Diagnosing Alzheimer’s earlier: the biomarker breakthrough

By Alexandra Sommer

The race to find a way of spotting and treating Alzheimers at an early stage is heating up but there’s a long way still to go. Or is there?

According to the World Health Organization (WHO), people aged 60 and over will account for 22% of the world’s population by 2050.¹ The fact that we’re living long than ever before is, of course, something to celebrate. But with longevity comes a whole other set of challenges. One of these is what to do about Alzheimer’s.

Advancing age is the greatest risk factor

Dedicated to advancing Alzheimer’s research worldwide, alz.org says that it’s already the most expensive disease in the US and the only one currently without a way to ‘prevent, cure or even slow its progression’. Because Americans are living longer, numbers of Alzheimer’s sufferers are predicted to soar to as many as 16 million by 2050, ‘costing the nation $20 trillion over the next 40 years’.

If a treatment that delays the onset of Alzheimer’s by five years was introduced in 2025, alz.org calculates, it would reduce the number of people affected by 2.5 million. And, it would save the US $220 billion within the first five years of a treatment being made available.

A World Health Organization (WHO) paper estimated that the number of people with dementia worldwide in 2010 was 35.6 million.¹  By 2050 this is expected to rise to 115.4 million in 2050. The total number of cases worldwide each year is nearly 7.7 million – one case every four seconds.
So, the race is well and truly on to find a cure for Alzheimer’s

What causes Alzheimer’s?

Although scientists are not yet sure what causes Alzheimer’s in most people, it’s agreed that a genetic mutation is usually the cause of the early-onset of the disease. According to the U.S. National Institute on Aging, ‘Late-onset Alzheimer’s arises from a complex series of brain changes that occur over decades. The causes probably include some combination of genetic, environmental and lifestyle factors.’²

Research on normal brain ageing is beginning to shed light on why it mainly strikes older people, with symptoms becoming apparent in their mid-60s. The apolipoprotein E (APOE) gene is involved and one of them is APOE ε4. This increases a person’s chance of developing the disease but people who don’t carry APOE ε4 may also end up with Alzheimer’s. The possible relationship between cognitive decline and conditions like heart disease, stroke, high blood pressure, diabetes and obesity is also being explored.

This, inevitably, has led to the question of whether a change in lifestyle, including diet, might make a difference. For instance, the MIND diet, rich in vegetables, berries, whole grains and nuts, lowered the risk by ‘as much as 53 per cent in participants who adhered to the diet rigorously’.

Of course, this is exciting news. But the study was carried out on people who changed their diet after they’d had a stroke. The question of how to early diagnose people who are at risk of developing Alzheimer’s still remains.

It’s about early diagnosis

Oliver Schmidt of IBL International, a company that produces kits that help researchers study Alzheimer’s, says the problem is that ‘brain shrinkage and the hallmark protein deposits – amyloid plaques and tau fibrils – can only be definitely identified during a post-mortem brain examination. Alzheimer’s will have begun to take hold many years earlier, well before the cognitive impairment that characterises the disease have become visible.

This is where, as Pravat K Mandala of the National Brain Research Center puts it, ‘There is an urgent need for the development of reliable diagnostic biomarkers that can detect AD pathology at an incipient stage. Such biomarkers will not only aid in early detection, but will also pave the way to effective clinical trials.’³

The biomarker breakthrough

A story posted in July 2014 on FierceDiagnostics.com announced that UK researchers have discovered 10 protein biomarkers in the blood that ‘may help predict the onset of Alzheimer’s’. This adds up to a giant leap forward in Alzheimer’s Diagnostics and for the treatment of the disease.

Kings College/Proteome Sciences, who carried out the study, believe that a blood test based on their biomarker is far simpler than things like PET brain scans and plasma in lumbar fluid.

Earlier this year, drug manufacturers Biogen and Eli Lilly released updates on their programs to develop drugs that clear amyloid plaque buildups from the brain and slow Alzheimer’s cognitive declines. Both drugs show signs of being able to do what they say but it appears there’s still a long way to go.

But, yet another study also argues researchers need to open their minds and move away from the ‘age-old amyloid cascade hypothesis’ which is limiting the scope of biomarker and drug development.

Looking forward

Finding a way to diagnose Alzheimer’s as early as possible will clearly benefit the drug companies enormously. But the biggest winners will be the millions of people and those who care for them who would otherwise suffer terribly.

We simply can’t afford to let the situation with Alzheimer’s carry on much longer. Can we look forward to the day when Alzheimer’s Disease is just a memory?

References 

1. "Alzheimer Disease and other Dementias, Background Paper 6.11,"  Béatrice Duthey, Ph.D , World Health Organization, 20 February 2013.

2. Alzheimer's Disease Fact Sheet, NIH National Institute on Aging, Accessed Nov. 9, 2017.

3. "Predictive Biomarkers for Alzheimer’s Disease Using State-of-the-Art Brain Imaging Techniques," . J Alzheimers Dis. 2012;31 Suppl 3:S1-3.