By far the largest part, namely about two thirds of all dementia diseases are Alzheimer’s diseases. However, Alzheimer’s disease can go undetected until it is too late for treatment. Large-scale screening programs could help detect early stages of disease, but current diagnostic methods are quite cumbersome and expensive.
A new study, published in the journal Frontiers, is the first to identify formic acid as a sensitive urinary biomarker that can reveal Alzheimer’s at an early stage, potentially paving the way for an inexpensive and convenient early detection method.
Study from China
A Chinese research group studied more than 500 patients with various degrees of Alzheimer’s disease and healthy controls with normal cognition to look for differences in the biomarkers in urine to investigate. Formic acid (also called methanoic acid) in the urine turned out to be a sensitive marker that can indicate a very early stage of Alzheimer’s disease.
‘Alzheimer’s disease is a progressive and latent chronic disease, meaning it can develop and persist for many years before overt cognitive impairment appears,’ the study authors said. “The early stages of the disease occur before the stage of irreversible dementia, and this is the ‘golden window’ for intervention and treatment. Therefore, large-scale screening for early stages of Alzheimer’s disease in the elderly is necessary.”
Although methods for diagnosing Alzheimer’s disease already exist, they are relatively expensive, impractical and unsuitable for mass routine testing. These include positron emission tomography of the brain, which is expensive and exposes the patient to radiation. There are also biomarker tests that can indicate Alzheimer’s, but these require invasive ones blood draws or a spinal tap, which can be daunting for patients.
All of this means that many patients are currently not diagnosed until it is too late for effective treatment. A non-invasive, inexpensive, and convenient urine test could be just the thing. This idea is not entirely new either, formaldehyde has already been identified as a biomarker. But this substance was not suitable for real early detection.
formic acid
This time, the research group focused on formic acid (a metabolite of formaldehyde) to see if it is a better biomarker. The study, which involved 574 subjects, found that the more severe the progression of Alzheimer’s disease, the higher the level of formic acid in a person’s urine. And especially in the early stages of the disease, formic acid was a significantly better indicator than all previously known biomarkers that were examined in blood or urine.
In addition, it has been shown that a combination of biomarkers from the blood and formic acid from the urine can be used to determine the stage of the disease with unprecedented accuracy.
“Urinary formic acid showed excellent sensitivity for early Alzheimer’s screening,” the Chinese authors said. “Detecting urinary Alzheimer’s biomarkers is convenient and inexpensive and should be included in routine screening of older people.”
However, as is so often the case, further research is needed. The current cross-sectional study can only prove correlations, but no causality. The conclusions would need to be verified by a long-term follow-up study. Animal experiments are also advisable to confirm the theoretical explanations, according to the authors, who are nevertheless certain that they have made important progress in Alzheimer’s research.
Antibody drug slows down the disease
A new drug brings hope to many Alzheimer’s patients. According to a study, it slows the progression of Alzheimer’s. This is reported by an international team of scientists after examining almost 1,800 patients in the early stages of dementia in the “New England Journal of Medicine”. The antibody lecanemab cannot cure or stop Alzheimer’s, but it can slow down the mental deterioration, according to the German Alzheimer’s researcher Frank Jessen from the German Center for Neurodegenerative Diseases (DZNE), who was not involved in the study. He speaks of a “historic milestone in Alzheimer’s research”.
The researchers write that the safety of the treatment must be further investigated in longer studies. They report side effects such as brain swelling and microbleeding in the brain. No deaths occurred as a result of the treatment. A few days ago, however, there was an article in the specialist magazine “Science” about a death in connection with the therapy, overall it was the second. You have to watch this very closely, said Jessen. He could imagine that there would be restrictions for certain patient groups, such as people with an increased tendency to bleed.
In the USA, lecanemab is already being tested in an accelerated approval process. An application for market approval is also planned in Japan and Europe by the end of March 2023.