Procalcitonin (PCT) on systemic bacterial infection and differential diagnosis, treatment and prognosis judgment than the C- reactive protei
Procalcitonin (PCT) on systemic bacterial infection and differential diagnosis, treatment and prognosis judgment than the C- reactive protein (CRP) and various inflammatory factors (bacterial endotoxin, TNF- alpha, IL-2) is more sensitive and has clinical and practical value.
1. The sensitivity and specificity of PCT were higher than those of other inflammatory factors.
PCT in bacterial infection especially the sensitivity and specificity of sepsis and were above 95%, especially the specificity of diagnosis of severe sepsis and septic shock as high as 100%, PCT appeared in the plasma, at elevated concentrations in the plasma of patients with systemic bacterial infection than CRP and other inflammatory factors there are early, could be detected by 2 hours, 6 hours to rise sharply, 8-24 hours to maintain a high level. The CRP in 8-12 hours after the slow rise.
2. PCT has a short half-life in plasma, which is an important index for the observation of curative effect and prognosis.
PCT in plasma in a short time, the half-life of 22-29 hours, in vitro and in vivo stability, not easy to be degraded, and the detection of PCT is not affected by the clinical use of drugs (except OKT3), associated with the severity of positive infection. Therefore, the dynamic observation of the changes of plasma PCT concentration can better determine the prognosis and curative effect. However, CRP has a relatively long half-life, and it takes longer to recover to normal level, which is not suitable for the observation of prognosis and curative effect.
3, the increase of PCT concentration is not affected by the state of immunosuppression.
When the body is in serious bacterial infection or sepsis, even in patients with immunosuppression or no obvious clinical manifestations, the plasma concentration of PCT were significantly increased, and the serious degree of increased and positively related to the infection, while CRP is commonly used in systemic inflammatory reaction in the early one of the indicators, but when the body is immunosuppression, the plasma concentration of CRP is increased.
4. PCT has special value in differential diagnosis of systemic and local bacterial infections.
PCT in bacterial sepsis, especially the sense of frame gram negative bacilli) causing a systemic inflammatory response often increased significantly, and the higher level and the severity of infection was positively correlated. After surgery, local infection caused by bacteria and virus infection, PCT, CRP and cytokines can be increased, but when the secondary infection, PCT was significantly increased, while CRP decreased and cytokine. Therefore, the changes of CRP and cytokine levels were not consistent with the severity of infection. Thus, PCT is a more specific indicator of systemic infection. More studies have shown that the combination of CRP and PCT can improve the sensitivity of diagnosis.
5. PCT is of great value in the diagnosis and differential diagnosis of benign and malignant tumors.
The serum PCT concentration in the majority of patients with benign and malignant tumors in the normal range or slightly increased, when the infection, especially systemic infection, PCT increased significantly. The positive rate of PCT was as high as 100%, and the amplitude of the increase was more than 10 times the normal level.
6, PCT is an important indicator of neonatal sepsis and septic shock.
The sensitivity, specificity, accuracy and positive predictive value of PCT in the diagnosis of neonatal sepsis and septic shock were higher than that of CRP, but the negative predictive value was lower than CRP. According to reports, when PCT< 2 g pct=" " >, g/L, 96 cases of children died in 24 cases, mortality rate of up to 25%.
7, PCT concentration can help doctors determine whether respiratory tract infection patients need antibiotics.
Most respiratory infections are caused by viruses, not bacteria, but the virus can damage the respiratory tract and cause secondary infections. Determination of PCT concentration can help doctors determine whether patients with respiratory tract infection need antibiotics to reduce unnecessary antibiotic use. According to the hospital in Basel, Switzerland Mullerd in Lancet (2004 363:9408) on the report, when the PCT< 0.25 g/L, do not advocate or limit the use of antibiotics, such as PCT more than 0.25 g/L or more than 0.5 g/L, advocate the use of antibiotics.
Source: Jiangxi medical laboratory, June 2005 twenty-third volume third: 259244