After we arrive at the hospital with a cold, fever, and diarrhea, the doctor will routinely prescribe the bleeding routine, C-reactive protein and procalcitonin tests. The blood test is to see if the white blood cells are elevated, but what are the tests for C-reactive protein and procalcitonin? This is the inflammatory index, which is the index to distinguish bacterial or viral infection, local or systemic infection. Procalcitonin (PCT) and C-reactive protein (CRP) are both acute phase reactive proteins, which have been widely used clinically as indicators of inflammation.
The serum PCT concentration of normal population is extremely low. When bacterial infection is especially serious, the PCT level will increase greatly. After the infection is controlled, the blood PCT level will decrease, indicating a good prognosis. If PCT maintains the original level or continues to increase, it indicates the prognosis bad. Therefore, PCT can be used as a marker of bacterial infection, and it plays an important role in the early and rapid diagnosis of various infectious diseases, the monitoring of the disease course, and the guidance of medication. PCT never rises or slightly rises during viral infection. Therefore, serum PCT can effectively distinguish bacterial infections from viral infections.
It is worth noting that certain non-infectious diseases such as trauma, surgery, organ transplantation, blood diseases, acute respiratory distress syndrome, etc. can cause PCT abnormalities and need to be distinguished from infectious diseases. Therefore, it is necessary to closely observe the dynamic changes of PCT and closely integrate it with the patient’s medical history and clinical manifestations.
C-reactive protein, as an extremely sensitive indicator of acute phase response protein, is the first acute phase response protein to be recognized, and it increases rapidly and significantly during acute myocardial infarction, trauma, infection, inflammation, surgery, malignant tumors, etc. .
CRP is a non-specific indicator, which is mainly used in combination with clinical monitoring of diseases: ① screening for microbial infection; ② assessing the activity of inflammatory diseases, which rises 6 to 12 hours after myocardial infarction, which can reach 2000 times the normal level. Plasma concentration>5mg/L can be used as the beginning of an obvious acute phase reaction; ③monitoring of systemic lupus erythematosus, leukemia, and surgical infections (the serum concentration rises again); ④monitoring of neonatal sepsis and meningitis (this It may be difficult to do bacterial culture at the time); ⑤Monitor rejection after kidney transplantation.