The plasma level of soluble urokinase receptor is elevated in patients with Streptococcus pneumoniae bacteraemia and predicts mortality

Soluble Urokinase Plasminogen Activator Receptor (SuPAR) Analysis for Diagnosis of Periprosthetic Joint Infection

Soluble urokinase plasminogen activator receptors (suPARs) are a biomarker for inflammatory diseases. This study aims to investigate its diagnostic properties regarding periprosthetic joint infections (PJI). This retrospective cohort study included adult patients who underwent joint puncture for suspected PJI. The presence of PJI was determined according to the criteria of the European Bone and Joint Infection Society (EBJIS). Laboratory study analyses included the determination of white blood cells (WBC) in whole blood, C-reactive protein (CRP) in blood plasma, and suPAR in both blood plasma and synovial fluid. Appropriate diagnostic cut-off values were identified utilizing Youden's J, and their diagnostic performance was determined by calculating the positive (PPV) and negative predictive value (NPV) for each marker. Sixty-seven cases were included in the final analysis. Forty-three samples (64%) were identified as periprosthetic joint infection (PJI) and twenty-four specimen (36%) were PJI negative cases. The PPV and NPV were 0.80 and 0.70 for synovial suPAR, 0.86 and 0.55 for CRP, 0.84 and 0.31 for WBC and 1.00 and 0.31 for plasma suPAR. Synovial suPAR showed a solid diagnostic performance in this study and has the potential to be an alternative or complementary biomarker for PJI. Further investigations in larger patient collectives are indicated.

Point-of-care prognostication in moderate Covid-19: Analytical validation and prognostic accuracy of a soluble urokinase plasminogen activator receptor (suPAR) rapid test

The soluble urokinase plasminogen activator receptor (suPAR) has been proposed as a biomarker for risk stratification of patients presenting with acute infections. However, most studies evaluating suPAR have used platform-based assays, the accuracy of which may differ from point-of-care tests capable of informing timely triage in settings without established laboratory capacity. Using samples and data collected during a prospective cohort study of 425 patients presenting with moderate Covid-19 to two hospitals in India, we evaluated the analytical performance and prognostic accuracy of a commercially-available rapid diagnostic test (RDT) for suPAR, using an enzyme-linked immunosorbent assay (ELISA) as the reference standard. Our hypothesis was that the suPAR RDT might be useful for triage of patients presenting with moderate Covid-19 irrespective of its analytical performance when compared with the reference test. Although agreement between the two tests was limited (bias = -2.46 ng/mL [95% CI = -2.65 to -2.27 ng/mL]), prognostic accuracy to predict supplemental oxygen requirement was comparable, whether suPAR was used alone (area under the receiver operating characteristic curve [AUC] of RDT = 0.73 [95% CI = 0.68 to 0.79] vs. AUC of ELISA = 0.70 [95% CI = 0.63 to 0.76]; p = 0.12) or as part of a published multivariable prediction model (AUC of RDT-based model = 0.74 [95% CI = 0.66 to 0.83] vs. AUC of ELISA-based model = 0.72 [95% CI = 0.64 to 0.81]; p = 0.78). Lack of agreement between the RDT and ELISA in our cohort warrants further investigation and highlights the importance of assessing candidate point-of-care tests to ensure management algorithms reflect the assay that will ultimately be used to inform patient care. Availability of a quantitative point-of-care test for suPAR opens the door to suPAR-guided risk stratification of patients with Covid-19 and other acute infections in settings with limited laboratory capacity.

Evaluation of plasma soluble urokinase plasminogen activator receptor (SuPAR) levels in ulcerative colitis

BACKGROUND AND STUDY AIM

Soluble urokinase plasminogen activator receptor (SuPAR), a soluble form of the urokinase-type plasminogen activator receptor, is a biomarker produced by macrophages, monocytes, neutrophils, active T cells, endothelial cells, and circulating tumor cells. SuPAR is a novel biomarker showing altered inflammation in many inflammatory diseases. This study aims to investigate the SuPAR level in ulcerative colitis (UC) patients, and to evaluate the SuPAR level in active, and remission patients.

PATIENTS AND METHODS

Patient and healthy control SuPAR levels were analyzed by immunoassay method. SuPAR levels between UC patients and control group were compared. The difference between SuPAR levels in patients with active UC and UC in remission was analyzed. The relationship between C-reactive protein level, Total Mayo score, Mayo Endoscopic score used to predict disease activity, and amount of SuPAR were evaluated.

RESULTS

SuPAR levels were determined in the UC patient group (2170,3 ± 121,0 pg/ml), and healthy controls (2130,7 ± 164,8 pg/ml) (p = 0. 805). Median SuPAR levels were determined in moderate UC (2479 pg/ml), mild UC (1944 pg/ml), and patients in remission (1774 pg/ml) (p = 0,207). There were no significant relationships between SuPAR levels and CRP levels, Total Mayo score, disease duration in the UC group (r = 0.177, r = 0.267, and r = 0,007; respectively p > 0.05). A slightly positive correlation was found between Mayo Endoscopic Score and SuPAR level (r = 0.303; p = 0.031).

CONCLUSION

SuPAR is of limited value in the diagnosis of ulcerative colitis and in the assessment of disease activation.

The accuracy of soluble urokinase-type plasminogen activator receptor for the diagnosis of neonatal sepsis: a meta-analysis

Background

Neonatal sepsis is one of the major causes of morbidity and mortality in newborns. However, atypical clinical manifestations and symptoms make the early diagnosis of neonatal sepsis a challenge. Relatively high-serum soluble urokinase-type plasminogen activator receptor (suPAR) has been implicated as a diagnostic biomarker for adult sepsis. Therefore, the meta-analysis is intended to explore the diagnostic value of suPAR for neonatal sepsis.

Methods

The PubMed, Cochrane Library, Embase, Web of Science, China National Knowledge Infrastructure, China Biological Medicine Disk, and Wanfang databases were retrieved from inception to 31 December 2022 to collect diagnostic accuracy studies about suPAR for neonatal sepsis. Two reviewers independently screened the literature, extracted data, and assessed the risk of bias in the included studies using the quality assessment of diagnostic accuracy studies-2 (QUADAS-2) tool. Then, a meta-analysis was performed using Stata 15.0 software.

Results

A total of six articles involving eight studies were included. The results of the meta-analysis showed that the pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and diagnostic odds ratio were 0.89 [95%CI (0.83-0.93)], 0.94 [95%CI (0.77-0.98)], 14 [95%CI (3.5-55.2)], 0.12 [95%CI (0.08-0.18)], and 117 [95%CI (24-567)], respectively. The area under the curve (AUC) of summary receiver operator characteristic (SROC) curves was 0.92 [95%CI (0.90-0.94)]. Sensitivity analysis confirmed the stability of the results, and publication bias was not observed. Fagan's nomogram results demonstrated the clinical availability of the findings.

Conclusion

Current evidence suggests that suPAR has potential diagnostic value for neonatal sepsis. Owing to the limited quality of the included studies, more high-quality studies are needed to verify the above conclusion.

Association between variables measured in the ambulance and in-hospital mortality among adult patients with and without infection: a prospective cohort study

BACKGROUND

Patients presenting with infection to the ambulance are common, but risk factors for poor outcome are not known. The primary aim of the current study was to study the association between variables measured in the ambulance and mortality among adult patients with and without infection. The secondary aim was to study the association between these variables and mortality in a subgroup of patients who developed sepsis within 36 h.

METHODS

Prospective cohort study of 553 ambulance patients with, and 318 patients without infection, performed in Stockholm during 2017-2018. The association between 21 variables (8 keywords related to medical history, 6 vital signs, 4 blood tests, and age, gender, comorbidity) and in-hospital mortality was analysed using logistic regression.

RESULTS

Among patients with infection, inability of the patient to answer questions relating to certain symptoms such as pain and gastrointestinal symptoms was significantly associated with mortality in univariable analysis, in addition to oxygen saturation < 94%, heart rate > 110 /min, Glasgow Coma Scale (GCS) < 15, soluble urokinase Plasminogen Activator Receptor (suPAR) 4.0-7.9 ng/mL, suPAR ≥ 8.0 ng/mL and a Charlson comorbidity score ≥ 5. suPAR ≥ 8.0 ng/mL remained significant in multivariable analysis (OR 25.4; 95% CI, 3.2-199.8). Among patients without infection, suPAR ≥ 8.0 ng/mL and a Charlson comorbidity score ≥ 5 were significantly associated with mortality in univariable analysis, while suPAR ≥ 8.0 ng/mL remained significant in multivariable analysis (OR 56.1; 95% CI, 4.5-700.0). Among patients who developed sepsis, inability to answer questions relating to pain remained significant in multivariable analysis (OR 13.2; 95% CI, 2.2-78.9), in addition to suPAR ≥ 8.0 ng/mL (OR 16.1; 95% CI, 2.0-128.6).

CONCLUSIONS

suPAR ≥ 8.0 ng/mL was associated with mortality in patients presenting to the ambulance both with and without infection and in those who developed sepsis. Furthermore, the inability of the ambulance patient with an infection to answer questions relating to specific symptoms was associated with a surprisingly high mortality. These results suggest that suPAR and medical history are valuable tools with which to identify patients at risk of poor outcome in the ambulance and could potentially signal the need of enhanced attention.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03249597. Registered 15 August 2017-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03249597 .

Concentrations of urinary neopterin, but not suPAR, positively correlate with age in rhesus macaques

Identifying biomarkers of age-related changes in immune system functioning that can be measured non-invasively is a significant step in progressing research on immunosenescence and inflammaging in free-ranging and wild animal populations. In the present study, we aimed to investigate the suitability of two urinary compounds, neopterin and suPAR, as biomarkers of age-related changes in immune activation and inflammation in a free-ranging rhesus macaque (Macaca mulatta) population. We also investigated age-associated variation in gene transcription from blood samples to understand the underlying proximate mechanisms that drive age-related changes in urinary neopterin or suPAR. Neopterin was significantly positively correlated with age, and had a moderate within-individual repeatability, indicating it is applicable as a biomarker of age-related changes. The age-related changes in urinary neopterin are not apparently driven by an age-related increase in the primary signaler of neopterin, IFN-y, but may be driven instead by an age-related increase in both CD14+ and CD14− monocytes. suPAR was not correlated with age, and had low repeatability within-individuals, indicating that it is likely better suited to measure acute inflammation rather than chronic age-related increases in inflammation (i.e., “inflammaging”). Neopterin and suPAR had a correlation of 25%, indicating that they likely often signal different processes, which if disentangled could provide a nuanced picture of immune-system function and inflammation when measured in tandem.

Proteomic, Metabolomic, and Lipidomic Analyses of Lung Tissue Exposed to Mustard Gas

Sulfur mustard (HD) poses a serious threat due to its relatively simple production process. Exposure to HD in the short-term causes an inflammatory response, while long-term exposure results in DNA and RNA damage. Respiratory tract tissue models were exposed to relatively low concentrations of HD and collected at 3 and 24 h post exposure. Histology, cytokine ELISAs, and mass spectrometric-based analyses were performed. Histology and ELISA data confirmed previously seen lung damage and inflammatory markers from HD exposure. The multi-omic mass spectrometry data showed variation in proteins and metabolites associated with increased inflammation, as well as DNA and RNA damage. HD exposure causes DNA and RNA damage that results in variation of proteins and metabolites that are associated with transcription, translation and cellular energy.

Personalised Approach to Diagnosing and Managing Ischemic Stroke with a Plasma-Soluble Urokinase-Type Plasminogen Activator Receptor

Background: The increasing incidence of ischemic stroke has led to the search for a novel biomarker to predict the course of disease and the risk of mortality. Recently, the role of the soluble urokinase plasminogen activator receptor (suPAR) as a biomarker and indicator of immune system activation has been widely examined. Therefore, the aim of the current study was to assess the dynamics of changes in serum levels of suPAR in ischemic stroke and to evaluate the prognostic value of suPAR in determining mortality risk. Methods: Eighty patients from the Department of Neurology, diagnosed with ischemic stroke, were enrolled in the study. Residual blood was obtained from all the patients on the first, third and seventh days after their ischemic stroke and the concentrations of suPAR and C-reactive protein (CRP), as well as the number of leukocytes and National Institute of Health’s Stroke Scale (NIHSS) scores, were evaluated. Results: On the first day of ischemic stroke, the average suPAR concentration was 6.55 ng/mL; on the third day, it was 8.29 ng/mL; on the seventh day, it was 9.16 ng/mL. The average CRP concentration on the first day of ischemic stroke was 4.96 mg/L; on the third day, it was 11.76 mg/L; on the seventh day, it was 17.17 mg/L. The number of leukocytes on the first day of ischemic stroke was 7.32 × 103/mm3; on the third day, it was 9.27 × 103/mm3; on the seventh day, it was 10.41 × 103/mm3. Neurological condition, which was assessed via the NIHSS, on the first day of ischemic stroke, was scored at 10.71 points; on the third day, it was scored at 12.34 points; on the seventh day, it was scored at 13.75 points. An increase in the values of all the evaluated parameters on the first, third and seventh days of hospitalisation was observed. The patients with hypertension, ischemic heart disease and type 2 diabetes showed higher suPAR and CRP concentrations at the baseline as well as on subsequent days of hospitalisation. The greatest sensitivity and specificity were characterised by suPAR-3, where a value above 10.5 ng/mL resulted in a significant increase in mortality risk. Moreover, an NIHSS-1 score above 12 points and a CRP-3 concentration above 15.6 mg/L significantly increased the risk of death in the course of the disease. Conclusions: The plasma suPAR concentration after ischemic stroke is strongly related to the patient’s clinical status, with a higher concentration on the first and third days of stroke resulting in a poorer prognosis at a later stage of treatment. Therefore, assessing the concentration of this parameter has important prognostic value.

Specific Combinations of Inflammatory, Angiogenesis and Vascular Integrity Biomarkers Are Associated with Clinical Severity, Coma and Mortality in Beninese Children with Plasmodium Falciparum Malaria

Malaria-related deaths could be prevented if powerful diagnostic and reliable prognostic biomarkers were available to allow rapid prediction of the clinical severity allowing adequate treatment. Using quantitative ELISA, we assessed the plasma concentrations of Procalcitonin, Pentraxine-3, Ang-2, sTie-2, suPAR, sEPCR and sICAM-1 in a cohort of Beninese children with malaria to investigate their potential association with clinical manifestations of malaria. We found that all molecules showed higher levels in children with severe or cerebral malaria compared to those with uncomplicated malaria (p-value < 0.005). Plasma concentrations of Pentraxine-3, Procalcitonin, Ang-2 and the soluble receptors were significantly higher in children with coma as defined by a Blantyre Coma Score < 3 (p < 0.001 for Pentraxine-3, suPAR, and sTie-2, p = 0.004 for PCT, p = 0.005 for sICAM-1, p = 0.04 for Ang-2). Moreover, except for the PCT level, the concentrations of Pentraxine-3, suPAR, sEPCR, sICAM-1, sTie-2 and Ang-2 were higher among children who died from severe malaria compared to those who survived (p = 0.037, p = 0.035, p < 0.0001, p= 0.0008, p = 0.01 and p = 0.02, respectively). These findings indicate the ability of these molecules to accurately discriminate among clinical manifestations of malaria, thus, they might be potentially useful for the early prognostic of severe and fatal malaria, and to improve management of severe cases.

Soluble Urokinase Plasminogen Activator Receptor Levels Correlation with Other Inflammatory Factors in Prognosis of Disability and Death in Patients with Ischemic Stroke

Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker elevated in cardiovascular diseases. The aim of this 3-year follow-up prospective study was to evaluate suPAR levels in patients with a first ischemic stroke in correlation with CRP, PCT, NT-proCNP and endothelin 1-21 and to investigate the impact of suPAR on the outcome. Fifty-one patients (mean age 73.7+ = 11.9 years, 26 female and 25 male) were included. Samples were collected on the first (suPAR 1), third (suPAR 3) and seventh days after stroke onset (suPAR 7). Plasma samples were analyzed using ELISA. A phone interview was conducted to collect follow-up information after 24 and 36 months (modified Rankin Scale, mRS). A positive correlation between suPAR levels and other inflammatory biomarkers (except endothelin 3) was observed. A positive correlation between suPAR 3 and mRS score at 24 months was observed (p = 0.042). The logistic regression model revealed no significant effect of suPAR on death occurrence in the first 24 months: suPAR 1 (p = 0.8794), suPAR 3 (p = 0.2757), and suPAR 7 (p = 0.3652). The suPAR level is a potential inflammatory marker in ischemic stroke, and there is a correlation with other markers. There is no major impact on mortality. However, the suPAR level is associated with a degree of disability or dependence in daily activities 2 years after a stroke.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) as a Biomarker of Systemic Chronic Inflammation

Systemic chronic inflammation (SCI) is persistent, health-damaging, low-grade inflammation that plays a major role in immunosenescence and in development and progression of many diseases. But currently, there are no recognized standard biomarkers to assess SCI levels alone, and SCI is typically measured by combining biomarkers of acute inflammation and infection, e.g., CRP, IL-6, and TNFα. In this review, we highlight 10 properties and characteristics that are shared by the blood protein soluble urokinase plasminogen activator receptor (suPAR) and SCI, supporting the argument that suPAR is a biomarker of SCI: (1) Expression and release of suPAR is upregulated by immune activation; (2) uPAR and suPAR exert pro-inflammatory functions; (3) suPAR is associated with the amount of circulating immune cells; (4) Blood suPAR levels correlate with the levels of established inflammatory biomarkers; (5) suPAR is minimally affected by acute changes and short-term influences, in contrast to many currently used markers of systemic inflammation; (6) Like SCI, suPAR is non-specifically associated with multiple diseases; (7) suPAR and SCI both predict morbidity and mortality; (8) suPAR and SCI share the same risk factors; (9) suPAR is associated with risk factors and outcomes of inflammation above and beyond other inflammatory biomarkers; (10) The suPAR level can be reduced by anti-inflammatory interventions and treatment of disease. Assessing SCI has the potential to inform risk for morbidity and mortality. Blood suPAR is a newer biomarker which may, in fact, be a biomarker of SCI since it is stably associated with inflammation and immune activation; shares the same risk factors as many age-related diseases; is both elevated by and predicts age-related diseases. There is strong evidence that suPAR is a prognostic marker of adverse events, morbidity, and mortality. It is associated with immune activity and prognosis across diverse conditions, including kidney disease, cardiovascular disease, cancer, diabetes, and inflammatory disorders. Thus, we think it likely represents a common underlying disease-process shared by many diseases; that is, SCI. We review the supporting literature and propose a research agenda that can help test the hypothesis that suPAR indexes SCI, with the potential of becoming the new gold standard for measuring SCI.

The Diagnostic and Prognostic Value of suPAR in Patients with Sepsis: A Systematic Review and Meta-Analysis

BACKGROUND

Soluble urokinase-type plasminogen activator receptor (suPAR) has the potential to diagnose infectious diseases. Due to the lack of reliable biomarkers and the importance of timely diagnosis for sepsis treatment, we conducted this systematic review and meta-analysis to evaluate the value of suPAR diagnosis and prognosis for sepsis.

METHODS

PubMed, Embase, Web of Science, and Cochrane Library databases were searched for studies, which reported the value of suPAR diagnosis and/or prognosis in patients with sepsis.

RESULTS

A total of 30 studies involving 6,906 patients were included. Sensitivity and specificity of suPAR for diagnosing sepsis were 0.76 [95% confidence interval (CI), 0.63-0.86] and 0.78 (95% CI, 0.72-0.83), respectively. The area under the summary receiver-operating characteristic curve (AUC) was 0.83 (95% CI, 0.80-0.86). Pooled sensitivity and specificity for predicting mortality were 0.74 (95% CI, 0.67-0.80) and 0.70 (95% CI, 0.63-0.76), respectively, with AUC of 0.78 (95% CI, 0.74-0.82). In addition, AUC for differentiating sepsis from systemic inflammatory response syndrome (SIRS) was 0.81 (95% CI, 0.77-0.84), and the sensitivity and specificity were 0.67 (95% CI, 0.58-0.76) and 0.82 (95% CI, 0.73-0.88), respectively.

CONCLUSION

suPAR is a feasible biomarker for timely diagnosis and prognosis of sepsis. Compared with effective value of procalcitonin (PCT) identified by previous meta-analysis, suPAR has similar clinical guiding value, whereas suPAR exhibits higher specificity, which can facilitate the deficiencies of PCT. suPAR also shows a diagnostic value in differentiating sepsis from SIRS. Considering the lack of biomarkers for sepsis and the similar clinical value of suPAR and PCT, suPAR should be considered as a biomarker in clinical practice for sepsis.

Soluble Urokinase Plasminogen Activator Receptor: A Biomarker for Predicting Complications and Critical Care Admission of COVID-19 Patients

The novel coronavirus infection has spread worldwide, causing a wide spectrum of clinical manifestations. Most patients develop moderate clinical illness, but a substantial number will experience severe pneumonia, which may rapidly progress to acute respiratory distress syndrome and multiple organ failure. In this population, soluble urokinase plasminogen activator receptor (suPAR) could serve as a quick triage test and independent marker of clinical severity, hospital and intensive care unit admission, complications, and mortality.

Soluble urokinase plasminogen activator receptor (suPAR) as a prognostic marker of mortality in healthy, general and patient populations: protocol for a systematic review and meta-analysis

INTRODUCTION

Chronic inflammation is increasingly recognised as a major contributor to disease, disability and ultimately death, but measuring the levels of chronic inflammation remains non-canonised, making it difficult to relate chronic inflammation and mortality. Soluble urokinase plasminogen activator receptor (suPAR), an emerging biomarker of chronic inflammation, has been proposed as a prognostic biomarker associated with future incidence of chronic disease and mortality in general as well as patient populations. Proper prognostic biomarkers are important as they can help improve risk stratification in clinical settings and provide guidance in treatment or lifestyle decisions as well as in the design of randomised trials. Here, we wish to summarise the evidence about the overall association of the biomarker suPAR with mortality in healthy, general and patient populations across diseases.

METHODS AND ANALYSIS

The search will be conducted using Medline, Embase and Scopus databases from their inception to 03 June 2020 to identify studies investigating 'suPAR' and 'mortality'. Observational studies and control groups from intervention studies written in English or Danish will be included. The 'Quality In Prognosis Studies' tool will be used to assess the risk of bias for the studies included. Unadjusted and adjusted mortality outcome measures (eg, risk ratios, ORs, HRs) with 95% CIs will be extracted for healthy individuals, general and patient populations. The primary outcome is all-cause mortality within any given follow-up. Subgroup analyses will be performed based on time of outcome, cause of death, population type, adjustments for conventional risk factors and inflammation markers.

ETHICS AND DISSEMINATION

This systematic review will synthesise evidence on the use of suPAR as a prognostic marker for mortality. The results will be disseminated by publication in a peer-reviewed journal. Data used will be obtained from published studies, and ethics approval is therefore not necessary for this systematic review.

TRIAL REGISTRATION NUMBER PROSPERO

CRD42020167401.

Medicina de precisión en sepsis: utilidad de los biomarcadores en pacientes biomarcadores en pacientes críticamente enfermos

Durante años la evolución del cuidado intensivo ha intentado ofrecer una atención basada en protocolos y paquetes de manejo agrupados por patologías y cuadro sindromáticos. Aunque se logró disminuir la mortalidad en diferentes patologías (sepsis y síndromes coronario agudo y de distrés respiratorio agudo), no se han resuelto por completo los problemas clínicos, en especial el diagnóstico y el manejo. Una nueva opción ha surgido en el horizonte denominada “medicina de precisión”, entendida como estrategia de prevención y tratamiento que tiene en cuenta la variabilidad individual. La sepsis es un síndrome con múltiples aristas en cuanto al fenotipo y genotipo, cuyo diagnóstico temprano es relevante para los desenlaces clínicos. Hasta el momento el enfoque principal ha sido la identificación de un germen etiológico para diferenciarla del síndrome de respuesta inflamatoria sistémica (SIRS). En los últimos años el paradigma en enfermedades infecciosas ha cambiado debido a estudios que demuestran como la respuesta inmunitaria del paciente séptico tiene un papel clave en el desarrollo de la enfermedad, con implicaciones en el diagnóstico, pronóstico y tratamiento, que podrían ayudar a cambiar el abordaje en los próximos años gracias a una estrategia basada en medicina de precisión. Hoy los aislamientos microbiológicos y los cultivos siguen siendo el estándar de referencia con varias desventajas como el tiempo para obtener resultados, sobre todo en infecciones por gérmenes resistentes u hongos, que pueden retrasar el inicio de la terapia antimicrobiana. Como alternativa se ha planteado el uso de biomarcadores en sepsis que siendo productos de la respuesta inflamatoria del individuo ante la infección, son útiles para el diagnóstico y pronóstico primordialmente en los críticamente enfermos. Decidimos realizar esta revisión narrativa acerca de la utilidad de los biomarcadores en pacientes con sepsis críticamente enfermos, para enfocarlos en un modelo de medicina personalizada.

Urinary suPAR: a non-invasive biomarker of infection and tissue inflammation for use in studies of large free-ranging mammals

Studies of large free-ranging mammals incorporating physiological measurements typically require the collection of urine or faecal samples, due to ethical and practical concerns over trapping or darting animals. However, there is a dearth of validated biomarkers of immune activation and inflammation that can be measured non-invasively. We here evaluate the utility of urinary measurements of the soluble form of the urokinase plasminogen activator receptor (suPAR), for use as a health marker in studies of wild large mammals. We investigate how urinary suPAR concentrations change in response to viral infection and surgical trauma (inflammation), comparing it to the measurement of a marker of cellular immune activation, urinary neopterin (uNEO), in captive rhesus macaques. We then test the field utility of urinary suPAR, assessing the effects of soil and faecal contamination, sunlight, storage at different temperatures, freeze-thaw cycles, and lyophilization. We find that suPAR concentrations rise markedly in response to both infection and surgery-associated inflammation, unlike uNEO concentrations, which only rise in response to the former. Our field validation demonstrates that urinary suPAR is reasonably robust to many of the issues associated with field collection, sample processing, and storage, as long as samples can be stored in a freezer. Urinary suPAR is thus a promising biomarker applicable for monitoring various aspects of health in wild primates and potentially also other large mammals.

A Comparative Study of the Diagnostic and Prognostic Utility of Soluble Urokinase-type Plasminogen Activator Receptor and Procalcitonin in Patients with Sepsis and Systemic Inflammation Response Syndrome

Introduction

Differentiation between sepsis and systemic inflammation response syndrome (SIRS) remains a diagnostic challenge for clinicians as both may have similar clinical presentation. A quick and accurate diagnostic tool that can discriminate between these two conditions would aid in appropriate therapeutic decision-making. This prospective study was conducted to evaluate the diagnostic and prognostic utility of soluble urokinase-type plasminogen activator receptor (suPAR) and procalcitonin (PCT) in sepsis and SIRS patients.

Materials and methods

Eighty-eight patients were enrolled, of which 29 were SIRS and 59 were sepsis patients. The levels of suPAR and PCT were measured on the day of admission (day 1), day 3, and day 7.

Results

The levels of suPAR and PCT were significantly higher (p = 0.05 and p < 0.001, respectively) in sepsis group as compared to the SIRS group. The soluble urokinase-type plasminogen activator receptor was a better diagnostic tool in predicting sepsis over PCT [area under curve (AUC) 0.89 vs 0.82] on day 1. The best cutoff for suPAR was 5.58 pg/mL [96% sensitivity and 90% negative predictive value (NPV)] and the best cut-off for PCT was 1.96 ng/mL (93.1% sensitivity and 80% NPV). However, PCT had better prognostic trends (p = 0.006) to identify nonsurvivors in sepsis group.

Conclusion

Our findings suggest that both suPAR and PCT can be used as potential test tools to differentiate between SIRS and sepsis. Procalcitonin showed significant prognostic trends to identify nonsurvivors. The soluble urokinase-type plasminogen activator receptor showed better diagnostic potential than PCT on day 1.

Clinical significance

Both suPAR and PCT can be used as surrogate biomarkers to distinguish sepsis from SIRS. Procalcitonin showing a significant prognostic trend to identify nonsurvivors can help the clinicians to take relevant clinical decisions. Also, the use of biomarkers like PCT and suPAR could reduce the inappropriate use of antibiotics in noninfective SIRS.

How to cite this article

Sharma A, Ray S, Mamidipalli R, Kakar A, Chugh P, Jain R, et al. A Comparative Study of the Diagnostic and Prognostic Utility of Soluble Urokinase-type Plasminogen Activator Receptor and Procalcitonin in Patients with Sepsis and Systemic Inflammation Response Syndrome. Indian J Crit Care Med 2020;24(4):245–251.

The diagnostic value of soluble urokinase-type plasminogen activator receptor (suPAR) for the discrimination of vertebral osteomyelitis and degenerative diseases of the spine

Background

There is still a challenge in discriminating between vertebral osteomyelitis and degenerative diseases of the spine. To this end, we determined the suitability of soluble urokinase-type plasminogen activator receptor (suPAR) and compared the diagnostic potential of suPAR to CRP.

Methods

Patients underwent surgical stabilization of the lumbar and/or thoracic spine with removal of one or more affected intervertebral discs, as therapy for vertebral osteomyelitis (n = 16) or for erosive osteochondrosis (control group, n = 20). In this prospective study, we evaluated the suPAR and CRP levels before (pre-OP) and after surgery (post-OP) on days 3–5, 6–11, 40–56, and 63–142.

Results

The suPAR levels in vertebral osteomyelitis patients were significantly higher than those from controls pre-OP, 3–5 days post-OP, and 6–11 days post-OP. Significantly higher CRP levels were observed in the vertebral osteomyelitis group than in the controls pre-OP and 6–11 days post-OP. Levels of suPAR and CRP correlated positively in all patients in the pre-OP period: r = 0.63 (95% CI: 0.37–0.79), p < 0.0001. The values for the area under the receiver operating characteristics curve (AUC) for pre-OP and the overall model post-OP were 0.88 (95% CI: 0.76–1.00) and 0.84 (95% CI: 0.71–0.97) for suPAR, 0.93 (95% CI: 0.85–1.00) and 0.77 (95% CI: 0.62–0.93) for CRP, and 0.98 (95% CI: 0.96–1.00) and 0.91 (95% CI: 0.82–1.00) for the combination of suPAR and CRP. The AUC for suPAR pre-OP revealed an optimum cut-off value, sensitivity, specificity, NPV, and PPV of 2.96 ng/mL, 0.69, 1.00, 0.80, and 1.00, respectively. For CRP, these values were 11.58 mg/L, 0.88, 0.90, 0.90, and 0.88, respectively.

Conclusion

The present results show that CRP is more sensitive than suPAR whereas suPAR is more specific than CRP. Moreso, our study demonstrated that improvement in the diagnostic power for discrimination of vertebral osteomyelitis and degenerative diseases of the spine can be achieved by a combination of both suPAR and CRP.

Trial registration

ClinicalTrials.gov, NCT02554227, posted Sept. 18, 2015, and updated Aug. 13, 2019

The role of soluble urokinase plasminogen activator receptor (suPAR) in the diagnostics of diabetic foot infection

Background: To investigate the role of soluble urokinase plasminogen activator receptor (suPAR) in the diagnosis of diabetic foot infection and to determine whether it is superior to other infection markers like leukocyte, neutrophil, erythrocyte sedimentation rate, c-reactive protein and procalcitonin.Methods: The present prospective study consisted of four groups: Group 1, healthy volunteers (n = 38); Group 2, patients without diabetic foot ulcers (n = 40); Group 3, diabetic patients with uninfected foot ulcers (n = 33); and Group 4, patients who had diabetic foot infection (n = 48). In each group, the leukocyte, neutrophil, erythrocyte sedimentation rate, c-reactive protein and procalcitonin and suPAR levels were examined. The results were then statistically compared. In addition, the patients in Group 4 were further divided according to the presence of mild, moderate, and severe infection. Also osteomyelitis were evaluated in Group 4 and statistically compared.Results: All infection markers were significantly higher in group 4 patients than those in the other three groups (p < .05). Similarly, all infection markers in the severe diabetic foot infection group were statistically higher than mild diabetic foot infection group (p < .05); however, only suPAR and erythrocyte sedimentation rate were significantly high in cases with osteomyelitis (p < .05). In the receiver operating characteristic analysis, the optimal cut-off value for suPAR was determined to be 2.8 ng/ml, and the sensitivity and specificity above this value were 95.8% and 82.8%, respectively.Conclusions: The current study demonstrated that suPAR might be used as a supportive diagnostic method for the diagnosis of diabetic foot infections.

Serum plasminogen activator urokinase receptor predicts elevated risk of acute respiratory distress syndrome in patients with sepsis and is positively associated with disease severity, inflammation and mortality

The present study aimed to evaluate the predictive value of serum soluble urokinase plasminogen activator receptor (suPAR) regarding the risk of acute respiratory distress syndrome (ARDS) in sepsis patients, and investigate its correlation/association with disease severity, inflammation and mortality in sepsis patients with ARDS. A total of 57 sepsis patients with ARDS and 58 sepsis patients without ARDS were recruited for the present case-control study. Laboratory tests, acute physiology and chronic health evaluation (APACHE) II score and sequential organ failure assessment (SOFA) score were evaluated, and mortality during hospitalization was recorded. Blood samples were collected and serum suPAR was detected by ELISA. Furthermore, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-10 and IL-17, as well as C-reactive protein (CRP) were detected. The results indicated that the serum levels of suPAR in sepsis patients with ARDS were higher than those in sepsis patients without ARDS. Receiver operating characteristics (ROC) curve analysis indicated that it was possible to distinguish sepsis patients with ARDS from sepsis patients without ARDS based on their serum suPAR levels, and multivariate logistic regression analysis suggested that serum suPAR levels were an independent predictor of the risk of ARDS in sepsis patients. In sepsis patients with ARDS, serum suPAR levels were positively correlated with the APACHE II score, SOFA score and the levels of CRP, TNF-α, IL-1β and IL-8. In addition, serum suPAR levels were lower in survivors compared with those in non-survivors, and ROC curve analysis suggested that serum suPAR was able to predict the probability of mortality. In conclusion, serum suPAR independently predicted an elevated risk of ARDS in patients with sepsis, and was correlated/associated with greater disease severity, higher inflammation and increased mortality in patients with sepsis and ARDS.

SuPAR correlates with mortality and clinical severity in patients with necrotizing soft-tissue infections: results from a prospective, observational cohort study

Necrotizing soft tissue infections (NSTI) have a 90-day mortality rate of 18–22%. Tools are needed for estimating the prognosis and severity of NSTI upon admission. We evaluated soluble urokinase-type plasminogen activator receptor (suPAR) levels at admission as a prognostic marker of NSTI severity and mortality. In a prospective, observational cohort study, suPAR was measured in 200 NSTI patients. We compared admission suPAR levels in survivors and non-survivors, patients with septic shock and non-shock, amputation and non-amputation, correlations with Simplified Acute Physiology Score II (SAPS II) and the Sequential Organ Failure Assessment (SOFA) score. Admission suPAR levels were higher in septic shock vs. non-septic shock patients (9.2 vs. 5.8 ng/mL, p-value < 0.001) and non-survivors vs. survivors (11 vs. 6.1 ng/mL, p-value < 0.001) and correlated with SAPS II (r = 0.52, p < 0.001) and SOFA score (r = 0.64, p < 0.001). Elevated suPAR upon admission was associated with 90-day mortality (log-rank test p < 0.001), however not after adjustment for age, sex, and SOFA score. The AUC for suPAR and 90-day mortality was 0.77. We found that suPAR is a promising candidate for prognosis and severity in patients with NSTI.

suPAR in the assessment of post intensive care unit prognosis: a pilot study

OBJECTIVE

To determine the performance of soluble urokinase-type plasminogen activator receptor upon intensive care unit discharge to predict post intensive care unit mortality.

METHODS

A prospective observational cohort study was conducted during a 24-month period in an 8-bed polyvalent intensive care unit. APACHE II, SOFA, C-reactive protein, white cell count and soluble urokinase-type plasminogen activator receptor on the day of intensive care unit discharge were collected from patients who survived intensive care unit admission.

RESULTS

Two hundred and two patients were included in this study, 29 patients (18.6%) of whom died after intensive care unit discharge. Nonsurvivors were older and more seriously ill upon intensive care unit admission with higher severity scores, and nonsurvivors required extended use of vasopressors than did survivors. The area under the receiver operating characteristics curves of SOFA, APACHE II, C-reactive protein, white cell count, and soluble urokinase-type plasminogen activator receptor at intensive care unit discharge as prognostic markers of hospital death were 0.78 (95%CI 0.70 - 0.86); 0.70 (95%CI 0.61 - 0.79); 0.54 (95%CI 0.42 - 0.65); 0.48 (95%CI 0.36 - 0.58); and 0.68 (95%CI 0.58 - 0.78), respectively. SOFA was independently associated with a higher risk of in-hospital mortality (OR 1.673; 95%CI 1.252 - 2.234), 28-day mortality (OR 1.861; 95%CI 1.856 - 2.555) and 90-day mortality (OR 1.584; 95%CI 1.241 - 2.022).

CONCLUSION

At intensive care unit discharge, soluble urokinase-type plasminogen activator receptor is a poor predictor of post intensive care unit prognosis.

Soluble mannose receptor levels in blood correlate to disease severity in patients with community-acquired pneumonia

PURPOSE

Community-acquired pneumonia (CAP) is the most common form of pneumonia and is a leading infectious cause worldwide. Identification of patients that are at risk to develop severe disease has proven to be a major challenge. Soluble mannose receptor (sMR; sCD206) is a new serum marker for macrophage activation. Recent studies showed that sMR levels are increased in patients suffering from severe infections making it a potential biomarker for improved discrimination of disease severity. For measuring sMR, no standardized assay is available. Aim of this study is to develop an assay for standardized measurement of sMR. Next, this assay was used to assess sMR plasma levels for its ability to predict severe disease development in a patient cohort for community-acquired pneumonia.

METHODS

We developed a well-validated sandwich ELISA that enables standardized measurement of sMR in plasma and serum samples. Repeatability was tested by calculating the percentage coefficient of variation (%CV) within and between runs and within and between operators. sMR levels were assessed in a cohort of 100 patients with community-acquired pneumonia.

RESULTS

All %CV values were <10%, indicating low variation. Higher sMR levels were observed in patients with severe disease when compared to patients without severe disease development (p = 0.004). Patients with sMR levels between 100-430 ng/ml had 22.7% chance to develop severe disease whereas patients with levels between 430-1000 ng/ml had 33.3% chance to develop severe disease.

CONCLUSIONS

We suggest that sMR has potential as a new biomarker for the prediction of disease severity in patients with community-acquired pneumonia.

suPAR as a marker of infection in acute kidney injury - a prospective observational study

Background

Soluble urokinase-type plasminogen activator receptor (suPAR) has emerged as a new sepsis biomarker. It is not known whether suPAR has a role in critically ill patients with severe acute kidney injury (AKI).

Methods

Our main aims were to describe serial serum suPAR concentrations in patients with severe AKI, to investigate a potential association between suPAR and C-reactive protein (CRP), and to compare suPAR and CRP as diagnostic markers of infection in patients with AKI. Between April 2013 – April 2014, we recruited adult patients (≥18 years) with AKI KDIGO stage 2/3 admitted to a multidisciplinary Intensive Care Unit (ICU) in a University Hospital in UK. Serial serum suPAR and CRP concentrations were measured for 6 days. We compared the characteristics and serial suPAR and CRP concentrations of patients with and without an infection using Chi-squared, Fisher’s exact, t-test and Mann-Whitney tests as appropriate, and calculated the area under the receiver operating characteristics curve (AUC).

Results

Data of 55 patients with AKI stage 2/3 were analysed (62% male; mean age 60.5) of whom 43 patients received continuous renal replacement therapy. suPAR was not detectable in effluent fluid.

There was no significant correlation between daily suPAR and CRP concentrations. In patients with an infection, suPAR results were significantly higher than in those without an infection across all time points; there was no significant difference in CRP levels between both groups. After exclusion of patients with an infection before or on day of admission to ICU, the AUC of suPAR for predicting an infection later was 0.62 (95% CI 0.43–0.80) compared to 0.50 (95% CI 0.29–0.71) for CRP.

Conclusions

In critically ill patients with AKI stage 2/3, suPAR is a better marker of infection than CRP.

Trial registration

The study was retrospectively registered on the ISRCTN registry on 25 November 2012 (ISRCTN88354940).

Activation of coagulation and endothelium with concurrent impairment of anticoagulant mechanisms in patients with typhoid fever

OBJECTIVES

Typhoid fever caused by Salmonella Typhi remains a major burden worldwide. Gastrointestinal bleeding can be seen in up to 10 percent of patients and may be fatal. The coagulopathy, which may be the driver of this severe complication in patients with typhoid fever, however is ill defined. The aim of this study was to evaluate the activation of coagulation, anticoagulation, and fibrinolysis in patients with acute typhoid fever.

METHODS

Parameters of coagulation and fibrinolysis were measured in 28 hospitalized patients with culture-confirmed or PCR-confirmed typhoid fever and compared to 38 age- and sex-matched healthy volunteers.

RESULTS

Patients demonstrated activation of the coagulation system, as reflected by elevated in vitro thrombin generation and high plasma levels of fibrinogen, D-dimer and prothrombin fragment F1 + 2 in concert with consumption of coagulation factors resulting in a prolonged prothrombin-time and activated-partial-thromboplastin-time. Concurrently, the anticoagulant proteins, protein C and antithrombin, were significantly lower in comparison to healthy controls. Patients also demonstrated evidence of activation and inhibition of fibrinolysis and a marked activation of endothelial cells. The extent of coagulation activation was associated with the course of the disease, repeated testing during convalescence showed a return toward normal values.

CONCLUSIONS

Activation of coagulation is an important clinical feature of typhoid fever and is associated with severity of disease.

Serum suPAR and syndecan-4 levels predict severity of community-acquired pneumonia: a prospective, multi-centre study

Background

Community-acquired pneumonia (CAP) is a major cause of death worldwide and occurs with variable severity. There are few studies focused on the expression of soluble urokinase-type plasminogen activator receptor (suPAR) and syndecan-4 in patients with CAP.

Methods

A prospective, multi-centre study was conducted between January 2014 and December 2016. A total of 103 patients with severe CAP (SCAP), 149 patients with non-SCAP, and 30 healthy individuals were enrolled. Clinical data were recorded for all enrolled patients. Serum suPAR and syndecan-4 levels were determined by quantitative enzyme-linked immunosorbent assay. The t test and Mann–Whitney U test were used to compare between two groups; one-way analysis of variance and the Kruskal–Wallis test were used to compare multiple groups. Correlations were assessed using Pearson and Spearman tests. Area under the curve (AUCs), optimal threshold values, sensitivity, and specificity were calculated. Survival curves were constructed and compared by log-rank test. Regression analyses assessed the effect of multiple variables on 30-day survival.

Results

suPAR levels increased in all patients with CAP, especially in severe cases. Syndecan-4 levels decreased in patients with CAP, especially in non-survivors. suPAR and syndecan-4 levels were positively and negatively correlated with severity scores, respectively. suPAR exhibited high accuracy in predicting SCAP among patients with CAP with an AUC of 0.835 (p < 0.001). In contrast, syndecan-4 exhibited poor diagnostic value for predicting SCAP (AUC 0.550, p = 0.187). The AUC for predicting mortality in patients with SCAP was 0.772 and 0.744 for suPAR and syndecan-4, respectively; the respective prediction threshold values were 10.22 ng/mL and 6.68 ng/mL. Addition of both suPAR and syndecan-4 to the Pneumonia Severity Index significantly improved their prognostic accuracy, with an AUC of 0.885. Regression analysis showed that suPAR ≥10.22 ng/mL and syndecan-4 ≤ 6.68 ng/mL were reliable independent markers for prediction of 30-day survival.

Conclusion

suPAR exhibits high accuracy for both diagnosis and prognosis of SCAP. Syndecan-4 can reliably predict mortality in patients with SCAP. Addition of both suPAR and syndecan-4 to a clinical scoring method could improve prognostic accuracy.

Trial registration

ClinicalTrials.gov, NCT03093220. Registered on 28 March 2017 (retrospectively registered).

Presepsin: A potential biomarker of PJI? A comparative analysis with known and new infection biomarkers

There is still no "gold standard" for the diagnosis and prognosis of post-operative periprosthetic joint infection (PJI). Among serum biomarkers, an emerging molecule is presepsin, the soluble fraction of CD14, recently described in other settings as a powerful diagnostic tool to detect sepsis at different degrees of severity. The aim of this study was to investigate the diagnostic and prognostic value of presepsin in PJI. A total of 30 patients with PJI and 30 patients without PJI were enrolled. Presepsin, C-reactive protein (CRP), serum interleukin (IL)-6, triggering receptor expressed on myeloid cells 1 (TREM-1), CCL2, matrix metalloproteinase 9 (MMP-9), CD163, osteopontin (OPN), and toll-like receptor 2 (TLR2) were measured at different times after surgery. Receiver operating characteristic (ROC) curves and area under the curve (AUC) were analyzed for each biomarker. Presepsin showed greater diagnostic value than CRP and IL-6; CD163, TREM-1, and MMP-9 had very low diagnostic potential. Presepsin, OPN, CCL2, suPAR, and TLR2 all decreased significantly with increasing time of recovery after surgery in PJI patients. Presepsin can be considered a useful tool for the diagnosis and clinical monitoring of PJI and can be backed by a panel of new inflammatory markers involved in monocyte-/macrophage-mediated inflammatory responses, such as OPN, CCL2, TLR2, and suPAR.

How biomarkers reflect the prognosis and treatment of necrotising soft tissue infections and the effects of hyperbaric oxygen therapy: the protocol of the prospective cohort PROTREAT study conducted at a tertiary hospital in Copenhagen, Denmark

INTRODUCTION

Not enough is known regarding the prognosis and treatment of necrotising soft tissue infections (NSTIs). Mortality has been shown to be 25%-35%, with survivors coping with amputations and prolonged rehabilitation. This study will evaluate soluble urokinase-type plasminogen activator receptor (suPAR) as a possible prognostic marker of NSTI severity and mortality, as well as whether hyperbaric oxygen therapy (HBOT) can modulate markers of endothelial damage during NSTI. We hypothesise that in patients with NSTI, suPAR can provide prognostic risk assessment on hospital admission and that HBOT can reduce the endothelial damage that these patients are exposed to.

METHODS AND ANALYSIS

This is a prospective observational study. Biomarkers will be measured in 150 patients who have been diagnosed with NSTI. On admission, baseline blood samples will be obtained. Following surgery and HBOT, daily blood samples will be obtained in order to measure endothelial and prognostic biomarkers (soluble thrombomodulin, syndecan-1, sE-selectin, vascular endothelial (VE)-cadherin, protein C and suPAR levels). Clinical data will be acquired during the first 7 days of stay in the intensive care unit. The primary outcomes in studies I and II will be endothelial biomarker levels after HBOT, and in study III suPAR levels as a marker of disease prognosis and severity.

ETHICS AND DISSEMINATION

The study has been approved by the Regional Scientific Ethical Committee of Copenhagen (H-16021845) and the Danish Data Protection Agency (RH-2016-199). Results will be presented at national and international conferences and published in peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Identifier NCT03147352. (Pre-results).

Soluble urokinase-type plasminogen activator receptor and urokinase-type plasminogen activator receptor contribute to chemoresistance in leukemia

The soluble urokinase-type plasminogen activator receptor (suPAR) and the urokinase-type plasminogen activator receptor (uPAR) have been proposed as useful biomarkers of tumor progression. Recently, suPAR was associated with chemoresistance in lung cancer. However, its clinical significance in leukemia has not previously been investigated. The present study examined the plasma levels of suPAR and the expression of the uPAR on bone marrow (BM) cells in 86 patients with leukemia at diagnosis prior to chemotherapy and 26 normal subjects (control group). The plasma suPAR levels were measured using ELISA, whilst uPAR expression was assayed by flow cytometry analysis. In addition, cell surface uPAR expression on K562 and multidrug-resistant K562/ADM cell lines was studied by western blotting. On admission and follow-up, the levels of suPAR in patients with leukemia were significantly increased compared with controls. Systemic levels of suPAR were strongly associated with the numbers of white blood cells. A case was defined as uPAR-positive (uPAR+) if >20% of the gated cells expressed uPAR. In comparison with 26 healthy BM samples that were negative for uPAR expression, 48 (55.8%) of the 86 leukemia patients were uPAR+. uPAR expression on the cell surface of multidrug-resistant K562/ADM cells was increased compared with that on K562 cells. In conclusion, plasma suPAR expression may be a useful marker for subtype classification of patients with leukemia and cell surface uPAR may be associated with resistance to chemotherapy or disease progression.

Serum soluble urokinase-type plasminogen activator receptor as a biological marker of bacterial infection in adults: a systematic review and meta-analysis

The serum concentration of soluble urokinase-type plasminogen activator receptor (suPAR) reflects immune activation. We performed a meta-analysis to evaluate the usefulness of suPAR for the diagnosis and prognosis of bacterial infections. PubMed, Embase and Cochrane Library databases were searched for studies reporting the detection of suPAR in adult patients with bacterial infections. Seventeen studies were selected from 671 studies. The pooled sensitivity and specificity of suPAR for diagnosing infection were 0.73 and 0.79, respectively, and the area under the summary receiver operating characteristic curve (AUC) was 0.82. Subgroup analyses revealed suPAR showed similar AUC values for diagnosing sepsis and bacteremia, but the AUC for differentiating sepsis from systemic inflammatory response syndrome (SIRS) was only 0.68. Elevated suPAR levels were significantly associated with a high risk of death, with a pooled risk ratio of 3.37 (95% confidence interval, 2.60–4.38). The pooled sensitivity and specificity for predicting mortality were 0.70 and 0.72, respectivfely, with an AUC of 0.77. Serum suPAR could be a biomarker for the diagnosis and prognosis of bacterial infection, but it is relatively ineffective for differentiating sepsis from SIRS. Further investigation is required to evaluate whether using of suPAR in combination with other biomarkers can improve diagnostic efficacy.

The diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) compared to C-reactive protein (CRP) and procalcitonin (PCT) in children with systemic inflammatory response syndrome (SIRS)

BACKGROUND

The aim of the present study was to determine the diagnostic and prognostic values of suPAR and to compare them to CRP and PCT in pediatric patients with systemic inflammatory response syndrome (SIRS).

MATERIAL-METHODS

A prospective case-control study was performed.The study was performed in a tertiary university hospital which has a 649-bed capacity. Patients included 27 children with SIRS and 27 control subjects without any infection or immunosuppressive condition. Blood samples were obtained on the day of admission and on the 4-7th days of the hospital stay.

RESULTS

The median (min-max) serum levels of suPAR obtained on the first day of the admission were 10.06 (2.7-57.46) and 2.22 (1.08-5.13) ng/Ml for the SIRS group and control group, respectively. The median serum levels of suPAR in the SIRS group was significantly higher than that in the control group (p < 0.05). The serum suPAR levels was significantly higher in nonsurvivors than in survivors in SIRS group (p < 0.05). In the SIRS group, the area under the receiver operating characteristics curve (AUC^ROC) for suPAR revealed an optimum cut-off value, sensitivity, specificity, NPV and PPV of 0.978, 3.8 ng/mL, 96%, 96%, 96%, and 96%, respectively.

CONCLUSIONS

We conclude that suPAR does have diagnostic value in children with SIRS. Additionally, persistent high serum suPAR level predicts mortality in SIRS in children.

Role of suPAR and Lactic Acid in Diagnosing Sepsis and Predicting Mortality in Elderly Patients

This study investigated the diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) and serum lactate in elderly patients with sepsis and evaluated their capacity to predict mortality and their correlation to Sequential Organ Failure Assessment (SOFA) score. The study included 80 participants, divided into two groups: 40 cases (mean age, 68.9 ± 5.9) admitted to the intensive care unit and 40 healthy controls (mean age, 67.1 ± 6.2). Elderly patients with sepsis had significantly higher levels of serum suPAR and lactic acid compared to healthy controls. Receiver operating characteristic (ROC) curve analysis showed that suPAR (cutoff value, ≥4.37 ng/ml) has higher area under the curve (AUC) than lactic acid (cutoff value, ≥1.95 mmol/l) for diagnosing sepsis. Serum lactate has superior prognostic value compared to suPAR with AUC of 0.82 (cutoff value, 2.2 mmol/l) and 0.72 (cutoff value, 6.3 ng/ml), respectively. The diagnostic power of combined usage of suPAR and lactate serum concentrations showed AUC of 0.988 (95% confidence interval 0.934 to 1.0). The combination of both biomarkers either together or with SOFA score may serve as a useful guide to patients who need more intensive resuscitation.

Increased Risk of Acute Kidney Injury following Pneumococcal Pneumonia: A Nationwide Cohort Study

Purpose

Pneumococcal disease leads to renal complications ranging from persistent proteinuria to end-stage renal disease. Studies on the association between pneumococcal pneumonia (PP) and acute kidney injury (AKI) are scant. This study assessed the relationship between PP and risk of AKI.

Methods

This nationwide population-based cohort study examined data from the Taiwan National Health Insurance Research Database for the period 2000–2011. We identified inpatients with newly diagnosed PP according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. In addition, we selected a comparison cohort from inpatient claims without the diagnosis of PP that was randomly frequency-matched with the PP cohort according to age, sex, index year and comorbidities. We analyzed the risks of AKI by using Cox proportional hazards regression models, adjusted for sex, age, and comorbidities.

Results

A total of 10,069 patients with PP and 10,069 controls were enrolled in this study. After adjustments for age, sex, and comorbidities, patients with PP had a 1.11-fold risk of developing AKI compared with the comparison cohort.

Conclusion

This study indicates that AKI risks are higher in patients with PP compared with the comparison cohort. Careful follow-up observation and aggressive treatment are necessary for patients with PP to reduce the risk of AKI.

Increased circulating soluble urokinase-type plasminogen activator receptor (suPAR) levels in patients with slow coronary flow

Introduction

Slow coronary flow (SCF) is an angiographic phenomenon characterized by delayed opacification of epicardial coronary arteries without an obstructive coronary disease. Serum soluble urokinase-type plasminogen activator receptor (suPAR) levels seem closely related to atherosclerosis due to increased inflammation and prothrombotic state. We studied whether circulating suPAR is related to SCF.

Material and methods

The present study was cross-sectional and observational. It included 75 individuals who underwent coronary angiography with suspected CAD and had angiographically normal coronary arteries of varying coronary flow rates. The relationship between suPAR, C-reactive protein (CRP) and SCF was investigated. Forty patients with isolated SCF (mean age: 46.0 ±4.14 years) and 35 age- and gender-matched control participants with normal coronary flow (NCF) and normal coronary arteries (NCA) (mean age: 46.0 ±5.7 years) were included in the study. We used logistic regression analysis to determine the predictors of SCF.

Results

The clinical characteristics were not statistically significantly different between SCF and NCA groups. Serum suPAR level was significantly higher in the SCF group than the control group (2.5–5.4 ng/ml vs. 0.1–1.4 ng/ml; p < 0.001). Also the serum CRP level was higher in the CSF group than the control group (1.57 ±0.43 mg/l vs. 0.53 ±0.23 mg/l; p < 0.001).

Conclusions

This study revealed significantly increased serum suPAR levels in patients with SCF. Although we cannot draw conclusions on the underlying pathological process of SCF, we believe that these findings may be pioneering for further studies investigating the specific roles of circulating suPAR in the SCF phenomenon in the coronary vasculature.

Clinical value of alkaline phosphatase on the surface membrane of neutrophils for prediction of bacteremia in patients with systemic inflammatory response syndrome

In this study, the utility and diagnostic accuracy of alkaline phosphatase on the surface membrane of neutrophils (mNAP) for bacteremia in patients with systemic inflammatory response syndrome (SIRS) was investigated and assessed. A total of 149 patients with SIRS were included. mNAP values were significantly higher in bacteremic SIRS group compared with that in non-bacteremic SIRS group (P < 0.001). The mNAP levels were significantly higher in SIRS patients with gram-negative bacteremia than those with gram-positive bacteremia. (P < 0.001). The receiver operating characteristic (ROC) curve analysis revealed the areas under ROC (AUC) of 0.806 for mNAP in differentiating SIRS patients with bacteremia from those without, similar to that for procalcitonin (PCT) (0.797). Combination of PCT and mNAP gave an AUC of 0.841. mNAP shares a similar diagnostic accuracy to PCT in predicting bacteremia in SIRS patients. The combination of mNAP and PCT provides a better prediction of bacteremia in patients with SIRS than either test alone.

Serum soluble urokinase-type plasminogen activator receptor levels in male patients with acute exacerbation of schizophrenia

Inflammatory abnormalities have been shown in the pathogenesis of schizophrenia. Soluble urokinase-type plasminogen activator receptor (suPAR) is a protein that is measurable in the circulating blood and reflects the inflammation in the body. We aimed to investigate serum suPAR levels in patients with schizophrenia who were in acute state and to compare with healthy controls. Forty five patients and 43 healthy controls were included in the study. We found no significant difference in suPAR levels between patients and controls, suggesting that suPAR as an inflammatory marker does not have a role in the inflammatory process of acute schizophrenia.

Could soluble urokinase plasminogen receptor (suPAR) be used as a diagnostic biomarker for ventilator-associated pneumonia?

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker that is increasingly used for evaluation of systemic inflammation. This study was performed to investigate whether suPAR may possess a diagnostic value in patients with ventilator-associated pneumonia (VAP).

METHODS

This clinical study was performed in the anesthesia intensive care units (ICUs) of our university. In addition to descriptive data, WBC, serum levels of C-reactive protein (CRP) and suPAR prior to and after development of VAP were noted and compared in 31 patients (22 men, 9 women) diagnosed with VAP (Study Group) and 19 patients without VAP (Control Group) in ICU (14 men, 5 women).

RESULTS

The suPAR (P = 0.023), CRP (P = 0.037), WBCs (P = 0.024) in patients with VAP were significantly higher than patients without VAP. There was no remarkable difference in terms of WBCs (P = 0.052) and suPAR levels (P = 0.616) between groups on the first day of connection to mechanical ventilator. The suPAR and CRP levels in patients with VAP were significantly higher than prior to development of VAP (P = 0.001 for both). Area under curve value after diagnosis of pneumonia was found 0.248 (P = 0.002).

CONCLUSION

To conclude, our results suggest that suPAR can be a useful diagnostic biomarker in patients with VAP. However, clinical trials on larger series are warranted to explore the clinical significance more accurately.

Biomarkers in infection and sepsis: Can they really indicate final outcome?

Infectious diseases are among the most common reasons for admission to hospital and can easily lead to sepsis. Sepsis is globally associated with increased mortality, and although biomarkers could help clinicians in the early diagnosis of sepsis and immediate onset of antibiotics, there are always questions to be answered about their usefulness in the prognosis of infectious diseases. This article reviews some of the available biomarkers used in infectious diseases and sepsis in order to evaluate their utility to predict mortality and unfavourable outcome. Several studies present the pros and cons of each compound, but it is obvious that the ideal biomarker, with high sensitivity and specificity, cost effectiveness and with definite cut-off ranges and time of blood sampling, is yet to be found.

suPAR: The unspecific marker for disease presence, severity and prognosis

Investigation of biomarkers that can promptly predict unfavourable outcome of critically illness is an emerging necessity taking into consideration the need for early intervention, the shortage of available beds in intensive care units and the considerable cost of hospitalisation. The most promising biomarker is soluble urokinase-type plasminogen activator receptor (suPAR). Three studies in large populations of critically ill patients and patients admitted to the emergency department have shown that concentrations >12 ng/mL can safely predict unfavourable outcome. This review presents a thorough analysis of the data from these studies.

Usefulness of suPAR in the risk stratification of patients with sepsis admitted to the emergency department

To investigate the role of suPAR in patients with sepsis admitted to the Emergency Department (ED). We performed multicentre prospective trial including patients admitted to the ED of three different Italian hospitals. Patients were studied upon admission on day 1, 2, 4 and 7. They were subdivided into two groups: sepsis (group 1) and severe sepsis or septic shock (group 2). The two groups were comparable for age, gender and CRP level on day 1. Patients with severe sepsis or septic shock displayed significantly higher baseline levels of suPAR, PCT and lactate. In both groups, suPAR decreased across the time (p < 0.0005). Group 1 was not different from group 2 (p = 0.545) in mortality at 7 days, while group 2 had higher mortality at 30 days than group 1 (p = 0.022). At the multivariate analysis, lactate1 (p = 0.012) and age (p = 0.019) were independent predictors of mortality at 7 days, whereas suPAR1 (p = 0.023) and age (p = 0.032) were independent predictors of mortality at 30 days. Lactate and suPAR resulted the most predictive biomarkers in the risk stratification of patients with suspected infection initially admitted to the ED, according to their role in predicting 7- and 30-day mortality, respectively.

What was old is new again: using the host response to diagnose infectious disease

A century of advances in infectious disease diagnosis and treatment changed the face of medicine. However, challenges continue to develop including multi-drug resistance, globalization that increases pandemic risks and high mortality from severe infections. These challenges can be mitigated through improved diagnostics, focusing on both pathogen discovery and the host response. Here, we review how 'omics' technologies improve sepsis diagnosis, early pathogen identification and personalize therapy. Such host response diagnostics are possible due to the confluence of advanced laboratory techniques (e.g., transcriptomics, metabolomics, proteomics) along with advanced mathematical modeling such as machine learning techniques. The road ahead is promising, but obstacles remain before the impact of such advanced diagnostic modalities is felt at the bedside.

Host response biomarkers in the diagnosis of sepsis: a general overview

Critically ill patients who display a systemic inflammatory response syndrome (SIRS) are prone to develop nosocomial infections. The challenge remains to distinguish as early as possible among SIRS patients those who are developing sepsis. Following a sterile insult, damage-associated molecular patterns (DAMPs) released by damaged tissues and necrotic cells initiate an inflammatory response close to that observed during sepsis. During sepsis, pathogen-associated molecular patterns (PAMPs) trigger the release of host mediators involved in innate immunity and inflammation through identical receptors as DAMPs. In both clinical settings, a compensatory anti-inflammatory response syndrome (CARS) is concomitantly initiated. The exacerbated production of pro- or anti-inflammatory mediators allows their detection in biological fluids and particularly within the bloodstream. Some of these mediators can be used as biomarkers to decipher among the patients those who developed sepsis, and eventually they can be used as prognosis markers. In addition to plasma biomarkers, the analysis of some surface markers on circulating leukocytes or the study of mRNA and miRNA can be helpful. While there is no magic marker, a combination of few biomarkers might offer a high accuracy for diagnosis.

Soluble urokinase-type plasminogen activator receptor is a novel biomarker predicting acute exacerbation in COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a chronic inflammatory condition, and progresses with acute exacerbations. (AE). During AE, levels of acute phase reactants such as C-reactive protein (CRP) and inflammatory cells in the circulation increase. Soluble urokinase-type plasminogen activator receptor (suPAR) levels increase in acute viral and bacterial infections and in diseases involving chronic inflammation. The purpose of this study was to investigate the effectiveness of suPAR in predicting diagnosis of AE of COPD (AE-COPD) and response to treatment.

METHODS

The study population consisted of 43 patients diagnosed with AE-COPD and 30 healthy controls. suPAR, CRP, and fibrinogen levels were measured on the first day of hospitalization and on the seventh day of treatment.

RESULTS

We found that fibrinogen (P<0.001), CRP (P<0.001), and suPAR (P<0.001) were significantly higher in patients with AE-COPD than in healthy controls. Fibrinogen (P<0.001), CRP (P=0.001), and suPAR (P<0.001) were significantly decreased by the seventh day of treatment. However, the area under receiver operator characteristic curve showed that suPAR is superior to CRP and fibrinogen in distinguishing AE-COPD. There was a correlation between fibrinogen, CRP, and suPAR. However, only fibrinogen was a powerful predictor of suPAR in multiple linear regression. In multiple logistic regression, only suPAR and fibrinogen were strong predictors of AE-COPD (P=0.002 and P=0.014, respectively). Serum suPAR was negatively correlated with forced expiratory volume in 1 second (r=-478, P=0.001).

CONCLUSION

suPAR is a marker of acute inflammation. It is well correlated with such inflammation markers as CRP and fibrinogen. suPAR can be used as a predictor of AE-COPD and in monitoring response to treatment.

Increased concentrations of the soluble mannose receptor in serum from patients with pneumococcal bacteraemia, and prediction of survival

BACKGROUND

The soluble mannose receptor (sMR) is a new serum marker of macrophage activation. The aim of the present study was to investigate sMR as a prognostic marker in patients with invasive pneumococcal disease (IPD), and compare it to other inflammatory biomarkers.

METHODS

Samples from 128 patients with IPD were collected at the time of first positive blood culture and analysed using an in-house sMR assay. Clinical data were retrieved from patient files. The main outcome investigated was in-hospital mortality.

RESULTS

The median sMR concentration in the entire group of patients was 0.77 mg/L. There was a significant difference in sMR concentration between patients below (n = 92, sMR = 0.82 mg/L) or above (n = 36, sMR = 0.73 mg/L) the age of 75 (p < 0.001). In the entire group there was a significant difference in sMR concentrations between survivors (n = 107, sMR = 0.72 mg/L) and non-survivors (n = 21, sMR = 1.38 mg/L), but for patients 75 years or older this difference was not statistically significant. For prediction of survival sMR seemed most promising (area under the receiver operating characteristic curve (AUC) = 0.79) compared with sCD163 (AUC = 0.70) and CRP (AUC = 0.73). In patients 75 years or older the AUC was lower for all three markers (sMR = 0.56, sCD163 = 0.38, CRP = 0.66).

CONCLUSIONS

The results of this study designate sMR as a potential new biomarker in infectious disease. Additionally, it emphasizes the importance of research into macrophage malfunction in elderly patients.