Abstract T MP53: Whole Blood Immuno-Chromatography for Rapid Detection of Cerebral Ischemia in the Pre-Hospital Setting

Abstract

BACKGROUND: Pre-hospital detection of ischemic brain injury will exclude stroke mimics and refine patient triage. Using “dipstick” immuno-chromatography, we validated a rapid-sequence method to identify visinin-like protein-1 (VILIP-1), a neuronal injury marker, in blood sampled after focal cerebral ischemia in rats. METHODS: Transgenic (Tg) rats were constructed to over-express tumor necrosis factor-alpha (TNFα) in brain. Suture-occlusion of the middle cerebral artery (MCAO) was performed in TNFα-Tg animals and wild type (WT) littermates for 1 hr. Arterial blood was sampled at pre-ischemic baseline, after 60 min of MCAO, and at 15 min or 24 hrs of post-ischemic reperfusion. VILIP-1 immuno-reactivity was normalized to pre-ischemic baseline and compared to sham-ischemic animals. Brain infarct volume was measured at 24 hrs. VILIP-1 immuno-reactivity was then correlated with infarct volume to derive Pearson product moment. RESULTS: VILIP-1 immuno-reactivity was increased after 24 hrs of post-ischemic reperfusion in TNFα-Tg animals (133 ± 13 [SD]% of baseline) compared to sham-ischemic rats (100 ± 22; p ≤ 0.05; ANOVA; n = 5 per group). At 15 min (159 ± 36%) and 24 hrs (above), VILIP-1 expression was greater than pre-ischemic baseline ( p ≤ 0.05). Immuno-reactivity of VILIP-1 at 15-min post-ischemic reperfusion was strongly correlated with infarct volume measured at 24 hrs in TNFα-Tg rats (Pearson 0.79; p ≤ 0.01). CONCLUSIONS: Whole blood immuno-chromatography of VILIP-1 is feasible and correlates positively with infarct volume measured at 24 hrs in the rat. These promising results underscore the need to study VILIP-1 immuno-reactivity as an indicator of ischemic brain injury in the pre-hospital setting.