Basal IL-6 and S100b levels are associated with infarct volume

The study of biomarkers related to the infarct volume of acute ischaemic stroke (AIS) is a valuable clinical strategy. We conducted a prospective study to evaluate the relationship between a wide panel of biomarkers involved in different biochemical pathways and lesion volume.

We studied 332 patients with AIS. Infarct volume was calculated from diffusion weighted imaging (DWI). Blood samples were drawn within 24 h of symptom onset to test a panel of biomarkers that included high-sensitivity C-reactive protein (hs-CRP), IL-6, neuron-specific enolase (NSE), N-terminal pro-B-type natriuretic peptide (NT-ProBNP), S100b, troponin and IL-10.

The median lesion volume was 2.5 cc (IQR: 0.6-15.3). Patients with previous atrial fibrillation, cardioembolic aetiology and total anterior circulation infarct TACI classification had higher lesion volumes than those without them. Patients with previous recent TIA had smaller ischaemic lesions than those without it. Age and NIHSS were significantly correlated with lesion volume. In a linear regression analysis adjusted by aetiology, S100b and IL-6 emerged as the only biomarkers independently associated with infarct volume. In contrast, previous recent TIA and small-vessel disease were inversely related to infarct volume.

The correlation between the two blood marker levels and ischaemic lesion volume would support the use of these biomarkers as a surrogate endpoint in AIS, especially in centres without DWI 24/7 but these could not substitute basic neuroimaging. Our findings should be further explored in larger, preferably multicentre studies.