Plasma level of soluble urokinase-type plasminogen activator receptor as a predictor of disease severity and case fatality in patients with bacteraemia: a prospective cohort study

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.

Prognostic significance of APACHE II score and plasma suPAR in Chinese patients with sepsis: a prospective observational study

Background

Timely risk stratification is the key strategy to improve prognosis of patients with sepsis. Previous study has proposed to develop a powerful risk assessment rule by the combination of Acute Physiology and Chronic Health Evaluation II (APACHE II) score and plasma soluble urokinase plasminogen activator receptor (suPAR). That reaffirmation of suPAR as a prognostic marker in Chinese patients with severe sepsis is the aim of the study.

Methods

A total of 137 consecutive Chinese patients with sepsis were enrolled in a prospective study cohort. Demographic and clinical characteristics, conventional risk factors and important laboratory data were prospectively recorded. Sequential plasma suPAR concentrations were measured by an enzymeimmunoabsorbent assay on days 1, 3, and 7 after admission to the intensive care unit (ICU). Receiver operating characteristic (ROC) curves and Cox regression analysis were used to examine the performance of suPAR in developing a rule for risk stratification.

Results

The results showed that plasma suPAR concentrations remained relatively stable within survivors and non-survivors during the first week of disease course. Regression analysis indicated that APACHE II ≥15 and suPAR ≥10.82 ng/mL were independently associated with unfavorable outcome. With the above cutoffs of APACHE II and suPAR, strata of disease severity were determined. The mortality of each stratum differed significantly from the others.

Conclusions

Combination of APACHE II score and suPAR may supply the powerful prognostic utility for the mortality of sepsis.

Soluble Urokinase Plasminogen Activator Receptor: A New Biomarker in the Pediatric Intensive Care Unit

OBJECTIVE

To evaluate the value of soluble urokinase plasminogen activator receptor (suPAR) in diagnosing sepsis and predicting mortality in critically ill children.

METHODS

In a prospective cohort study, 69 critically ill children admitted into the pediatric intensive care unit (PICU) were randomly enrolled in addition to 15 healthy children as a control group. Clinical examination was performed, including calculation of the Pediatric Risk of Mortality (PRISM) and Pediatric Index of Mortality2 (PIM2). suPAR was measured in patients at admission as well as in the controls. Patients were followed up for 30 d.

RESULTS

suPAR level was significantly higher among the total patient cohort compared to controls (p < 0.0001). suPAR was also significantly higher among patients with sepsis compared to both controls (p < 0.0001) and patients without sepsis (p < 0.0001). Furthermore, suPAR level was significantly elevated in non-survivors compared to survivors (p 0.008). Receiver operating characteristic curve (ROC curve) analysis revealed an area under the curve (AUC) of 0.80 for suPAR for diagnosis of sepsis while C-reactive protein (CRP) had an AUC of 0.82. Regarding the prognosis, suPAR had an AUC of 0.69 for prediction of mortality, whereas the AUC for PRISM, PIM2, and CRP were 0.82, 0.81, and 0.77 respectively.

CONCLUSIONS

suPAR has both a diagnostic and a prognostic value for critically ill children. However, it does not seem to be superior to the classic laboratory markers and clinical scoring systems.

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.

Soluble urokinase plasminogen activator receptor informs on the progression course after multiple injuries

PURPOSE

The purpose of this study is to study the use of soluble urokinase plasminogen activator receptor (suPAR) for the prognosis of multiple organ dysfunction (MOF) after multiple traumas.

METHODS

Serum suPAR was measured within the first 24 h after multiple injuries in 85 patients. Measurements were repeated after 4 d or at sepsis onset.

RESULTS

Odds ratio for trauma-associated MOF was 4.09 (p: 0.026) with admission suPAR greater than 8 ng/ml. More than 40% increases of suPAR were associated with odds ratio 9.33 (p: 0.047) for severe sepsis.

CONCLUSIONS

suPAR is a useful surrogate biomarker for development of MOF and severe sepsis after multiple traumas.

The diagnostic value of soluble urokinase plasminogen activator receptor compared with C-reactive protein and procalcitonin in children with febrile neutropenia

The aim of the present study was to determine the diagnostic value of soluble urokinase plasminogen activator receptor (suPAR) in pediatric patients with febrile neutropenia. A prospective case-control study was performed. Patients included 29 children with febrile neutropenia (FN) and 27 control subjects without any infection or immunosuppressive condition. Blood samples were obtained on the day of admission and on the 4th to 7th days of the hospital stay. The median (minimum-maximum) serum levels of suPAR obtained on the first day of the admission were 2.08 (0.93-9.42) and 2.22 (1.08-5.13) ng/mL for the FN group and the control group, respectively. The median serum levels of suPAR in the FN and control groups were not significantly different (P = .053). The mean serum suPAR level was significantly higher in nonsurvivors than in survivors in the FN group (P < .05). In the FN group, the area under the receiver operating characteristics curve (AUCROC) for suPAR was 0.546, but no optimum cutoff value, sensitivity, specificity, negative predictive value (NPV), or positive predictive value (PPV) was obtained. We conclude that suPAR is not useful as a diagnostic biomarker in children with febrile neutropenia; however, persistent high serum suPAR level may predict mortality in FN in children.

Increased plasma level of soluble urokinase plasminogen activator receptor is associated with incidence of heart failure but not atrial fibrillation

AIMS

Soluble urokinase plasminogen activator receptor (suPAR) in plasma is a novel inflammatory marker thought to be released from the cell surface of neutrophils, T cells, and macrophages. Other inflammatory markers, mainly acute phase proteins produced in the liver, have been associated with the incidence of heart failure (HF) and atrial fibrillation (AF). We investigated the association between suPAR and incident HF and AF in a population-based cohort.

METHODS AND RESULTS

Soluble urokinase plasminogen activator receptor was measured in 4530 subjects (aged 46–68 years, 61% women), who participated in the Malmö Diet and Cancer study during 1991–1996. Incident cases of HF and AF were identified from the Swedish hospital discharge register during a median follow-up of 16.3 years. During follow-up, 109 subjects (55% men) were diagnosed with new-onset HF and 321 individuals (50% men) with AF. suPAR was significantly associated with increased plasma levels of NT-proBNP (P<0.001). suPAR was significantly associated with incidence of HF [hazard ratio (HR) for the third vs. first tertile 3.33, 95% confidence interval (CI) 1.91–5.81 after adjustment for age and sex; and HR 1.82, 95% CI 1.02–3.27, P for trend 0.018 after adjustment for conventional risk factors and biomarkers]. suPAR was significantly associated with incidence of AF, when adjusted for age and sex (HR 1.40, 95% CI 1.06–1.85). However, this relationship was non-significant after adjustment for conventional risk factors and biomarkers.

CONCLUSION

Soluble urokinase plasminogen activator receptor was associated with increased plasma levels of NT-proBNP and incidence of HF, but not with AF among middle-aged subjects.

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.

[Use of biomarkers in sepsis. Update and perspectives]

Sepsis and related complications are a challenge for intensive care medicine. Despite many advances in antibiotic therapy sepsis remains one of the most common diseases of patients in intensive care units and is designated as the main cause of death in critically ill patients. Persisting sepsis leads to impaired immunity, resulting in immunosuppression. Unspecific predictive signs complicate an early diagnosis; however, an early initiation of adequate therapy is of crucial importance for the prognosis. Scoring systems can be applied for the initial evaluation but are controversially discussed concerning the monitoring of disease progression and therapy as well as outcome prediction. Biomarkers are considered as a complementary approach.

Are there new approaches for diagnosis, therapy guidance and outcome prediction of sepsis?

Beside many efforts to improve outcome, sepsis is still one of the most frequent causes of death in critically ill patients. It is the most common condition with high mortality in intensive care units. The complexity of the septic syndrome comprises immunological aspects - i.e., sepsis induced immunosuppression - but is not restricted to this fact in modern concepts. So far, exact mechanisms and variables determining outcome and mortality stay unclear. Since there is no typical risk profile, early diagnosis and risk stratification remain difficult, which hinders rapid and effective treatment initiation. Due to the heterogeneous nature of sepsis, potential therapy options should be adapted to the individual. Biomarkers like C-reactive protein and procalcitonin are routinely used as complementary tools in clinical decision-making. Beyond the acute phase proteins, a wide bunch of promising substances and non-laboratory tools with potential diagnostic and prognostic value is under intensive investigation. So far, clinical decision just based on biomarker assessment is not yet feasible. However, biomarkers should be considered as a complementary approach.

Cyclization of the urokinase receptor-derived ser-arg-ser-arg-tyr Peptide generates a potent inhibitor of trans-endothelial migration of monocytes

The receptor for the urokinase-type plasminogen activator (uPAR) is a widely recognized master regulator of cell migration and uPAR_88-92 is the minimal sequence required to induce cell motility. We and others have previously documented that the uPAR_88-92 sequence, even in the form of synthetic linear peptide (SRSRY), interacts with the formyl peptide receptor type 1 (FPR1), henceforth inducing cell migration of several cell lines, including monocytes. FPR1 is mainly expressed by mammalian phagocytic leukocytes and plays a crucial role in chemotaxis. In this study, we present evidence that the cyclization of the SRSRY sequence generates a new potent and stable inhibitor of monocyte trafficking. In rat basophilic leukaemia RBL-2H3/ETFR cells expressing high levels of constitutively activated FPR1, the cyclic SRSRY peptide ([SRSRY]) blocks FPR1 mediated cell migration by interfering with both internalization and ligand-uptake of FPR1. Similarly to RBL-2H3/ETFR cells, [SRSRY] competes with fMLF for binding to FPR1 and prevents agonist-induced FPR1 internalization in human monocyte THP-1 cells. Unlike scramble [RSSYR], [SRSRY] inhibits fMLF-directed migration of monocytes in a dose-dependent manner, with IC₅₀ value of 0.01 nM. PMA-differentiated THP-1 cell exposure to fMLF gradient causes a marked cytoskeletal re-organization with the formation of F-actin rich pseudopodia that are prevented by the addition of [SRSRY]. Furthermore, [SRSRY] prevents migration of human primary monocytes and trans-endothelial migration of monocytes. Our findings indicate that [SRSRY] is a new FPR1 inhibitor which may suggest the development of new drugs for treating pathological conditions sustained by increased motility of monocytes, such as chronic inflammatory diseases.

Soluble urokinase-type plasminogen activator receptor levels in patients with schizophrenia

BACKGROUND

The etiology of schizophrenia remains largely unknown but alterations in the immune system may be involved. In addition to the psychiatric symptoms, schizophrenia is also associated with up to 20 years reduction in life span. Soluble urokinase-type plasminogen activator receptor (suPAR) is a protein that can be measured in blood samples and reflects the levels of inflammatory activity. It has been associated with mortality and the development of type 2 diabetes and cardiovascular disease.

METHODS

suPAR levels in patients with schizophrenia were compared to healthy controls from the Danish Blood Donor Study. SuPAR levels were dichotomized at >4.0 ng/ml, which is considered the threshold for low grade inflammation. A multiple logistic regression model was used and adjusted for age, sex, and current smoking.

RESULTS

In total we included 1009 subjects, 105 cases with schizophrenia (10.4%) and 904 controls (89.6%). The mean suPAR values were 4.01 ng/ml (SD = 1.43) for the cases vs 1.91 ng/ml (SD = 1.35) for the controls (P < .001). Multiple logistic regression with odds ratio (OR) for suPAR levels >4.0 ng/ml yielded: schizophrenia, OR: 46.15 95% CI 22.69-93.87, P < .001; age, OR: 1.02 95% CI 0.99-1.02, P = .15; male sex, OR: 0.70 95% CI 0.35-1.36, P = .29; and current smoking, OR: 3.51 95% CI 1.78-6.94, P < .001.

CONCLUSIONS

Patients with schizophrenia had significantly higher suPAR levels than healthy controls. Further studies are warranted to clarify if elevated suPAR levels are involved in the pathophysiology of schizophrenia and/or the increased mortality found in patients with schizophrenia.

Use of early biomarkers in neonatal brain damage and sepsis: state of the art and future perspectives

The identification of early noninvasive biochemical markers of disease is a crucial issue of the current scientific research, particularly during the first period of life, since it could provide useful and precocious diagnostic information when clinical and radiological signs are still silent. The ideal biomarker should be practical and sensitive in the precocious identification of at risk patients. An earlier diagnosis may lead to a larger therapeutic window and improve neonatal outcome. Brain damage and sepsis are common causes of severe morbidity with poor outcome and mortality during the perinatal period. A large number of potential biomarkers, including neuroproteins, calcium binding proteins, enzymes, oxidative stress markers, vasoactive agents, and inflammatory mediators, have been so far investigated. The aim of the present review was to provide a brief overview of some of the more commonly investigated biomarkers used in case of neonatal brain damage and sepsis.

The role of the soluble urokinase plasminogen activator (suPAR) in children with pneumonia

Although pneumonia is one of the most important health problems in children, there is still no widely accepted disease severity score, the data on the correlation between the conventional inflammatory markers or chest X-ray and the disease severity remain disputable, and thus, there is an urgent need for a new pneumonia biomarker. The soluble urokinase plasminogen activator (suPAR) is a soluble form of the urokinase plasminogen activator that plays an important role in the innate host defense in the pulmonary tissue. suPAR levels have been associated with a general activation of the immune system rather than with a particular etiological factor. suPAR has a high prognostic value in critically ill patients, especially with sepsis, but there is a growing number of studies focusing on suPAR in respiratory diseases. The aim of this review is to summarize the knowledge on the role of the suPAR/uPAR in lung pathology and its possible use in pneumonia in children.

Soluble urokinase-type plasminogen activator receptor (suPAR) – a possible biomarker for bacteremia in sepsis / Forma solubilă a receptorului pentru activatorul de plasminogen de tip urokinază (suPAR) – un biomarker posibil pentru bacteriemie în sepsis

Background. Validating new sepsis biomarkers can contribute to early diagnosis and initiation of therapy. The aim of this study is to evaluate the sepsis predictive capacity of soluble urokinase plasminogen receptor (suPAR) and its role in evaluating the prognosis of bloodstream infections. Material and method. We conducted a prospective pilot study on 49 systemic inflammatory response syndrome (SIRS) patients admitted to the intensive care unit (ICU), that were divided, on the basis of bacteremia in group A (SIRS with bacteremia, n=14) and group B (SIRS without bacteremia, n=35). Hemoculture and blood samples were drawn on the first day to determine suPAR, C-reactive protein (CRP) and procalcitonin (PCT). We set to identify significant cut-off values in estimating bacteremia and mortality in septic patients. Results. In group A, suPAR values were 14.3 ng/mL (range 10-45.5 ng/mL) and in group B, 9.85 ng/mL (range 3.4-48 ng/mL) p=0.008. Area under the curve (AUC) for suPAR was 0.745 (95% CI: 0.600-0.859), for CRP 0.613 (95% CI: 0.522-0.799) and for PCT 0.718 (95% CI: 0.477-0.769). Cut-off value for suPAR in bacteremia prediction was 9.885 ng/mL, with 100% sensibility and 51.43% specificity. Mortality in group A was 85.7% (12/14) and in group B 74.3% (26/39), p>0.05. Area under the curve (AUC) for suPAR was 0.750 (95% CI: 0.455-0.936), for CRP 0.613 (95% CI: 0.413-0.913) and for PCT 0.618 (95% CI: 0.373-0.888). Cut-off value of suPAR in predicting mortality was 11.5 ng/mL, with 66.67% sensibility and 100% specificity. Conclusions. In our study suPAR had a predictive capacity for bacteremia and seems to be an independent factor for mortality prognosis in septic patients.

Risk factors associated with serum levels of the inflammatory biomarker soluble urokinase plasminogen activator receptor in a general population

The soluble urokinase plasminogen activator receptor (suPAR) is a biomarker of mortality risk in various patient populations. However, little is known about the implications of lifestyle for suPAR levels in the general population. Lifestyle, demographic, and cardiovascular disease (CVD) risk factor data were collected from 5,538 participants in the Danish population-based Inter99 study. Their suPAR levels were measured using a sandwich enzyme-linked immunosorbent assay. In the final adjusted model, smoking and morbid obesity were strongly associated with higher suPAR levels (P < 0.001). An unhealthy diet and alcohol abstinence in men were also associated with higher suPAR levels. Physical activity in leisure time had a modest impact on suPAR levels in univariate analysis, but not in the final adjusted model. In conclusion, smoking and morbid obesity were strongly associated with higher serum suPAR levels in this general population. Diet and alcohol consumption also seemed to impact suPAR levels. Lifestyle changes are likely to affect suPAR since ex-smokers had suPAR levels comparable to those of never-smokers.

Soluble urokinase-type plasminogen activator receptor (suPAR) as new biomarker of the prosthetic joint infection: correlation with inflammatory cytokines

Post-operative prosthetic joint infection (PJI) is the most common cause of failure of total joint arthroplasty, requiring revision surgery, but a gold standard for the diagnosis and the treatment of PIJ is still lacking. PJI is mainly due to Gram-positive bacteria, in particular, Staphylococcus Aureus, and more rarely by Gram-negative bacteria such as Pseudomonas. This study aimed to examine the diagnostic value of SuPAR in post-operative PJI, in order to explore the possible application of this new biomarker in the early diagnosis of PJI. The level of SuPAR has been measured in PJI patients and healthy controls, correlated with canonical inflammatory markers, such as C-reactive protein, IL-6, IL-1 and TNFα and the chemokine CCL2. Serum suPAR displayed a strongly significative increase in PJI patients compared to not infected controls, and a significative positive correlation with C-reactive protein, IL-6, IL-1 and TNFα and the chemokine CCL2. Also serum CCL2 showed statistically significative increase in PJI patients, and it displayed a strong positive correlation with serum suPAR. This study provides a clear indication of the diagnostic potential of suPAR, in association to routine inflammatory parameters such as CRP, in the diagnosis of PJI.

Soluble urokinase plasminogen activator receptor predicts mortality in patients with systemic inflammatory response syndrome

OBJECTIVE

The soluble urokinase plasminogen activator receptor (suPAR) reflects inflammation. However, the prognostic value of suPAR measurements, particularly at the very early onset of systemic inflammatory response syndrome (SIRS), is less well defined.

METHODS

The prognostic potential of suPAR levels in patients with SIRS was evaluated. From November 2010 until April 2013, 902 adult patients presenting with SIRS were investigated. Blood samples for laboratory testing of inflammation markers were collected simultaneously with initial blood cultures. suPAR testing was performed using suPARnostic(©) assay.

RESULTS

Analyses of receiver operating characteristics curves revealed areas under the curve (AUCs) of 0.818 for predicting overall mortality within 48 h (36/902 patients died), 0.739 for 30-day mortality (117/902 died) and 0.706 for predicting 90-day mortality (151/902 died). AUCs for procalcitonin (0.777, 0.671 and 0.638), interleukin-6 (0.709, 0.593 and 0.569) and C-reactive protein (0.66, 0.594 and 0.586) as well as renal function and age were markedly lower. Using multivariable regression analyses, suPAR levels (P < 0.001) remained significant predictors of 48-h mortality, whereas suPAR levels (P < 0.001) and bacteraemia (P = 0.002 and P = 0.001, respectively) remained significant predictors of 30- and 90-day mortality. Using Kaplan-Meier survival plots, patients with suPAR <9.15 ng mL(-1) at SIRS onset had a clear benefit.

CONCLUSION

suPAR plasma level determined at early SIRS is predictive for mortality.

Urine soluble urokinase-type plasminogen activator receptor levels correlate with proteinuria in Puumala hantavirus infection

OBJECTIVES

Urokinase-type plasminogen activator receptor (uPAR) is upregulated during inflammation and known to bind to β3 -integrins, receptors used by pathogenic hantaviruses to enter endothelial cells. It has been proposed that soluble uPAR (suPAR) is a circulating factor that causes focal segmental glomerulosclerosis and proteinuria by activating β3 -integrin in kidney podocytes. Proteinuria is also a characteristic feature of hantavirus infections. The aim of this study was to evaluate the relation between urine suPAR levels and disease severity in acute Puumala hantavirus (PUUV) infection.

DESIGN

A single-centre, prospective cohort study.

SUBJECTS AND METHODS

Urinary suPAR levels were measured twice during the acute phase and once during convalescence in 36 patients with serologically confirmed PUUV infection. Fractional excretion of suPAR (FE suPAR) and of albumin (FE alb) was calculated.

RESULTS

The FE suPAR was significantly elevated during the acute phase of PUUV infection compared to the convalescent phase (median 3.2%, range 0.8-52.0%, vs. median 1.9%, range 1.0-5.8%, P = 0.005). Maximum FE suPAR was correlated markedly with maximum FE alb (r = 0.812, P < 0.001) and with several other variables that reflect disease severity. There was a positive correlation with the length of hospitalization (r = 0.455, P = 0.009) and maximum plasma creatinine level (r = 0.780, P < 0.001) and an inverse correlation with minimum urinary output (r = -0.411, P = 0.030). There was no correlation between FE suPAR and plasma suPAR (r = 0.180, P = 0.324).

CONCLUSION

Urinary suPAR is markedly increased during acute PUUV infection and is correlated with proteinuria. High urine suPAR level may reflect local production of suPAR in the kidney during the acute infection.

The predictive value of soluble urokinase plasminogen activator receptor (SuPAR) regarding 90-day mortality and 12-month neurological outcome in critically ill patients after out-of-hospital cardiac arrest. Data from the prospective FINNRESUSCI study

AIM

The whole body ischaemia-reperfusion after cardiac arrest (CA) induces a systemic inflammation-reperfusion response. The expression of urokinase plasminogen activator receptor (uPAR) is known to be induced after hypoxia and increased levels of soluble form suPAR have been measured after hypoxia and ischaemia. Our aim was to evaluate, whether ischaemia/reperfusion injury after out-of-hospital cardiac arrest (OHCA) increases suPAR concentrations in serum and to evaluate the prognostic value of suPAR regarding 90-day mortality and 12-month neurological outcome.

METHODS

This is a pre-determined substudy of prospective FINNRESUSCI study. Total of 287 patients treated in the intensive care units after OHCA and with consent from the next-of-kin and serum samples between baseline and day 4 were included. Outcome and neurological outcome were evaluated according the Pittsburgh Cerebral Performance Categories (CPC). Kaplan-Meier survival curves, areas under receiver operational characteristics curves and positive likelihood ratios for mortality and poor neurological outcome were calculated.

RESULTS

Non-survivors had higher levels of suPAR after OHCA. Kaplan-Meier survival curves indicated high 90-day mortality in the highest concentration quintiles. LR+ for 1-year CPC 3-5 was 1.8-2.7 for the whole patient cohort and in shockable rhythms 2.0-2.4. In therapeutic hypothermia prognostic value remained.

CONCLUSIONS

We found that high SuPAR concentrations were associated with poor outcome in patients with OHCA admitted to critical care. However, suPAR alone had inadequate predictive value for poor outcome and did not associate with 12-month neurological outcome.

Biomarkers of sepsis and their potential value in diagnosis, prognosis and treatment

Biomarkers have great potential to improve the diagnosis and treatment of sepsis. The available literature supports the potential utility of sTREM-1, IL-27, suPAR, neutrophil CD64, presepsin, cfDNA and miRNAs as novel diagnostic, prognostic and treatment response biomarkers. The future of sepsis biomarkers lies in extensive validation studies of such novel biomarkers across heterogeneous populations and exploration of their power in combination. Furthermore, the use of a companion diagnostics model may augment the ability of investigators to identify novel sepsis biomarkers and develop specific therapeutic strategies based on biomarker information.

Serum Levels of Soluble Urokinase Plasminogen Activator Receptor in Infants with Late-onset Sepsis

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) has been studied in a variety of diseases. The aim of the study is to investigate the levels of suPAR in neonates with sepsis.

METHODS

The infants enrolled to this prospective study were classified into four groups. Group 1, 2, and 3 were referred as the patient groups (40 infants), and group 4 was referred as control group (26 infants). Blood samples for whole blood count, C-reactive protein (CRP), suPAR and blood culture were obtained before initiating antimicrobial therapy, and two further samples were obtained on day 3 and at the end of the treatment for CRP and suPAR.

RESULTS

The mean gestational ages of patient and control groups was similar. The median level of initial suPAR was 18.8 ng/mL (range 6.8-30.1 ng/mL) in the patient groups, and 6.0 ng/mL (range 3.7-10.8 ng/mL) in the control group (P < 0.001). A significant decrease in suPAR level was observed from the inclusion to the third day and end of the treatment (P < 0.001). The area under the curve (AUC) for suPAR is 0.959 (95% Cl: 0.919-0.999) and for CRP is 0.782 (95% Cl: 0.669-0.895). At a cut-off value of 11.3 ng/mL for suPAR the specificity was 100%, and the sensitivity was 82.5%. There was a positive correlation between laboratory values of CRP and suPAR (r: 0.359, P = 0.003).

CONCLUSION

This is the first study that investigated the levels of suPAR in neonates and our results demonstrate that suPAR is a powerful marker of inflammation in infants with sepsis.

Clinical value of plasma soluble urokinase-type plasminogen activator receptor levels in term neonates with infection or sepsis: a prospective study

Background. suPAR, the soluble form of the urokinase-type plasminogen activator receptor, has been identified as a biomarker of infection in adults but its properties in neonatal infection are not known. Methods. Plasma suPAR levels were determined by ELISA in 47 term neonates with infection (19 bacterial and 28 viral) and in 18 healthy neonates as controls. Thirteen out of 47 infected neonates were septic. In all infected neonates, suPAR levels were repeated at 24 hours, 48 hours, 3–5 days, and 7–10 days following admission. Results. Plasma suPAR levels were significantly increased in infected neonates upon admission, whereas they were highest in septic neonates, in comparison with controls (P < 0.001) and correlated positively with serum CRP levels (P = 0.001). At infection subsidence, suPAR concentrations decreased significantly in comparison with baseline (P < 0.001) but remained higher than in controls (P = 0.01). Receiver operating characteristic analysis resulted in significant areas under the curve for detecting either infected or septic neonates, but not for discriminating between bacterial and viral cause of infection. Conclusions. suPAR is a diagnostic biomarker of infection or sepsis in term neonates; however, it cannot discriminate bacterial from viral infections and also its utility for monitoring the response to treatment is questioned.

Diagnostic Value of 25-Hydroxyvitamin D Level and New Cytokines in Neonatal Sepsis

The aim of this study was to evaluate diagnostic value of 25-hydroxyvitamin D level, Upar, IL-33 and ST2 in comparison with C-reactive protein, TNF-α and Interleukin-6 in neonatal sepsis. A total of 106 term babies were included 20 of whom were the control group. We used only data of high probable sepsis with blood culture positive infants, therefore 46 infants were excluded. Blood was collected from infants from the first day of sepsis (1.value) and 48–72 hours later (2.value). There were significant differences between the controls and sepsis (1.value) for 25-hydroxyvitamin D levels (35±19ng/ml and 69±7.5ng/ml, p=0.01), for IL-33 levels (90±34 ng/ml and 412±170 ng/ml, p=0.01), for sST2 levels (453±44 ng/ml and 4120±2720ng/ml, p=0.01), for sUpar levels (2.1±1.3 ng/ml and 11.4 ± 5.2 ng/ml, p=0.01), respectively. There were significant differences between sepsis (1.value) and sepsis (2.value.) with reference to 25-hydroxyvitamin D, IL-33, sST2, and suPAR levels, respectively. In the light of these results, it may be suggested that 25-hydroxyvitamin D level, upar, IL-33 and ST2 can be used as an acute phase reactant like C-reactive protein, TNF-α and Interleukin-6 in diagnosis of neonatal sepsis.

Biomarkers and molecular analysis to improve bloodstream infection diagnostics in an emergency care unit

Molecular pathogen detection from blood is still expensive and the exact clinical value remains to be determined. The use of biomarkers may assist in preselecting patients for immediate molecular testing besides blood culture. In this study, 140 patients with ≥ 2 SIRS criteria and clinical signs of infection presenting at the emergency department of our hospital were included. C-reactive protein (CRP), neutrophil-lymphocyte count ratio (NLCR), procalcitonin (PCT) and soluble urokinase plasminogen activator receptor (suPAR) levels were determined. One ml EDTA blood was obtained and selective pathogen DNA isolation was performed with MolYsis (Molzym). DNA samples were analysed for the presence of pathogens, using both the MagicPlex Sepsis Test (Seegene) and SepsiTest (Molzym), and results were compared to blood cultures. Fifteen patients had to be excluded from the study, leaving 125 patients for further analysis. Of the 125 patient samples analysed, 27 presented with positive blood cultures of which 7 were considered to be contaminants. suPAR, PCT, and NLCR values were significantly higher in patients with positive blood cultures compared to patients without (p < 0.001). Receiver operating characteristic curves of the 4 biomarkers for differentiating bacteremia from non-bacteremia showed the highest area under the curve (AUC) for PCT (0.806 (95% confidence interval 0.699–0.913)). NLCR, suPAR and CRP resulted in an AUC of 0.770, 0.793, and 0.485, respectively. When compared to blood cultures, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for SepsiTest and MagicPlex Sepsis Test were 11%, 96%, 43%, 80%, and 37%, 77%, 30%, 82%, respectively. In conclusion, both molecular assays perform poorly when one ml whole blood is used from emergency care unit patients. NLCR is a cheap, fast, easy to determine, and rapidly available biomarker, and therefore seems most promising in differentiating BSI from non-BSI patients for subsequent pathogen identification using molecular diagnostics.

Soluble urokinase plasminogen activator receptor: an indicator of pneumonia severity in children

Enhanced level of soluble urokinase plasminogen activator receptor (suPAR) level has been associated with activation of the immune system. It may be a novel biomarker for pneumonia severity, yet data on this subject are limited. In the present study we seek to determine the suPAR level in hospitalized children with community-acquired pneumonia (CAP), its correlation with pneumonia severity, and to compare the suPAR level between pneumonia and healthy conditions. The study encompassed a total of 596 children: 447 with pneumonia and 119 healthy. suPAR was measured in 227 out of the 447 pneumonia patients and in all healthy subjects. We used clinical indicators (fever, time for defeverscence, heart and breath rate, saturation, and length of antibiotic treatment and of hospitalization) and laboratory indicators (CRP, procalcitonin, white blood cell count, and sodium) to assess the CAP severity. The finding were that the suPAR concentration in children with pneumonia was significantly higher (median 7.11 ng/mL) than in healthy individuals (4.68 ng/mL). We found a positive correlation between the suPAR and the following factors: fever, time for defeverscence, length of hospital stay, and elevated CRP and procalcitonin levels. There was a reverse correlation with sodium concentration and capillary blood saturation. Moreover, the suPAR level was significantly higher in children with a severe course of pneumonia compared with those having non-severe pneumonia (7.79 vs. 6.87 ng/mL; p = 0.006). In conclusion, suPAR elevation is observed in pneumonia and may reflect its severity.

Year in review 2012: Critical Care--management

Outcomes research plays a key role in defining the effects of medical care in critical care. Last year Critical Care published a number of papers that evaluated patient-centered and policy-relevant outcomes. We present this review article focusing on key reported outcomes associated with severe community-acquired pneumonia, mortality associated with decisions regarding triage to the ICU, and both short-term and long-term mortality associated with ICU admissions. We further analyze the literature, assessing outcomes such as quality of life and the psychological burden associated with critical care. We also reviewed processes of care, and studies looking at cost analysis of treatment associated with critical care.

Soluble Urokinase Plasminogen Activator Receptor for Risk Prediction in Patients Admitted with Acute Chest Pain

BACKGROUND

Plasma concentrations of soluble urokinase plasminogen activator receptor (suPAR) predict mortality in several clinical settings, but the long-term prognostic importance of suPAR in chest pain patients admitted on suspicion of non–ST-segment elevation acute coronary syndrome (NSTEACS) is uncertain.

METHODS

suPAR concentrations were measured on admission in 449 consecutive chest pain patients in a single center between January 3, 2005, and February 14, 2006. Patients were followed for all-cause mortality from discharge until July 28, 2011.

RESULTS

The diagnoses at discharge comprised high-risk NSTEACS [non–ST elevation myocardial infarction or unstable angina with electrocardiogram (ECG) abnormalities] in 77 patients (17.2%) and low-risk NSTEACS without evidence of myocardial ischemia in 257 (57.2%) of patients. Another 115 (25.6%) of patients received other diagnoses. During a median follow-up of 5.7 years (range, 0.01–6.6 years) there were 162 (36.1%) deaths. suPAR was predictive of mortality independent of age, sex, smoking, final diagnosis for the hospitalization, comorbidities (diabetes, hypertension, previous myocardial infarction, and heart failure), and variables measured on the day of admission (renal function, inflammatory markers, and markers of myocardial ischemia) with a hazard ratio (95% CI) of 1.93 (1.48–2.51) per SD increase in log-transformed suPAR, P &lt; 0.0001. The use of suPAR improved the predictive accuracy of abnormal ECG findings and increased troponin concentrations regarding all-cause mortality (c statistics, 0.751–0.805; P &lt; 0.0001).

CONCLUSIONS

suPAR is a strong predictor of adverse long-term outcomes and improves risk stratification beyond traditional risk variables in chest pain patients admitted with suspected NSTEACS.

The pathogenesis of nephropathia epidemica: new knowledge and unanswered questions

Puumala virus (PUUV) causes an acute hemorrhagic fever with renal syndrome (HFRS), a zoonosis also called nephropathia epidemica (NE). The reservoir host of PUUV is the bank vole (Myodes glareolus). Herein we review the main clinical manifestations of NE, acute kidney injury, increased vascular permeability, coagulation abnormalities as well as pulmonary, cardiac, central nervous system and ocular manifestations of the disease. Several biomarkers of disease severity have recently been discovered: interleukin-6, pentraxin-3, C-reactive protein, indoleamine 2,3-dioxygenase, cell-free DNA, soluble urokinase-type plasminogen activator, GATA-3 and Mac-2 binding protein. The role of cytokines, vascular endothelial growth hormone, complement, bradykinin, cellular immune response and other mechanisms in the pathogenesis of NE as well as host genetic factors will be discussed. Finally therapeutic aspects and directions for further research will be handled.

Soluble urokinase-type plasminogen activator receptor as a prognostic biomarker in critically ill patients

PURPOSE

The aim of this study was to assess the role of blood soluble urokinase-type plasminogen activator receptor (suPAR) levels in the diagnosis and prognostication of sepsis in critically ill patients.

METHODS

Serum suPAR levels were measured prospectively in adult intensive care unit (ICU) patients on admission and then daily until ICU discharge (maximum of 14 days) using an enzyme-linked immunosorbent assay kit. Normal levels were established in 31 healthy controls.

RESULTS

We included 258 patients (161 men); median admission Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scores were 17 (9-23) and 6 (3-9), respectively. The mortality rate was 13.6%. Sepsis was diagnosed on admission in 94 patients (36%), of whom 23 had severe sepsis and 49 had septic shock. On admission, septic patients had higher suPAR levels than did nonseptic patients (8.9 [5.9-12.7] vs 3.7 [2.7-5.4] ng/mL), but the predictive value of suPAR for diagnosing sepsis was weaker than that of C-reactive protein. During the week after ICU admission, serum suPAR concentrations correlated with Sequential Organ Failure Assessment scores over time. High suPAR levels on admission were a strong independent predictor for ICU and 28-day mortality. In the global population, a suPAR level higher than 6.15 ng/mL had 66% sensitivity and 64% specificity for prediction of ICU mortality, with a receiver operating characteristic area under the curve of 0.726 (95% confidence interval, 0.645-0.808).

CONCLUSIONS

In ICU patients, serum suPAR concentrations have limited use for identifying sepsis, but their time course correlated with the degree of organ dysfunction, and they have prognostic value in septic and nonseptic populations.

Plasma levels of soluble urokinase-type plasminogen activator receptor associate with the clinical severity of acute Puumala hantavirus infection

Objectives

Urokinase-type plasminogen activator receptor is a multifunctional glycoprotein, the expression of which is increased during inflammation. It is known to bind to β₃-integrins, which are elementary for the cellular entry of hantaviruses. Plasma soluble form of the receptor (suPAR) levels were evaluated as a predictor of severe Puumala hantavirus (PUUV) infection and as a possible factor involved in the pathogenesis of the disease.

Design

A single-centre prospective cohort study.

Subjects and Methods

Plasma suPAR levels were measured twice during the acute phase and once during the convalescence in 97 patients with serologically confirmed acute PUUV infection using a commercial enzyme-linked immunosorbent assay (ELISA).

Results

The plasma suPAR levels were significantly higher during the acute phase compared to the control values after the hospitalization (median 8.7 ng/ml, range 4.0–18.2 ng/ml vs. median 4.7 ng/ml, range 2.4–12.2 ng/ml, P<0.001). The maximum suPAR levels correlated with several variables reflecting the severity of the disease. There was a positive correlation with maximum leukocyte count (r = 0.475, p<0.001), maximum plasma creatinine concentration (r = 0.378, p<0.001), change in weight during the hospitalization (r = 0.406, p<0.001) and the length of hospitalization (r = 0.325, p = 0.001), and an inverse correlation with minimum platelet count (r = −0.325, p = 0.001) and minimum hematocrit (r = −0.369, p<0.001).

Conclusion

Plasma suPAR values are markedly increased during acute PUUV infection and associate with the severity of the disease. The overexpression of suPAR possibly activates β₃-integrin in PUUV infection, and thus might be involved in the pathogenesis of the disease.

Hospital mortality prognostication in sepsis using the new biomarkers suPAR and proADM in a single determination on ICU admission

PURPOSE

The soluble form of the urokinase-type plasminogen activator receptor (suPAR) and proadrenomedullin (proADM) are two new and promising sepsis biomarkers. We assessed the prognostic value of a single determination of proADM and suPAR, comparing them with C-reactive protein (CRP) and procalcitonin (PCT), and evaluating whether their addition to severity scores (APACHE II and SOFA) could improve their prognostic accuracy.

METHODS

A single-centre prospective observational study conducted in an adult intensive care department at Marques de Valdecilla University Hospital in Spain. APACHE II and SOFA scores, CRP, PCT, suPAR and proADM levels on the day of ICU admission were collected.

RESULTS

A total of 137 consecutive septic patients were studied. The best area under the curve (AUC) for the prediction of in-hospital mortality was for APACHE II (0.82) and SOFA (0.75) scores. The ROC curve for suPAR yielded an AUC of 0.67, higher than proADM (0.62), CRP (0.50) and PCT (0.44). Significant dose-response trends were found between hospital mortality and suPAR (OR Q4 = 4.83, 95% CI 1.60-14.62) and pro-ADM (OR Q4 = 3.00, 95% CI 1.06-8.46) quartiles. Non-significant associations were found for PCT and CRP. The combination of severity scores and each biomarker did not provide superior AUCs.

CONCLUSIONS

SuPAR and, to a lesser extent, proADM levels on ICU admission were better tools in prognosticating in-hospital mortality than CRP or PCT. However, neither of the two new biomarkers has been demonstrated to be excessively useful in the current setting. The prognostic accuracy was better for severity scores than for any of the biomarkers.

Role of biomarkers in the management of antibiotic therapy: an expert panel review: I - currently available biomarkers for clinical use in acute infections

In the context of worldwide increasing antimicrobial resistance, good antimicrobial prescribing in more needed than ever; unfortunately, information available to clinicians often are insufficient to rely on. Biomarkers might provide help for decision-making and improve antibiotic management. The purpose of this expert panel review was to examine currently available literature on the potential role of biomarkers to improve antimicrobial prescribing, by answering three questions: 1) Which are the biomarkers available for this purpose?; 2) What is their potential role in the initiation of antibiotic therapy?; and 3) What is their role in the decision to stop antibiotic therapy? To answer these questions, studies reviewed were limited to recent clinical studies (<15 years), involving a substantial number of patients (>50) and restricted to controlled trials and meta-analyses for answering questions 2 and 3. With regard to the first question concerning routinely available biomarkers, which might be useful for antibiotic management of acute infections, these are currently limited to C-reactive protein (CRP) and procalcitonin (PCT). Other promising biomarkers that may prove useful in the near future but need to undergo more extensive clinical testing include sTREM-1, suPAR, ProADM, and Presepsin. New approaches to biomarkers of infections include point-of-care testing and genomics.

Soluble urokinase plasminogen activator receptor is compartmentally regulated in decompensated cirrhosis and indicates immune activation and short-term mortality

OBJECTIVE

Patients with decompensated cirrhosis are susceptible to bacterial infections, which are associated with organ failure and a high mortality rate. Reliable biomarkers are needed to identify patients who require intensified treatment. Our objective was to study the regulation and prognostic relevance of elevated concentrations of soluble urokinase plasminogen activator receptor (suPAR) in patients with advanced cirrhosis.

DESIGN, SETTING AND PARTICIPANTS

We examined the associations between serum and ascitic fluid (AF) suPAR and liver function, bacterial infection, and short-term mortality in 162 consecutive patients with decompensated cirrhosis undergoing diagnostic paracentesis in a tertiary health care centre in Germany.

MAIN OUTCOME MEASURE

Twenty-eight-day mortality.

RESULTS

Circulating suPAR levels were increased in patients with decompensated cirrhosis and correlated with the severity of liver dysfunction and systemic inflammation but were not indicative of bacterial infection. Circulating suPAR levels >14.4 ng mL(-1) predicted 28-day mortality, even after adjustment for liver function and confounders [HR = 3.05 (1.35-6.90); P = 0.0076] equal to the MELD score (AUC = 0.71; 95% CI = 0.61-0.81; P < 0.001). Cut-off levels derived from cohorts without liver disease were not applicable due to the low specificity. AF suPAR levels were elevated during spontaneous bacterial peritonitis (SBP), but not during episodes in which bacteria or bacterial DNA was translocated into the ascites. AF suPAR levels correlated poorly with systemic suPAR but were associated with a more severe course of SBP and a worse outcome. In vitro experiments revealed that monocytes, and to a lesser extent neutrophils, secrete suPAR after Toll-like-receptor ligation, which led to rapid urokinase plasminogen activator receptor cleavage followed by increased synthesis.

CONCLUSION

Blood and ascitic suPAR levels provide distinct, but relevant prognostic information on the severity of complications in patients with end-stage liver disease.

The importance of biomarkers in neonatology

Despite a 35% decline in the mortality rate for infants aged <5 years over the past two decades, every year nearly 40% of all deaths in this age group occur in the neonatal period, defined as the first 28 days of life. New knowledge on molecular and biochemical pathways in neonatal diseases will lead to the discovery of new candidate biomarkers potentially useful in clinical practice. In the era of personalized medicine, biomarkers may play a strategic role in accelerating the decline in neonatal mortality by assessing the risk of developing neonatal diseases, by implementing tailored therapeutic treatment, and by predicting the clinical outcome. However, there is an urgent need to reduce the gap in translating newly acquired knowledge from bench to bedside. Traditional and candidate biomarkers for neonatal sepsis and necrotizing enterocolitis will be discussed in this review, such as C-reactive protein (CRP), procalcitonin (PCT), serum amyloid A (SAA), soluble form of CD14 subtype presepsin (sCD14-ST), lipolysaccharide binding protein (LBP), angiopoietins (Ang)-1 and -2, soluble form of triggering receptor expressed on myeloid cells (sTREM-1), soluble form of urokinase-type plasminogen activator receptor (suPAR), platelet-activating factor (PAF) and calprotectin. New frontiers in managing critically ill newborns may be opened by metabolomics, a diagnostic tool based on the recognition of metabolites contained in biological fluids. Metabolomics represents the passage from a descriptive science to a predictive science, having the potential to translate benchtop research to real clinical benefits.

Soluble receptor for urokinase plasminogen activator in community-acquired pneumonia in children

Community-acquired pneumonia (CAP) is a leading single cause of mortality in children under 5 years of age. In search of new diagnostic markers, soluble urokinase plasminogen activator receptor (suPAR) seems to offer promise as a novel clinical tool. The goal of the present study was to assess the relation between suPAR and the severity of CAP. suPAR was measured in 74 (39 males, 35 females) patients aged from 1 month to about 15 years. Correlation between the level of suPAR and inflammatory markers (white blood cell, neutrophil count, C-reactive protein-CRP, and procalcitonin-PCT) was assessed by Spearmann's rank coefficient. We found that the median suPAR level in children with pneumonia was 8.29 ng/mL (range 2.44-18.31 ng/mL). In the multivariate logit model, age and CRP level were statistically important. The older children (age above the median value) had higher suPAR (above the median value) less frequently than the younger children (OR = 0.31), whereas the children with greater CRP values (above the median value) had higher suPAR levels than the children with lower CRP concentration (under the median value) (OR = 4.54). There was also a positive correlation between suPAR and PCT levels. In conclusion, we demonstrate a positive correlation between serum suPAR and the non-specific inflammatory markers CRP and PCT in the community acquired pneumonia in children.

Usefulness of soluble urokinase plasminogen activator receptor to predict repeat myocardial infarction and mortality in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous intervention

The plasma level of the inflammatory biomarker soluble urokinase plasminogen activator receptor (suPAR) is an independent predictor of cardiovascular disease and all-cause mortality in healthy subjects. The prognostic capability of suPAR, its temporal course, and its relation to plasma C-reactive protein (CRP) in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous intervention (PCI) is unknown. Therefore, the plasma suPAR and CRP levels were measured in 296 consecutive patients with ST-segment elevation myocardial infarction admitted for primary PCI at baseline and every 6 to 8 hours thereafter until the cardiac biomarker levels had peaked. The end points were all-cause mortality and fatal or nonfatal recurrent myocardial infarction (MI). During a median follow-up period of 5.75 years, 69 deaths and 48 nonfatal and 14 fatal recurrent MIs occurred. All-cause mortality increased significantly from 8.1% to 41.5% across increasing quartiles of suPAR levels at the end of follow-up (log-rank p <0.0001). After adjustment for other independent prognostic factors, a highly significant increase was seen in all-cause mortality (hazard ratio 1.45, 95% confidence interval, 1.19 to 1.76; p <0.001) and recurrent MI (hazard ratio 1.53, 95% confidence interval 1.16 to 2.01; p <0.01) for each standard deviation increment of suPAR levels). In contrast to plasma CRP, the suPAR levels remained stable after primary PCI. Furthermore, CRP did not predict mortality or reinfarction after adjustment for age and gender (p = 0.34). In conclusion, suPAR is a stable plasma biomarker after ST-segment elevation myocardial infarction treated with primary PCI that predicts all-cause mortality and recurrent MI.

Soluble urokinase plasminogen activator receptor is associated with inflammation in the vulnerable human atherosclerotic plaque

BACKGROUND AND PURPOSE

Recently, plasma soluble urokinase plasminogen activator receptor (suPAR) has gained interest as a marker of cardiovascular risk. suPAR is released through the cleavage of urokinase plasminogen activator receptor (uPAR), which is found in monocytes, activated T-lymphocytes and endothelial cells, all involved in atherosclerosis. suPAR levels have been well studied in plasma, but no studies have focused on suPAR in human atherosclerotic plaques. The aim of this study was to determine whether suPAR measured in the plaque is associated with symptomatic plaques and plaque inflammation.

METHODS

Plasma and carotid plaques from 162 patients were analyzed. Lipids, collagen, uPAR, and macrophages were measured histologically. Cytokines and suPAR were measured in homogenized plaque extracts using multiplex immunoassay and ELISA, respectively. Plasma levels of suPAR were analysed with ELISA. CD3, CD4, as well as uPAR mRNA expression were assessed with quantitative real-time polymerase chain reaction in plaque homogenates from 123 patients.

RESULTS

Plaque and plasma suPAR levels were higher in symptomatic patients compared with asymptomatic patients. Plaque suPAR levels correlated with plaque content of lipids and macrophages and with proinflammatory chemokines and cytokines monocyte chemoattractant protein 1, tumor necrosis factor α, interleukin 1β, interleukin 6, platelet-derived growth factor AB/BB, monocyte inflammatory protein 1β, regulated on activation normal T-cell expressed and secreted, and s-CD40L. uPAR mRNA and histological staining for uPAR correlated with plaque content of suPAR.

CONCLUSIONS

This study shows that suPAR in human carotid plaques and plasma is associated with the presence of symptoms and that plaque suPAR is associated with the vulnerable inflammatory plaque. These findings strengthen the hypothesis of suPAR as a future marker of vulnerable atherosclerotic plaques.

SuPAR and PAI-1 in critically ill, mechanically ventilated patients

PURPOSE

SuPAR (soluble urokinase plasminogen activator receptor) and PAI-1 (plasminogen activator inhibitor 1) are active in the coagulation-fibrinolysis pathway. Both have been suggested as biomarkers for disease severity. We evaluated them in prediction of mortality, acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), sepsis and renal replacement therapy (RRT) in operative and non-operative ventilated patients.

METHODS

We conducted a prospective, multicenter, observational study. Blood samples and data of intensive care were collected. Mechanically ventilated patients with baseline suPAR and PAI-1 measurements were included in the analysis, and healthy volunteers were analysed for comparison. Receiver operating characteristics (ROC), logistic regression, likelihood ratios and Kaplan-Meier analysis were performed.

RESULTS

Baseline suPAR was 11.6 ng/ml (quartiles Q1-Q3, 9.6-14.0), compared to healthy volunteers with suPAR of 0.6 ng/ml (0.5-11.0). PAI-1 concentrations were 2.67 ng/ml (1.53-4.69) and 0.3 ng/ml (0.3-0.4), respectively. ROC analysis for suPAR 90-day mortality areas under receiver operating characteristic curves (AUC) 0.61 (95 % confidence interval (CI): 0.55-0.67), sepsis 0.68 (0.61-0.76), ALI/ARDS 0.64 (0.56-0.73) and RRT 0.65 (0.56-0.73). Patients with the highest quartile of suPAR concentrations had an odds ratio of 2.52 (1.37-4.64, p = 0.003) for 90-day mortality and 3.16 (1.19-8.41, p = 0.02) for ALI/ARDS. In non-operative patients, the AUC's for suPAR were 90-day mortality 0.61 (0.54-0.68), RRT 0.73 (0.64-0.83), sepsis 0.70 (0.60-0.80), ALI/ARDS 0.61 (0.51-0.71). Predictive value of PAI-1 was negligible.

CONCLUSIONS

In non-operative patients, low concentrations of suPAR were predictive for survival and high concentrations for RRT and mortality. SuPAR may be used for screening for patients with potentially good survival. The association with RRT may supply an early warning sign for acute renal failure.

Soluble urokinase-type plasminogen activator receptor in patients with suspected infection in the emergency room: a prospective cohort study

OBJECTIVES

The soluble form of urokinase-type plasminogen activator (suPAR) was evaluated as an early prognostic marker of sepsis in patients with suspected infection.

DESIGN

A single-centre prospective cohort study.

METHODS

The cohort comprised 539 patients in the emergency department with suspected infection: 59 without systemic inflammatory response syndrome (SIRS) and without bacterial infection (group 1), 68 with bacterial infection and without SIRS (group 2), 54 with SIRS and without bacterial infection (group 3), 309 with sepsis (SIRS and bacterial infection) and without organ failure (group 4) and 49 with severe sepsis (SIRS, bacterial infection and organ failure) (group 5). suPAR was measured on admission using a commercial solid-phase enzyme-linked immunosorbent assay.

RESULTS

The median soluble form of the receptor (suPAR) concentrations in groups 1-5 were 4.7, 5.0, 4.4, 4.8 and 7.9 ng mL(-1) , respectively (P < 0.001). The levels were significantly higher in nonsurvivors compared with survivors (8.3 vs. 4.9 ng mL(-1) , P < 0.001) and in patients with severe sepsis (group 5) compared with those in the other groups (7.9 vs. 4.8 ng mL(-1) , P < 0.001). Area under the receiver operating characteristics curve (AUC(ROC) ) for the prediction of case fatality was 0.79 (95% confidence interval [CI]: 0.72-0.86, P < 0.0001) and 0.75 for severe sepsis (95% CI: 0.68-0.81, P < 0.0001). At a cut-off level of 6.4 ng mL(-1) , suPAR had 76% sensitivity and 69% specificity for fatal disease; at a cut-off level of 6.6 ng mL(-1) , the sensitivity and specificity for severe sepsis were 67% and 72%, respectively. In multivariate models, high suPAR remained an independent predictor of case fatality and severe sepsis after adjusting for potential confounders.

CONCLUSIONS

A high suPAR level predicts case fatality and severe sepsis in patients with suspected infection.

Soluble urokinase plasminogen activator receptor suPAR as a marker for inflammation in pediatric inflammatory bowel disease

OBJECTIVE

In inflammatory bowel disease (IBD), more means to monitor early therapeutic response are needed. In pediatric IBD, blood inflammatory markers erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP) may be low in 10 to 20% of patients with severe disease. Recently, soluble urokinase plasminogen activator receptor (suPAR) was described as a potential blood inflammatory marker in adult IBD.

METHODS

We tested the performance of suPAR by the start of therapy with glucocorticoids (n = 19) or TNF-α-antagonist (n = 16) in pediatric IBD (Crohn's disease n = 19, ulcerative colitis (UC) n = 16).

RESULTS

The levels of suPAR were low in both patient groups studied. There was no difference in the values regarding the presence of Crohn's disease or ulcerative colitis. Thus, all analyses were performed on the entire sample set. Glucocorticoid therapy, however, resulted in a significant decline in suPAR levels from a median of 3.06 to 2.54 ng/ml (p < 0.01). In contrast, TNF-α-antagonist had no effect. The suPAR levels did not associate with ESR or CRP or fecal calprotectin (FC).

CONCLUSIONS

In pediatric IBD, the suPAR levels in blood are low and do not reflect the level of intestinal inflammation assessed with FC. The introduction of corticoids, however, results in a decline of suPAR levels in blood but not reflect therapeutic response to TNF-α-antagonist. Thus, suPAR is of limited value in assessing systemic inflammatory responses in pediatric IBD.