The condition, known as chronic traumatic encephalopathy (CTE), is frequently diagnosed among football players and other athletes that take repeated hits to the head. It can lead to confusion, depression, aggression, memory decline and other cognitive issues. Recently, ex-football player Aaron Hernandez, who was convicted of murder and later killed himself at the age of 27, was found to have CTE.
There is no medication that can cure the disease and it can only be diagnosed through an autopsy — that is, after the patient is already dead.
Autopsies of those who suffered from CTE show atypical masses of a protein called tau in the brain, which researchers suspect may kill off neurons. However, researchers at Boston University (BU) recently determined that the protein CLL11, found in the brain, spinal fluid and blood, may be a marker for CTE. The results were published in the journal PLOS ONE on September 26.
The researchers studied the brains of 23 athletes who were diagnosed with CTE after death. They compared the CLL11 levels in the athletes' brains to CLL11 protein levels in 50 brains of people who died from Alzheimer's disease and 18 brains of people who died of other causes. They noticed that CLL11 levels were highest in those who had played football for long periods of time. Because the protein levels were not as high in the brains of people who had Alzheimer's, researchers think this may be an indication that CLL11 elevation is specific to brain trauma and not just any type of neurodegeneration.
This is a breakthrough discovery because though there is no cure for CTE, being able to diagnose the disease while athletes are alive could help them change their lifestyles to try to contain the disease before it is aggravated by additional blows.
Biotech company Quanterix in Cambridge, Massachusetts, is collaborating with BU researchers to generate a blood test that detects CLL11, Quartz reported. However, this test won't be commercially available any time soon. Because the BU researchers cannot conduct blood tests checking for CLL11 in any living people, it is still unknown whether the levels in blood are as high as in the brain. They also need to prove that the protein isn't found in other neurodegenerative disease like dementia.
However, researchers are optimistic that they will eventually have a way to diagnose the disease.
"I am pretty optimistic we will have a test, or maybe a series of tests, that are diagnostic for CTE during life, and I think that will happen in the next five years," says Ann McKee, the senior author of the study.
"We are making a lot of progress. We know a lot more about this disease than when we started, and we are starting to tease out the important markers and pathways that are involved."