Wang Tao, Cui Yun-Liang, Lin Zhao-Fen, Chen De-Chang
Department of Emergency Medicine, Changzheng Hospital, Second Military Medical University, Shanghai 200003, China.
Chin Med J (Engl). 2016 Feb 20;129(4):417-23. doi: 10.4103/0366-6999.176064.
Both procalcitonin (PCT) and plasma endotoxin levels cannot be solely used for a definite diagnosis of bacteremia or sepsis, and there has been few study comparing the values of the two biomarkers for the diagnosis of bacteremia. The aim of this study was to identify bacteria causing bacteremia and evaluate the role of the two biomarkers in the diagnosis of bacteremia in Intensive Care Unit (ICU).
The medical records of 420 patients in ICU were retrospectively reviewed. Patients (n = 241) who met the inclusion criteria were subjected to blood culture (BC) for the analysis of the endotoxin or PCT levels. The exclusion criteria included the presence of infection with human immunodeficiency virus and/or AIDS, neutropenia without sepsis, pregnancy, treatment with immunosuppressive therapies, or blood diseases such as hematological tumors. Patients' BC episodes were divided into BC negative, Gram-negative (GN) bacteria, Gram-positive bacteria, and fungi groups. The PCT and plasma endotoxin levels were compared in the different groups.
A total of 241 patients with 505 episodes of BC were analyzed. The GN bacteria group showed higher levels of PCT and endotoxin than the BC negative, Gram-positive bacteria, and fungi groups. GN bacteremia was more prevalent than Gram-positive bacteremia. The GN bacteremia caused by non-Enterobacteriaceae infection presented higher endotoxin level than that by Enterobacteriaceae, but no significant difference in PCT levels was observed between the two groups. The plasma endotoxin significantly differed among different groups and was bacterial species dependent.
Plasma endotoxin was more related to GN than to Gram-positive bacteremia, and that endotoxin level was species dependent, but PCT level remained relatively more stable within the GN bacteria caused bacteremia. Both GN and positive bacteria caused bacteremia in the ICU patients in different regions of China. And PCT is a more valuable biomarker than endotoxin in the diagnosis of bacteremia.
降钙素原（PCT）和血浆内毒素水平均不能单独用于确诊菌血症或脓毒症，且很少有研究比较这两种生物标志物在菌血症诊断中的价值。本研究旨在确定引起菌血症的细菌，并评估这两种生物标志物在重症监护病房（ICU）菌血症诊断中的作用。
回顾性分析420例ICU患者的病历。符合纳入标准的患者（n = 241）接受血培养（BC）以分析内毒素或PCT水平。排除标准包括感染人类免疫缺陷病毒和/或艾滋病、无脓毒症的中性粒细胞减少症、妊娠、接受免疫抑制治疗或患有血液系统疾病如血液肿瘤。将患者的血培养情况分为血培养阴性、革兰阴性（GN）菌、革兰阳性菌和真菌组。比较不同组的PCT和血浆内毒素水平。
共分析了241例患者的505次血培养情况。GN菌组的PCT和内毒素水平高于血培养阴性、革兰阳性菌和真菌组。GN菌血症比革兰阳性菌血症更常见。非肠杆菌科感染引起的GN菌血症的内毒素水平高于肠杆菌科感染引起的，但两组的PCT水平无显著差异。血浆内毒素在不同组间有显著差异，且与细菌种类有关。
血浆内毒素与GN菌血症的相关性高于革兰阳性菌血症，且内毒素水平与细菌种类有关，但在GN菌引起的菌血症中PCT水平相对更稳定。在中国不同地区的ICU患者中，GN菌和革兰阳性菌均可引起菌血症。在菌血症诊断中，PCT是比内毒素更有价值的生物标志物。
