A technique published in the journal Genome Biology showed differences in the tiny fragments of genetic material floating in the blood could be used to identify patients.
The test was accurate 93% of the time in trials on 202 people.
One of the main goals of Alzheimer’s research is to find ways of detecting the disease earlier.
It starts years before symptoms appear and it is thought that future treatments will need to be given before large parts of the brain are destroyed. This will require new ways of testing for the condition.
The team at the Saarland University, in Germany, analysed 140 microRNAs (fragments of genetic code) in patients with Alzheimer’s disease and in healthy people.
They found 12 microRNAs in the blood which were present in markedly different levels in people with Alzheimer’s. These became the basis of their test.
More research is needed to improve accuracy and to see whether it would work in the clinic is still needed before the test would be considered as a way of diagnosing patients.
Currently, a diagnosis of Alzheimer’s disease can only be confirmed post-mortem and diagnosis during life is made based on the results of memory and thinking tests and brain scans. There is a growing focus on developing more sensitive methods of detection, to help improve the accuracy of diagnosis. This includes the search for changes in blood that could be translated into a clinically useful blood test to aid diagnosis of the disease.
To investigate this further, the team studied molecules called miRNA, which play a role in fine-tuning the activity of genes in the body. miRNA have already been linked to diseases such as cancer and heart disease and research is underway to investigate their role in Alzheimer’s.
The team analysed blood samples from 48 people with Alzheimer’s and 22 unaffected controls, looking for changes in the levels of miRNA between the two groups. They discovered 140 miRNAs whose levels were altered in people with Alzheimer’s and 12 of these were made into a ‘panel’ for further testing. The 12 miRNA’s were thought to regulate the activity of more than 2000 genes, including genes responsible for nerve cell development and the projection of nerve cells across the brain.