血清降钙素原及C反应蛋白在感染性疾病中的应用前景

Application potential of serum procalcitonin and C-reactive protein in infectious diseases

血清降钙素原（PCT）是降钙素前肽物质，正常情况下由甲状腺C细胞产生。C反应蛋白（CRP）是一种急性时相反应蛋白，在白细胞介素-6作用下由肝细胞分泌产生。有关资料表明，感染时血清PCT及CRP水平升高，并与感染严重程度呈正相关。在临床检测中发现两者在诊断感染性疾病灵敏度上差异不明显，但在特异性上PCT明显高于CRP。两者联合检测在鉴别诊断感染性疾病和非感染性疾病、监测危重症及感染、指导抗生素的合理应用、判断治疗效果及评估预后上有重要的临床应用价值与良好的应用前景。PCT产生机制及其在重症感染时的来源、作用机制尚不清楚，有待于进一步研究。

Serum procalcitonin （PCT） is propeptide of calcitonin, normally produced by thyroid C cells. And C-reactive protein （CRP） is a sort of acute phase protein secreted by hepatic cells in the induction of IL-6. Substantial studies have shown that the serum levels of PCT and CRP are increased remarkably in the patients who suffered from infectious diseases, and the levels are positively correlated with the severity of the infectious disorders. There is no apparent difference in the sensitivity of diagnosing infectious diseases between the 2 proteins, but the specificity of PCT is higher than that of CRP. It is of great clinical application value and promising application prospect when the 2 proteins are combined together in the differential diagnosis of infection and noninfectious diseases, the monitoring of critical illness and severe infection, the guiding of appropriate antibiotics usage, and the evaluation of curative effects and prognosis. However, how the PCT is produced and through what mechanism it exerts effect remain unclear and need further studies.