Table 3. Promising new biomarkers of infection.

Biomarker	Biological, structural and/or pathophysiological characteristics	Available data
sTREM-1	Surface receptor of mature polymorphonuclear and monocytes up-regulated when exposed to bacterial and fungal pathogens	Diagnostic value for pneumonia and meningitis and prognostic value in sepsis (3)
suPAR/CD87	Constitutive cellular receptor in endothelium and leucocyte up-regulated during inflammatory and immune response	Prognostic value in sepsis. Possible useful for antibiotic management in sepsis (3)
ProADM	Adrenomedullin precursor (mediator of cell proliferation and hormone regulation) with increased secretion during immune response to bacterial and viral infection	Prognostic value in pneumonia (3)
Presepsin	Glycoprotein receptor of monocytes/macrophages	Diagnostic and prognostic value in sepsis (3)
PTX3	Protein produced by various cells (monocytes, neutrophils and endothelial cells) in response to proinflammatory cytokines and bacterial products; acts as part of the innate immune system by activating the classical and lectin complement pathways; closely related to CRP as both are members of the pentraxin family	Candidate prognostic marker in sepsis (50,51)

sTREM-1, soluble triggering receptor expressed on myeloid cells-1; suPAR, soluble urokinase-type plasminogen receptor; ProADM, proadrenomedullin; PTX3, pentraxin-3; CRP, C-reactive protein.