Right before Thanksgiving the kids on the Cambridge Ridge and Latin varsity football team were out on a windswept field getting ready for their final game of the season.  There’s always more to teach, but one thing coach Ryan Saulnier hopes his players understand is the need to be on the lookout for signs of a head injury.  Concussions – for coaches, trainers and even doctors – are tough to diagnose.

“You blow your ACL and doctors are really good at fixing knees these days, but concussions are still a big mystery,” said Saulnier. “As coaches and teachers and administrators, we always try to err on the side of caution because we don’t know.”

But a few miles west of the Cambridge football field, a Lexington bio-tech company has developed something that could take the guesswork out of diagnosing concussions:  a blood test.  A machine in the lab filters blood to find a nearly invisible sign of concussion - a protein called a biomarker.  Quanterix CEO Kevin Hrursovski compares it to finding a single grain in two-thousand swimming pools filled with sand. 

“The amount that’s in the blood is such a small amount that nobody can see it,” said Hrusovsky.  “We can see it and that’s the breakthrough - the ability to see in blood the brain health because of sensitivity of our technology.”

He says soon to be released National Institutes of Health research shows the blood test not only identifies concussions, but also indicates how severe they are.

“The information that’s going to come out from this study is going to be the first time they’re going to be able to make predictions so they can start to give the athlete, or any kind of patient, some idea of how serious that concussion was and what is the likely time it’s going to take to recover,” said Hrusovsky.

The blood test also shows promise measuring something researchers say may be a bigger danger to football players than concussions:  smaller, frequent hits to the head.   At Boston University Medical School, Robert Stern used the Quanterix blood test in a study of about 100 former NFL football players.  These players had no history of concussion, but all of them endured smaller hits.  Blood tests revealed evidence of tau, a protein associated with degenerative brain disease.

“The more hits they had the greater the tau levels,” said Stern, “which to me, indicates the greater amount of damage to their brains.”

Stern says the impact of that damage, including memory loss and personality changes, may not show up for decades after a player hangs up his helmet.  He is now conducting a national study using blood tests to measure the relationship between smaller hits and tau in former football players.   He hopes on day to see a blood test, much like a cholesterol test, to measure the progression of brain disease.

“We need an objective way of saying this person has been injured or this person has had so many of these little hits that we’re detecting changes in their blood,” said Stern, “suggesting that maybe their brain’s getting hurt.”

The machine that holds so much promising in measuring the impact of hits – both big and small - is now about the size of an industrial washing machine.   Quanterix’s Hrusovksy says his company is now working on reducing the size of the technology and within three years expects it be about the size of a mobile phone.