Table 2.

Selected sepsis biomarkers.

BiomarkerFunctionUtility in sepsis diagnosisGuidelinesReferences
ProcalcitoninPrecursor of calcitonin, a calcium regulator; procalcitonin is released as part of the inflammatory response, although its role is unclearSensitivity of 0.77 and specificity of 0.79 for sepsis diagnosis in patients with SIRS response, with an area under the curve of 0.85Surviving Sepsis Guidelines support its use as an aid in diagnosing sepsis, although other guidelines do not(2730)
CRPDirectly binds to pathogens, activating complement system and neutrophilsIsolated admission CRP has sensitivity of 0.89 and specificity of 0.59 for sepsis diagnosis in critically ill patientsNot currently recommended for sepsis diagnosis by any major guidelines(3134)
Lactic acidMetabolite produced during anaerobic metabolismIncreased lactic acid concentrations associated with increased mortality in septic patientsIncluded as part of Sepsis-3 definition of septic shock(9, 3537)