Abstract: Elevated number of Circulating Endothelial Cells (CEC) have been implicated in disease conditions associated with the formation or destruction of blood vessels such as acute coronary syndrome, thrombocytopenic purpura, sickle cell disease, sepsis, lupus, nephrotic syndromes, rejection of organ transplants, surgical trauma and cancer. This invention provides a method for assessing the levels of CEC which vary between different studies using a sensitive enrichment, imaging, and enumberation analysis. CD146 is one of the most specific endothelium-associated cell-surface antigens which can be used in image cytometry. CEC analysis provides an essential tool in prognostic/diagnostic evaluation in the clinic.

Abstract: A method and composition for the purpose of detecting and measuring analytes, such as antibodies, which are capable of binding with certain binding partners such as antigens. A homogenous assay is performed in the presence of free unbound antibodies. Such a homogeneous assay testing for specific antibodies is herein possible by defining of test subsets of microparticles having specific antigens thereon which are capable of binding with specific target antibodies. The microparticle suspension also includes at least two calibration subsets of microparticles having a binding partner thereon with at least two known levels of concentration which is capable of binding with human antibodies for the purpose of assay calibration. A verification subset of microparticles is included with another binding partner thereon at a known concentration, capable of binding with anti-human antibodies.