Last week, Boston University’s School of Medicine released the findings of a study into chronic trauamtic encephalopathy (CTE) and Alzheimer’s disease that could lead to new methods of detecting CTE in living brains. Currently CTE can only be definitively diagnosed by examining the brain of a deceased individual.

The study was released in the peer-reviewed journal PLOS ONE. It outlines BU researchers’ investigation into a protein named CCL11, which has been shown to decline the cognitive functions of both mice and human brains. The BU study states that levels of CCL11 naturally increase in cerebrospinal fluid (CSF) as humans age. CSF is a liquid that exists between the brain and the inner lining of the skull.

BU’s paper continues to state that “CCL11 and related molecules play a role in neuroinflammation and neuordegeneration.” These conditions have been shown to impair the memory and cognition of mice. In humans increased levels of CCL11 have been observed in sufferers of Alzheimer’s disease, amyotrophic lateral sclerosis (ALS), and Huntington’s disease.

This new study states that increased levels of CCL11 have also been observed in the brains and CSF of individuals who have been diagnosed - post-mortem - with CTE. The CTE infected brains in the study belonged to individuals who had played football. The study showed that the levels of CCL11 in the brain increased depending on how long those individuals had played football.

CCL11 is a protein that makes its way into the human bloodstream. This means levels of CCL11 can be checked through blood testing. “This is just the beginning”, said Dr. Ann McKee (via The LA Times), who is a co-author of the study. McKee said that finding a biological marker for CTE would be a key step in identifying methods to prevent, slow, or reverse the affects of CTE.

CTE is a condition that affects individuals who have suffered concussions. When an individual sustains impact that causes their brain to swivel within their CSF, the brain of that individual releases a protein called pTau. The build-up of pTau causes degradation of brain tissue, which can cause the sufferer to experience symptoms such as memory loss, depression, anxiety, dementia, and increased levels of suicidality.

CTE was named by Dr. Bennet Omalu, who was played by Will Smith in the 2015 film Concussion, although the condition had been recognized since at least the 1920s; when it was known as dementia pugilistica (named for its association with boxers). Since the early 2000s evidence of CTE has been found in the brains of over 100 deceased NFL players. The condition has also been discovered in the brains of NHL players, professional wrestlers, soccer players, and rugby players.

Professional mixed martial artist Jordan Parsons, who was killed in a hit and run incident in 2016, was posthumously diagnosed with CTE in October last year. Also in 2016 Gary Goodridge, who fought at UFC 8 in 1996 and in the Bulgarian MMA Federation in 2010, told Inside MMA that he had been diagnosed with degenerative dementia, which is commonly associated with CTE.

If BU’s findings are correct, it could be the first step in a simple blood test being able to tell mixed martial artists, boxers, and other combat sports athletes how likely they are to suffer the affects of CTE later in life.