Folding is a danger signal
To date, there is no effective treatment for Alzheimer's disease. This is largely due to the fact that the disease cannot be diagnosed before the onset of visible symptoms. Unfortunately, by this point, the brain damage is already irreversible.
As it turned out in a recent study, in patients at high risk of developing Alzheimer's disease, disorders of foldig (folding into a three-dimensional structure) of the β-amyloid protein can begin 15-20 years before the first clinical symptoms appear. Improperly folded proteins accumulate and form amyloid plaques in the brain.
The researchers examined blood samples from 150 participants who had been diagnosed with dementia during a 14-year follow-up period. These samples were compared with samples of 620 randomly selected healthy study participants who matched patients with Alzheimer's disease by age, gender and level of education.
Participants with abnormal protein folding had a 23-fold increase in the chances of diagnosis over 14 years. In patients with other types of dementia, the risk of developing Alzheimer's disease was not increased, which indicates the extreme specificity of this disease.
The scientists also included in their analysis a number of other possible predictors of the development of the disease, including a specific variant of the APOE4 gene and pre-existing diseases (diabetes, high blood pressure, depression) or lifestyle factors (body mass index, education level). With the exception of the APOE4 gene variant, the presence of which showed a 2.4 times higher risk in those people who later developed Alzheimer's disease, none of the studied factors correlated with the risk of the disease.
When predicting the risk of developing the disease, it does not matter how many years have passed between the moment of receiving a blood sample and the clinical onset of the disease: from 0 to 8 or from 8 to 14.
The measurement of beta-amyloid clotting changes is based on a technology known as an immuno-infrared sensor, which measures the ratio of improperly folded proteins relative to the norm. Improperly folded proteins tend to accumulate in amyloid plaques, while healthy structures do not. These two structures absorb infrared light at different frequencies, which means that a blood test can determine the ratio of healthy and pathological beta-amyloid in a sample.
Such a test can be an inexpensive way to identify people at high risk who do not yet have any symptoms of the disease.
Now scientists want to test how reliable such an analysis is on a larger sample. If abnormal coagulation of β-amyloid is detected in the blood plasma, this should also be confirmed using an established method of early diagnosis of Alzheimer's disease – for example, by examining cerebrospinal fluid or using special imaging methods.
Article by Stocker et al. The prediction of Alzheimer's disease diagnosis within 14 years through Aß misfolding in blood plasma compared to APOE4 status, and other risk factors is published in the journal Alzheimer's & Dementia.
Elena Panasyuk, portal "Eternal youth" http://vechnayamolodost.ru according to DKFZ: Protein misfolding as a risk marker for Alzheimer's disease – up to 14 years before the diagnosis.