Abstract 2948: Ischemic Transient Neurological Events Identified by Immune Response to Cerebral Ischemia
Background and Purpose: Deciphering whether a transient neurological event (TNE) is of ischemic or nonischemic etiology can be challenging. Ischemia of cerebral tissue elicits an immune response in stroke and transient ischemic attack (TIA). This response, as detected by RNA expressed in immune cells, could potentially distinguish ischemic from nonischemic TNE.
Design/Methods: Analysis of 208 TIAs, ischemic strokes, controls and TNE was performed. RNA from blood was processed on microarray. TIAs (n=26) and ischemic strokes (n=94) were compared to controls (n=44) to identify differentially expressed genes (FDR<0.05, fold change ≥|1.2|). Genes common to TIA and stroke were used predict ischemia in TIA-DWI positive / minor-stroke (n=17), nonischemic TNE (n=13) and TNE of unclear etiology (n=14).
Results: Seventy-four genes expressed in TIA were common to those in ischemic stroke. Functional pathways common to TIA and stroke related to activation of innate and adaptive immune systems, involving predominantly granulocytes and B-cells. A prediction model using the common response to ischemia distinguished TIA and strokes from controls with 89% sensitivity and specificity. In the validation cohort, 17/17 TIA-DWI positive / minor-strokes were predicted to be ischemic, and 10/13 nonischemic TNE were predicted to be nonischemic. In TNE of unclear etiology, 71% were predicted to be ischemic. These subjects had higher ABCD2 scores.
Conclusions: A common peripheral response to ischemia in TIA and stroke was identified, relating to activation of innate and adaptive immune systems. TNE of ischemic etiology were identified based upon gene profiles that may be of clinical utility with further development.
- © 2012 by American Heart Association, Inc.