Eosinophils May Be Involved in Thrombus Growth in Acute Coronary Syndrome Histologic Examination of Aspiration Samples

Abstract

SummaryThrombus aspiration therapy allows for the examination of thrombus and atheroma fragments in acute coronary syndrome (ACS). Inflammatory cells and platelet activation play key roles in thrombus formation in ACS. However, histopathologic evaluation of thrombi in ACS has not been adequately addressed. We performed histologic analysis of tissue samples obtained by thrombus aspiration therapy. We studied 165 samples from patients with ACS. The area of each sample, percentage of red thrombus, and percentage of white thrombus were measured. Samples were stained immunohistochemically with antibodies against macrophages, activated platelets, and interleukin (IL)-5. Seventy-six samples included atheroma fragments. Macrophages, neutrophils, and activated platelets were observed in thrombi and in atheroma fragments. Eosinophil infiltration was also observed predominantly in the area between white thrombus and red thrombus in 106 samples. We categorized all samples into 3 groups according to the grade of eosinophil infiltration (eos-, eos+, eos++ group). Sample area in the eos++ group was greater than that in the eosgroup (P < 0.0001). In addition, the percentage of the red thrombus areas in the eos++ group and the eos+ group was greater than that in the eos-group (P < 0.009, P < 0.02, respectively). However, there was no difference in the percentage of white thrombus area between the 3 groups. Staining for IL-5 was identified in inflammatory cells within thrombi. Eosinophils may play an important role in coronary occlusion by promoting thrombus growth. (Int Heart J 2009; 50: 267-277)

Ischemic priapism: Can eosinophil count and platelet functions be positive predictive factors in etiopathogenesis

“…7,14 Some studies reported that EC is related to vasospastic angina pectoris and large thrombus formation. 15 A connection may exist between EC and vasculogenic events due to the strong vasoconstrictor, procoagulant, and local inflammatory effects of eosinophils. We included EC, PC, and MPV counts as suspected predictive factors demonstrating platelet activation in our study.…”

Thrombus Aspiration Therapy and Coronary Thrombus Components in Patients with Acute ST-Elevation Myocardial Infarction

“…At the time of plaque disruption, locally released tissue factor-positive and leukocyte-derived MPs play an important role in fibrin-rich thrombus formation [35][36][37][38][39][40][41][42] . Moreover, activated inflammatory cells, such as neutrophils, macrophages and eosinophils, contribute to the growth of a thrombus 17,89,90) . Our study also demonstrated that erythrocyte-rich thrombi often contain more inflammatory cells, such as MPO-positive neutrophils, thus leading to increased plasma MPO levels, which reflects a high thrombus burden 78,84) .…”

Allergic Inflammation Is Associated With Coronary Instability and a Worse Clinical Outcome After Acute Myocardial Infarction

“…5,6 Importantly, eosinophils have been recently involved in thrombus growth and coronary vasospasm. 7,8 Of note, we reported that higher eosinophil cationic protein (ECP) levels were associated to the atherosclerotic burden and to a worse prognosis in patients undergoing stent implantation. 9,10 Moreover, in a postmortem study, eosinophil infiltration was found at the site of late drug-eluting stent thrombosis.…”