Biomarkers in sepsis-looking for the Holy Grail or chasing a mirage!

Table 3 Biomarkers for diagnosis of sepsis-current understanding in diagnosis of sepsis

Biomarker	Diagnosis of sepsis	Differentiating sepsis and SIRS	Guiding antibiotic initiation	Organism identification
Procalcitonin	Better than CRP; cannot be used independently; diagnosis based on clinical context	Better than CRP; cannot be used independently; diagnosis based on clinical context	Delays antibiotic administration; No short term mortality benefit	Higher in Gram negative bacteremia than Gram positive. Higher in bacteremia than in candidemia. No defined cutoffs. Treatment to be based on clinical judgement
Presepsin	Possible role	Possible role	No significant data	No significant data
nCD64	Possible role; when combined with CRP, higher diagnostic accuracy and high negative predictive value	No significant data	No significant data	Increased in bacterial and viral infection more than fungal
suPAR	Possible role	Performed poorly	No significant data	No significant data
IL6	Inferior to PCT, CRP	Inferior to PCT, CRP	No significant data	No significant data

CRP: C-reactive protein; IL6: Interleukin 6; PCT: Procalcitonin; SIRS: Systemic inflammatory response syndrome; suPAR: Soluble urokinase plasminogen activator receptor.