Development of a newly immunoassay specific for mouse presepsin (sCD14-ST)

Presepsin (sCD14-ST) is used as a marker for sepsis diagnosis. The production mechanism of presepsin is unique in that it is produced through phagocytosis of microorganisms. However, some studies have demonstrated that non-infected patients had increased presepsin levels and that presepsin is related to the risk or severity of diseases. This study was designed to describe a sensitive sandwich enzyme-linked immunosorbent assay for mouse presepsin developed to investigate the association of presepsin with diseases. Polyclonal antibodies were generated from peptide-immunized rabbit antiserum. Mouse presepsin standard was prepared using the recombinant method as an Fc-fusion protein. The linear detection range of the method was 4.7-300 pg/mL with a detection limit of 1.4 pg/mL. The assay detected mouse presepsin where mouse soluble CD14 (sCD14) was digested by cathepsin D proteinase and the cross-reactivity of sCD14 was not observed. The normal levels of mouse presepsin and sCD14 were compared; 65.9 ± 21.4 pg/mL and 43.2 ± 7.2 ng/mL were determined, respectively. Moreover, the levels of presepsin and sCD14 were compared with a lipopolysaccharide (LPS)-injected sepsis mouse model. The newly developed analytical method had high specificity to presepsin and is an efficient tool for studying the association between presepsin and diseases.