OBJECTIVETo determine the changes of serum Tau protein, glial fibrillary acidic protein (GFAP), tumor necrosis factor alpha (TNF-α), and malonaldehyde (MDA) in rats after blast-related traumatic brain injury (BTBI) and to provide relative information for further studies on BTBI mechanism and seek specific biomarkers for BTBI.

METHODSNinety male Sprague-Dawley rats were randomly assigned into three groups: control group, moderate blast injury group, and severe blast injury group (n=30 for each). Rats in the moderate and severe blast injury groups were respectively exposed to corresponding levels of BTBI. After explosion, serum levels of Tau, GFAP, TNF-α, and MDA in each group were determined by Elisa assay at different time points after injury (8 h, 24 h, 3 d, and 6 d). The extent of brain damage was detected by Nissl staining and TUNEL assay.

RESULTSSerum levels of Tau and GFAP rapidly increased and reached the peak at 24 h after either moderate or severe blast injury. All the values were significantly higher than control group at all time points (P<0.05). Serum TNF-α level of both injury groups peaked at 8 h after BTBI and stayed significantly higher than control group at all time points (P<0.05). Serum MDA of two injury groups began to significantly increase at 3 d and the level stayed significantly higher than control group until 6 d (P<0.05). Moreover, unlike the other biomarkers, serum MDA of severe blast injury group was significantly higher than moderate blast injury group at 6 d (P<0.05).

CONCLUSIONThe changes of serum Tau, GFAP, and TNF-α showed a good sensitivity at the acute phase after BTBI (within 24 h). However, their specificity and correlation with the extent of injury were limited in this experiment. Moreover, although the change of serum MDA showed a poor sensitivity and specificity to the diagnosis of BTBI during the first few days, it can reflect the injury degree at 6 d after injury. Therefore, further studies are needed to improve the methods of detecting more serum markers and investigate the significance of multiple markers in diagnosing BTBI.