How is sepsis being detected

What is sepsis?

   A life-threatening organ dysfunction caused by a dysregulated host response to infection, that is when the body's response to infection damages its own tissues and organs and thus endangers life. In that case, it is called sepsis.

Biochemical indicators of infection
         Biomarkers of infection are clinical tests developed in recent years that are useful in determining infection and can help emergency physicians quickly determine the presence of infection and infer the type of pathogen that may be infecting the patient. Commonly used biomarkers of infection include serum C-reactive protein (CRP), serum calcitoninogen (PCT), interleukin-6 (IL-6) and serum amyloid (SAA), and heparin-binding protein (HBP).

Calcitoninogen (PCT)
         PCT is a non-hormonally active glycoprotein, and PCT levels are positively correlated with the severity of bacterial infection. When PCT is 0.1 to 0.25 ng/mL, it suggests that a bacterial infection is unlikely. When PCT is 0.25 to 0.5 ng/mL, a bacterial infection requiring treatment may be present, and when PCT is greater than 0.5 ng/mL, a bacterial infection requiring treatment is likely to be present. The majority of experts suggest that PCT 0.5 ng/mL is the diagnostic threshold of sepsis. PCT rises rapidly after 2-4 hrs of infection and reaches its peaks at 12-48 hrs. The specificity of PCT is high and is uniformly recommended by the consensus of many domestic and international guidelines.

Interleukin 6 (IL-6)        
          IL-6 is a pleiotropic cytokine induced by IL-1 and tumor necrosis factor-α (TNF-α). IL-6 levels are significantly increased in bacterial infections and positively correlated with the levels of HBP and SAA, which can be used as a common index for infection assessment and detection, and its concentration is consistent with the severity of the patient's disease. In addition, IL-6 is important for the determination of sepsis and the severity of the disease. For the results of some studies have shown that serum IL-6 levels are significantly higher in patients in septic shock than in non-septic shock patients.

C-reactive protein (CRP)
          CRP is an acute time-phase reactive protein, and most infections trigger a rapid rise in its concentration, usually starting 2 hrs after infection and peaking at 24-48 hrs. The rise in CRP in bacterial infections is significant, while the rise in CRP in viral infections is mostly normal or slight. CRP is significantly elevated in bacterial infections, while it is mostly normal or slightly elevated in viral infections. Therefore, CRP is usually used as one of the reference indicators to identify bacterial or viral infections. The half-life of CRP is 18 h. When the infection is controlled, it can drop rapidly within 1~2 days. However, the value of CRP in bacterial infection is not clear.

Serum amyloid A (SAA)
           SAA is a sensitive, acute, time-phase reactive protein that can be used as a sensitive indicator of infection and inflammation control in the body. When SAA and CRP are elevated at the same time, it indicates a possible bacterial infection. In contrast, when SAA is elevated but CRP is not, it often indicates a viral infection; SAA has a half-life of about 50 min. When the antigen is cleared by the body, SAA can rapidly decrease to normal levels. Therefore, SAA can be used as a sensitive indicator of infection and inflammation control in the body.

Heparin binding protein (HBP)         
             HBP is a protein molecule released by the body to activate neutrophil acidophil granules. It has been shown that HBP is significantly elevated in patients with sepsis when IL-6 levels are normal or mildly elevated. Its accuracy in diagnosing sepsis is greater than that of other cytokines, especially in the early and rapid diagnosis of severe bacterial infections. HBP, as an acute temporal protein, is one of the effective biomarkers for assessing the severity of disease in patients with sepsis, and is more important in the early diagnosis and efficacy monitoring of patients with septic shock. As an acute temporal protein, HBP is one of the effective biomarkers for assessing the severity of disease in septic patients and is more important in the early diagnosis and monitoring of the efficacy of septic shock patients.

                                                         Heavy Chain Related Products Recommendation
Serum amyloid A (SAA) 

Calcitoninogen (PCT) 

C-reactive protein (CRP) 

Interleukin 6 (IL-6)