Adhesion molecules in nonrheumatic aortic valve disease: endothelial expression, serum levels and effects of valve replacement

OBJECTIVES: We studied the expression of intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and endothelial selectin (E-selectin) on aortic valve endothelium in patients undergoing valve replacement. We also assessed the relation between serum levels and endothelial expression and also the changes in serum levels following surgery. BACKGROUND: Nonrheumatic aortic valve disease is believed to be a degenerative condition. Increased tissue and soluble adhesion molecule levels are described in inflammatory conditions. METHODS: Aortic valves from 22 surgical (16 bicuspid, 6 tricuspid) and 6 autopsy (4 normal, 2 thickened) cases were studied by immunohistochemistry. Soluble adhesion molecules were measured in peripheral blood preoperatively, and at 6 and 18 months postoperatively, and compared with controls. RESULTS: The majority of the surgically removed tricuspid and bicuspid valves expressed adhesion molecules (E-selectin, 75% and 100%; ICAM-1, 75% and 80%; VCAM-1, 69% and 60%, respectively). The normal postmortem valves did not express these, while the diseased ones did. Endothelial expression of E-selectin correlated strongly with serum levels (r = 0.695, p = 0.004). Soluble E-selectin levels were significantly higher at baseline compared with controls (p = 0.017) and fell significantly at 18 months postoperatively (p = 0.005). CONCLUSIONS: Adhesion molecule expression on diseased valves supports an inflammatory component in "degenerative" aortic valve disease. The diseased valves may be the main source of elevated soluble E-selectin in this condition as blood levels correlate with endothelial expression and blood levels fall at 18 months postoperatively.