Co-expression of vascular and lymphatic endothelial cell markers on early endothelial cells present in aspirated coronary thrombi from patients with ST-elevation myocardial infarction

• CD34, CD31 and D2-40 co-expression for the first time on the same non-tumorous cell
• Coronary thrombi angiogenesis shows blood and lymphatic endothelial cell plasticity.
• Aspirated coronary thrombus may be considered as novel angiogenesis model.
• Unitary marker exclusive for blood or lymphatic cells remains to be found.

IntroductionAngiogenesis is the growth of both new vascular and lymphatic blood vessels from the existing vasculature. During this process, blood endothelial cells (BECs) and lymphatic endothelial cells (LECs) express specific markers, which help their discrimination and easier identification. Since the coronary thrombi material aspirated from patients with ST-elevation myocardial infarction (STEMI) proved as good angiogenesis model, we investigated the expression of CD34 and CD31 as BECs markers, and D2-40, LYVE-1 and VEGFR3 as LEC markers in this material.Materials and methodsAspirated thrombi were stained immunohistochemically for CD34, CD31, D2-40, LYVE-1 and VEGFR3. Organizational patterns of immunopositive cells were graded as single cells, clusters or microvessels. Double immunofluorescence for CD31, D2-40, LYVE-1 and VEGRF3 was done. Thrombi were also graded as fresh (< 1 day old), lytic (1–5 days old) and organized (> 5 days old).ResultsSerial sections of aspirated thrombi showed concordant BEC and LEC markers immunopositivity. Double immunoflorescence proved co-expression of CD31 and LEC markers on the same cells. Cells expressing LEC markers organized in clusters and microvessels were mainly present in lytic and organized thrombi.ConclusionCo-expression of BEC and LEC markers on the same non-tumorous cell during thrombus neovascularization indicates existing in vivo plasticity of endothelial cells under non-tumorous pathological conditions. It also points that CD34 and CD31 on one hand, and D2-40, LYVE-1 and VEGFR3 immunostaining on the other hand, cannot solely be a reliable indicators whether vessel is lymphatic or not.