Background: Here, we report on a head-to-head comparison of the fully-automated Elecsys® Anti-SARS-CoV-2 immunoassay with the EDI TM enzyme linked immunosorbent assays (ELISA) for the detection of SARS-CoV-2 antibodies in human plasma. Methods: SARS-CoV-2 antibodies were measured with the Elecsys® assay and the EDI TM ELISAs (IgM and IgG) in 64 SARS-CoV-2 RT-PCR confirmed COVID-19 patients with serial blood samples (n = 104) collected at different time points from symptom onset. Blood samples from 200 healthy blood donors and 256 intensive care unit (ICU) patients collected before the COVID-19 outbreak were also used. Results: In COVID-19 patients, the percentage of positive results rose with time from symptom onset, peaking to positivity rates after 15-22 days of 100% for the Elecsys® assay, of 94% for the EDI TM IgM-ELISA and of 100% for the EDI TM IgG ELISA. In the 104 blood samples, the agreement between positive/negative classifications of the Elecsys® assay and the EDI TM ELISAs (IgM or IgG) was 90%. The false positivity rates in the healthy blood donors and the ICU patients were < 1% for the Elecsys® assay and < 3% for the EDI TM ELISAs. Conclusions: Our results indicate a high sensitivity and specificity for the Elecsys® assay and an acceptable agreement with the EDI TM ELISAs.

Rationale:The neuropeptide catestatin is an endogenous nicotinic cholinergic antagonist that acts as a pleiotropic hormone.Objective: Catestatin shares several functions with angiogenic factors. We therefore reasoned that catestatin induces growth of new blood vessels. Methods and Results:Catestatin induced migration, proliferation, and antiapoptosis in endothelial cells and exerted capillary tube formation in vitro in a Matrigel assay, and such effects were mediated via G protein, mitogen-activated protein kinase, and Akt. Catestatin-induced endothelial cell functions are further mediated by basic fibroblast growth factor, as shown by blockade of effects by a neutralizing fibroblast growth factor antibody. Furthermore, catestatin released basic fibroblast growth factor from endothelial cells and stimulated fibroblast growth factor signaling. In addition to its function on endothelial cells, catestatin also exerted effects on endothelial progenitor cells and vascular smooth muscle cells. In vivo, catestatin induced angiogenesis in the mouse cornea neovascularization assay and increased blood perfusion and number of capillaries in the hindlimb ischemia model. In addition to angiogenesis, catestatin increased density of arterioles/arteries and incorporation of endothelial progenitor cells in the hindlimb ischemia model, indicating induction of arteriogenesis and postnatal vasculogenesis. Conclusion:We conclude that catestatin acts as a novel angiogenic cytokine via a basic fibroblast growth factor-dependent mechanism. (Circ Res. 2010;107:1326-1335.) Key Words: angiogenesis Ⅲ blood vessels Ⅲ endothelium Ⅲ endothelial progenitor cells C hromogranin (Cg)A, the index member of the chromogranin/secretogranin protein family, is the major soluble protein of catecholamine storage vesicles of sympathetic nerve terminals and the adrenal medulla. 1,2 CgA is a proprotein giving rise to biological active peptides like the dysglycemic hormone pancreastatin, 3 the vasodilator vasostatin, 4 and catestatin 5 (CST) ), which inhibits catecholamine release by acting as a nicotinic cholinergic antagonist, resulting in a negative-feedback mechanism. Although plasma CgA is high in human essential (hereditary) hypertension, the plasma concentration of CST is lower in both established cases and in normotensive subjects with a family history of the disease, 6 suggesting a mechanism whereby diminished CST might increase the risk for later development of hypertension. Consistent with the human findings, high blood pressure has been reported in mice after targeted ablation of the Chga gene (Chga knockout), and such high blood pressure can be "rescued" either by replacement with CST or introduction of the human ortholog in the Chga knockout background. 7 Angiogenesis, the growth of new vessels from the preexisting vasculature, is an important process in many physiological conditions including embryonic development and wound healing. However, defects in the regula- Original received February 25, 2010; revision received September 27, 2010;...