High-speed Turbidimetric Calprotectin Immunoassay - A New Rapid-response Biomarker for Sepsis and other Diseases and Conditions

The project aims to produce and document a clinical assay and reagents for automatic measurement of the protein calprotectin in serum and plasma samples, and clinically verify the value of these reagents. The main challenge in this field has been that previous methods have been slow and cumbersome, and that the calibration has not been satisfactory. The present project has succeeded in carrying out mass spectroscopy analyses of antigens and calibrators, and to present antigens and recombinant calibrators. Reagents have been completed, and clinical verification taking place in Norway, Sweden and the United States. Furthermore the project has succeded in producing recombinant calprotectin dimer S100A8 and S100A9 monomers of calprotectin, for the manufacture of calibrators and controls as well as antigens for immunization of antibody-producing hens. There is thus achieved an improvement in the standardization of the measurement methods.

Background: Calprotectin is a major component of neutrophils that are the first line of defence at a site of infection. Calprotectin is the first biomarker to be released into the blood stream during infection. Other biomarkers such as CRP are generated in the liver and are detected some time after an initial infection. A New Bioarker for Sepsis: The immediate release of calprotectin at the onset of infection makes calprotectin an ideal marker for sepsis and acute bacterial diseases. Summary: Gent ian AS has - over the last 5 years and through extensive R&D - developed a new nanoparticle immunoassay technology using avian antibodies. The company has a European patent for its technology, and patents are pending in other jurisdictions. Gentian AS has been co-ordinator for a FP6 STREP project, and presently sells 10+ million nanoparticle immunoassays based on in its new technology. Gentians annual turnover is 13 million NOK and rapidly growing. Gentian has invented a new formulation of nanoparticles conjugated to avian antibodies that enables sensitive measurement of calprotectin in a very wide concentration range in a highly automated non-separation immunoassay on clinical chemistry automates. The formulation supports a diverse range of body fluids including blood, plasma and faecal extracts. Gentian has also invented a new method for antigen preparation and standardisation and control materials for calprotectin that will be combined with the new nanoparticle materials. Furthermore, Gentian will, with its partners University of California Los Angeles (UCLA), Uppsala University Hospital and The Mayo Clinic, investigate the use of nanoparticle-based avian antibody immunoassays in new and established clinical areas for calprotectin measurements. The results will form the basis for new commercial non-separation calprotectin immunoassay products for routine clinical chemistry analysers, which will grow even faster than the Gentian cystatin C assay.