Early and Effective Diagnosis of Sepsis Using Flow Cytometry

Objective Sepsis is a major global health issue due to its high death and morbidity rates. To avoid the negative effects of sepsis and decrease mortality, it is vital to diagnose and treat it as soon as possible. Blood cultures can take up to 2 days to give result, and they are not always reliable. According to recent studies, neutrophil CD64 expression might be a sensitive and specific option for assessing sepsis. This study aimed to evaluate the diagnostic performance of a flow cytometry analysis for the expression of neutrophil CD64 in sepsis and its comparison with other standard tests in a tertiary care center.

Materials and Methods Prospective analysis on 40 blood samples from suspected sepsis patients admitted to intensive care units with criteria for the systemic inflammatory response syndrome on presentation was performed for expression of neutrophil CD64, C-reactive protein, procalcitonin, and complete blood count. Ten healthy volunteers were also enrolled in this prospective study. The laboratory results were compared in different groups.

Results The neutrophil CD64 had the highest diagnostic value to differentiate between patients of sepsis and nonsepsis groups with a sensitivity of 100% (95% confidence interval [CI]: 77.19–100%) and 100% (95% CI: 55.32–86.83%); specificity of 90.00% (95% CI: 59.58–99.49%) and 87.24% (95% CI: 66.69–99.61%); and likelihood ratio of 10.00 and 7.84, respectively.

Conclusion The neutrophil CD64 expression provides a more sensitive, specific, and novel marker for the early detection of sepsis in critically ill patients.

The role of procalcitonin in identifying high-risk cancer patients with febrile neutropenia: A useful alternative to the multinational association for supportive care in cancer score

Background

The Multinational Association for Supportive Care in Cancer (MASCC) risk index has been utilized to determine the risk for poor clinical outcomes in patients with febrile neutropenia (FN) in an emergency center (EC). However, this index comprises subjective elements and elaborated metrics limiting its use in ECs. We sought to determine whether procalcitonin (PCT) level (biomarker of bacterial infection) with or without lactate level (marker of inadequate tissue perfusion) offers a potential alternative to MASSC score in predicting the outcomes of patients with FN presenting to an EC.

Methods

We retrospectively identified 550 cancer patients with FN who presented to our EC between April 2018, and April 2019, and had serum PCT and lactate levels measured.

Results

Compared with patients with PCT levels <0.25 ng/ml, those with levels ≥0.25 ng/ml had a significantly higher 14‐day mortality rate (5.2% vs. 0.7%; p = 0.002), a higher bloodstream infection (BSI) rate, and a longer hospital length of stay (LOS). Logistic regression analysis showed that patients with PCT levels ≥0.25 ng/ml and lactate levels >2.2 mmol/L were more likely to be admitted and have an LOS >7 days, BSI, and 14‐day mortality than patients with lower levels. PCT level was a significantly better predictor of BSI than MASSC score (p = 0.003) or lactate level (p < 0.0001).

Conclusions

Procalcitonin level is superior to MASCC index in predicting BSI. The combination of PCT and lactate levels is a good predictor of BSI, hospital admission, and 14‐day mortality and could be useful in identifying high‐risk FN patients who require hospital admission.

C-Reactive Protein at Hospital Discharge and 1-Year Mortality in Acute Infective Endocarditis: A Prospective Observational Study

Background: An accurate biomarker at hospital discharge is needed to identify patients with acute infective endocarditis (IE) who are at high risk of mortality. This prospective observational study evaluated the prognostic value of C-reactive protein (CRP).

Methods: Patients with acute IE (n = 343) and hospitalized at 2 university-affiliated medical centers from January 2014 to December 2019 were enrolled. Patients were categorized as having low or high CRP (n = 217 and 126, respectively) at hospital discharge according to the optimal cutoff (CRP = 6.5 mg/L) determined via receiver-operating characteristic curve analysis. The primary endpoint was all-cause death, from hospital discharge to 1 year. The secondary endpoint was the cumulative rate of rehospitalization or paravalvular abscess at 1 year.

Results: At the 12-month follow-up, the mortality rate of the high-CRP group (21.43%) was significantly higher than that of the low-CRP group (2.76%, log-rank P < 0.0001). The multivariate regression analysis indicated that the high-CRP group had a higher excess mortality hazard risk (HR = 4.182; 95% CI: 2.120, 5.211; P < 0.001). The cumulative 1-year incidence of paravalvular abscess of the high-CRP group (11.90%) was significantly higher than that of the low-CRP (5.07%; P = 0.022). The cumulative rate of heart rehospitalizations of the 2 groups were similar (18.25% cf. 14.29%, P = 0.273).

Conclusion: For hospitalized patients with acute IE, a high CRP at discharge suggests a poor prognosis for 1-year mortality and paravalvular abscess.

One-step-immunoassay of procalcitonin enables rapid and accurate diagnosis of bacterial infection

Procalcitonin (PCT) (i.e. a precursor of calcitonin) attracts much attention as a reliable biomarker of bacterial infections because its concentration increases rapidly in the blood when bacterial infections occur in the body. Sepsis may occur due to indiscriminate and vigorous proliferation of infectious bacteria, and accordingly early diagnosis and treatment of bacterial infection are of crucial importance. However, current diagnostic methods for sepsis suffer from long assay time, multiple and complex assay steps, inaccuracy, and requirement of analytical equipments. The goal of this study is to develop an advanced one-step-immunoassay that enables quick and accurate diagnosis of sepsis through measuring the PCT concentration in patient sera, which is based on self-enhancement of optical detection signals from large gold particles (i.e. clusters of gold nanoparticles) that are formed on the agglomerates of PCT-bound 3-dimensional (3D) probes. The 3D probe is constructed through attaching polyclonal anti-PCT antibodies (IgGs) to the surface of a modified hepatitis B virus (HBV) capsid, where both tandem repeats of the B domain of Staphylococcal protein A (SPA_B) and the hexa-histidine tag are inserted into each HBV core protein (i.e. subunit of HBV capsid). That is, anti-PCT IgGs are attached via strong interaction between the Fc region and surface-exposed SPA_B. Furthermore, hook effect-free and PCT concentration-dependent optical signals were consistently generated by adding both bovine serum albumin (BSA) and nickel ions to patient sera and also by optimally adjusting the 3D probe concentration. Compared to conventional chemiluminescent microparticle immunoassay (CMIA) showing poor linearity of detection signals, this novel immunoassay accurately detected PCT with good linearity between PCT concentrations and optical signals in a wide range of PCT concentrations (0.05–200 ng mL⁻¹) and also showed a sufficiently low limit of detection, resulting in 100% sensitivity and 100% specificity when tested with 30 sepsis patients and 30 healthy individuals.

An advanced one-step-immunoassay enables quick and accurate diagnosis of sepsis with generation of clear optical signals in assay solution, which is based on sensitive detection of procalcitonin in patient sera.

Predicting Bacterial Versus Viral Infection, or None of the Above: Current and Future Prospects of Biomarkers

Sepsis and pneumonia cause significant morbidity and mortality worldwide. Despite improvements in diagnostic methodologies for organism identification, the early recognition and further risk stratification of these infections can be challenging. Although traditional clinical scoring systems are beneficial for the management of sepsis and pneumonia, biomarkers supporting the diagnosis and management of these infectious diseases are needed. Many biomarkers have been identified and there is no lack of studies and meta-analyses assessing the utility of biomarkers. Focusing primarily on sepsis and pneumonia, this article discusses the most commonly used biomarkers for which clinical laboratory testing methods are available.

Procalcitonin and C-Reactive Protein As Markers of Bacteremia in Patients With Febrile Neutropenia Who Receive Chemotherapy for Acute Leukemia: A Prospective Study From Nepal

PURPOSE

The purpose of this study was to evaluate the clinical significance of the biomarkers procalcitonin (PCT) and C-reactive protein (CRP) in patients with febrile neutropenia (FN) undergoing chemotherapy for acute leukemia.

METHODS

We conducted a prospective, observational study in patients who developed FN while undergoing chemotherapy for acute leukemia. PCT and CRP were obtained in patients who presented with FN. Blood cultures also were obtained. The primary goals were to evaluate the ability of PCT and CRP to predict bacteremia in patients with FN. The secondary goals were to assess the prognostic role of PCT and CRP and to assess the microbiologic profile and culture sensitivity patterns in the study population.

RESULTS

A total of 124 episodes of FN that involved 67 patients with acute leukemia occurred in the study. PCT was superior to CRP in the prediction of bacteremia. The median PCT level in the bacteremia group was 3.25 ng/mL compared with 0.51 ng/mL in the group without bacteremia (P < .01). The median values of CRP in the bacteremia and without-bacteremia groups were 119.3 mg/L and 94.5 mg/L, respectively (P = .07). There were no differences in median PCT and CRP in patients who died and those who improved. Of the 42 positive cultures, Gram-negative bacteremia was common (86%), and Escherichia coli was the most frequent organism isolated. Carbapenem resistance was seen in 39% of positive cultures.

CONCLUSION

PCT is an effective biomarker to predict bacteremia in patients with FN undergoing chemotherapy for acute leukemia.

Role of procalcitonin, Il-6 and C- reactive protein in suspected cases of sepsis

OBJECTIVES

To study the role of serum procalcitonin as a diagnostic biomarker in sepsis and to compare it with other sepsis markers (IL-6, CRP) in patients of suspected sepsis.

MATERIALS AND METHODS

A total of 80 patients were included in this study from ICU and each patient was investigated for serum Procalcitonin, Interleukin-6 and C-reactive protein levels by ELISA along with blood cultures by BacT/Alert system.

RESULT

Procalcitonin along with CRP is a better diagnostic tool for sepsis.

The accuracy assessment of presepsin (sCD14-ST) for mortality prediction in adult patients with sepsis and a head-to-head comparison to PCT: a meta-analysis

Objective: The soluble cluster of differentiation 14 subtype (sCD14-ST) or presepsin has recently been identified as a promising biomarker in sepsis. The present meta-analysis is performed to assess the prognostic value of presepsin in septic patients. Further, we compare the prognostic performance between presepsin and procalcitonin (PCT) in predicting all-cause mortality in these patients.

Methods: A systemic and comprehensive search was conducted in PubMed, Embase and Cochrane databases by using Exploded Medical Subject Headings and appropriate corresponding keywords. Studies were eligible if they assessed the prognostic value of presepsin in sepsis and provided sufficient information to construct a 2×2 contingency table. A bivariate meta-analysis model was used to calculate the pooled sensitivity, specificity, positive/negative likelihood ratios and diagnostic odds ratio. The Chi-square and I² index were used to assess the heterogeneity and inconsistency. The Deek’s funnel plot asymmetry test was used to assess the likelihood of publication bias.

Results: Nine publications, comprising 1,561 patients, were included in this study. The overall area under the receiver operating characteristic curve (AUROC) of presepsin was 0.77 (95% CI, 0.73–0.81) with a pooled prognostic sensitivity (SEN) and specificity (SPE) of 0.83 (95% CI, 0.72–0.90) and 0.69 (95% CI, 0.63–0.74), respectively. Additionally, the PLR, NLR and DOR of presepsin were 2.6 (95% CI, 2.1–3.3), 0.25 (95% CI, 0.15–0.44) and 10 (95% CI, 5–22), respectively. The AUROC of PCT was 0.81 (95% CI, 0.78–0.84) with a pooled SEN of 0.76 (95% CI, 0.55–0.89) and SPE of 0.74 (95% CI, 0.33–0.94). There is no statistically significant difference in the performance of pooled SEN and SPE between presepsin and PCT, with a p value of 0.39 and 0.71, respectively.

Conclusions: Based on the results of this meta-analysis, both presepsin and PCT are promising biomarkers for the prognosis of mortality in sepsis.

Uso de procalcitonina como diagnóstico de sepsis o shock séptico: revisión sistemática y metaanálisis

Introducción: La procalcitonina (PCT) es una prohormona de la calcitonina, producida por las células C de la glándula tiroides y convertida intracelularmente por enzimas proteolíticas en la hormona activa. La producción de PCT durante procesos inflamatorios, está ligada a endotoxinas bacterianas y a citoquinas inflamatorias. La mortalidad por sepsis, depende en gran medida de la detección precoz y del inicio de una terapia adecuada, incluyendo la administración de antibióticos apropiados, sin embargo, no está claro si el rendimiento diagnóstico de la PCT en el contexto de la nueva definición de sepsis en el tercer consenso es igual que con la definición previa.Métodos: Se incluyeron estudios que describieran el uso de PCT dentro de las primeras 24 horas de admisión, como prueba diagnóstica de sepsis. Se realizó la búsqueda en las bases de datos de Medline (Pubmed) y Embase. La calidad metodológica se evaluó según la Colaboración Cochrane en el desarrollo de Revisiones Sistemáticas sobre Test de Análisis para la herramienta QUADAS-II. El sesgo de publicación fue estudiado con el Test de Asimetría de Deeks. Se usó el módulo de MIDAS de STATA 14 para el análisis univariado y la construcción de la Curva de ROC.Resultados: Se obtuvieron 2076 registros (783 de Medline y 1293 de Embase). De los 12 estudios seleccionados, se incluyeron un total de 1353 pacientes, con una prevalencia en los estudios revisados entre el 9% y 88%, con un promedio del 47%. La Sensibilidad agrupada fue 0,83% (IC95% (0,74-0,89)) y la Especificidad fue 0,84% (IC95%(0,76-0,89)). El área bajo la Curva fue 0,90 (IC95%(0,87-0,92)). La heterogeneidad entre los estudios es importante I2 88% (IC95%(77-100)). Existe un sesgo de publicación según el test de Deek, con resultado P=0,04. En el análisis sobre la Probabilidad Post test según el nomograma de Fagan, es del 56%, teniendo en cuenta una probabilidad pretest del 20% según el LR positivo 5.Conclusión: La PCT es una prueba diagnóstica con buen rendimiento para sepsis o shock séptico, en pacientes adultos, no gestantes. Aunque hay sesgo de publicación y una gran heterogeneidad en los resultados, la prueba se considera adecuada para el escenario de sepsis según las nuevas definiciones.

Prospective evaluation of serum procalcitonin in critically ill patients with suspected sepsis- experience from a tertiary care hospital in Pakistan

BACKGROUND

Sepsis is the leading cause of mortality in critically ill patients. Procalcitonin (PCT) is a promising marker for identification of bacterial sepsis. The aim of this study was to determine the diagnostic accuracy of serum PCT concentration in patients with suspected sepsis admitted to mixed medical-surgical Intensive care unit (ICU).

MATERIAL AND METHODS

A cross-sectional study conducted at section of Chemical Pathology, Department of Pathology and Laboratory Medicine and ICU. Patients with suspected sepsis were included, serum PCT cut off ≥0.5 ng/ml was taken for diagnosing sepsis. Diagnostic accuracy was measured in terms of sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) taking blood culture as gold standard. Furthermore, different cut offs were compared by using receiver operating characteristic curves (ROC). Data analysis was done on SPSS version 20.

RESULTS

Median age of the study group (n = 103) was 48 years (IQR: 22), 60% being males. Out of the 103 patients included 82 patients had PCT levels above the optimal cut off. At a serum PCT cutoff of 0.5 μg/L, the sensitivity and specificity for the diagnosis of sepsis was found to be 93.75% and 43.59% respectively. NPV was higher compared to PPV making PCT a reliable marker to for the screening out of sepsis patients. Furthermore, it was revealed that PCT having an AUC = 0.70 outperformed WBC (AUC = 0.5) and CRP (AUC = 0.6).

CONCLUSION

Elevated PCT concentration is a promising indicator of sepsis in newly admitted critically ill patients capable of complementing clinical signs and routine laboratory parameters.

Use of biomarkers in the prediction of culture-proven infection in the surgical intensive care unit

PURPOSE

The purpose of this study was to prospectively analyze the predictive role of classic predictors for suspected infection (temperature, WBC and derivatives) with two biomarkers, procalcitonin and lactate, on the incidence of culture-proven infection in the surgical intensive care unit (SICU).

MATERIALS AND METHODS

One hundred forty-six consecutive patients admitted for suspected infection had admission and 12-h procalcitonin values, admission and every 6-h lactate values for 24 h, and admission temperature, leukocyte count, lymphocyte count and percentage measured and analyzed in this study.

RESULTS

Peak (highest measured value ≤24-h of admission) procalcitonin values were not predictive for culture-proven infection. However, a culture-negative subset was identified when peak procalcitonin values were  < 2.9 ng/mL and when peak lactate values were  < 1.3 mmol/L with a probability of 98.3% (P < .001). No other admission predictor was statistically associated with culture-proven infection. Following boosted-tree partitioning, a C-index of 0.85 was calculated with a misclassification rate of 23.3%.

CONCLUSIONS

The ability to utilize procalcitonin values in the diagnosis of culture-proven infection was not realized in this study. However, the association of admission peak procalcitonin values with admission peak lactate values identified a group of patients who were culture-negative for suspected infection. No other admission predictor was associated with culture-proven infection.

Value of procalcitonin for diagnosing perioperative pneumonia, urinary infections and superficial surgical site infections in patients undergoing primary hip and knee arthroplasty

Serum procalcitonin (PCT) levels may be helpful for the diagnosis of infections during the perioperative period of arthroplasty. However, there is much debate in the literature regarding the appropriate cut-off value for different types of surgery and local bacterial infection. The present study aimed to evaluate serum PCT levels in patients undergoing arthroplasty and to determine the cut-off value that may represent perioperative pneumonia, urinary infections and superficial surgical site infections. The present retrospective study included a total of 500 patients treated between July 2014 and August 2015. The case group contained 25 patients with perioperative infections (pneumonia, urinary and superficial surgical site infections), and the control group contained 25 patients without any post-surgical complications. Serum levels of PCT and white blood cells (WBC) were measured pre-operatively (D0) and at post-operative D4, D6 and D8, and the sensitivity, specificity and predictive value of these parameters were assessed. Regarding the comparison of the mean PCT levels between the case and the control group, a significant difference was seen at D8 (P=0.007), while no significant differences were observed at D0 (P=0.010), D4 (P=0.069) and D6 (P=0.093). No statistically significant differences in WBC levels between groups were observed for (P>0.01). In the control group, the PCT levels at D4 (0.062±0.020 ng/ml) were 2-fold of the mean baseline value, followed by a decrease until D6 (0.051±0.019 ng/ml) and a return close to the normal range by D8 (0.032±0.015 ng/ml). The PCT levels in the case group had rapidly increased on D4 (0.510±1.208 ng/ml). In contrast to the control group, they continuously increased on D6 (0.527±1.360 ng/ml) and D8 (0.686±1.117 ng/ml). From a clinical point of view, infection events were indicated in these patients during post-operative follow-up. For PCT, the area under the receiver operating characteristic curve (AUC) was 0.978 [95% confidence interval (CI), 0.933-1.022], and for WBC, the AUC was 0.562 (95% CI, 0.398-0.0.726). Based on the above data, the PCT value was a significant predictor of infection (AUC>0.9). For PCT, the cut-off point of 0.0995 ng/ml was associated with a sensitivity of 96% and a specificity of 100%. However, WBC were not a significant predictor of infection (0.5<AUC<0.7), and the cut-off value of 7.05×10⁹/l was associated with a sensitivity of 64% and a specificity of 44%. In conclusion PCT was found to be a promising marker for diagnosing bacterial infections post-arthroplasty due to its high specificity. Based on the sensitivity and the specificity, detecting PCT may be more valuable than using WBC in the diagnosis of sepsis-associated pathological changes in the perioperative period.

The delta neutrophil index (DNI) as a prognostic marker for mortality in adults with sepsis: a systematic review and meta-analysis

We performed a meta-analysis to seek evidence for the usefulness of the delta neutrophil index (DNI) as a prognostic blood biomarker for mortality in the early stage of sepsis in adults. A literature search was performed using criteria set forth in a predefined protocol. Studies of adults with sepsis that provided a DNI measurement and that had mortality as the outcome, were included. Review articles, editorials, and non-human studies were excluded. The methodological quality of identified studies was assessed independently by two authors using the Quality in Prognosis Studies (QUIPS) tool. A total of 1,822 patients from eleven studies were ultimately included. Standardized mean differences between non-survivors and survivors were compared. An elevated DNI was associated with mortality in patients with sepsis (standardized mean difference [SMD] 1.22; 95% confidence interval 0.73–1.71; I² = 91%). After excluding two studies—one that included paediatric patients and one with a disproportionately low mortality rate—heterogeneity was minimized (SMD 0.74, 95% confidence interval 0.53–0.94; I² = 43%). Overall, the findings suggest that high DNI values are associated with mortality in septic patients.

A Two-Biomarker Model Predicts Mortality in the Critically Ill with Sepsis

RATIONALE

Improving the prospective identification of patients with systemic inflammatory response syndrome (SIRS) and sepsis at low risk for organ dysfunction and death is a major clinical challenge.

OBJECTIVES

To develop and validate a multibiomarker-based prediction model for 28-day mortality in critically ill patients with SIRS and sepsis.

METHODS

A derivation cohort (n = 888) and internal test cohort (n = 278) were taken from a prospective study of critically ill intensive care unit (ICU) patients meeting two of four SIRS criteria at an academic medical center for whom plasma was obtained within 24 hours. The validation cohort (n = 759) was taken from a prospective cohort enrolled at another academic medical center ICU for whom plasma was obtained within 48 hours. We measured concentrations of angiopoietin-1, angiopoietin-2, IL-6, IL-8, soluble tumor necrosis factor receptor-1, soluble vascular cell adhesion molecule-1, granulocyte colony-stimulating factor, and soluble Fas.

MEASUREMENTS AND MAIN RESULTS

We identified a two-biomarker model in the derivation cohort that predicted mortality (area under the receiver operator characteristic curve [AUC], 0.79; 95% confidence interval [CI], 0.74-0.83). It performed well in the internal test cohort (AUC, 0.75; 95% CI, 0.65-0.85) and the external validation cohort (AUC, 0.77; 95% CI, 0.72-0.83). We determined a model score threshold demonstrating high negative predictive value (0.95) for death. In addition to a low risk of death, patients below this threshold had shorter ICU length of stay, lower incidence of acute kidney injury, acute respiratory distress syndrome, and need for vasopressors.

CONCLUSIONS

We have developed a simple, robust biomarker-based model that identifies patients with SIRS/sepsis at low risk for death and organ dysfunction.

The prognostic value of procalcitonin, C-reactive protein and cholesterol in patients with an infection and multiple organ dysfunction

BACKGROUND

To establish the prognostic value of procalcitonin, C-reactive protein and cholesterol levels for mortality in patients with an infection and multiple organ dysfunction.

METHODS

A prospective case-control study was performed, including 67 patients admitted to the intensive care unit with an infection and multiple organ dysfunction in whom cholesterol, procalcitonin, and C-reactive protein levels were measured on admission and during the course of treatment.

RESULTS

The associations between in-hospital mortality and procalcitonin, C-reactive protein, and cholesterol levels were analyzed. Logistic regression analysis showed that cholesterol (odds ratio [OR], 1.858; 95% CI, 1.170-2.949; P = 0.009) and C-reactive protein (OR, 4.408; 95% CI, 2.019-9.624; P < 0.001) levels were predictors of mortality. A receiver operating characteristic curve analysis yielded an area under the curve (AUC) of 0.774 and 95% CI of 0.693-0.855 (P < 0.001) for C-reactive protein, an AUC of 0.66 and 95% CI of 0.535-0.784 (P = 0.019) for procalcitonin, and an AUC of 0.654 and 95% CI of 0.593-0.715 (P < 0.001) for cholesterol as predictors of mortality. When combined with the bioscore system for mortality, these markers yielded an AUC of 0.845 and 95% CI of 0.770-0.921 (P < 0.001), with sensitivity of 89.1% and specificity of 83.1%.

CONCLUSIONS

The combination of procalcitonin, C-reactive protein, and cholesterol levels in a single scoring system yielded high predictive value for mortality.

Sepsis and Septic Shock: Lingering Questions

Sepsis and septic shock are major health conditions in the United States, with a high incidence and mortality. The Surviving Sepsis Campaign, which was formed in 2002, formulates guidelines for the management of severe sepsis and septic shock and has actually demonstrated a reduction in mortality with institution of "sepsis bundles." Despite this, some elements of the guidelines have been questioned, and recent data suggest that strict compliance with bundles and protocols may not be necessary. Still, prompt recognition and treatment of sepsis and septic shock remain of utmost importance.

Biomarkers for diagnosis of sepsis in patients with systemic inflammatory response syndrome: a systematic review and meta-analysis

Background

Sepsis is one of the most common diseases that seriously threaten human health. Although a large number of markers related to sepsis have been reported in the last two decades, the diagnostic accuracy of these biomarkers remains unclear due to the lack of similar baselines among studies. Therefore, we conducted a large systematic review and meta-analysis to evaluate the diagnostic value of biomarkers from studies that included non-infectious systemic inflammatory response syndrome patients as a control group.

Methods

We searched Medline, Embase and the reference lists of identified studies beginning in April 2014. The last retrieval was updated in September 2016.

Results

Ultimately, 86 articles fulfilled the inclusion criteria. Sixty biomarkers and 10,438 subjects entered the final analysis. The areas under the receiver operating characteristic curves for the 7 most common biomarkers, including procalcitonin, C-reactive protein, interleukin 6, soluble triggering receptor expressed on myeloid cells-1, presepsin, lipopolysaccharide binding protein and CD64, were 0.85, 0.77, 0.79, 0.85, 0.88, 0.71 and 0.96, respectively. The remaining 53 biomarkers exhibited obvious variances in diagnostic value and methodological quality.

Conclusions

Although some biomarkers displayed moderate or above moderate diagnostic value for sepsis, the limitations of the methodological quality and sample size may weaken these findings. Currently, we still lack an ideal biomarker to aid in the diagnosis of sepsis. In the future, biomarkers with better diagnostic value as well as a combined diagnosis using multiple biomarkers are expected to solve the challenge of the diagnosis of sepsis.

Electronic supplementary material

The online version of this article (doi:10.1186/s40064-016-3591-5) contains supplementary material, which is available to authorized users.

Soluble TREM-1 as a diagnostic and prognostic biomarker in patients with septic shock: an observational clinical study

OBJECTIVES

The impact of TREM-1-mediated inflammation was investigated in different inflammatory settings.

METHODS

Secondary analyses of an observational clinical pilot study, including 60 patients with septic shock, 30 postoperative controls and 30 healthy volunteers.

RESULTS

Plasma levels of sTREM-1 were found to identify patients with septic shock more effectively than procalcitonin and C-reactive protein. Moreover, sTREM-1 was identified to be an early predictor for survival in patients with septic shock.

CONCLUSION

Due to its diagnostic as well as prognostic value in sepsis syndrome, implementation of sTREM-1 measurements in routine diagnostics should be taken into account.

Procalcitonin Levels in Survivors and Nonsurvivors of Sepsis: Systematic Review and Meta-Analysis

Procalcitonin (PCT) is an acute-phase reactant that has been used to diagnose and potentially track the treatment of sepsis. Procalcitonin values rise initially as the infection sets in and eventually fall with resolution. Its level has been reported to be significantly higher in potential nonsurvivors of a septic episode than among survivors. However, there is also a significant amount of evidence against this. We thus conducted a meta-analysis to pool data from all the available studies regarding PCT levels in survivors and nonsurvivors of sepsis. An extensive literature search was conducted using the key words "procalcitonin," "sepsis," and "prognosis." The references of the relevant studies were also scanned. The data from the eligible studies were extracted and analyzed for any significant pooled mean difference between survivors and nonsurvivors both on days 1 and 3. The mean difference in the day 1 PCT values between survivors and nonsurvivors was found to be statistically significant (P = 0.02). The mean difference on day 3 was also statistically significant (P = 0.002). However, in a subgroup consisting of studies on patients with severe sepsis and septic shock, day 1 difference was not found to be significant (P = 0.62). We found heterogeneity of 90% in our study population, which decreased to 62% after exclusion of studies conducted in emergency department patients. Procalcitonin levels in early stages of sepsis are significantly lower among survivors as compared with nonsurvivors of sepsis.

Continuous evaluation of changes in the serum proteome from early to late stages of sepsis caused by Klebsiella pneumoniae

Serum protein profiles of patients with bacterial sepsis from the day of diagnosis until recovery/mortality were compared from early to late stages in response to severe sepsis using two dimensional electrophoresis. The proteins exhibiting changes during the course of sepsis (20‑28 day mortality) were selected and identified by matrix‑assisted laser desorption ionization‑time of flight‑tandem mass spectrometry. Among the proteins identified, haptoglobin (Hp), transthyretin (TTR), orosomucoid 1/α1 acid glycoprotein (ORM1), α1 antitrypsin (A1AT), serum amyloid A (SAA) and S100A9 exhibited differential expression patterns between survivors (S; n=6) and non‑survivors (NS; n=6), particularly during the early stages of sepsis. Expression factors (EFs), taken as the ratio between the NS and S during early stages, showed ratios of Hp, 0.39 (P≤0.012); TTR, 3.96 (P≤0.03); ORM1, 0.69 (P≤0.79); A1AT, 0.92 (P≤0.87) and SAA, 0.69 (P≤0.01). S100A9, an acute phase protein, exhibited an EF ratio of 1.68 (P≤0.004) during the end stages of sepsis. A delayed rise in levels was observed in Hp, A1AT, ORM1, S100A9 and SAA, whereas TTR levels increased during the early stages of sepsis in NS. Analysis of inflammatory responses in the early stages of sepsis revealed increased mRNA expression in leukocytes of interleukin (IL)‑6 (EF, 2.50), IL‑10 (EF, 1.70) and prepronociceptin (EF, 1.6), which is a precursor for nociceptin in NS compared with S, and higher Toll‑like receptor‑4 (EF, 0.30) levels in S compared with NS. Therefore, a weaker acute phase response in the early stages of sepsis in NS, combined with an inefficient inflammatory response, may contribute to sepsis mortality.

Provider Decisions to Treat Respiratory Illnesses with Antibiotics: Insights from a Randomized Controlled Trial

RATIONALE

Lower respiratory tract illness (LRTI) frequently causes adult hospitalization and antibiotic overuse. Procalcitonin (PCT) treatment algorithms have been used successfully in Europe to safely reduce antibiotic use for LRTI but have not been adopted in the United States. We recently performed a feasibility study for a randomized clinical trial (RCT) of PCT and viral testing to guide therapy for non-pneumonic LRTI.

OBJECTIVE

The primary objective of the current study was to understand factors influencing PCT algorithm adherence during the RCT and evaluate factors influencing provider antibiotic prescribing practices for LRTI.

STUDY DESIGN

From October 2013-April 2014, 300 patients hospitalized at a community teaching hospital with non-pneumonic LRTI were randomized to standard or PCT-guided care with viral PCR testing. Algorithm adherence data was collected and multivariate stepwise logistic regression of clinical variables used to model algorithm compliance. 134 providers were surveyed anonymously before and after the trial to assess knowledge of biomarkers and viral testing and antibiotic prescribing practices.

RESULTS

Diagnosis of pneumonia on admission was the only variable significantly associated with non-adherence [7% (adherence) vs. 26% (nonadherence), p = 0.01]. Surveys confirmed possible infiltrate on chest radiograph as important for provider decisions, as were severity of illness, positive sputum culture, abnormal CBC and fever. However, age, patient expectations and medical-legal concerns were also at least somewhat important to prescribing practices. Physician agreement with the importance of viral and PCT testing increased from 42% to 64% (p = 0.007) and 49% to 74% (p = 0.001), respectively, after the study.

CONCLUSIONS

Optimal algorithm adherence will be important for definitive PCT intervention trials in the US to determine if PCT guided algorithms result in better outcomes than reliance on traditional clinical variables. Factors influencing treatment decisions such as patient age, presence of fever, patient expectations and medical legal concerns may be amenable to education to improve PCT algorithm compliance for LRTI.

The diagnostic ability of procalcitonin and interleukin-6 to differentiate infectious from noninfectious systemic inflammatory response syndrome and to predict mortality

PURPOSE

The purpose of the study was to quantify the ability of procalcitonin (PCT) and interleukin-6 (IL-6) to differentiate noninfectious systemic inflammatory response syndrome (SIRS) and sepsis and to predict hospital mortality.

MATERIALS

We recruited consecutively adult patients with SIRS admitted to an intensive care unit. They were divided into sepsis and noninfectious SIRS based on clinical assessment with or without positive cultures. Concentrations of PCT and IL-6 were measured daily over the first 3 days.

RESULTS

A total of 239 patients were recruited, 164 (68.6%) had sepsis, and 68 (28.5%) died in hospital. The PCT levels were higher in sepsis compared with noninfectious SIRS throughout the 3-day period (P < .0001). On admission, PCT concentration was diagnostic of sepsis (area under the curve of 0.63 [0.55-0.71]), and IL-6 was predictive of mortality, (area under the curve of 0.70 [0.62-0.78]). Peak IL-6 concentration improved the risk assessment of Sequential Organ Failure Assessment (SOFA) score for prediction of mortality among those who went on to die by an average of 5% and who did not die by 2%

CONCLUSIONS

Procalcitonin measured on intensive care unit admission was diagnostic of sepsis, and IL-6 was predictive of mortality. Addition of IL-6 concentration to SOFA score improved risk assessment for prediction of mortality. Future studies should include clinical indices, for example, SOFA score, for prognostic evaluation of biomarkers.

Early monitoring of ventriculostomy-related infections with procalcitonin in patients with ventricular drains

Several factors are implicated in the increased vulnerability of multiple trauma victims to infection, especially in intensive care units. The incidence of EVD related infections ranges from 5 to 20%. To assess the accuracy of serum procalcitonin (PCT) in predicting central nervous system (CNS) infection in patients with EVDs. Thirty-six adult patients with severe head trauma were enrolled in this prospective study, after exclusion of other causes of fever; patients were subjected to sampling of C-reactive protein (CRP), PCT, and cerebrospinal fluid (CSF) cultures every other day. Five patients developed ventriculostomy-related infections, and all had an elevated serum PCT concentration. Patients with negative CSF cultures had mean serum PCT <2.0 ng/ml, while patients with positive culture had early elevation of serum PCT with mean of 4.18 ng/ml, CRP did not show similar early changes. Patients who acquire CNS infection had prolonged length of stay in hospital and length of ventilation. In absence of other nosocomial infections, early high serum PCT concentrations appear to be a reliable indicator of bacterial CNS infection in patients with EVD.

Carriere K, Chung CR. Clinical Usefulness of Procalcitonin and C-Reactive Protein as Outcome Predictors in Critically Ill Patients with Severe Sepsis and Septic Shock

Sepsis is a major cause of mortality and morbidity in critically ill patients. Procalcitonin (PCT) and C-reactive protein (CRP) are the most frequently used biomarkers in sepsis. We investigated changes in PCT and CRP concentrations in critically ill patients with sepsis to determine which biochemical marker better predicts outcome. We retrospectively analyzed 171 episodes in 157 patients with severe sepsis and septic shock who were admitted to the Samsung Medical Center intensive care unit from March 2013 to February 2014. The primary endpoint was patient outcome within 7 days from ICU admission (treatment failure). The secondary endpoint was 28-day mortality. Severe sepsis was observed in 42 (25%) episodes from 41 patients, and septic shock was observed in 129 (75%) episodes from 120 patients. Fifty-five (32%) episodes from 42 patients had clinically-documented infection, and 116 (68%) episodes from 99 patients had microbiologically-documented infection. Initial peak PCT and CRP levels were not associated with treatment failure and 28-day mortality. However, PCT clearance (PCTc) and CRP (CRPc) clearance were significantly associated with treatment failure (p = 0.027 and p = 0.030, respectively) and marginally significant with 28-day mortality (p = 0.064 and p = 0.062, respectively). The AUC for prediction of treatment success was 0.71 (95% CI, 0.61–0.82) for PCTc and 0.71 (95% CI, 0.61–0.81) for CRPc. The AUC for survival prediction was 0.77 (95% CI, 0.66–0.88) for PCTc and 0.77 (95% CI, 0.67–0.88) for CRPc. Changes in PCT and CRP concentrations were associated with outcomes of critically ill septic patients. CRP may not be inferior to PCT in predicting outcome in these patients.

Utility of presepsin (sCD14-ST) as a diagnostic and prognostic marker of sepsis in the emergency department

BACKGROUND

Presepsin (PSEP) is released during infectious diseases and can be detected in the blood. PSEP has shown promising results as sepsis marker. We examined the diagnostic and prognostic validity of PSEP in patients suspicious of sepsis on admission in the emergency department (ED).

METHODS

One hundred twenty three patients with signs of SIRS and/or sepsis and 123 healthy individuals were enrolled. PSEP was determined on admission, after 8, 24 and 72 h.

RESULTS

Mean PSEP concentrations of the control group and the patient group were 130 and 1945 pg/ml. PSEP differed between SIRS, sepsis, severe sepsis and septic shock and showed strong association with 30-day mortality ranging from 10.3% in the 1st to 32.1% in the 4th quartile. The ROC curve analyses revealed an AUC value of 0.743. Combined assessment of PSEP and MEDS score increased the AUC up to 0.878 demonstrating the close relationship with outcome. Based on the PSEP values in the different severity degrees, decision thresholds for risk stratification were established. The course of PSEP during the first 72 h was associated with effectiveness of treatment and outcome.

CONCLUSIONS

PSEP allowed outcome prediction already on admission to a similar degree as the clinical scores MEDS and APACHE II. Combination of PSEP with MEDS score improved the discriminatory power for outcome prediction.

Use of a Combination Biomarker Algorithm To Identify Medical Intensive Care Unit Patients with Suspected Sepsis at Very Low Likelihood of Bacterial Infection

Sepsis remains a diagnostic challenge in the intensive care unit (ICU), and the use of biomarkers may help in differentiating bacterial sepsis from other causes of systemic inflammatory syndrome (SIRS). The goal of this study was to assess test characteristics of a number of biomarkers for identifying ICU patients with a very low likelihood of bacterial sepsis. A prospective cohort study was conducted in a medical ICU of a university hospital. Immunocompetent patients with presumed bacterial sepsis were consecutively enrolled from January 2012 to May 2013. Concentrations of nine biomarkers (α-2 macroglobulin, C-reactive protein [CRP], ferritin, fibrinogen, haptoglobin, procalcitonin [PCT], serum amyloid A, serum amyloid P, and tissue plasminogen activator) were determined at baseline and at 24 h, 48 h, and 72 h after enrollment. Performance characteristics were calculated for various combinations of biomarkers for discrimination of bacterial sepsis from other causes of SIRS. Seventy patients were included during the study period; 31 (44%) had bacterial sepsis, and 39 (56%) had other causes of SIRS. PCT and CRP values were significantly higher at all measured time points in patients with bacterial sepsis. A number of combinations of PCT and CRP, using various cutoff values and measurement time points, demonstrated high negative predictive values (81.1% to 85.7%) and specificities (63.2% to 79.5%) for diagnosing bacterial sepsis. Combinations of PCT and CRP demonstrated a high ability to discriminate bacterial sepsis from other causes of SIRS in medical ICU patients. Future studies should focus on the use of these algorithms to improve antibiotic use in the ICU setting.

High serum trypsin levels and the -409 T/T genotype of PRSS1 gene are susceptible to neonatal sepsis

Neonatal sepsis remains an important and common cause of morbidity and mortality among newborn infants, especially in developing countries. The aim of the present study was to determine whether serum trypsin levels and genotypes of cationic trypsinogen (PRSS1) gene could be served as markers for predicting neonatal sepsis. The serum trypsin levels and genotypes of PRSS1 were examined in both 50 infants with infection during neonatal period and 56 healthy neonates as controls. The infected infants were further subdivided into infants with sepsis group (n=18) and infected infants without sepsis (n=32). The genotype of PRSS1 was analyzed by direct sequencing, and the serum trypsin level was measured by immunoassay. It showed that the median value of serum trypsin was significantly higher in infected infants (31.90 ng/mL) than in controls (12.85 ng/mL; P=0.030). More importantly, sepsis subgroup (50.95 ng/mL) had significantly higher median serum trypsin than infected infants without sepsis subgroup (19.10 ng/mL) and controls (12.85 ng/mL) (P=0.015 and P=0.002, respectively). Additionally, the median serum trypsin levels were found significantly higher in infants who had T/T (37.90 ng/mL) genotype of PRSS1 compared with those who had C/T genotype (12.80 ng/mL; P=0.005). This study suggested that serum trypsin and rs10273639 C/T of PRSS1 were revealed to be novel markers for predicting neonatal sepsis.

Cholesterol rather than procalcitonin or C-reactive protein predicts mortality in patients with infection

Serum cholesterol procalcitonin (PCT) and C-reactive protein (CRP) levels were measured consecutively in 76 critically ill patients at admission to the intensive care unit. The presence of infection was defined according to the CDC (Centers for Disease Control and Prevention) criteria; in-house mortality, underlying diseases, and severity of sepsis were monitored. Nonsurvivors had significantly lower cholesterol levels compared with survivors (69 mg/dL [range, 37-88 mg/dL] vs. 96 mg/dL [range, 71-132 mg/dL], P = 0.006) whereas no significant differences were noted for serum PCT and CRP levels. In a cohort of patients with cholesterol levels of 50 mg/dL or less, 82% did not survive as compared with patients with cholesterol levels of 100 mg/dL or greater (mortality, 21%). In a control group without infection, no difference of cholesterol, PCT, or CRP was found between survivors and nonsurvivors. Our data show that low cholesterol levels in patients with infectious disease have a prognostic value and may be useful markers to identify high-risk patients already at admission.

Host response biomarkers in sepsis: the role of procalcitonin

Procalcitonin is the prohormone of calcitonin and present in minute quantities in health. However, during infection, its levels rise considerably and are correlated with the severity of the infection. Several assays have been developed for measurement of procalcitonin levels; in this article, we will briefly present the PCT-sensitive Kryptor(®) test (Brahms, Hennigsdorf, Germany), one of the most widely used assays for procalcitonin in recent studies. Many studies have demonstrated the value of procalcitonin levels for diagnosing sepsis and assessing disease severity. Procalcitonin levels have also been successfully used to guide antibiotic administration. However, procalcitonin is not specific for sepsis, and values need to be interpreted in the context of a full clinical examination and the presence of other signs and symptoms of sepsis.

Procalcitonin versus C-reactive protein: Usefulness as biomarker of sepsis in ICU patient

Background:

Early diagnosis and appropriate therapy of sepsis is a daily challenge in intensive care units (ICUs) despite the advances in critical care medicine. Procalcitonin (PCT); an innovative laboratory marker, has been recently proven valuable worldwide in this regard.

Objectives:

This study was undertaken to evaluate the utility of PCT in a resource constrained country like ours when compared to the traditional inflammatory markers like C - reactive protein (CRP) to introduce PCT as a routine biochemical tool in regional hospitals.

Materials and Methods:

PCT and CRP were simultaneously measured and compared in 73 medico-surgical ICU patients according to the American College of Chest Physicians (ACCP) criteria based study groups.

Results:

The clinical presentation of 75% cases revealed a range of systemic inflammatory responses (SIRS). The diagnostic accuracy of PCT was higher (75%) with greater specificity (72%), sensitivity (76%), positive and negative predictive values (89% and 50%), positive likelihood ratio (2.75) as well as the smaller negative likelihood ratio (0.33). Both serum PCT and CRP values in cases with sepsis, severe sepsis and septic shock were significantly higher from that of the cases with SIRS and no SIRS (P < 0.01).

Conclusion:

PCT is found to be superior to CRP in terms of accuracy in identification and to assess the severity of sepsis even though both markers cannot be used in differentiating infectious from noninfectious clinical syndrome.

Procalcitonin as an early diagnostic and monitoring tool in urosepsis following percutaneous nephrolithotomy

To evaluate the value of procalcitonin (PCT) as an early marker for diagnosis and differentiation of without urosepsis, urosepsis, severe urosepsis, and uroseptic shock following PCNL and the ability of PCT to assess the effectiveness of antibiotic therapy in patients with urosepsis. From June 2012 to August 2013, 267 patients undergoing PCNL for renal calculi, and who fulfilled selection criteria, were recruited into our study. The patients' medical records were reviewed retrospectively. One of selection criteria was the scores of PCT and WBC were collected at operative day, postoperative day one, day two, day three, day five and day seven. The area under the ROC curve for the prediction of urosepsis was 0.960 for PCT and 0.634 for WBC. PCT concentrations were higher in patients with uroseptic shock versus severe urosepsis versus urosepsis versus without urosepsis following PCNL. WBC values showed no significant difference between patients with urosepsis, severe urosepsis and uroseptic shock following PCNL. With time, in patients with successfully treated urosepsis following PCNL, the PCT concentrations significantly declined and kept decreasing from postoperative day two to postoperative day seven and the WBC scores showed no significant change over the first postoperative 2 days and were decreased only after postoperative day three. PCT appears to be a useful early marker to diagnosis and discriminate urosepsis, severe urosepsis and uroseptic shock following PCNL. Daily PCT measurements may be a valuable tool in monitoring the effectiveness of antibiotic therapy in urosepsis following PCNL.

Laboratory detection of sepsis: biomarkers and molecular approaches

Sepsis, severe sepsis, and septic shock cause significant morbidity and mortality worldwide. Rapid diagnosis and therapeutic interventions are desirable to improve the overall mortality in patients with sepsis. However, gold standard laboratory diagnostic methods for sepsis, pose a significant challenge to rapid diagnosis of sepsis by physicians and laboratories. This article discusses the usefulness and potential of biomarkers and molecular test methods for a more rapid clinical and laboratory diagnosis of sepsis. Because new technologies are quickly emerging, physicians and laboratories must appreciate the key factors and characteristics that affect the clinical usefulness and diagnostic accuracy of these test methodologies.

Can procalcitonin be an accurate diagnostic marker for the classification of diabetic foot ulcers?

BACKGROUND

The differentiation of infected diabetic foot ulcers (IDFU) from non infected diabetic foot ulcers (NIDFU) is a challenging issue for clinicians.

OBJECTIVES

Recently, procalcitonin (PCT) was introduced as a remarkable inflammatory marker. We aimed to evaluate the accuracy of PCT in comparison to other inflammatory markers for distinguishing IDFU from NIDFU.

MATERIALS AND METHODS

We evaluated PCT serum level as a marker of bacterial infection in patients with diabetic foot ulcers. Sixty patients with diabetic foot ulcers were consecutively enrolled in the study. A total of 30 patients were clinically identified as IDFU by an expert clinician, taking as criteria for purulent discharges or at least two of manifestations of inflammation including warmth, redness, swelling and pain.

RESULTS

Procalcitonin, white blood cells (WBCs), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), were found significantly higher in the IDFU group compared to the NIDFU group. The best cut-off value, sensitivity and specificity were 40.5 mm/h, 90% and 94% for ESR, 7.1 mg/dL, 80% and 74% for CRP, 0.21, 70% and 74% for PCT, and 7.7×10(9)/L, 66% and 67% for WBCs, respectively. The area under the receiver operating characteristic curve for ESR was the greatest (0.967; P < 0.001), followed by CRP (0.871; P < 0.001), PCT (0.729; P < 0.001), and finally WBCs (0.721; P = 0.001).

CONCLUSIONS

These results suggest that PCT can be a diagnostic marker in combination with other markers like ESR and CRP to distinguish infected from non-infected foot ulcers, when clinical manifestations are un specific. Additional research is needed before the routine usage of PCT to better define the role of PCT in IDFU.

Diagnostic value and prognostic evaluation of Presepsin for sepsis in an emergency department

Introduction

Presepsin levels are known to be increased in sepsis. The aim of this study was to evaluate the early diagnostic and prognostic value of Presepsin compared with procalcitonin (PCT), Mortality in Emergency Department Sepsis (MEDS) score and Acute Physiology and Chronic Health Evaluation II (APACHE II) score in septic patients in an emergency department (ED) and to investigate Presepsin as a new biomarker of sepsis.

Methods

This study enrolled 859 consecutive patients with at least two diagnostic criteria for systemic inflammatory response syndrome (SIRS) who were admitted to Beijing Chao-yang Hospital ED from December 2011 to October 2012, and 100 age-matched healthy controls. Patients were stratified into four groups: SIRS, sepsis, severe sepsis, and septic shock. Plasma Presepsin and serum PCT were measured, and MEDS score and APACHE II score were calculated at enrollment. Comparisons were analyzed using the Kruskal-Wallis and Mann–Whitney U tests.

Results

On admission, the median levels of plasma Presepsin increased with sepsis severity. The areas under the receiver operating characteristic (AUC) curves of Presepsin were greater than those of PCT in diagnosing sepsis, and predicting severe sepsis and septic shock. The AUC of Presepsin for predicting 28-day mortality in septic patients was slightly lower than that of PCT, MEDS score and APACHE II score. The AUC of a combination of Presepsin and MEDS score or APACHE II score was significantly higher than that of MEDS score or APACHE II score alone in predicting severe sepsis, and was markedly higher than that of Presepsin alone in predicting septic shock and 28-day mortality in septic patients, respectively. Plasma Presepsin levels in septic patients were significantly higher in non-survivors than in survivors at 28 days’ follow-up. Presepsin, MEDS score and APACHE II score were found to be independent predictors of severe sepsis, septic shock and 28-day mortality in septic patients. The levels of plasma Presepsin were positively correlated with PCT, MEDS score and APACHE II score in every septic group.

Conclusion

Presepsin is a valuable biomarker for early diagnosis of sepsis, risk stratification, and evaluation of prognosis in septic patients in the ED.

Novel biomarkers to detect infection in revision hip and knee arthroplasties

BACKGROUND

A periprosthetic joint infection is one of the most challenging complications associated with THA and TKA. In the diagnostic process for detecting a periprosthetic joint infection, one of the most important steps is analysis of laboratory infection biomarkers.

QUESTIONS/PURPOSES

We investigated the sensitivity and specificity of the biomarkers procalcitonin, interleukin 6 (IL-6), and interferon α (IFN-α) as compared with conventional biomarkers (C-reactive protein [CRP], leukocyte level) for a periprosthetic joint infection associated with revision arthroplasties.

METHODS

We prospectively included and analyzed 84 patients (124 revision arthroplasties). The blood parameters of interest were procalcitonin, IL-6, IFN-α, leukocyte level, and CRP. Samples were taken preoperatively and on the first, third, and seventh postoperative days. The sensitivity and specificity of these biomarkers then were calculated.

RESULTS

Considering the preoperative values of 84 patients (124 operations), procalcitonin, IL-6, CRP, and leukocyte level correlated with periprosthetic joint infection, whereas IFN-α did not. A procalcitonin cut-off level of 0.35 ng/mL revealed a sensitivity of 80% and specificity of 37%. An IL-6 cut-off level of 2.55 pg/mL had a sensitivity of 92% and specificity of 59%.

CONCLUSIONS

In this study procalcitonin and IL-6 were helpful for detecting periprosthetic joint infections in revision arthroplasties, although CRP generally was superior. Procalcitonin and IL-6 may be considered adjuvant tests when the diagnosis of a periprosthetic joint infection is in doubt. This study showed, in addition to conventional biomarkers such as CRP and leukocyte level, procalcitonin and IL-6 were helpful for detecting infections associated with revision arthroplasties.

Maximal chemiluminescent intensity in response to lipopolysaccharide assessed by endotoxin activity assay on admission day predicts mortality in patients with sepsis

OBJECTIVE

Sepsis is the leading cause of death among critically ill patients. There are, however, few appropriate biomarkers to predict mortality in patients with sepsis. We focused on maximal chemiluminescent intensity in response to lipopolysaccharide assessed by endotoxin activity assay and evaluated the diagnostic value of maximal chemiluminescent intensity on admission day as a predictor of mortality in patients with sepsis.

DESIGN

Prospective, observational study.

SETTING

ICU.

PATIENTS

One hundred and thirty-two patients with sepsis.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Within 12 hours after admission, a whole-blood sample was collected, and variables assessed by endotoxin activity assay were measured in each patient. Severity of illness was assessed simultaneously by Acute Physiology and Chronic Health Evaluation (APACHE) II score and Sequential Organ Failure Assessment (SOFA) score. The primary outcome was 28-day mortality. One hundred and fifteen patients survived and 17 died. maximal chemiluminescent intensity values were significantly lower in the nonsurvivors than in the survivors (p <0.05). We investigated maximal chemiluminescent intensity, APACHE II score, and SOFA score as predictors of 28-day mortality. Receiver operating characteristic analysis showed that area under the curve for maximal chemiluminescent intensity was 0.902, which was superior to the area under the curves for APACHE II score (0.836) and SOFA score (0.807). At the optimal cutoff value for maximal chemiluminescent intensity, 21,000 RLU/s, the sensitivity for correct prediction of 28-day mortality was 82.4% and the specificity was 92.2%. Kaplan-Meier analysis showed that low maximal chemiluminescent intensity (<21,000 RLU/s) closely correlated with poor overall patient survival compared with high maximal chemiluminescent intensity (>21,000 RLU/s) (p <0.001 by log-rank test). After adjusting for APACHE II score by Cox regression analysis, maximal chemiluminescent intensity was identified as an independent predictor for the probability of 28-day mortality.

CONCLUSION

Maximal chemiluminescent intensity level measured on admission day appears to have high predictive value for mortality in patients with sepsis.

Procalcitonin: Does It Have a Role in the Diagnosis, Management and Prognosis of Patients with Sepsis?

There is growing interest in the use of procalcitonin as a biomarker of bacterial infection. In particular, focus has been on the use of procalcitonin to facilitate a more timely diagnosis of sepsis and to guide the appropriate duration of antibiotic therapy. However, there is a lack of consensus in the literature concerning the role of measuring procalcitonin levels in clinical practice. This article reviews the evidence surrounding the utility of this biomarker for patients with sepsis in the intensive care environment. It is concluded that raised procalcitonin levels add little as a diagnostic criterion, however evidence supports the incorporation of procalcitonin-based algorithms relating to antibiotic stewardship in this patient population.

CRISPLD2 is expressed at low levels during septic shock and is associated with procalcitonin

Introduction

Previous studies have shown that cysteine-rich secretory protein containing LCCL domain 2 (CRISPLD2) is a novel lipopolysaccharide (LPS)-binding protein, and the upregulation of CRISPLD2 expression protects mice against LPS-induced lethality. The aim of this study was to examine the expression of CRISPLD2 in patients with sepsis and characterize the association of this protein with procalcitonin.

Methods

The expression of CRISPLD2 was determined in100 healthy volunteers and 119 septic patients. According to the definition of sepsis, patients were divided into three groups sepsis, severe sepsis, and septic shock. The relationship between CRISPLD2 levels and procalcitonin was also examined and statistically analyzed.

Results

The CRISPLD2 levels in healthy individuals were 219.3±69.1 µg/ml. Patients with sepsis exhibited higher CRISPLD2 levels than observed in healthy individuals (p = 0.001), but CRISPLD2 expression was not upregulated in patients with septic shock. No significant differences were observed between the levels of CRISPLD2 in surviving and non-surviving spesis patients. CRISPLD2 levels were negatively correlated with procalcitonin levels(r = −0.334, p<0.001).

Conclusions

The present study is the first to demonstrate the decreased expression of CRISPLD2 in septic shock and its association with PCT in sepsis. Further studies are needed to clarify the potential association between CRISPLD2 expression and clinical outcomes to determine if it could be used as a novel sepsis biomarker.

Is there value in plasma cytokine measurements in patients with severe trauma and sepsis?

For the past thirty years, since IL-1β and TNFα were first cloned, there have been efforts to measure plasma cytokine concentrations in patients with severe sepsis and trauma, and to use these measurements to predict clinical outcome and response to therapies. The numbers of cytokines and chemokines that have been measured in the plasma have literally exploded with the development of multiplex immune approaches. Dozens of relatively small cohort studies have shown plasma cytokine concentrations correlating with outcome in sepsis and trauma. Despite what appears to be a consensus that plasma cytokine concentrations should be useful in the clinical setting, only two cytokines, IL-6 and procalcitonin, have approached routine clinical use. IL-6 has been used as a research tool for entry into sepsis-intervention trials, while procalcitonin is being used clinically at a large number of institutions to distinguish sepsis from other inflammatory processes. For most cytokines, the relative lack of sensitivity and specificity of individual or multiplex cytokine measurements has hindered their utility to predict clinical trajectory in individual patients. The problem rests with a general misunderstanding of cytokine biology, failing to appreciate the general paracrine nature of these mediators, the presence of binding proteins, chaperones and inhibitors in the plasma, and the rapid clearance of these proteins by binding to cell receptors and clearance predominantly by the kidney. The future of using plasma cytokine measurements as an indicator of sepsis/trauma severity or predicting outcome is generally behind us, although there is optimism that procalcitonin measurements may ultimately prove to have utility in the diagnosis of severe sepsis.

Clinical application of sepsis biomarkers

Sepsis is one of the leading causes of death in the critically ill. Early diagnosis is important to avoid delay in instituting appropriate treatment. However, diagnosis can be delayed because of difficulty in interpreting clinical features. Sepsis biomarkers can aid early diagnosis. This article reviews the application of readily available biomarkers for diagnosis of sepsis, for predicting prognosis, and for antibiotic stewardship. 178 biomarkers are described in the literature--ranging from specimen cultures, which lack sensitivity and specificity for early diagnosis of sepsis, to biomarkers such as C-reactive protein, procalcitonin, and genetic biomarkers, which have their own limitations. Future research will mainly focus on use of more than one biomarker, but the main problem in sepsis biomarker research seems to be a lack of a recommended biomarker.

Procalcitonin as a diagnostic marker for sepsis: a systematic review and meta-analysis

BACKGROUND

Procalcitonin is a promising marker for identification of bacterial infections. We assessed the accuracy and clinical value of procalcitonin for diagnosis of sepsis in critically ill patients.

METHODS

We searched Medline, Embase, ISI Web of Knowledge, the Cochrane Library, Scopus, BioMed Central, and Science Direct, from inception to Feb 21, 2012, and reference lists of identified primary studies. We included articles written in English, German, or French that investigated procalcitonin for differentiation of septic patients--those with sepsis, severe sepsis, or septic shock--from those with a systemic inflammatory response syndrome of non-infectious origin. Studies of healthy people, patients without probable infection, and children younger than 28 days were excluded. Two independent investigators extracted patient and study characteristics; discrepancies were resolved by consensus. We calculated individual and pooled sensitivities and specificities. We used I(2) to test heterogeneity and investigated the source of heterogeneity by metaregression.

FINDINGS

Our search returned 3487 reports, of which 30 fulfilled the inclusion criteria, accounting for 3244 patients. Bivariate analysis yielded a mean sensitivity of 0 · 77 (95% CI 0 · 72-0 · 81) and specificity of 0 · 79 (95% CI 0 · 74-0 · 84). The area under the receiver operating characteristic curve was 0 · 85 (95% CI 0 · 81-0 · 88). The studies had substantial heterogeneity (I(2)=96%, 95% CI 94-99). None of the subgroups investigated--population, admission category, assay used, severity of disease, and description and masking of the reference standard--could account for the heterogeneity.

INTERPRETATION

Procalcitonin is a helpful biomarker for early diagnosis of sepsis in critically ill patients. Nevertheless, the results of the test must be interpreted carefully in the context of medical history, physical examination, and microbiological assessment.

FUNDING

Ministry of Education and Research, the Deutsche Forschungsgemeinschaft, Thuringian Ministry for Education, Science and Culture, the Thuringian Foundation for Technology, Innovation and Research, and the German Sepsis Society.

Predictors of survival in sepsis: what is the best inflammatory marker to measure?

PURPOSE OF REVIEW

Sepsis is relevant due to its high morbidity and mortality. For both sepsis diagnosis and outcome prediction many biomarkers have been described in the literature. Most of these markers are objects of scientific interest rather than being introduced into daily clinical practice. However, due to their unspecific character and their insufficient predictive value for the individual person, research focus is still on new aspects in sepsis-related biomarkers.

RECENT FINDINGS

Beyond the widely used acute-phase proteins C-reactive protein (CRP) and procalcitonin (PCT), many new molecules have been studied deriving from different organs or cells affected, due to the systemic nature of sepsis. Cytokines, coagulation factors/characteristics, vasoactive hormones, and several others have been recently proved to be relevant in sepsis syndrome and probably useful for outcome prediction. However, single time point measurements may be less predictive than consideration of the time-dependent course of parameters. Clinical decision just based on a biomarker is still not feasible because of the huge inter-individual differences in the inflammatory response.

SUMMARY

Many biomarkers display relevant correlation with the clinical outcome of patients with severe sepsis and septic shock. Consideration of their time courses may be more reliable than absolute levels. Clinical decision should not be based only on biomarkers but organ dysfunctions, for example, should also be taken into account.

D-dimer is a significant prognostic factor in patients with suspected infection and sepsis

PURPOSE

The aim of the study was to determine whether C-reactive protein (CRP), procalcitonin (PCT), and d-dimer (DD) are markers of mortality in patients admitted to the emergency department (ED) with suspected infection and sepsis.

BASIC PROCEDURES

We conducted a prospective cohort in a university hospital in Medellín, Colombia. Patients were admitted between August 1, 2007, and January 30, 2009. Clinical and demographic data and Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores as well as blood samples for CRP, PCT, and DD were collected within the first 24 hours of admission. Survival was determined on day 28 to establish its association with the proposed biomarkers using logistic regression and receiver operating characteristic curves.

MAIN FINDINGS

We analyzed 684 patients. The median Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores were 10 (interquartile range [IQR], 6-15) and 2 (IQR, 1-4), respectively. The median CRP was 9.6 mg/dL (IQR, 3.5-20.4 mg/dL); PCT, 0.36 ng/mL (IQR, 0.1-3.7 ng/mL); and DD, 1612 ng/mL (IQR, 986-2801 ng/mL). The median DD in survivors was 1475 ng/mL (IQR, 955-2627 ng/mL) vs 2489 ng/mL (IQR, 1698-4573 ng/mL) in nonsurvivors (P=.0001). The discriminatory ability showed area under the curve-receiver operating characteristic for DD, 0.68; CRP, 0.55; and PCT, 0.59. After multivariate analysis, the only biomarker with a linear relation with mortality was DD, with an odds ratio of 2.07 (95% confidence interval, 0.93-4.62) for values more than 1180 and less than 2409 ng/mL and an odds ratio of 3.03 (95% confidence interval, 1.38-6.62) for values more than 2409 ng/mL.

PRINCIPAL CONCLUSIONS

Our results suggest that high levels of DD are associated with 28-day mortality in patients with infection or sepsis identified in the emergency department.

[Usefulness of procalcitonin upon admission to intensive care in the diagnosis and prognosis of sepsis]

OBJECTIVE

To assess the usefulness of procalcitonin (PCT) upon admission to the Intensive Care Unit (ICU) in the diagnosis and prognosis of sepsis

DESIGN

A 12-month prospective observational cohort study was carried out

SETTING

An 11-bed polyvalent ICU Belonging to a University hospital

PATIENTS

Fifty patients with systemic inflammatory response syndrome (SIRS) were included. The mean age of the patients was 51.66 years, and 68% of them were males

VARIABLES OF INTEREST

Upon admission, the concentration of PCT and C-reactive protein (CRP) was assessed. At discharge, the final diagnosis and outcome were reviewed

RESULTS

Thirty-six patients had sepsis. Mean PCT ± SD was higher in sepsis than in non-infectious SIRS (19.3 ± 4.9 vs. 0.65 ± 0.2) ng/ml) (P=.001). PCT had greater discriminating power than CRP (AUC 0.932 vs. 0.827). The cut-off value of PCT for the diagnosis of sepsis was 0.92 ng/dl, with a sensitivity of 80.56%, specificity 85.71%, positive predictive value 93.55% and negative predictive value 63.16%, LR+ 5.64 and LR- 0.23. Mortality was higher in patients with sepsis (52.78% vs. 21.43%) (P=.039). Mean PCT ± SD upon admission among survivors and deceased patients with sepsis was 18.7 ± 6.7 and 19.5 ± 7.5 ng/ml, respectively (P=.934).

CONCLUSIONS

PCT upon admission to the ICU is useful for the diagnosis of sepsis, and is more effective than PCR in this respect. However, it is of no help in estimating the short-term prognosis.

Dynamic change of procalcitonin, rather than concentration itself, is predictive of survival in septic shock patients when beyond 10 ng/mL

Procalcitonin (PCT) concentration of greater than 10 ng/mL is compatible for septic shock. Its predictive value for survival is not well established, mainly because of much overlap and variation of PCT in this condition. We hypothesized that dynamic change of PCT, rather than PCT itself, is predictive of hospital survival when greater than 10 ng/mL. Thirty-seven septic shock patients with PCT concentration of greater than 10 ng/mL were enrolled in this prospective cohort study. Patients were divided into survivors (n = 25) and nonsurvivors (n = 12) based on 28-day hospital outcome. Subsequent PCT measurements were taken 5 days after enrollment. Sequential Organ Failure Assessment (SOFA) scores were recorded simultaneously. Dynamic changes of the PCT and SOFA score were defined as the difference between the subsequent and initial measurement. There were no significant differences between survivors and nonsurvivors in age, sex, initial measurement of PCT, and SOFA. All survivors had a decrease in PCT concentration; median decrease was 9.73 ng/mL. All nonsurvivors had an increase in PCT concentration; median increase was 5.95 ng/mL. Significant decrease in PCT concentration (>25%) was observed in all the 25 survivors, whereas there was none in 12 nonsurvivors. Procalcitonin of initial, subsequent measurements, and dynamics significantly correlated with their counterparts of SOFA score. In conclusion, significant decrease in PCT concentration, rather than PCT concentration itself, may be a useful indicator of survival in septic shock patients when PCT concentration is greater than 10 ng/mL. Procalcitonin concentration highly correlated with the SOFA score in septic shock patients even when the PCT concentration is greater than 10 ng/mL.