A Panel of CSF and Serum Biomarkers Reflecting Injury Severity and Outcome in a Human Spinal Cord Injury Study

Abstract

Acute spinal cord injury (SCI) results in catastrophic neurological impairment. We aimed to examine the temporal profile and severity correlation of biomarkers, and their relationship with the American Spinal Injury Association Scale (AIS) improvement in human SCI. 15 SCI and 10 non-SCI healthy subjects were classified according to the initial and discharge AIS grade. Serial cerebrospinal fluid (CSF) and serum samples were collected. Spectrin breakdown products (SBDP) 150, SBDP145, glial fibrillary acidic protein (GFAP), and GFAP breakdown product (GBDP) 38/44K were found to be elevated in the acute phase CSF samples in SCI patients on immunoblotting. SBDP150, ubiquitin C-terminal hydrolase-L1 (UCH-L1), GFAP, S100B, neurofilament light chain protein (NF-L), Tau & interleukin (IL) -6 were elevated in the acute phase CSF and serum samples on ELISA. CSF SBDP150, UCH-L1, GFAP, S100B and Tau were seen to peak on day 1 after injury, while CSF IL-6 and NF-L peaked on day 5. Serum SBDP150, IL-6, S100B, GFAP, UCHL-1 and Tau peaked on day 1, while serum NF-L peaked on day 5 post-injury. CSF alpha II-spectrin, SBDP150/145, and GBDP 44-38K levels (by immunoblots), CSF SBDP150, S100B, GFAP, UCHL-1 and Tau (ELISA) and serum UCHL-1 and Tau (ELISA) at specific time points showed SCI severity-correlation. CSF SBDP150, GFAP, and Tau and serum UCHL-1 and Tau (ELISA) were seen to have the best correlation with the severity at discharge. Receiver Operating Characteristic Curve analysis showed that CSF and serum biomarkers (SBDP150, IL-6, S100B, GFAP, NF-L, UCHL-1 and Tau) were associated with the severity of SCI.