(ANSA) - ROME, JAN 09 - A blood test based on a new Alzheimer's marker has been developed by a group of researchers from the University of Pittsburgh, in the United States, together with those from the University of Gothenburg, in Sweden, and from University of Brescia.
Their results, published in the journal 'Brain', show that the new biomarker, based on an antibody that specifically binds to the tau protein made in the brain, outperforms current tests used to detect Alzheimer's-related neurodegeneration.
Currently, diagnosis requires a brain scan or cerebrospinal fluid analysis, but "these tests are expensive and many patients don't have access to them," says senior author Thomas Karikari, assistant professor of psychiatry at the University of Pittsburgh.
Hence the need to develop less invasive and cheaper tests.
Current blood-based diagnostic methods can already detect abnormalities of tau present in plasma, but have difficulty detecting markers specific to the brain, i.e., not affected by tau proteins produced by non-brain cells.
The team developed a technique to selectively detect 'brain-derived tau' (BD-Tau): a special antibody that binds to it making it easily detectable in the blood.
They validated their test on more than 600 patient samples including those whose diagnosis was confirmed after death and that of patients with early stage disease.
Tests showed that the detected BD-tau levels matched cerebrospinal fluid tau levels and reliably distinguished Alzheimer's from other neurodegenerative diseases.
They also correlated with the severity of amyloid plaques and tau tangles in the brain tissue, confirmed by autopsy.
Scientists hope that introducing such tests could help identify and enroll patients from population groups hitherto excluded from research into clinical trials.