A simple test has been developed that could detect Alzheimer’s disease 15 years before it takes hold of the body – and potentially help with prevention, researchers say.
Based on an immuno-chemical analysis using an infrared sensor, the test offers hope for researchers looking for a way to find the earliest markers of the disease years before clinical symptoms appear.
Researchers at the German Ruhr-Universitaet-Bochum and German Centre for Neurogenerative Diseases (DZNE) in Göttingen say they achieved impressive results after analysing samples from 141 patients.
It works because the surface of the infrared sensor is coated with specific antibodies that extract biomarkers for Alzheimer’s from the blood or the cerebrospinal fluid.
The biomarkers can identify any pathological changes more than 15 years before any clinical symptoms appear.
Prof Dr Klaus Gerwert, head of the department of biophysics at RUB, said: “If we wish to have a drug at our disposal that can significantly inhibit the progress of the disease, we need blood tests that detect Alzheimer’s in its pre-dementia stages.”
At the moment, a diagnosis of Alzheimer’s disease can only be done at the moment when the first clinical symptoms appear – when irreversible damage to the brain has already occurred.
But Professor Jens Wiltfang, head of the department for psychiatry and psychotherapy at the University of Göttingen, said the findings could herald the beginnings of being able to prevent dementia or delay its onset.
The team developed an infrared sensor for detecting misfolding of amyloid beta peptides, which change when Alzheimer’s is present.
When this occurs, more amyloid beta peptides accumulate and gradually form visible plaque deposits in the brain. This happens more than15 years before first clinical symptoms appear.
The infrared sensor extracts the amyloid beta peptide from cerebrospinal fluid and blood.
The study, which is published in Analytical Chemistry, looked at samples from 141 patients and a diagnostic precision of 84% in the blood and 90% in cerebrospinal fluid was achieved, compared with the clinical gold standard.
The test revealed an increase of misfolded biomarkers as spectral shift of amyloid beta band below threshold, which denotes Alzheimer’s.
It has also been tested for early detection of Morbus Alzheimer’s on a small group of patients, the results for which suggest that even in pre-dementia stages, an increased concentration of misfolded Amyloid beta peptides can be detected in body fluids.
Nabers A, OlleschJ, Schartner J et al. The Amyloid-beta secondary structure distribution in CSF and blood measured by an immuno-IR-sensor: a novel biomarker candidate for Alzheimer’s disease. Analytical Chemistry March 2016. doi: 10.1021/acs.analchem.5b04286
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