Procalcitonin: a valuable indicator of infection in a medical ICU?

OBJECTIVE: To assess the use of procalcitonin (PCT) for the diagnosis of infection in a medical ICU. DESIGN: Prospective, observational study. PATIENTS: Seventy-seven infected patients and 24 patients with systemic inflammatory response syndrome (SIRS) due to other causes. Seventy-five patients could be classified into sepsis (n = 24), severe sepsis (n = 27) and septic shock (n = 24), and 20 SIRS patients remained free from infection during the study. Plasma PCT and C-reactive protein (CRP) levels were evaluated within 48 h of admission (day 0), at day 2 and day 4. RESULTS: As compared with SIRS, PCT and CRP levels at day 0 were higher in infected patients, regardless of the severity of sepsis (25.2 +/- 54.2 ng/ml vs 4.8 +/- 8.7 ng/ml; 159 +/- 92 mg/l vs 71 +/- 58 mg/l, respectively). At cut-off values of 2 ng/ml (PCT) and 100 mg/l (CRP), sensitivity and specificity were 65% and 70% (PCT), 74% and 74% (CRP). PCT and CRP levels were significantly more elevated in septic shock (38.5 +/- 59.1 ng/ml and 173 +/- 98 mg/l) than in SIRS (3.8 +/- 6.9 ng/ml and 70 +/- 48 mg/l), sepsis (1.3 +/- 2.7 ng/ml and 98 +/- 76 mg/l) and severe sepsis (9.1 +/- 18. 2 ng/ml and 145 +/- 70 mg/l) (all p = 0.005). CRP, but not PCT, levels were more elevated in severe sepsis than in SIRS (p<0.0001). Higher PCT levels in the patients with four dysfunctional organs and higher PCT and CRP levels in nonsurvivors may only reflect the marked inflammatory response to septic shock. CONCLUSION: In this study, PCT and CRP had poor sensitivity and specificity for the diagnosis of infection. PCT did not clearly discriminate SIRS from sepsis or severe sepsis.     

Lipopolysaccharide-binding protein in critically ill neonates and children with suspected infection: comparison with procalcitonin,interleukin-6, and C-reactive protein

Objective To evaluate markers of infection in critically ill neonates and children, comparing lipopolysaccharide-binding protein (LBP) with procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP).Design and setting Prospective, observational study in the level III multidisciplinary neonatal and pediatric intensive care unit.Patients Sixty patients with systemic inflammatory response syndrome (SIRS) and suspected infection classified into two groups: SIRS/sepsis (n=33) and SIRS/no sepsis (n=27). We included 29 neonates aged less than 48 h (neonates <48 h), 12 neonates older than 48 h (neonates >48 h), and 19 children. Median disease severity was high in neonates aged under 48 h and moderate in neonates aged over 48 h and children.Interventions Serum LBP, PCT, IL-6, and CRP were measured on two consecutive days. Area under the receiver operating characteristic (ROC) curve (AUC), sensitivity, specificity, and predictive values were evaluated.Results Serum LBP was higher in patients with SIRS/sepsis than in patients with SIRS/no sepsis. AUC for LBP on the first day of suspected infection was 0.89 in the younger neonates, 0.93 in the older neonates, and 0.91 in children.Conclusions In critically ill neonates aged under 48 h LBP on the first day of suspected infection is a better marker of sepsis than IL-6 and PCT, and is similar to CRP. In critically ill neonates aged over 48 h and children LBP is a better marker than IL-6 and CRP, and is similar to PCT.     

Non-infectious causes of elevated procalcitonin and C-reactive protein serum levels in pediatric patients with hematologic and oncologic disorders

BACKGROUND: Procalcitonin (PCT) is considered a sensitive and specific diagnostic and prognostic marker of systemic bacterial infection, but its value is questionable in certain clinical conditions, particularly in hemato-oncological patients. MATERIALS AND METHODS: We analyzed PCT and C-reactive protein (CRP) levels in 56 patients of a pediatric hematology-oncology unit during 110 consecutive non-infectious febrile episodes related to administration of T-cell antibodies (group A; n = 22), alemtuzumab (monoclonal CD52 antibody, CAMPATH-1H/group B; n = 8), interleukin-2 (IL-2/group C; n = 41), prophylactic donor granulocyte transfusions (group D; n = 9), or to acute graft-versus-host disease (aGvHD/group E; n = 10) and compared the results with 20 episodes of Gram-negative sepsis (group F). MAIN RESULTS: In the majority of the non-infectious episodes PCT and CRP increased to serum levels statistically indistinguishable from Gram-negative sepsis. Median peak levels of PCT (normal < 0.5 ng/ml)/CRP (normal < 8 mg/l) for groups A-F were 4.34/59.0 (A), 10.14/93.5 (B), 1.11/175.0 (C), 1.43/164 (D), 0.96/34.0 (E), and 8.14 ng/ml /126.0 mg/l (F). Highest single levels were observed in groups A and F. CONCLUSIONS: PCT and CRP are of limited value as diagnostic markers of sepsis during T-cell-directed immunomodulatory treatment, granulocyte support, or acute GvHD.     

Procalcitonin and C-reactive protein as markers of systemic inflammatory response syndrome severity in critically ill children

OBJECTIVES: To analyse the clinical value of procalcitonin (PCT), C-reactive protein (CRP) and leucocyte count in the diagnosis of paediatric sepsis and in the stratification of patients according to severity. DESIGN: Prospective, observational study. SETTING: Paediatric intensive care unit (PICU). PATIENTS: Ninety-four children. MEASUREMENT AND RESULTS: Leucocyte count, PCT and CRP were measured when considered necessary during the PICU stay. Patients were classified, when PCT and CRP were measured, into one of six categories (negative, SIRS, localized infection, sepsis, severe sepsis, and septic shock) according to the definitions of the American College of Chest Physicians /Society of Critical Care Medicine. A total of 359 patient day episodes were obtained. Leucocyte count did not differ across the six diagnostic classes considered. Median plasma PCT concentrations were 0.17, 0.43, 0.79, 1.80, 15.40 and 19.13 ng/ml in negative, systemic inflammatory response syndrome (SIRS), localized infection, sepsis, severe sepsis, and septic shock groups, respectively, whereas median plasma CRP concentrations were 1.35, 3.80, 6.45, 5.70, 7.60 and 16.2 mg/dl, respectively. The area under the ROC curve for the diagnosis of septic patients was 0.532 for leucocyte count (95% CI, 0.462-0.602), 0.750 for CRP (95% CI, 0.699-0.802) and 0.912 for PCT (95% CI, 0.882-0.943). We obtained four groups using CRP values and five groups using PCT values that classified a significant percentage of patients according to the severity of the different SIRS groups. CONCLUSIONS: PCT is a better diagnostic marker of sepsis in critically ill children than CRP. The CRP, and especially PCT, may become a helpful clinical tool to stratify patients with SIRS according to disease severity.     

Is procalcitonin better than C‐reactive protein for early diagnosis of bacterial pneumonia in children?

Early diagnosis of bacterial pneumonia plays a pivotal role in the management. We evaluated the diagnostic accuracy of procalcitonin (PCT) as compared with C‐reactive protein (CRP) for the early diagnosis of bacterial pneumonia in children. In total, 92 children consisting of 46 patients of bacterial pneumonia were admitted in the Military hospital, Rawalpindi, Pakistan and equal number of controls were included. Patient's investigations were carried out at admission. PCT and CRP were analyzed on Vidas analyzer and Immulite 1000, respectively. Out of 46 pneumonia patients, 28 were male and 18 female, with a median age of 4 years. PCT levels were significantly high median (range) of 2.69 ng/ml (0.30–13.00) vs. 0.45 ng/ml (0.10–2.00) in controls. Serum CRP levels were moderately elevated with median (range) 6.5 mg/l (0.30–60) vs. 0.30 mg/l (0.30–5.0) in controls. The area under receiver characteristic curves for PCT and CRP were 0.89 (95% CI=0.83–0.96) and 0.79 (95% CI=0.70–0.88), respectively. In total, 38 patients were diagnosed to have bacterial pneumonia with PCT (sensitivity 83% at cutoff ≥1 ng/ml) and 26 children with CRP (sensitivity 57% at cutoff ≥6 mg/L). PCT has better diagnostic accuracy than CRP and can be utilized for early diagnosis of bacterial pneumonia in children. J. Clin. Lab. Anal. 24:1–5, 2010. © 2010 Wiley‐Liss, Inc.     

Neutrophil and monocyte CD64 indexes,lipopolysaccharide-binding protein,procalcitonin and C-reactive protein in sepsis of critically ill neonates and children

Objective  

To compare the diagnostic accuracy of neutrophil and monocyte CD64 indexes (CD64in and CD64im) for sepsis in critically ill neonates and children with that of lipopolysaccharide-binding protein (LBP), procalcitonin (PCT) and C-reactive protein (CRP).     

Value of combined detection of serum amyloid A,C-reactive protein and procalcitonin in differential diagnosis of respiratory tract infection in children of China

ObjectiveTo explore the diagnostic value of combined detection of serum amyloid A (SAA), C-reactive protein (CRP) and procalcitonin (PCT) in children with bacteria or non-bacterial respiratory tract infection.Methods200 children with respiratory tract infections diagnosed in our hospital were included in the study. According to the results of the aetiological examination, they were divided into bacterial infection group and non-bacterial infection group. At the same time, 100 healthy children admitted to the hospital for physical examination during the same period were selected as the healthy subjects control group. Changes in serum SAA, PCT and CRP in three groups were compared. Comparison of a positive rate of the single index and combined detection were performed. Children with bacterial infections were treated with conventional antibiotics. The changes in serum SAA, PCT and CRP in the infection group before and after treatment were compared. The efficacy of SAA, PCT and CRP alone and in combination was compared.ResultsThe serum SAA, PCT and CRP levels in the bacterial infection group were higher than those in the non-bacterial infection group and healthy children, and the differences were statistically significant. The positive detection rates and combined detection rates of serum SAA, PCT and CRP in the bacterial infection group were higher than those in the non-bacterial infection group and the healthy subject''s control group. After conventional antibiotic treatment, serum SAA, PCT and CR levels in children with bacterial infection were significantly decreased.ConclusionThe combined detection based on SAA, CRP and PCT can effectively identify and diagnose respiratory tract infection in children, providing a certain reference for the promotion of the diagnostic scheme.

Key messages

• Serum SAA, PCT and CRP were highly expressed in children with respiratory tract infection, and the expression level was the highest in children with bacterial pneumonia.
• The combined detection of serum SAA, CRP and PCT indicators have higher diagnostic efficiency and can effectively make a differential diagnosis of respiratory tract infection in children.

     

Values of combined C-reactive protein,procalcitonin and serum amyloid A in differential diagnosis of bacterial and non-bacterial community acquired pneumonia in children

This research aimed to explore the clinical value of C-reactive protein (CRP), procalcitonin (PCT), and serum amyloid A (SAA) in early diagnosis of bacterial pneumonia. CRP, PCT, and SAA levels of children with bacterial pneumonia, children with non-bacterial pneumonia, and healthy children were compared. The sensitivity and specificity of CRP, PCT, and SAA in the diagnosis of bacterial pneumonia in children were compared. CRP, PCT, and SAA levels were significantly lower in healthy children when compared with children with Community acquired pneumonia (CAP). ROC analyses showed that CRP, PCT, and SAA all had good accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. The combination of CRP, PCT, and SAA further enhanced the accuracy in distinguishing bacterial pneumonia from non-bacterial pneumonia. In conclusion, the expression levels of CRP, PCT, and SAA could indicate the status of bacterial pneumonia. The combined test of CRP, PCT, and SAA had the highest diagnostic accuracy.     

Interleukin-27 is a novel candidate diagnostic biomarker for bacterial infection in critically ill children

Introduction

Differentiating between sterile inflammation and bacterial infection in critically ill patients with fever and other signs of the systemic inflammatory response syndrome (SIRS) remains a clinical challenge. The objective of our study was to mine an existing genome-wide expression database for the discovery of candidate diagnostic biomarkers to predict the presence of bacterial infection in critically ill children.

Methods

Genome-wide expression data were compared between patients with SIRS having negative bacterial cultures (n = 21) and patients with sepsis having positive bacterial cultures (n = 60). Differentially expressed genes were subjected to a leave-one-out cross-validation (LOOCV) procedure to predict SIRS or sepsis classes. Serum concentrations of interleukin-27 (IL-27) and procalcitonin (PCT) were compared between 101 patients with SIRS and 130 patients with sepsis. All data represent the first 24 hours of meeting criteria for either SIRS or sepsis.

Results

Two hundred twenty one gene probes were differentially regulated between patients with SIRS and patients with sepsis. The LOOCV procedure correctly predicted 86% of the SIRS and sepsis classes, and Epstein-Barr virus-induced gene 3 (EBI3) had the highest predictive strength. Computer-assisted image analyses of gene-expression mosaics were able to predict infection with a specificity of 90% and a positive predictive value of 94%. Because EBI3 is a subunit of the heterodimeric cytokine, IL-27, we tested the ability of serum IL-27 protein concentrations to predict infection. At a cut-point value of ≥5 ng/ml, serum IL-27 protein concentrations predicted infection with a specificity and a positive predictive value of >90%, and the overall performance of IL-27 was generally better than that of PCT. A decision tree combining IL-27 and PCT improved overall predictive capacity compared with that of either biomarker alone.

Conclusions

Genome-wide expression analysis has provided the foundation for the identification of IL-27 as a novel candidate diagnostic biomarker for predicting bacterial infection in critically ill children. Additional studies will be required to test further the diagnostic performance of IL-27.The microarray data reported in this article have been deposited in the Gene Expression Omnibus under accession number {"type":"entrez-geo","attrs":{"text":"GSE4607","term_id":"4607"}}GSE4607.     

血浆miR-223-3p，PCT，IL-6和CRP水平联合检测对脓毒症实验诊断及预后的价值研究

目的　探讨微小核糖核酸-223-3p（miR223-3p）联合降钙素原（PCT）、白细胞介素-6（IL-6）及C反应蛋白（CRP）对脓毒症诊断及预后预测的意义。方法　选取2018年1月～2020年10月三亚市中医院和三亚中心医院收治的脓毒症患者146例,根据患者28天的生存情况,将其分为存活组（n=101）和死亡组（n=45）。选取同期60例体检健康者作为对照组。检测各组血浆miR-223-3p,PCT,IL-6及CRP水平。应用受试者工作特征（ROC）曲线分析miR-223-3p联合PCT,IL-6及CRP对脓毒症诊断及预后预测的价值。结果　脓毒症组血浆miR-223-3p（2.15±0.92 vs 0.37±0.08）,PCT（13.50±6.48 ng/ml vs 0.02±0.01ng/ml）,IL-6（74.12±15.70 pg/ml vs 5.37±1.45pg/ml）及CRP（37.26±10.15 mg/L vs 3.82±1.46mg/L）水平均明显高于对照组,差异均有统计学意义（t=8.783~14.620,P<0.001）。死亡组血浆miR-223-3p（3.04±1.16 vs 1.31±0.50）,PCT（21.28±10.28 ng/ml vs 6.72±3.15ng/ml）,IL-6（102.83±21.75 pg/ml vs 56.17±10.20pg/ml）及CRP（56.40±15.30mg/L vs 25.75±8.24mg/L）水平均明显高于存活组,差异均有统计学意义（t=7.415~16.317,均P<0.001）。ROC曲线分析显示,miR-223-3p联合PCT,IL-6及CRP诊断脓毒症的曲线下面积最大（0.905,95%CI :0.847~0.968）,其敏感度和特异度分别为92.0%和83.4%;miR-223-3p联合PCT,IL-6及CRP预测脓毒症患者死亡的曲线下面积最大（0.933,95%CI :0.875～0.990）,其敏感度和特异度为分别95.3%和87.5%。相关性分析显示,脓毒症患者血浆miR-223-3p表达水平与PCT,IL-6及CRP均呈正相关性（r=0.825,0.792,0.753,均P<0.001）。结论　脓毒症患者血浆miR-223-3p表达水平明显升高,联合PCT,IL-6及CRP检测对脓毒症的诊断及预后预测具有良好的价值。     

降钙素原和免疫炎性因子在粒细胞减少的恶性血液病菌血症患者中的临床应用价值

本研究探讨降钙素原（procalcitonin,PCT）、免疫炎性因子C-反应蛋白（C-reactive protein,CRP）、血清淀粉样蛋白A（serum amyloid A,SAA）,白介素-6（interleukin-6,IL-6）对中性粒细胞减少的恶性血液病菌血症患者的诊断价值.对四川大学华西医院2011年3月-2012年10月确诊为恶性血液病伴发热的1253例住院患者进行了回顾性分析,按照严格的纳入排除标准选取297例,以血培养作为金标准分为菌血症组和非菌血症组,分析数据,评价诊断效能.结果表明：在恶性血液病粒细胞减少的患者中,菌血症组患者血清PCT、CRP、IL-6以及SAA水平较非菌血症组增高,差异具有统计学意义（P＜0.05）.PCT的曲线下面积（AUC）为0.974（P ＜0.05）,明显优于CRP（AUC =0.681,P＜0.05）、IL-6（AUC=0.661,P＜0.05）和SAA（AUC=0.605,P＜0.05）,差异具有统计学意义.当PCT的cut-off值为1.06 ng/ml时,灵敏度达95.8％,特异度达92.1％,Youden指数为0.879,阴、阳性预测值分别为97.8％和85.0％,阴、阳性似然比分别为0.05和12.2,均明显优于CRP、IL-6和SAA.结论：在恶性血液病中性粒细胞减少合并细菌感染的患者中,血清PCT的诊断效能优于传统免疫炎性因子CRP、IL-6、SAA.PCT可作为预测细菌感染的一个快速可靠的指标,为临床合理使用抗生素、降低死亡风险提供实验室依据.     

Predictive value of procalcitonin and interleukin 6 in critically ill patients with suspected sepsis

OBJECTIVE: To evaluate the performance of procalcitonin (PCT), interleukin-6 (IL-6), C-reactive protein, leukocyte count, D-dimer, and antithrombin III at onset of septic episode and 24 h later in prediction of hospital mortality in critically ill patients with suspected sepsis. DESIGN AND SETTING: Prospective, cohort study in two university hospital intensive care units. PATIENTS: 61 critically ill patients with suspected sepsis. MEASUREMENTS AND RESULTS: The outcome measure was hospital mortality. Hospital survivors ( n=41) and nonsurvivors ( n=20) differed statistically significantly on day 1 (admission) in PCT, IL-6, SOFA score, and APACHE II score, and 24 h later in PCT, IL-6, and D-dimer values. AT III, CRP, and leukocyte count did not differ. The areas under receiver operating curves showed reasonable discriminative power (>0.75) in predicting hospital mortality only for day 2 IL-6 (0.799) and day 2 PCT (0.777) values which were comparable to that of APACHE II (0.786), and which remained the only independent predictor of mortality. CONCLUSIONS: Admission and day 2 IL-6, and day 2 PCT, and day 2 D-dimer values differed significantly between hospital survivors and nonsurvivors among critically ill patients with suspected sepsis. However, in prediction of hospital mortality, only the discriminative power of day 2 PCT and IL-6 values, and APACHE II was reasonable as judged by AUC analysis (>0.75).     

Procalcitonin in patients with acute and chronic renal insufficiency

BACKGROUND: Bacterial infections are associated with a high morbidity and mortality rate in patients with acute and chronic renal failure. Because C-reactive-protein (CRP) is elevated in many patients with renal failure, even in the absence of infection, procalcitonin (PCT) might be useful for the detection of systemic bacterial infections. This cross-sectional observation study measured PCT and CRP in several groups of patients with various types, degrees and treatments of kidney diseases, including patients with sepsis treated with renal replacement therapy. PATIENTS AND METHODS: We determined PCT and CRP in 85 renal patients with different stages and treatments of renal insufficiency: chronic renal failure (CRF) n=23, patients undergoing continuous ambulatory peritoneal dialysis (CAPD) n=20, patients undergoing hemodialysis therapy (HD) n=42 and in a group of 40 patients with septic conditions, including 20 patients with acute renal failure (ARF). The infectious status of the patients was monitored. RESULTS: PCT in serum (reference value in healthy controls < 1 microg/l) was within the normal range in patients with CRF and in patients on both short-term HD (< 1 year) and long-term HD (> 1 year) (median of 0.25 microg/l and 0.61 microg/l). However, PCT was elevated in patients on CAPD (median of 1.18 microg/l). In patients with sepsis, PCT was massively elevated in both the presence and absence of ARF. In contrast, CRP (reference value < 5 mg/l) was markedly increased in patients undergoing short- and long-term HD (medians of 14.5 and 51.1 mg/l) but not in patients on CAPD. In patients with CRF and systemic bacterial infections, both PCT and CRP were markedly elevated (median PCT 63 microg/l, CRP 130 mg/l) but, in contrast to PCT, CRP values overlapped in infected and non-infected patients. There was no relevant decrease in plasma concentrations of PCT by hemofiltration or hemodialysis in patients with sepsis. CONCLUSION: With the exception of CAPD patients, PCT levels were not significantly affected by renal diseases or treatments but were markedly elevated in the presence of infections. Thus PCT is a valuable marker for early diagnosis of systemic bacterial infections in patients with CRF or patients undergoing HD. In contrast, CRP is elevated in several groups with renal diseases and has low specificity for the diagnosis of bacterial infections.     

儿童肺炎支原体肺炎感染指标的诊断价值

目的探讨WBC、C反应蛋白（CRP）、血清淀粉样蛋白A（SAA）、降钙素原（PCT）在儿童肺炎支原体肺炎（MPP）诊治中的价值。 方法回顾性分析本院儿科确诊的154例住院患儿（MPP组）,以临床症状结合影像学的诊断结果作为诊断标准,并选择同期非肺部感染患儿51例,作为对照组。对2组间WBC、CRP、SAA、PCT 4项炎性标志物的检测结果进行分析。 结果MPP组中WBC、CRP、SAA、PCT检测结果均显著高于对照组,差异有统计学意义（P均<0.05）。单项检测时,PCT诊断敏感度最高［85.71%（132/154）］,CRP和SAA特异度高［96.08%（49/51）、96.08%（49/51）］;2项联合检测时,WBC＋PCT诊断敏感度最高［94.81%（146/154）］,WBC＋SAA和CRP＋SAA诊断特异度最高［均为96.08%（49/51）］;3项联合检测时,WBC＋CRP＋PCT和WBC＋PCT＋SAA诊断敏感度最高［均为96.10%（148/154）］,WBC＋CRP＋SAA诊断特异度最高［92.16%（47/51）］;CRP＋SAA＋PCT＋WBC联合检测的诊断敏感度最高［98.70%（152/154）］,但特异度较低［60.78%（31/51）］。 结论儿童MPP时,在检测肺炎支原体抗体的同时,通过联合检测WBC、CRP、SAA、PCT 4项炎症标志物可有效提高临床的诊断效能。     

Diagnostic accuracy of lipopolysaccharide-binding protein for predicting bacteremia/clinical sepsis in children with febrile neutropenia: comparison with interleukin-6, procalcitonin, and C-reactive protein

Purpose

In febrile neutropenia (FN), no reliable marker has been identified to discriminate between severe infection and other causes of fever early in the clinical course. Since lipopolysaccharide-binding protein (LBP) has proven to be an accurate biomarker of bacteremia/clinical sepsis in critically ill non-immunocompromised infants and children, we performed a prospective study to determine the diagnostic accuracy of LBP in children with FN.

Methods

Concentrations of LBP, procalcitonin (PCT), interleukin-6 (IL-6), and C-reactive protein (CRP) were prospectively measured on two consecutive days in 90 FN episodes experienced by 47 children. Receiver operating characteristic curve analysis was performed for each biomarker to predict bacteremia/clinical sepsis and severe sepsis.

Results

Eighteen of the 90 episodes were classified as bacteremia/clinical sepsis. On both days 1 and 2, all biomarkers had a low to intermediate diagnostic accuracy for sepsis, and no significant differences were found between them (area under the curve (AUC) for LBP, 0.648 and 0.714; for PCT, 0.665 and 0.744; for IL-6, 0.775 and 0.775; and for CRP, 0.695 and 0.828). Comparison of their AUCs to the AUC of maximum body temperature on admission (AUC?=?0.668) also failed to show any significant differences. In severe sepsis, however, the best diagnostic accuracies were found for IL-6 and PCT (AUC 0.892 and 0.752, respectively), and these were significantly higher than those for LBP (AUC 0.566) on admission.

Conclusions

On admission and 24 h later, the LBP concentration is less accurate for predicting bacteremia/clinical sepsis compared to IL-6, PCT, and CRP.     

不同生物化学指标在预测早产新生儿败血症中的价值

目的比较降钙素原（PCT）、C反应蛋白（CRP）和白细胞介素（IL）-6等3种不同生物化学指标在早期诊断早产新生儿败血症中的应用价值。方法以2010年1月-2012年9月入住且胎膜早破早产新生儿为研究对象,在出生后第1天检测外周血中PCT、CRP和IL-6的滴度,其中有败血症者45例,无败血症者39例。结果败血症组PCT、CRP和IL-6浓度均显著高于非败血症组。PCT和CRP诊断新生儿败血症的临界值分别为2.14μg/L和7.90 mg/L,灵敏度分别为76%和67%,特异度分别为85%和61%;IL-6诊断新生儿败血症的临界值为13.80 ng/L,其灵敏度和特异度则分别高达90%和94%。结论对于胎膜早破新生儿,IL-6是早期诊断败血症较可靠的生物化学指标。     

Detection of acute phase response and infection. The role of procalcitonin and C-reactive protein.

OBJECTIVE: Established parameters, e.g. C-reactive protein (CRP), do not differentiate specifically enough between patients developing an infection and those exhibiting an acute phase response following cardiac surgery. The objective of this prospective study was to investigate if procalcitonin (PCT) is more helpful than CRP. METHODS: During a 1-year period, seven out of 563 patients (1.2%) developed systemic infections (group A) after cardiac operations with cardiopulmonary bypass (CPB), and additional eight patients (1.4%) had local wound infections requiring surgical therapy (group B). Blood samples for PCT and CRP measurements were taken preoperatively, at the onset of infection (d1), as well as on the third day (d3), fifth day (d5), and seventh day (d7) following diagnosis of infection. Forty-four randomly selected patients undergoing cardiac surgery with CPB without clinical signs of infection, additional intensive care unit (ICU) management or additional antibiotic treatment served as control (group C) to assess the PCT and CRP contribution to acute phase response. PCT and CRP levels were measured preoperatively, on the first (d1), third (d3) and fifth day (d5) after operation. RESULTS: At the onset of infection, PCT levels (median interquartile range 25%-75%) increased significantly in group A as compared to baseline values (10.86 (3.28-15.13) ng/ml vs. 0.12 (0.08-0.21) ng/ml), and decreased during treatment to still significantly elevated values on d5 (0.56 (0.51-0.85) ng/ml). CRP levels were significantly elevated on all days investigated with no trend towards normalisation (d1: 164.5 (137-223) mg/l) vs. 1.95 (1.1-2.8) mg/l preoperatively, d5: 181.1 (134-189.6) mg/l. In group B, no increase in PCT levels, but a significant increase of CRP from d1 (165.9 (96.6-181.6) mg/l) vs. 3.7 (2-4.3) mg/l preoperatively) until d5 98 (92.8-226.2) mg/l was detected. In group C, postoperative PCT levels increased slightly but significantly in the absence of infection on d1 (0.46 (0.26-0.77) ng/ml vs. 0.13 (0.08-0.19) ng/ml preoperatively), and d3 (0.37 (0.2-0.65) ng/ml and reached baseline on d5 (0.24 (0.11-0.51) ng/ml)). CRP levels were significantly elevated as compared to baseline on all postoperative days investigated (baseline: 1.75 (0.6-2.9) mg/l, d1: 97.5 (74.5-120) mg/l), d3: 114 (83.05-168.5) mg/l, d5: 51.4 (27.4-99.8) mg/l)). PCT showed a significant correlation to CRP in group A (r =0.48, p < 0.001), a weak correlation in group C (r=0.27, p=0.002) and no correlation in group B. Intergroup comparison revealed a significant difference for PCT between all groups (A>C>B) and significantly higher CRP levels in group A vs. C and in group B vs. C. Thus, the pattern high PCT/high CRP appears to indicate a systemic infection, while low PCT/high CRP indicates either acute phase response or local wound problems, but no systemic infection. The cost for PCT measurements was 5.6-fold higher as compared to CRP. CONCLUSION: Due to the significant differences in the degree of increase, PCT appears to be useful in discriminating between acute phase response following cardiac surgery with CPB or local problems and systemic infections, with additional CRP-measurement increasing the specificity.     

降钙素原在危重患者败血症诊断中的意义

目的　探讨危重患者败血症早期快速诊断的可靠方法和降钙素原对危重患者败血症诊断的临床意义。方法　采用免疫发光法 (ILMA)对 12 0例中疑有败血症的危重患者测定血清降钙素原 (PCT) ,结合C反应蛋白 (CRP)测定和血培养结果进行分析。结果　PCT阳性 4 9例 ,CRP阳性 17例 ,血培养阳性 12例。感染灶组中PCT与CRP阳性率比较有明显差异 (P <0 .0 5 ) ;伴有多脏器功能障碍综合征与感染灶组比较 ,PCT阳性率有显著性差异 (P <0 .0 5 )。结论　PCT可以作为危重患者败血症早期诊断的指标 ,其动态变化亦可作为判断败血症预后的指标。     

血清PCT，IL-6，SAA，hs-CRP水平联合检测对快速筛查早期血流感染的价值

目的　探讨血清降钙素原（PCT）、 白细胞介素-6（IL-6）、血清淀粉样蛋白A（SAA）及超敏-C反应蛋白（hs-CRP）在快速鉴别早期血流感染中的应用价值。 方法 选取2018年3月～2020年8月血培养阳性患者119例,其中革兰阳性菌感染45例，革兰阴性菌感染72例，选取同时期44例健康体检者作为对照组。收集患者血培养当天的血清标本-80℃冻存备用，检测血清中PCT, IL-6 ,SAA及 hs-CRP水平。用统计分析比较血培养阳性组及健康体检组中四个感染指标水平差异，用受试者工作曲线（ROC）分析四个感染指标在早期血流感染中的诊断价值。结果　血培养阳性组患者血清PCT， IL-6，SAA及hs-CRP水平高于对照组[1.10（0.29，8.27）ng/ml vs 0.01（0.01，0.01）ng/ml, 75.20（33.30, 359.80）pg/ml vs2.00（2.00, 2.00）pg/ml, 148.10（77.15, 200.00）mg/L vs 5.00（5.00, 6.56）mg/L和[93.20(44.23, 158.07)mg/L vs 0.63（0.34,1.32）mg/L]，差异均有统计学意义（Z =-9.213～-9.472，均P<0.001）。ROC曲线分析，PCT, IL-6，SAA及 hs-CRP在诊断血流感染中的曲线下面积（AUC）分别为0.975，0.981，0.965和0.982（P<0.001）。数据分析发现血清PCT及SAA水平在革兰阴性菌组高于革兰阳性菌组[2.04（0.38, 21.60）ng/ml vs 0.60（0.17，2.75）ng/ml, 186.24（90.61，200.00）mg/L vs 104.49(44.94，200.00) mg/L]，差异均有统计学意义（Z = -3.107，-2.688，均P<0.05）。PCT，SAA及PCT联合SAA在鉴别革兰阴性菌与革兰阳性菌感染中的ROC曲线下面积为0.663, 0.644和0.708（均P<0.05）。结论　血清PCT, IL-6，SAA及hs-CRP可以为快速鉴别早期血流感染提供较好的实验依据，尤其PCT与SAA联合在鉴别革兰阴性菌与革兰阳性菌感染中有一定的诊断价值。     

Levels of three inflammation markers, C-reactive protein, serum amyloid A protein and procalcitonin, in the serum and cerebrospinal fluid of patients with meningitis.

The levels of C-reactive protein (CRP) and serum amyloid A protein (SAA) in blood are increased in patients with inflammatory diseases as acute phase proteins. Most of the presently used indicators of inflammation, such as body temperature, white cell count, erythrocyte sedimentation rate or CRP, are non-specific parameters. In contrast, procalcitonin (PCT) has been reported to be selectively induced by severe bacterial infection during the systemic inflammatory response syndrome (SIRS), and also in sepsis or multiorgan dysfunction syndrome. PCT expression is only slightly induced, if at all, by viral infections, autoimmune disorders, neoplastic diseases and trauma of surgical intervention. We measured the concentrations of CRP, SAA and PCT in the sera and cerebrospinal fluid (CSF) of 30 patients with bacterial, viral, or mycotic meningitis, and 12 patients with a noninflammatory central nervous system disease as controls. An extremely high CRP level in CSF of above 100 microg/L was seen in all seven bacterial meningitis patients and in only 10% of the viral meningitis patients. A high SAA level in CSF of greater than 10 microg/L was observed in all of the bacterial meningitis and mycotic meningitis patients, and in 95% of the viral meningitis patients. Among those with bacterial meningitis, the serum PCT level was more elevated in those with more serious bacterial meningitis. The PCT level in the CSF did not significantly differ among the patients with the three types of meningitis. However, the serum PCT level was very high above 0.1 microg/L in all seven bacterial meningitis patients, especially in the clinically serious cases.