Identification of Differential Proteins in Thrombi of Cardioembolic and Atherothrombotic Etiology in Patients with Ischemic Stroke

Knowing the precise etiology in ischemic stroke is necessary to ensure accurate diagnosis and decide on appropriate preventive treatments, especially in those of undetermined cause. Analysis of the thrombus protein composition could be useful to identify diagnostic biomarkers to help determine the stroke origin. Thrombi from 54 ischemic stroke patients with large vessel occlusion (LVO), of cardioembolic and atherothrombotic etiology, were analyzed using a proteomics approach. The proteome profile was compared between them to detect differential proteins of each etiology. Peptides of those differential proteins were quantified and related to the neurological function and clinical status of the patients. Of the 516 proteins identified, three showed significant differences between atherothrombotic and cardioembolic thrombi. These were fibronectin (FINC), 2,3-bisphosphoglycerate mutase (PMGE), and tropomyosin-1 (TPM1). Combining these proteins in a biomarker panel provided good sensitivity and high specificity for differentiating cardioembolic and atherothrombotic strokes. In addition, several of the quantified peptide levels correlated with clinical parameters related to stroke severity and prognosis. Three proteins differentially detected in ischemic stroke thrombi could be useful tools for accurately diagnosing ischemic stroke etiology, particularly in cases of undetermined cause. These biomarkers should be further analyzed in prospective multicenter studies to demonstrate their usefulness.