A study published last week reported the identification of what may be the earliest known biomarker associated with the risk of developing Alzheimer’s disease . The results suggest that this novel potential biomarker is present in cerebral spinal fluid at least a decade before signs of dementia manifest.
“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,” said Ramon Trullas, research professor at the CSIC Institute of Biomedical Research of Barcelona and lead author of the study that was published in Annals of Neurology. “This discovery may enable us to search for more effective treatments that can be administered during the preclinical stage.”
Alzheimer’s disease affects more than five million Americans and is the sixth leading cause of death in the United States. At present, the only way to accurately diagnose the disease is by post-mortem neuropathological analysis. The relationship of currently known biomarkers with the cause of the disease is unclear, making it nearly impossible to diagnose preclinical stages of the disease with any real certainty.
The CSIC researchers demonstrated that a decrease in the content of mitochondrial DNA in spinal fluid may be a preclinical indicator for Alzheimer’s disease. Furthermore, there may be a directly causative relationship. The hypothesis is that decreased DNA levels reflect the diminished ability of mitochondria to power the brain’s neurons, triggering their death.
The decrease in the concentration of DNA precedes the appearance of well-known biochemical Alzheimer’s biomarkers, suggesting that the pathophysiological process of Alzheimer’s disease starts earlier than previously thought and that mitochondrial DNA depletion may be one of the earliest predictors for the disease.