Abstract 26: Who is Going to Stroke? Biomarkers for the Unstable Carotid Atheroma
Unstable carotid stenosis is an important source of extracranial atheroembolism and stroke. Current interventional therapy is based on surrogate markers for stroke risk and no precise diagnostic tool is available for identification of either individuals or lesions at risk. Thus, biomarkers for the unstable carotid atheroma may improve selection of patient for intervention.
Here, a high-throughput pipeline for identification of circulating biomarkers for unstable carotid atherosclerosis was developed. Carotid plaques were part of the Biobank for Karolinska Endarterectomies (BiKE) and obtained from patients treated for symptomatic (S) and asymptomatic (AS) carotid stenosis together with peripheral plasma and ‘local’ plasma (n = 47) sampled after clamping prior to arteriotomy. Screening of proteins was processed through Luminex based, suspension-bead assays using over 10,000 antibodies from the Human Protein Resource (HPR) and compared to peripheral plasma (n = 200 total). Plasma analysis identified 150 significantly dysregulated candidates based on three comparisons: proteins enriched in local plasma compared to peripheral plasma; in local plasma from S compared with AS patients; in peripheral plasma from S compared with AS patients. Pathway analysis revealed that detected proteins were related to ossification, lysosomes, magnesium transport, prenylation, collagens, lipid metabolism, and transcription factors. Identified candidate proteins were further filtered using public database mining, comparisons with transcriptomic data from BiKE, and qPCR/IHC in matched endarterectomies. Among the identified candidates, THEMIS2 and BLVRB were examples of proteins successfully validated as upregulated in both plaques and plasma from S patients and localized to CD68+ macrophages.
Extensive analysis of plasma and tissue samples from patients undergoing carotid surgery permitted identification of several potential biomarkers for unstable carotid atherosclerosis. Further validation in larger cohorts of unstable atherosclerosis is necessary in order to determine predictive power for the identification of individuals at risk as well as for the development of targeted bioimaging for lesion detection.
Author Disclosures: U. Hedin: None. L. Matic Perisic: None. M. Iglesias: None. M. Lengquist: None. A. Razuvajev: None. J. Roy: None. F. Pontén: None. J. Odeberg: None.
- © 2015 by American Heart Association, Inc.