Exploring Potential Proteomic Biomarkers for Prognosis of Infective Endocarditis through Profiled Autoantibodies by an Immunomics Protein Array Technique.

Though infective endocarditis (IE) is a life-threatening cardiac infection with a high mortality rate, the effective diagnostic and prognostic biomarkers for IE are still lacking. The aim of this study was to explore the potential applicable proteomic biomarkers for IE through the Immunome™ Protein Array system. The system was employed to profile those autoantibodies in IE patients and control subjects. Our results showed that interleukin-1 alpha (IL1A), nucleolar protein 4 (NOL4), tudor and KH domain-containing protein (TDRKH), G antigen 2B/2C (GAGE2), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and X antigen family member 2 (XAGE2) are highly differentially-expressed among IE and non-IE control. Furthermore, bactericidal permeability-increasing protein (BPI), drebrin-like protein (DBNL), signal transducing adapter molecule 2 (STAM2), cyclin-dependent kinase 16 (CDK16), BAG family molecular chaperone regulator 4 (BAG4), and nuclear receptor-interacting protein 3 (NRIP3) are differentially-expressed among IE and healthy controls. On the other hand, those previously identified biomarkers for IE, including erythrocyte sedimentation rate, C-reactive protein, rheumatoid factor, procalcitonin, and N-terminal-pro-B-type natriuretic peptide demonstrated only minor significance. With scientific rationalities for those highly differentially-expressed proteins, they could serve as potential candidates for diagnostic biomarkers of IE for further analysis.