Haptoglobin 2-2 is Associated with Presence and Progression of MRI Depicted Carotid Intraplaque Hemorrhage
Year: 2015
Type: dissertation
Study design: Observational Study
Abstract: Intraplaque hemorrhage (IPH) is a source of free hemoglobin that binds the haptoglobin protein and forms a complex cleared by tissue macrophages. There are three haptoglobin genotypes: Hp1-1, Hp2-2 and Hp1-2. The Hb-Hp2-2 complex has a lower affinity for macrophages, resulting in vascular oxidative burden. We hypothesized that Hp2-2 patientsâ failure to clear hemoglobin results in a greater prevalence and progression of IPH. Eighty patients with advanced vascular disease (>30% carotid stenosis) underwent carotid MRI. IPH was quantified using the VesselMass software. Haptoglobin was genotyped and phenotyped using established protocols. Logistic and longitudinal regression analyses were performed. Hp2-2 patients had a significantly higher prevalence of baseline IPH (p=0.02). Longitudinal analysis of 35 IPH positive carotids indicated a significant progression of IPH volume over time in Hp2-2 patients (p=0.003). Therefore, Hp2-2 patients had a significantly higher prevalence and progression of carotid IPH. Hp2-2 genotype may be a biomarker of IPH and can identify at-risk populations for more targeted imaging investigations.
Source: TSpace (University of Toronto)
Author: Tina Binesh Marvasti
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2782332039