Identification and preliminary characterization of ubiquitin C terminal hydrolase 1 (UCHL1) as a biomarker of neuronal loss in aneurysmal subarachnoid hemorrhage.

By using two different approaches, ubiquitin C-terminal hydrolase 1 (UCHL1) was identified as a potential cerebrospinal fluid (CSF) biomarker of neuronal loss in aneurysmal subarachnoid hemorrhage (ASAH) and presumably other CNS damage and disease states. Appropriate antibodies and a sensitive ELISA were generated, and the release of UCHL1 into CSF was compared with that of pNF-H and S100beta in a cohort of 30 ASAH patients. Both UCHL1 and pNF-H showed persistent release into CSF in almost all patients in the second week postaneurysmal rupture (AR), and S100beta levels rapidly declined to baseline levels in 23 of 30 patients. Seven of thirty patients showed persistently elevated S100beta levels over the first 5 days post-AR and also had relatively higher levels of pNF-H and UCHL1 higher compared with the rest. These patients proved to have very poor outcomes, with 6 of 7 expiring. Patients who did reduce S100beta levels tended to have a better outcome if pNF-H and UCHL1 levels were also lower, and elevated UCHL1 levels in the second week post-AR were particularly predictive of poor outcome. Acute coordinated releases of large amounts of UCHL1, pNF-H, and S100beta in 16 of 30 patients were observed, suggesting sudden loss of brain tissues associated with secondary events. We conclude that measurement of the CSF levels of these proteins reveals details of ASAH progression and recovery and predicts patient outcome.

Detection of phosphorylated NF-H in the cerebrospinal fluid and blood of aneurysmal subarachnoid hemorrhage patients.

Blood and cerebrospinal fluid (CSF) of 30 Fisher grade 3 aneurysmal subarachnoid hemorrhage (ASAH) patients were analyzed for the presence of the phosphorylated axonal form of the major neurofilament subunit NF-H (pNF-H), a promising biomarker of axonal injury. Patient demographic data including development of vasospasm and outcome scores at 6 months after aneurysmal rupture (AR) were evaluated. Higher pNF-H blood levels in the first few days after AR were strongly predictive of a negative outcome. Blood pNF-H levels in most recovering patients showed a steady increase into the second week after AR, presumably reflecting axonal degeneration secondary to the original insult. Almost half of the patients studied showed sudden dramatic peaks of pNF-H protein release into CSF in the 3- to 14-day time period after AR, which must reflect profound, coordinated, and secondary loss of axons. Patients in whom vasospasm was detected had significantly more pNF-H in both blood and CSF compared with those in whom vasospasm was not detected. We conclude that the analysis of pNF-H levels in blood and CSF differentiates between patients with poor and favorable outcomes and also reveals several novel features of ASAH progression and recovery.

Alpha-II spectrin breakdown products in aneurysmal subarachnoid hemorrhage: a novel biomarker of proteolytic injury.

OBJECT: Aneurysmal subarachnoid hemorrhage (ASAH) is a serious event with grave consequences. Delayed ischemic neurological deficits caused by cerebral arterial vasospasm contribute significantly to death and disability. Biomarkers may reflect brain injury and provide an early warning of impending neurological decline and stroke from ASAH-induced vasospasm. Alpha-II spectrin is a cytoskeletal protein whose breakdown products are candidate surrogate markers of injury magnitude, treatment efficacy, and outcome. In addition, all spectrin breakdown products (SBDPs) can provide information on the proteolytic mechanisms of injury. METHODS: Twenty patients who received a diagnosis of Fisher Grade 3 ASAH were enrolled in this study to examine the clinical utility of SBDPs in the detection of cerebral vasospasm in patients with ASAH. All patients underwent placement of a ventriculostomy for continual cerebrospinal fluid drainage within 72 hours of ASAH onset. Cerebrospinal fluid samples were collected every 6 hours and analyzed using Western Blotting for SBDPs. Onset of vasospasm was defined as an acute onset of a focal neurological deficit or a change in Glasgow Coma Scale score of two or more points. All suspected cases of vasospasm were confirmed on imaging studies. RESULTS: Both calpain- and caspase-mediated SBDP levels are significantly increased in patients suffering ASAH. The concentration of SBDPs was found to increase significantly over baseline level up to 12 hours before the onset of cerebral arterial vasospasm. CONCLUSIONS: Differential expression of SBDPs suggests oncotic necrotic proteolysis may be predominant in acute brain injury after ASAH and cerebral arterial vasospasm.