Plasma activity of endothelial lipase impacts high-density lipoprotein metabolism and coronary risk factors in humans

Aim: endothelial lipase (el) is a determinant of plasma levels of high-density lipoprotein cholesterol (hdl-c). however,little is known about the impact of el activity on plasma lipid profile. we aimed to establish a new method to evaluate el-specific phospholipase activity in humans. methods: plasma samples were obtained from 115 patients with coronary artery disease (cad) and 154 patients without cad. plasma el protein was immunoprecipitated using an anti-el monoclonal antibody after plasma non-specific immunoglobulins were removed by incubation with proteina. the phospholipase activity of the immunoprecipitated samples was measured using a fluorogenic phospholipase substrate,bis-bodipy flc11-pc. results: the el-specific phospholipase assay revealed that plasma el activity was inversely correlated with hdl-c levels (r= -0.3088,p<0.0001). in addition,the el activity was associated with cigarette smoking. furthermore,el activity in cad patients was significantly higher than that in non- cad patients. concomitantly,the hdl-c level in cad patients were significantly lower than that in non-cad patients. conclusion: we have established a method for human plasma el-specific phospholipase activity by combination of el immunoprecipitation and a fluorogenic phospholipid substrate. plasma el activity was associated with not only plasma hdl-c levels but also the risks for cad.