Potential Alzheimer's biomarker targeted in brain fluid

Can the risk of developing Alzheimer's disease be spotted years before dementia hits? Spanish researchers view the task as feasible with a new potential biomarker they've pinpointed in cerebrospinal fluid (CSF). Details are published in the Annals of Neurobiology.

Scientists at the CSIC Institute of Biomedical Research in Barcelona and elsewhere zeroed in on mitochondrial DNA (mtDNA) as the potential key here, using a quantitative polymerase chain reaction machine on CSF samples from 282 subjects at various risks for Alzheimer's disease.

Patients without symptoms, but at risk of Alzheimer's disease, appeared to have a drop in mtDNA levels in their CSF. What's more, researchers measured patients without symptoms, but at risk of the disease, as having low mtDNA content in their CSF before any of the more telltale biomarkers appeared in the brain, such as amyloid and tau proteins. While more research is needed, they theorize that a decline in mtDNA levels in CSF could be a sign that mitochondria can't power the brain's neurons as well any longer, leaving them to die. Also, they see a possible link between lower mtDNA concentrations that appear to precede the appearance of the Alzheimer's biomarkers.

"If our initial findings can be replicated by other laboratories, the results will change the way we currently think about the causes of Alzheimer's disease," Ramon Trullas, the study's lead author and a research professor at the CSIC Institute of Biomedical Research, said in a statement. "The discovery may enable us to search for more effective treatments that can be administered during the preclinical stage."

That may be. The search for successful Alzheimer's treatments has so far remained elusive. Scientists are increasingly looking for ways to combat Alzheimer's as early as possible, and biomarker research has pointed to everything from epigenetic markers or new variations of amyloid protein that could potentially accomplish this and give drugmakers new targets. But even with biomarkers in play, the link between them and the causes of Alzheimer's remains less than definitive.

With that in mind, this latest work could advance the cause of early Alzheimer's diagnosis and treatment even further, enabling personalized treatments before Alzheimer's-related plaque begins to destroy the brain or patients begin to show any signs of the disease. Much more research is required here, but the work does give hope to the possibility of hitting the goal sometime down the line.

- read the release
- here's the journal abstract