New test could detect Alzheimer's 10 years before symptoms develop

by Jenny Hope for Daily Mail:Scientists hope a new test could detect Alzheimer’s disease at least a decade before symptoms appear - paving the way for early treatment.The discovery of a fall in levels of a certain type of genetic material could signal an increased risk of developing Alzheimer’s. The biological marker is found in cerebral spinal fluid (CSF) at least 10 years before signs of dementia become apparent.There are 800,000 people with dementia in the UK, and one in three people over 65 will die from the degenerative disease. Currently, the only way to accurately diagnose the disease is by post-mortem neuropathological analysis, although memory and other brain function tests are used to determine whether drugs and other treatment may help.Spanish researchers at the CSIC Institute of Biomedical Research of Barcelona believe they may have found a marker that could suggest the disease process is underway before symptoms start to show. A post-mortem review of mouse and human brains found that the amount of C1q in the brain increases as much as 300-fold with aging. By comparing brain tissue from mice of varying ages as well as postmortem samples from a 2-month-old infant and an older person, the researchers found that the growing C1q deposits weren't randomly distributed along nerve cells.  They found a drop in the content of mitochondrial DNA (mtDNA) - genetic material present in the energy centre of cells - in spinal fluid may be a signal for the disease.They suggest that decreased mtDNA levels reflect the diminishing ability of mitochondria to power brain cells, thus triggering their death.The drop in the concentration of mtDNA precedes the appearance of other recognised biochemical Alzheimer’s biomarkers, suggesting the process of Alzheimer’s disease starts earlier than previously thought and that mtDNA depletion may be one of the earliest predictors.Researchers have previously been unable to detect the genetic material in spinal fluid, but they used a new technique to amplify tiny amounts, says a study in the journal Annals of Neurology.The researchers hope other labs and hospitals will be able to replicate the results.They say by finding a way to block the degeneration, clinicians may be able to diagnose and treat the disease before symptoms even appear.Lead author Dr Ramon Trullas said: ‘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.‘This discovery may enable us to search for more effective treatments that can be administered during the pre-clinical stage.’ Dr Marie Janson of Alzheimer’s Research UK, the UK’s leading dementia research charity, said: ‘Problems with mitochondria have already been linked to Alzheimer’s, which is why Alzheimer’s Research UK is currently funding research to further examine this link.‘This small study suggests that decreased mitochondrial DNA in cerebrospinal fluid may indicate the earliest stages of Alzheimer’s, but more work is needed to confirm this in larger groups of people.‘It would be useful to see further studies investigate changes in mitochondrial DNA over time, to determine how long before symptoms such changes might be detected.‘We know Alzheimer’s begins to develop before symptoms appear, and the ability to detect the disease at this stage is crucial for recruiting the right people for clinical trials of potential new treatments.’Source: http://dailym.ai/13mG3ID