A new ELISA method for the measurement of total α2-plasmin inhibitor level in human body fluids

• Published in: Journal of immunological methods 2019-08, Vol.471, p.27-33
• Main Authors: Teráz-Orosz, Adrienn, Csapó, Andrea, Bagoly, Zsuzsa, Székely, Edina Gabriella, Tóth, Eszter, Kovács, Bettina, Bereczky, Zsuzsanna, Muszbek, László, Katona, Éva
• Format: Article
• Language: English
• Subjects: Alpha-2-plasmin inhibitor; Cerebrospinal fluid; Enzyme-linked immunosorbent assay; Fibrinolysis; Monoclonal antibody
• ISSN: 0022-1759; 1872-7905
• DOI: 10.1016/j.jim.2019.05.004

The ever-increasing research efforts to develop new antithrombotic therapies have led to the reassessment of the role of alpha-2-plasmin inhibitor (α2-PI) in pathological conditions. In particular, experimental stroke studies have suggested correlation between increased free α2-PI level and mortality. However there are only a small number of well-characterized and specific assays available for the measurements of free α2-PI. In plasma α2-PI undergoes both N- and/or C-terminal cleavages resulting four isoforms with modified susceptibility to FXIII catalyzed cross-linking to fibrin and/or loss of plasmin(ogen) binding. Present paper describes a new sandwich ELISA method for the determination of free total α2-PI in plasma and other body fluids. A newly generated biotinylated monoclonal antibody recognizes and captures all the four N- and/or C-terminally modified isoforms of α2-PI while HRPO-labeled polyclonal anti-α2-PI antibody detects the captured antigen. Performing the 2-step assay in streptavidin-coated microplate can be completed within three hours. The assay is well reproducible, total (within laboratory) imprecision in the normal, pathological and very low ranges were 7.4%, 9.1% and