Objective: To investigate changes in the level of circulating endothelial cells (CECs) and endothelin-1 (ET-1) in peripheral venous blood of the patients with congenital heart disease (CHD) complicated with pulmonary artery hypertension (PAH), and research on their effects in the onset and progress of CHD complicated with PAH.
Methods: A case-control study including 30 cases of healthy controls, 15 cases of left-to-right shunt CHD without PAH, 26 cases of CHD complicated with mild PAH, and 17 cases of CHD complicated with moderate-severe PAH was performed. We used flow cytometry to measure the percentage of CECs accounting for nucleated cells in whole blood, and enzyme linked immunosorbent assay (ELISA) to measure the level of ET-1 in serum. The differences of above-mentioned biomarkers between different groups were compared.
Results: (1) The level of CECs and ET-1in the group of moderate-severe PAH was significantly higher than those in the group of mild PAH and the group of CHD without PAH. Significantly difference was also observed between the level of CECs and ET-1 in the group of mild PAH and those in the group of CHD without PAH and the control group. Meanwhile, the level of CECs and ET-1 in the group of large shunt was significantly higher than those in the group few shunt and few-medium shunt. (2) Strong positive correlations were observed between pulmonary artery systolic pressure and percentage of CECs as well as ET-1 production. Mean pulmonary artery pressure also positively correlated with percentage of CECs as well as ET-1 production. (3) Arterial partial pressure of oxygen as well as arterial oxygen saturation negatively correlated with the level of CECs, whereas the volume of left-to-right shunt positively correlated with the level of ET-1. (4) The level of CECs and ET-1 were positively correlated as well in CHD patients.
Conclusions: CHD complicated with PAH is associated with increased CEC counts and ET-1 production. This study suggests that CECs and ET-1 could be used as clinical biomarkers to define medical strategies for control of PAH.
Keywords: Congenital heart disease; circulating endothelial cells; endothelin-1; pulmonary artery hypertension.