Professor Kaj Blennow also enjoys getting in the saddle for a dressage session.
He is one of the world’s leading experts on Alzheimer’s disease, known in particular for developing reliable methods of diagnosis. With over 2,300 scientific articles to his name, he is the most published and cited researcher in the field in Europe. And when he wants to take a break from molecules and genes, he prefers to do it on horseback.
“You don’t think about research on beta-amyloid or APOE genes when you are riding,” he says.
A drop of blood tells us about the brain
Beta-amyloid is, however, a protein that has occupied much of his thoughts. It occurs naturally in the brain, but if it is not cleared away, it begins to accumulate. Imagine the brain’s nerve cells as houses along a street. If rubbish isn’t collected regularly, piles build up and eventually block the road. The same happens in the brain when beta-amyloid clumps into “bin bags” that disrupt communication between nerve cells – affecting their function.
Kaj Blennow has developed methods to measure these proteins and shown how, with a simple blood test, Alzheimer’s disease can be detected up to 20 years before the “rubbish piles” appear.
From Lund to the world stage
Blennow’s career began in Lund, where he studied medicine. He was soon drawn to neurology –but also to psychiatry. His passion for research was sparked during his residency in Jönköping, and when he later moved to Gothenburg, he found himself at a department that had launched one of the world’s first prospective cohort studies – following people over time – on Alzheimer’s patients.
“At that time, we couldn’t really do much for patients. We examined symptoms, did CT scans, and a few other things. Diagnostics were very uncertain, as there were no biomarkers.”
Biomarkers are measurable traces in the body that reveal how we are doing. These biomarkers are often a protein, a molecule, or something else that can be detected in, for example, blood or saliva. In this case it was the blood marker with the complex name phospho-tau217.
Rejected research became a cornerstone
Over 30 years ago, Blennow wrote his first scientific article about tau and phospho-tau – possible markers for the nerve cell damage and neurofibrils found in Alzheimer’s. His research had developed methods to measure these substances in cerebrospinal fluid, showing clearly elevated levels in Alzheimer’s – but not in other dementias. Full of anticipation, he submitted the article to the prestigious Annals of Neurology.
It took a while, but then the response came: “No thank you, we don’t believe tau and phospho-tau will be clinically relevant.”
Today, these biomarkers are a cornerstone of Alzheimer’s diagnostics. The variant phospho-tau217 has proven in studies to be a highly specific marker that sharply distinguishes Alzheimer’s disease from other conditions. Blennow’s work has made it possible to detect biomarkers such as phospho-tau217 in blood as well. He is now awarded the Eric K. Fernström Nordic Prize for his work on biomarkers for neurodegenerative diseases in general and Alzheimer’s disease in particular.
“It’s gratifying and an honour,” he says when we reach him by phone after he received the news. “It’s especially nice to now receive the major Nordic prize, since the competition in Gothenburg was too tough for me to win the local prize back then.”
Recruited by a pharmaceutical company
Kaj Blennow was recently recruited by the pharmaceutical company Eli Lilly, where he will lead research on biomarkers focusing on Alzheimer’s and other brain diseases.
“It will be exciting – at a place like that, the resources exist to realise ideas.”
One mystery he most wants solved in the field concerns the APOE4 gene. It is known that those who inherit it from both parents have a 12-15 times higher risk of developing Alzheimer’s – often 15 years earlier than others.
“Why, we don’t know. And we have no medicines for it.”
His philosophy? To see the woods for the trees.
“If you don’t see the big picture, it’s not worth much. You have to be careful not to get stuck with a favourite tree you’ve researched for years. At the same time, as a researcher you need to be persistent – but only up to a point. You have to know when it’s time to change direction if something isn’t working. That’s why it’s smart to have several tracks going at the same time,” he notes.
A researcher’s life is not just breakthroughs. There are tough lows, says Blennow.
“But patient-centred research has always kept me on track. Seeing what life is like for someone affected by Alzheimer’s – and aiming for research to provide diagnostic tools and eventually lead to new treatments – that’s what keeps me motivated.”