Mean Platelet Volume and Integrin Alleles Correlate With Levels of Integrins αIIbβ3 and α2β1 in Acute Coronary Syndrome Patients and Normal Subjects
Objective—The interindividual variation in platelet α2β1 exceeds a 2-fold variance in platelet αIIbβ3 level. Our objective was to parse the contribution of mean platelet volume (MPV) and integrin gene alleles to this variation in large cohorts of patients with acute coronary syndrome (ACS) and normal subjects.
Methods and Results—Platelet αIIbβ3 and α2β1 levels were measured by flow cytometry in whole blood from 320 ACS patients and 128 normal subjects and compared with MPV, platelet count, ITGA2 rs1126643, and ITGB3 rs5918 alleles. In all subjects, a strong direct correlation was found between MPV and αIIbβ3 level (P<0.001). Neither MPV nor αIIbβ3 level correlated with ITGB3 rs5918 alleles. In the case of α2β1 level, MPV contributed modestly, whereas ITGA2 rs1126643 exerted a greater effect. An inverse correlation was found between MPV and the rs1126643 minor allele.
Conclusion—MPV is the major effector of platelet αIIbβ3 level, whereas the ITGA2 rs1126643 alleles influence α2β1 level more than MPV does. The rs1126643 minor allele, associated with lower MPV, likely exerts this effect via the influence of α2β1 on megakaryocyte maturation. Because of the hyperactivity of larger platelets, MPV is an accurate metric of risk for adverse outcome in ACS.
- Received August 18, 2011.
- Accepted October 3, 2011.
- © 2011 American Heart Association, Inc.