Serum neuron-specific enolase and S100 calcium binding protein B biomarker levels do not improve diagnosis of acute stroke.

Background: The high sensitivities and specificities reported for blood biomarkers as a supportive test in the diagnosis of acute stroke do not correspond with their performance for decision-making in emergency situations.

Methods: Seventy-two patients with suspected stroke were recruited: 44 with ischaemic stroke, 17 with haemorrhagic stroke and 11 stroke mimics, as well as a high-risk control group of 79 individuals. Serum neuron-specific enolase (NSE) and S100 calcium binding protein B (S100B) biomarker levels were determined on admission, using immunoassay kits. The sensitivities and specificities of NSE and S100B for distinguishing acute stroke from stroke mimics and high-risk controls were calculated.

Results: For cut-off values (NSE ≤ 14 micrograms per litre and S100B ≤130 nanograms per litre) the sensitivity was 53% and 55% respectively. Specificity was 64 for both versus the stroke mimic group. Specificity was higher (79% and 86% respectively) when calculated on the basis of the control group.

Conclusions: This study supports the evidence indicating that serum levels of NSE and S100B do not improve the diagnosis of acute stroke.