning, and social behavior, all hallmarks of AD. This test is now available and well-positioned to address several of the limitations of current tests.
Why Early Diagnosis Matters
Diagnosing patients at early stages with AD, such mild cognitive impairment begins with the patient’s medical history, along with mental status tests and physical and neurological exams. A myriad of medical issues can bring on memory loss. Conditions including Lyme disease, vitamin deficiencies, thyroid issues, drug interactions, and the various forms of dementia are often mistaken for AD.
An early AD diagnosis allows patients to start clinical interventions sooner, saving time, money, and the despair of caregivers and patients not knowing what is happening medically. Early diagnosis also gives patients the chance to have a say in their care.
Until now, only autopsy findings at death provided a definitive diagnosis of AD in people who lived with dementia. What’s more, AD often co-develops with other age-related neurological disorders, such as Parkinson’s disease, strokes, and different types of dementias.
Growing Need for AD Testing
An estimated 5.8 million Americans age 65 and older live with AD, with projections showing that by 2050 that number will reach 12.7 million. Although AD is the most common type of dementia, there are many other kinds, including Lewy body dementia, Huntington’s disease, and Creutzfeldt-Jakob disease. Given the cost and complexity of diagnosing AD, it’s no wonder researchers are striving to determine as many aspects of AD and other dementias as possible to find new treatments to prevent, halt or reverse disease progression.
One-in-three patients with memory issues do not have AD and can often get the more appropriate treatment for non-AD patients. It’s well understood that no drug, including the one recently approved by the FDA—exclusively for early AD patients or in the very early stages of dementia—can treat the underlying disease. Other drugs provide only temporary symptomatic relief.
Understanding the Causes of AD
The causes of AD are not yet fully understood, but many believe it is most likely due to a combination of age-related changes in the brain, along with genetic, environmental and lifestyle factors. The importance of these factors can increase or decrease the risk of AD and vary from person to person.
This progressive brain disease is characterized by changes in the brain—including amyloid plaques and neurofibrillary, or tau tangles—that result in loss of neurons and their connections. This affects a person’s ability to remember and think and, eventually, to live independently.
This association requires further scientific exploration; many studies have also demonstrated that as we age, many people may have brains riddled with plaques and tau but have no cognitive impairment whatsoever.
While many experts believe plaques and tangles play a role in blocking communication among nerve cells and disrupting processes that cells require, questions remain about their role in progressive dementia. A recent study of centenarians found varying levels of plaque and tau at autopsy, with no correlation to a reduction in mental functioning during life. This reinforces that while tau and plaque may be present in brain tissue, they may not be the primary cause of AD. Mounting evidence suggests that memory failure, personality changes, problems carrying out daily activities, and other symptoms of AD are caused by loss of activity of synapses and neurons.
Value of Accurate AD Test
Given the high disease burden of AD on patients, caregivers, and healthcare providers, having a definitive diagnosis as early as possible is essential for establishing care plans and planning for the future. Tests to assess the primary driver of disease, loss of synapse, and neural activity can improve the diagnosis of AD across the spectrum of early to late-onset disease. Our assays have demonstrated >95% sensitivity and specificity. Giving patients and families the answers they need enables providers to make a conclusive diagnosis and allows payers to establish protocols and prior authorizations for prescribing and reimbursing treatment. It also helps pharmaceutical companies identify appropriate clinical trial participants.
An AD test to assess synaptic loss can be a tool to manage appropriate patient access to future approved therapies, in addition to the clinical and economic benefits of improved early, accurate diagnosis. DISCERN identifies the AD-specific degeneration biomarker for a definitive diagnosis, differentiates AD from other non-AD dementias and identifies those with AD in addition to other degenerative pathologies. This is good news for every stakeholder, especially for patients and their families seeking answers and a path forward.