Early time point (<24 hrs) levels of serum and saliva t-Tau, NF-L, GFAP, UCH-L1 and IL-6, IL-10, TNF-α, were measured to evaluate identification of acute c/mTBI patients versus healthy controls.

The SIMOA Neurology 4-plex A and Cytokine 3-plex A immunoassays (Quanterix) were used to measure t-Tau, NF-L, GFAP, UCH-L1 and IL-6, IL-10, TNFα in serum and saliva respectively from acute c/mTBI samples versus controls.  Blood samples were collected from study subjects (n= 30 each) within 1-4 hr and 8-16 hr post-c/mTBI injury, as well as 30 healthy controls. Matching saliva samples were also collected from the 8-16 hr post-c/mTBI subgroup (n= 30).

IL-6, IL-10 and TNFα were significantly elevated in the 1-4 hr and 8-16 hr post-c/mTBI serum samples relative to healthy controls (p <0.0001). Receiving Operating Characteristic (ROC) curve analysis indicates that each of the 3 cytokines is discriminatory for c/mTBI patients vs healthy controls (AUC = 0.86-0.99). Median levels of GFAP, NF-L, UCH-L1 and t-Tau were significantly elevated in 1-4 hr and 8-16 hr post-c/mTBI serum samples relative to healthy controls. ROC analysis of neuronal biomarkers indicate moderate discriminatory ability for c/mTBI vs controls (AUC = 0.7-0.76). With the exception of IL-6, all the biomarkers levels in most saliva samples were very low.

The measurement of CNS proteins and inflammatory cytokines as biomarkers of c/mTBI may enhance diagnostic capability as well as prognosis with regards to the severity and outcome of brain injuries.