IgM detection via selective recognition by mannose-binding protein

C2+-dependent mannose-binding proteins (MBPs) belong to the family of anima l lectins isolated from the liver and serum of rabbits, humans and rodents. They perform in vivo as defense molecules that act as opsonins by enhancin g the clearance of mannose-rich pathogens and have been used in vitro for t he purification of immunoglobulin M (IgM). In this study, we used MBPs as a sensitive and specific reagent for the detection of IgM due to their high specificity for mannose found only in IgM carbohydrate regions. MBP per-for med as a sensitive alternative to the usually used anti-IgM, where very low concentrations of IgM should be detected. IgM plays a central role in the initial response of the immune system to the invasion of foreign pathogens, as the early detection of the appearance of pathogenic IgM in biological f luids is of great significance in the diagnosis and treatment of many acute pathological cases. The development of a highly sensitive and reliable ass ay for the detection of low concentrations of laM based on covalent binding on epoxy film-coated surfaces and selective recognition of IgM by MBP may be of clinical importance. (C) 2001 Elsevier Science B.V. All rights reserv ed.