Febrile Phase Soluble Urokinase Plasminogen Activator Receptor and Olfactomedin 4 as Prognostic Biomarkers for Severe Dengue in Adults

BACKGROUND

Dengue cases continue to rise and can overwhelm healthcare systems during outbreaks. In dengue, neutrophil mediators, soluble urokinase plasminogen activator receptor (suPAR) and olfactomedin 4, and mast cell mediators, chymase and tryptase, have not been measured longitudinally across the dengue phases. The utility of these proteins as prognostic biomarkers for severe dengue has also not been assessed in an older adult population.

METHODS

We prospectively enrolled 99 adults with dengue-40 dengue fever, 46 dengue with warning signs and 13 severe dengue, along with 30 controls. Plasma levels of suPAR, olfactomedin 4, chymase and tryptase were measured at the febrile, critical and recovery phases in dengue patients.

RESULTS

The suPAR levels were significantly elevated in severe dengue compared to the other dengue severities and controls in the febrile (P < .001), critical (P < .001), and recovery (P = .005) phases. In the febrile phase, suPAR was a prognostic biomarker of severe dengue, with an AUROC of 0.82. Using a cutoff derived from Youden's index (5.4 ng/mL) and an estimated prevalence of severe dengue (16.5%) in our healthcare institution, the sensitivity was 71.4% with a specificity of 87.9% in the febrile phase, and the positive and negative predictive values were 54.7% and 95.8%, respectively. Olfactomedin 4 was elevated in dengue patients but not in proportion to disease severity in the febrile phase (P = .04) There were no significant differences in chymase and tryptase levels between dengue patients and controls.

CONCLUSIONS

In adult dengue, suPAR may be a reliable prognostic biomarker for severe dengue in the febrile phase.

Prognostic Biomarkers and AKI: Potential to Enhance the Identification of Post-Operative Patients at Risk of Loss of Renal Function

Acute kidney injury (AKI) is a common complication after surgery and the more complex the surgery, the greater the risk. During surgery, patients are exposed to a combination of factors all of which are associated with the development of AKI. These include hypotension and hypovolaemia, sepsis, systemic inflammation, the use of nephrotoxic agents, tissue injury, the infusion of blood or blood products, ischaemia, oxidative stress and reperfusion injury. Given the risks of AKI, it would seem logical to conclude that early identification of patients at risk of AKI would translate into benefit. The conventional markers of AKI, namely serum creatinine and urine output are the mainstay of defining chronic kidney disease but are less suited to the acute phase. Such concerns are compounded in surgical patients given they often have significantly reduced mobility, suboptimal levels of nutrition and reduced muscle bulk. Many patients may also have misleadingly low serum creatinine and high urine output due to aggressive fluid resuscitation, particularly in intensive care units. Over the last two decades, considerable information has accrued with regard to the performance of what was termed "novel" biomarkers of AKI, and here, we discuss the most examined molecules and performance in surgical settings. We also discuss the application of biomarkers to guide patients' postoperative care.

SuPAR, biomarkers of inflammation, and severe outcomes in patients hospitalized for COVID-19: The International Study of Inflammation in COVID-19

Severe coronavirus disease 2019 (COVID-19) is a hyperinflammatory syndrome. The biomarkers of inflammation best suited to triage patients with COVID-19 are unknown. We conducted a prospective multicenter observational study of adult patients hospitalized specifically for COVID-19 from February 1, 2020 to October 19, 2022. Biomarkers measured included soluble urokinase plasminogen activator receptor (suPAR), C-reactive protein, interleukin-6, procalcitonin, ferritin, and D-dimer. In-hospital outcomes examined include death and the need for mechanical ventilation. Patients admitted in the United States (US, n = 1962) were used to compute area under the curves (AUCs) and identify biomarker cutoffs. The combined European cohorts (n = 1137) were used to validate the biomarker cutoffs. In the US cohort, 356 patients met the composite outcome of death (n = 197) or need for mechanical ventilation (n = 290). SuPAR was the most important predictor of the composite outcome and had the highest AUC (0.712) followed by CRP (0.642), ferritin (0.619), IL-6 (0.614), D-dimer (0.606), and lastly procalcitonin (0.596). Inclusion of other biomarkers did not improve discrimination. A suPAR cutoff of 4.0 ng/mL demonstrated a sensitivity of 95.4% (95% CI: 92.4%-98.0%) and negative predictive value (NPV) of 92.5% (95% CI: 87.5%-96.9%) for the composite outcome. Patients with suPAR < 4.0 ng/mL comprised 10.6% of the cohort and had a 0.8% probability of the composite outcome. Applying this cutoff to the validation cohort yielded a sensitivity of 93.8% (90.4%-96.7%) and NPV of 95.5% (93.1%-97.8%) for the composite outcome. Among commonly measured biomarkers, suPAR offered stronger discriminatory ability and may be useful in triaging low-risk patients with COVID-19.

Time to Change Our Viewpoints to Assess Renal Risks in Patients with Solitary Kidneys beyond Traditional Approaches?

Solitary functioning kidney (SFK) can be defined as the absence or hypofunction of a kidney due to acquired or congenital reasons. A congenital solitary functioning kidney (cSFK) is more common than is an acquired one (aSFK) and is characterized by the anatomical absence (agenesis) or hypofunction (hypoplasia; hypodysplasia) of one kidney from birth. Among the acquired causes, the most important is nephrectomy (Nx) (due to the donor, trauma or mass resection). Patients with SFK are at risk for the development of chronic kidney disease (CKD) in the long term. This risk potential is also significantly affected by hypertension. The relationship between hypertension and subclinical chronic inflammation is a connection that has not yet been fully clarified pathogenetically, but there are many studies highlighting this association. In recent years, studies examining different fibrosis and inflammation biomarkers in terms of the evaluation and prediction of renal risks have become increasingly popular in the literature. Oxidative stress is known to play an important role in homocysteine-induced endothelial dysfunction and has been associated with hypertension. In our study, we aimed to investigate the relationship between ambulatory blood pressure monitoring (ABPM) and urinary/serum fibrosis and inflammatory markers in patients with SFK. We prospectively investigated the relationship between ABPM results and soluble urokinase plasminogen activator receptor (suPAR), procollagen type III N-terminal peptide (PIIINP), homocysteine and other variables in 85 patients with SFK and compared them between cSFK and aSFK groups. In the etiology of SFK, a congenital or acquired origin may differ in terms of the significance of biomarkers. In particular, the serum homocysteine level may be associated with different clinical outcomes in patients with cSFK and aSFK.

Diagnostic value of soluble urokinase-type plasminogen activator receptor in patients with acute coronary syndrome: A systematic review and meta-analysis

BACKGROUND

In contemporary clinical practice, there is an increasing need for new clinically relevant biomarkers potentially optimizing management strategies in patients with suspected acute coronary syndrome (ACS). This study aimed to determine the diagnostic utility of soluble urokinase-type plasminogen activator receptor (suPAR) levels in individuals with suspected ACS.

METHODS

A literature search was performed in Web of Science, PubMed, Scopus, and the Cochrane Central Register of Controlled Trials databases, for studies comparing suPAR levels among patients with and without ACS groups. The methodological quality of the included papers was assessed using the Newcastle-Ottawa Scale (NOS). A fixed-effects model was used if I² < 50%; otherwise, the random-effects model was performed.

RESULTS

Five studies with 3417 participants were included in the meta-analysis. Pooled analysis showed that mean suPAR levels in the ACS group were statistically significantly higher than in the control group (3.56 ± 1.38 vs. 2.78 ± 0.54 ng/mL, respectively; mean difference: 1.04; 95% confidence interval: 0.64-1.44; I² = 99%; p < 0.001).

CONCLUSIONS

In the context of acute coronary syndrome, suPAR is a potential biomarker for the early identification of medical conditions in individuals who are being treated in emergency rooms.

A comprehensive review and meta-analysis of suPAR as a predictor of acute kidney injury

INTRODUCTION AND OBJECTIVE

The global impact of acute kidney injury (AKI) has not been thoroughly investigated. With the development of new techniques, soluble urokinase plasminogen activator receptor (suPAR) has become increasingly important in the diagnosis of AKI. Therefore, a systematic review and meta-analysis was carried out to evaluate the predictive value of suPAR for AKI.

MATERIAL AND METHODS

The review and meta-analysis investigated the relationship between suPAR levels and acute kidney injury. Pubmed, Scopus, Cochrane Controlled Register of Trials, and Embase were searched for relevant studies from inception to 10 January 2023. Stata (Ver. 16 StataCorp, College Station, TX, USA) was used for all statistical analyses. A random effects model using the Mantel-Haenszel approach was employed, and odds ratios (OR) and standard mean differences (SMD) with 95% confidence intervals (CI) were calculated for binary and continuous outcomes, respectively.

RESULTS

Nine studies reported suPAR levels among patients with and without AKI. Pooled analysis showed that suPAR levels in patients with and without AKI varied and amounted to 5.23 ± 4.07 vs. 3.23 ±0.67 ng/mL (SMD = 3.19; 95%CI: 2.73 to 3.65; p<0.001). The results from the sensitivity analysis did not alter the direction.

CONCLUSIONS

This results show that increasing suPAR levels are associated with the occurrence of AKI. SuPAR might act as a novel biomarker for CI-AKI in clinical practice.

Can serum soluble urokinase plasminogen activator receptor be an effective biomarker in comparing the inflammatory response between laparoscopic and open appendectomy?

Introduction

The inflammatory response after laparoscopy and laparotomy has been compared in studies in adults, but only a few studies have compared the immune response between laparoscopy and laparotomy in children.

Aim

To compare open and laparoscopic appendectomies regarding a new biomarker, suPAR, to evaluate the inflammatory response.

Material and methods

Patients between 3 and 17 years of age who were admitted to the pediatric surgery department and scheduled for appendectomy due to appendicitis were enrolled in the investigation. The patients were randomized to receive either laparoscopic (n = 20) or conventional open appendectomy (n = 20). The primary outcome was a change in preoperative and postoperative suPAR levels. The secondary outcomes were the white blood cell count, lymphocytes, neutrophils, platelets, C-reactive protein level, appendix diameter, symptoms, symptom duration, surgical complications, operative time, rescue analgesics, hospital stay, and family satisfaction.

Results

The mean age of the patients undergoing laparoscopic appendectomy was 10.55 ±2.743 (3-17) years. The mean age of the patients undergoing open appendectomy was 11.40 ±3.515 (3-17) years. A statistically significant difference was found when the postoperative suPAR values between the two groups were compared (p = 0.048). The operative time and hospital stay in the laparoscopic group were significantly shorter than those in the open group (p = 0.001, p = 0.047).

Conclusions

Laparoscopic appendectomy is associated with a shorter operative time, a shorter hospital stay, and a smaller inflammatory response caused by surgical stress than open appendectomy. suPAR is an effective marker for comparing postoperative inflammatory stress between open and closed appendectomies.

Prediction value of soluble urokinase plasminogen activator receptor (suPAR) in COVID-19 patients - a systematic review and meta-analysis

INTRODUCTION AND OBJECTIVE

In COVID-19, the rapid prediction of the severity of a patient's condition using modern biomarkers can accelerate the implementation of appropriate therapy, and thus improve the patient's prognosis.

MATERIAL AND METHODS

A meta-analysis was conducted of data available in the literature on the differences in baseline suPAR blood concentration between patients (1) who tested positive and negative for COVID-19, (2) who had severe and non-severe COVID-19, and (3) COVID-19 survivors and non-survivors.

RESULTS

SuPAR levels in SARS-CoV-2 negative and positive patients varied and amounted to 3.61±1.59 ng/ml vs. 6.45±3.13 ng/ml, respectively (MD = -3.18; 95%CI: -4.71 to -1.66; p<0.001). suPAR levels among non-severe and severe COVID-19 patients were 7.06±2.64 ng/ml and 5.06±3.16 ng/ml (MD = 0.18; 95%CI: -2.48 to 2.83; p=0.90), respectively. Pooled analysis showed that suPAR levels between severe versus critical COVID-19 patients to be 5.59±1.54 ng/ml and 6.49±1.43 ng/ml, respectively (MD = -1.00; 95%CI: -1.31 to -0.70; p<0.001). The suPAR levels between ICU survivors versus non-survivors amounted to 5.82±2.33 ng/ml and 8.43±4.66 ng/ml (MD = -3.59; 95%CI: -6.19 to -1.00; p=0.007). In the case of in-hospital mortality, the mean suPAR level among survivors to hospital discharge was 5.63±1.27 ng/ml, compared to 7.85±2.61 ng/ml for patients who did not survive (MD = -3.58; 95%CI: -5.42 to -1.74; p<0.001).

CONCLUSIONS

SuPAR levels are significantly elevated in severe COVID-19 illness and maybe useful in predicting mortality. Further studies are needed to determine cut-off points and clarify the association of suPAR levels with disease progression. This is of utmost importance given the ongoing pandemic and overburdened health care systems.

Levels of peri-implant sulcular fluid levels of soluble urokinase plasminogen activator receptor and TNF-α among cigarette smokers and non-smokers with peri-implantitis

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) and tumor necrosis factor-alpha (TNF-α) are inflammatory biomarkers. No studies have yet assessed the suPAR levels in relation with TNF-α in the peri-implant sulcular fluid (PISF) among cigarette smokers and non-smokers with peri-implantitis.

OBJECTIVE

The aim was to evaluate PISF levels of suPAR, and TNF-α among cigarette smokers and non-smokers with and without peri-implantitis.

METHODS

Sixty male patients with peri-implantitis were included. There were 20 cigarette smokers and 20 and non-smokers with peri-implantitis (Groups 1 and 2), and 20 non-smokers without peri-implantitis (Group 3). Demographic data and information related to cigarette smoking was recorded. Peri-implant clinicoradiographic parameters (plaque index [PI], gingival index [GI], probing depth [PD] and crestal bone loss [CBL]) were assessed. The PISF samples were collected and levels of suPAR and TNF-α were measured. Sample-size estimation was performed and all parameters were statistically assessed. Level of significance was set at P< 0.05.

RESULTS

Sixty individuals were included in Groups 1, 2 and 3 (20 in each). Peri-implant PI (P< 0.01), PD (P< 0.01) and mesial (P< 0.01) and distal (P< 0.01) CBL were significantly higher in Group 1 than in Groups 2 and 3. The PISF volume (P< 0.01) and suPAR (P< 0.01) and TNF-α levels (P< 0.01) were significantly higher in Groups 1 and 2 than in Group 3. There was no difference in PISF volume and suPAR and TNF-α levels between patients in Groups 1 and 2. In Group 2, there was a statistically significant correlation between peri-implant PD and PISF suPAR and TNF-α levels (P< 0.01). The suPAR and TNF-α levels are expressed in high concentrations in the PISF of smokers and non-smokers with peri-implantitis compared with non-smokers without peri-implantitis.

CONCLUSION

In non-smokers, PISF suPAR and TNF-α levels are correlated with peri-implant PD.

Soluble Urokinase Plasminogen Activator Receptor and Venous Thromboembolism in COVID-19

Background Venous thromboembolism (VTE) contributes significantly to COVID-19 morbidity and mortality. The urokinase receptor system is involved in the regulation of coagulation. Levels of soluble urokinase plasminogen activator receptor (suPAR) reflect hyperinflammation and are strongly predictive of outcomes in COVID-19. Whether suPAR levels identify patients with COVID-19 at risk for VTE is unclear. Methods and Results We leveraged a multinational observational study of patients hospitalized for COVID-19 with suPAR and D-dimer levels measured on admission. In 1960 patients (mean age, 58 years; 57% men; 20% Black race), we assessed the association between suPAR and incident VTE (defined as pulmonary embolism or deep vein thrombosis) using logistic regression and Fine-Gray modeling, accounting for the competing risk of death. VTE occurred in 163 (8%) patients and was associated with higher suPAR and D-dimer levels. There was a positive association between suPAR and D-dimer (β=7.34; P=0.002). Adjusted for clinical covariables, including D-dimer, the odds of VTE were 168% higher comparing the third with first suPAR tertiles (adjusted odds ratio, 2.68 [95% CI, 1.51-4.75]; P<0.001). Findings were consistent when stratified by D-dimer levels and in survival analysis accounting for death as a competing risk. On the basis of predicted probabilities from random forest, a decision tree found the combined D-dimer <1 mg/L and suPAR <11 ng/mL cutoffs, identifying 41% of patients with only 3.6% VTE probability. Conclusions Higher suPAR was associated with incident VTE independently of D-dimer in patients hospitalized for COVID-19. Combining suPAR and D-dimer identified patients at low VTE risk. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT04818866.

Postoperative Analgesic and Anti-inflammatory Effectiveness of Ginger (Zingiber officinale) and NSAIDs as Adjuncts to Nonsurgical Periodontal Therapy for the Management of Periodontitis

PURPOSE

The authors hypothesize that ginger (Zingiber officinale) tablets and non-steroidal anti-inflammatory drugs (NSAIDs) are effective in reducing postoperative self-rated pain and periodontal parameters (plaque index [PI], gingival index [GI], and probing depth [PD], clinical attachment loss [AL] and marginal bone loss) following non-surgical periodontal therapy (NSPT) in patients with periodontitis. The aim was to compare the postoperative analgesic and anti-inflammatory effectiveness of ginger tablets and NSAIDs as adjuncts to nonsurgical periodontal therapy for the management of periodontitis. Materials and Methods: Patients with periodontitis were included. All patients underwent NSPT. In groups 1 and 2, patients received postoperative ginger (400 mg) and non-steroidal anti-inflammatory drugs (400 mg), respectively. Demographic data were collected, and full-mouth periodontal parameters (PI, GI, PD and CAL) were evaluated at baseline and at 7, 14 and 21 days. Self-rated pain scores were assessed at baseline, and at 24 h, 3 and 7 days of follow-up. In both groups, self-rated pain was assessed pre- and postoperatively using the numeric rating scale (NRS). Power analysis was performed on data from a pilot investigation and group comparisons were done. Statistical significance was set at p < 0.01.

RESULTS

Baseline mean NRS scores in groups 1 and 2 were 4.19 ± 0.12 and 4.13 ± 0.08, respectively. All participants had stage II/grade B periodontitis. At baseline, self-rated pain scores were significantly higher among patients in groups 1 and 2 at 24 h (p < 0.01) and 3 days (p < 0.01) of follow-up. In groups 1 (p < 0.01) and 2 (p < 0.01), self-rated pain scores were significantly higher at 24 h compared with 3 days of follow-up. In both groups, there was a significant reduction in PI (p < 0.01), GI (p < 0.01) and PD (p < 0.01) at 7, 14 and 21 days of follow-up compared with baseline.

CONCLUSION

Ginger and traditional NSAIDs are effective in reducing postoperative pain and inflammation following NSPT in patients with moderate periodontitis.

Soluble Urokinase Plasminogen Activator Receptor Levels Are Associated with Severity of Fibrosis in Patients with Primary Sclerosing Cholangitis

The soluble urokinase-type plasminogen activator receptor (suPAR) has evolved as a useful biomarker for different entities of chronic liver disease. However, its role in patients with primary sclerosing cholangitis (PSC) is obscure. We analyzed plasma levels of suPAR in 84 patients with PSC and compared them to 68 patients with inflammatory bowel disease (IBD) without PSC and to 40 healthy controls. Results are correlated with clinical records. suPAR concentrations were elevated in patients with PSC compared to patients with IBD only and to healthy controls (p < 0.001). Elevated suPAR levels were associated with the presence of liver cirrhosis (p < 0.001) and signs of portal hypertension (p < 0.001). suPAR revealed a high accuracy for the discrimination of the presence of liver cirrhosis comparable to previously validated noninvasive fibrosis markers (area under the curve (AUC) 0.802 (95%CI: 0.702−0.902)). Further, we demonstrated that suPAR levels may indicate the presence of acute cholangitis episodes (p < 0.001). Finally, despite the high proportion of PSC patients with IBD, presence of IBD and its disease activity did not influence circulating suPAR levels. suPAR represents a previously unrecognized biomarker for diagnosis and liver cirrhosis detection in patients with PSC. However, it does not appear to be confounded by intestinal inflammation in the context of IBD.

Development and validation of SCOPE score: A clinical score to predict COVID-19 pneumonia progression to severe respiratory failure

Most patients infected with SARS-CoV-2 (COVID-19) experience mild, non-specific symptoms, but many develop severe symptoms associated with an excessive inflammatory response. Elevated plasma concentrations of soluble urokinase plasminogen activator receptor (suPAR) provide early warning of progression to severe respiratory failure (SRF) or death, but access to suPAR testing may be limited. The Severe COvid Prediction Estimate (SCOPE) score, derived from circulating concentrations of C-reactive protein, D- dimers, interleukin-6, and ferritin among patients not receiving non-invasive or invasive mechanical ventilation during the SAVE-MORE study, offers predictive accuracy for progression to SRF or death within 14 days comparable to that of a suPAR concentration of ≥6 ng/mL (area under receiver operator characteristic curve 0.81 for both). The SCOPE score is validated in two similar independent cohorts. A SCOPE score of 6 or more is an alternative to suPAR for predicting progression to SRF or death within 14 days of hospital admission for pneumonia, and it can be used to guide treatment decisions.

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SCOPE score is composed of C-reactive protein, D dimers, ferritin, and interleukin-6

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Values of 6 or more predict 6-fold risk for severe respiratory failure or death

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SCOPE score predicts risk for severe respiratory failure or death comparable to suPAR

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Anakinra treatment when SCOPE is 6 or more provides lower odds of poor outcome

Soluble urokinase plasminogen activator receptor levels are predictive of COVID-19 severity in Afro-Caribbean patients

Aim: To investigate association between soluble urokinase plasminogen activator receptor (suPAR) plasma levels at admission and incidence of complications in COVID-19 patients. Patients & methods: We considered Afro-Caribbean patients (n = 64) admitted to the hospital between 1 February 2020 and 28 February 2021. Primary outcome was time from the hospital admission until intensive care unit care or death. Results: Primary outcome (hazard ratio, HR [95%CI]) was associated with higher CT scan severity score (3.18 [1.15-8.78], p = 0.025), National Early Warning Score (NEWS2; 1.43 [1.02-2.02], p = 0.041) and suPAR (1.28 [1.06-2.06], p = 0.041). Kaplan-Meier analysis indicated patients with suPAR level above 8.95 ng/ml had a worse outcome (7.95 [3.33-18.97], p < 0.001). Conclusion: Our study suggests that COVID-19 patients with increased baseline suPAR levels are at a high risk of complications.

Thrombo-inflammatory biomarkers to predict sepsis outcome

Background: Sepsis has been redefined recently as life-threatening organ dysfunction caused by dysregulated host responses to infection and septic shock. Soluble urokinase plasminogen activator receptor (SuPAR) and plasminogen activator inhibitor-1(PAI-1) concentration positively correlate to the activation level of the immune system, and are markers of disease severity and aggressiveness. Objective: The study aimed to identify the blood level of plasminogen activator inhibitor-1 (PAI-1) and soluble urokinase plasminogen activator receptor (SuPAR) in sepsis and its association with mortality. Patient and methods: This is an observational prospective study that enrolled 60 adult patients with sepsis (according to SOFA), admitted to Menoufia and Zagazig university hospitals during the period from December 2019 till October 2020. Plasminogen activator inhibitor-1 (PAI-1) and soluble urokinase plasminogen activator receptor (SuPAR) were checked in all participants. Results: SuPAR and PAI.1 were significant independent predictors of hospital mortality. SuPAR showed sensitivity 100%, specificity 95.9%, and accuracy 94% for prediction of early mortality at a cutoff value of 13.4(pg/ml). While, PAI-1 demonstrated sensitivity 100%, specificity 93.9%, and accuracy of 95% at a cutoff value of 122.5 for predicting mortality. Conclusion: PAI-1 and suPAR were significant predictors of hospital mortality among sepsis patients. The sample size was relatively small, which may have decreased the statistical power of the results of the present study. Hence, additional studies with large sample sizes are required for further validation of the present results.

Utility of suPAR and NGAL for AKI Risk Stratification and Early Optimization of Renal Risk Medications among Older Patients in the Emergency Department

Diagnosis of acute kidney injury (AKI) based on plasma creatinine often lags behind actual changes in renal function. Here, we investigated early detection of AKI using the plasma soluble urokinase plasminogen activator receptor (suPAR) and neutrophil gelatinase-sssociated lipocalin (NGAL) and observed the impact of early detection on prescribing recommendations for renally-eliminated medications. This study is a secondary analysis of data from the DISABLMENT cohort on acutely admitted older (≥65 years) medical patients (n = 339). Presence of AKI according to kidney disease: improving global outcomes (KDIGO) criteria was identified from inclusion to 48 h after inclusion. Discriminatory power of suPAR and NGAL was determined by receiver-operating characteristic (ROC). Selected medications that are contraindicated in AKI were identified in Renbase®. A total of 33 (9.7%) patients developed AKI. Discriminatory power for suPAR and NGAL was 0.69 and 0.78, respectively, at a cutoff of 4.26 ng/mL and 139.5 ng/mL, respectively. The interaction of suPAR and NGAL yielded a discriminatory power of 0.80, which was significantly higher than for suPAR alone (p = 0.0059). Among patients with AKI, 22 (60.6%) used at least one medication that should be avoided in AKI. Overall, suPAR and NGAL levels were independently associated with incident AKI and their combination yielded excellent discriminatory power for risk determination of AKI.

A Low-Sodium DASH Dietary Pattern Affects Serum Markers of Inflammation and Mineral Metabolism in Adults with Elevated Blood Pressure

BACKGROUND

The blood pressure-lowering effects of the Dietary Approaches to Stop Hypertension (DASH) dietary pattern and reduced sodium intake are well established. The effects on other biomarkers related to vascular health are of interest and might assist in explaining the effects of the DASH diet and sodium reduction.

OBJECTIVES

We hypothesized that a low-sodium DASH diet improves (lowers) biomarkers of inflammation [C-reactive protein (CRP) and soluble urokinase plasminogen activator receptor (suPAR)] and mineral metabolism [phosphorus and fibroblast growth factor-23 (FGF23)].

METHODS

We conducted a secondary analysis of the DASH-Sodium trial using frozen serum samples. This controlled feeding study randomly assigned 412 adults (≥22 y) with elevated blood pressure (120-159/80-95 mmHg) to consume either a DASH diet or control diet. Within each arm, participants received 3 sodium levels [low (1150 mg), intermediate (2300 mg), high (3450 mg)] in random sequence, each for 30 d. To maximize contrast, samples collected at the end of the low-sodium DASH (n = 198) and high-sodium control (n = 194) diets were compared. Between-diet differences in serum CRP, suPAR, phosphorus, and FGF23 concentrations were assessed using linear regression adjusted for age, sex, race, income, education, smoking status, and BMI.

RESULTS

CRP concentrations did not differ between groups (P = 0.83), but suPAR was higher after the low-sodium DASH diet than the high-sodium control [geometric mean 2470 pg/mL (95% CI: 2380, 2560 pg/mL), compared with 2290 pg/mL (95% CI: 2210, 2380 pg/mL); P = 0.006]. Phosphorus was higher after the low-sodium DASH diet [geometric mean 3.50 mg/dL (95% CI: 3.43, 3.57 mg/dL)] compared with the high-sodium control diet [geometric mean 3.39 mg/dL (95% CI: 3.33, 3.46 mg/dL); P = 0.04]. FGF23 was also higher after the low-sodium DASH diet [geometric mean 35.3 pg/mL (95% CI: 33.3, 37.3 pg/mL) compared with 28.2 pg/mL (95% CI: 26.6, 29.8 pg/mL); P < 0.001].

CONCLUSIONS

Contrary to our hypothesis, biomarkers of inflammation and mineral metabolism were increased or unchanged by a low-sodium DASH diet compared with a high-sodium control diet in adults with elevated blood pressure.

Using soluble urokinase plasminogen activator receptor to stratify patients for medication review in the emergency department

AIMS

To investigate whether the association between levels of medication use (including polypharmacy and potentially inappropriate medications [PIMs]) and health outcomes such as readmission and mortality is dependent on baseline soluble urokinase plasminogen activator receptor (suPAR).

METHODS

This registry-based cohort study included medical patients admitted to the emergency department at Copenhagen University Hospital Hvidovre, Denmark. Patients were grouped according to their admission suPAR levels: low (0-3 ng/mL), intermediate (3-6 ng/mL), or high (>6 ng/mL). Hyper-polypharmacy was defined as ≥10 prescribed medications. PIMs were identified based on the EU(7)-PIM list, and data on admissions and mortality were obtained from national registries. Risk of 90-day readmission and mortality was assessed by Cox regression analysis adjusted for sex, age and Charlson comorbidity index. Results were reported as hazard ratios within 90 days of index discharge.

RESULTS

In total, 26 291 patients (median age 57.3 y; 52.7% female) were included. Risk of 90-day readmission and mortality increased significantly for patients with higher suPAR or higher number of medications. Among patients with low suPAR, patients with ≥10 prescribed medications had a hazard ratio of 2.41 (95% confidence interval = 2.09-2.78) for 90-day readmission and 8.46 (95% confidence interval = 2.53-28.28) for 90-day mortality compared to patients with 0 medications. Patients with high suPAR generally had high risk of readmission and mortality, and the impact of medication use was less pronounced in this group. Similar, but weaker, association patterns were observed between suPAR and PIMs.

CONCLUSION

The association between levels of medication use and health outcomes is dependent on baseline suPAR.

Soluble urokinase plasminogen activator receptor as a long-term prognostic biomarker in acute coronary syndromes

Purpose: The aim of our study was to analyse the long-term prognostic value of soluble urokinase plasminogen activator receptor (suPAR) in the setting of an acute coronary syndrome (ACS).Methods: We included 340 patients with an ACS who underwent coronary angiography and plasma suPAR concentration was measured. Patients were classified into low suPAR concentrations (<2.6 ng/mL) and high suPAR concentrations (≥2.6 ng/mL) and long-term events were evaluated. suPAR prognostic value was assessed beyond a clinical model that included age, GRACE score, estimated glomerular filtration rate, cardiac troponin-I peak and left ventricular ejection fraction <40%.Results: Higher suPAR concentrations were associated with an increased prevalence of cardiovascular risk factors. After multivariate adjustment, suPAR ≥2.6 ng/mL were independently associated with an increased risk of all-cause death (HR 2.3; 95%CI 1.2-4.4; p = .017), major adverse cardiovascular events (MACE) (HR 1.7; 95%CI 1.1-2.5; p = .020) and heart failure (HR 4.1; 95%CI 1.3-12.6; p = .015), but not with myocardial infarction. For long-term all-cause death significant improvement of reclassification and discrimination were seen after addition of suPAR to a clinical model.Conclusions: In the setting of an ACS, suPAR is associated with long-term all-cause death, heart failure and MACE, and provides incremental prognostic value beyond traditional risks factors.

Elevated suPAR Is an Independent Risk Marker for Incident Kidney Disease in Acute Medical Patients

Introduction

Identifying patients at high risk of developing kidney disease could lead to early clinical interventions that prevent or slow disease progression. Soluble urokinase plasminogen activator receptor (suPAR) is an inflammatory biomarker thought to be involved in the pathogenesis and development of kidney disease. We aimed to determine whether elevated plasma suPAR measured at hospital admission is associated with incident kidney disease in patients presenting to the emergency department.

Materials and Methods

This was a retrospective registry-based cohort study performed at the Emergency Department of Copenhagen University Hospital Amager and Hvidovre, Hvidovre, Denmark. Patients were included in the study from November 2013 to March 2017 and followed until June 2017. Patients were excluded if they were diagnosed with kidney disease or died prior to index discharge. Plasma suPAR was measured at hospital admission, and the main outcome was time to incident kidney disease, defined by ICD-10 diagnosis codes for both chronic and acute kidney conditions. Association between suPAR and time to incident kidney disease was assessed by Cox proportional hazard regression analysis.

Results

In total, 25,497 patients (median age 58.1 years; 52.5% female) were admitted to the emergency department and followed for development of kidney disease. In multivariable Cox regression analysis adjusting for age, sex, eGFR, CRP, cardiovascular disease, hypertension, and diabetes, each doubling in suPAR at hospital admission was associated with a hazard ratio of 1.57 (95% CI: 1.38–1.78, P < 0.001) for developing a chronic kidney condition and 2.51 (95% CI: 2.09–3.01, P < 0.001) for developing an acute kidney condition.

Discussion

In a large cohort of acutely hospitalized medical patients, elevated suPAR was independently associated with incident chronic and acute kidney conditions. This highlights the potential for using suPAR in risk classification models to identify high-risk patients who could benefit from early clinical interventions. The main limitation of this study is its reliance on accurate reporting of ICD-10 codes for kidney disease.

Effects of a highly controlled carbohydrate-reduced high-protein diet on markers of oxidatively generated nucleic acid modifications and inflammation in weight stable participants with type 2 diabetes; a randomized controlled trial

Carbohydrate-restricted diets are increasingly recognized as options for dietary management of type 2 diabetes mellitus (T2DM). We investigated the effects of a carbohydrate-reduced high-protein (CRHP) and a conventional diabetes (CD) diet on oxidative stress and inflammation in weight stable individuals with T2DM. We hypothesized that the CRHP diet would improve markers of oxidatively generated RNA and DNA modifications as well as inflammatory parameters. Thirty participants with T2DM were randomized to 6 weeks of CRHP or CD dietary treatment (30/50 energy percentage (E%) carbohydrate, 30/17E% protein, 40/33E% fat), followed by a cross-over to the opposite diet for a subsequent 6-week period. All meals were provided during the study and body weight was controlled. Diurnal urine samples were collected after 4 weeks on each diet and oxidatively generated RNA and DNA modifications were measured as 8-oxo-7,8-dihydroguanosine (8-oxoGuo) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), respectively. Fasting concentrations of soluble urokinase plasminogen activator receptor, high-sensitivity C-reactive protein, tumor necrosis factor alpha and interleukin-6 were measured before and after 6 weeks of interventions. Compared with the CD diet, the CRHP diet increased 24-hour urinary excretion of 8-oxoGuo by 9.3% (38.6 ± 12.6 vs. 35.3 ± 11.0 nmol/24 h, p = .03), whereas 8-oxodG did not differ between diets (24.0 ± 9.5 vs. 24.8 ± 11.1 nmol/24 h, p = .17). Changes in plasma inflammatory parameters did not differ between CRHP and CD diets, all p ≥ .2. The clinical implications of increased RNA oxidation following a CRHP diet as well as long-term effects of carbohydrate-restriction on markers of oxidatively generated nucleic acid modifications should be a field of future study.

Assessment of saliva and gingival crevicular fluid soluble urokinase plasminogen activator receptor (suPAR), galectin-1, and TNF-α levels in periodontal health and disease

OBJECTIVE

The aim of the study is to evaluate saliva and gingival crevicular fluid (GCF) levels of suPAR and galectin-1 in different periodontal health status and relationship between these molecules and TNF-α to understand the roles of these molecules in periodontal inflammation process.

BACKGROUND

Soluble urokinase plasminogen activator receptor (suPAR) has been described as a biological marker of inflammation and immunological activation. Galectin-1, a member of the galectin family, is an anti-inflammatory cytokine. However, to date, levels of these two molecules in periodontal health and disease have not been well documented.

METHODS

A total of 60 individuals, 20 with chronic periodontitis (group P), 20 with gingivitis (group G), and 20 with healthy periodontium (group H) were recruited for this study. Full-mouth clinical periodontal measurements were recorded in periodontal charts. GCF and whole saliva samples were collected to determine the levels of suPAR, galectin-1, and TNF-α in study groups using enzymelinked immunosorbent assay (ELISA) method.

RESULTS

The GCF total amount of suPAR, galectin-1, and TNF-α in GCF was similar in group P and G (P > .05). The GCF total amounts of these molecules in GCF were higher in the group G and P compared to the group H (P < .05), whereas the GCF concentrations of suPAR and galectin-1 were lower in the group G and P compared to the group H (P < .05).The saliva concentration of suPAR was significantly higher in group P compared to the group G and H (P < .05). It was also higher in the group G compared to the group H but there is no significant difference between the groups (P > .05). Salivary galectin-1 levels were similar in the study groups (P > .05).

CONCLUSION

Increased levels of GCF suPAR, galectin-1, and saliva suPAR in periodontal disease suggest that these molecules may play a role in the periodontal inflammation. suPAR and galectin-1 may be considered as potential biomarkers in periodontal disease.

Soluble urokinase plasminogen activator receptor associates with higher risk, advanced disease severity as well as inflammation, and might serve as a prognostic biomarker of severe acute pancreatitis

Background

This study aimed to explore the potential of soluble urokinase plasminogen activator receptor (suPAR) as a biomarker for severe acute pancreatitis (SAP) risk prediction and disease management in SAP patients.

Methods

Totally 225 acute pancreatitis (AP) patients (including 75 SAP, 75 moderate‐severe acute pancreatitis [MSAP], and 75 mild acute pancreatitis [MAP] patients) were recruited based on the Atlanta classification, and their serum samples were obtained within 24 hours after admission. Meanwhile, 75 health controls (HCs) were recruited with their serum samples collected at the enrollment. The serum suPAR was then detected using enzyme‐linked immunosorbent assay.

Results

The suPAR level was increased in SAP patients compared with MSAP patients (P = .023), MAP patients (P < .001), and HCs (P < .001). Receiver operating characteristic (ROC) curve presented that suPAR could not only differentiate SAP patients from HCs (AUC: 0.920, 95%CI: 0.875‐0.965) but also differentiate SAP patients from MSAP (AUC: 0.684, 95%CI: 0.600‐0.769) and MAP patients (AUC: 0.855, 95%CI: 0.797‐0.912). In SAP patients, suPAR was positively correlated with Ranson score (P < .001), acute physiology and chronic healthcare evaluation II score (P = .001), sequential organ failure assessment score (P < .001), and C‐reaction protein (P = .002). Further ROC curve exhibited that suPAR (AUC: 0.806, 95%CI: 0.663‐0.949) was of good value in predicting increased inhospital mortality of SAP patients.

Conclusion

Soluble urokinase plasminogen activator receptor is of good predictive value for SAP risk and may serve as a potential biomarker for disease severity, inflammation, and inhospital mortality in SAP patients.

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, an emerging biomarker in kidney and inflammatory diseases

Soluble urokinase plasminogen activator receptor (suPAR) is a circulating form of a physiological and pathophysiological important cell surface receptor, implicated in inflammation. Recent studies showed that suPAR is a promising biomarker, useful for diagnosis, assessment and prognosis of several diseases. This review summarises the majority of preliminary studies and analyses the significance and the clinical application of suPAR in various clinical conditions. SuPAR seems to have a significant value in the diagnosis as well as prognosis of many diseases; nonetheless, it merits large-scale studies to set cut-off values that help physicians in following up their patients and accordingly tailor their treatment plans.

Local Production of Soluble Urokinase Plasminogen Activator Receptor and Plasminogen Activator Inhibitor-1 in the Coronary Circulation Is Associated With Coronary Endothelial Dysfunction in Humans

Background Soluble urokinase plasminogen activator receptor (su PAR ) is a proinflammatory biomarker associated with immune activation and fibrinolysis inhibition. Plasminogen activator inhibitor ( PAI -1) is associated with excessive fibrin accumulation, thrombus formation, and atherosclerosis. The relationship between cross-coronary su PAR and PAI -1 production and endothelial dysfunction remains unknown. Methods and Results Seventy-nine patients (age 53±10 years, 75% women) with angina and normal coronary arteries or mild coronary artery disease (<40% stenosis) on angiogram underwent acetylcholine assessment of epicardial endothelial dysfunction (mid-left anterior descending coronary artery diameter decrease >20% after acetylcholine) and mircovascular endothelial dysfunction (coronary blood flow change <50% after acetylcholine). Simultaneous left main and coronary sinus su PAR and PAI -1 levels were measured in each patient before acetylcholine administration, and cross-coronary su PAR and PAI -1 production rates were calculated. Patients' characteristics, except for age (51±10 versus 57±9, P=0.02), and resting coronary hemodynamics were not significantly different between patients with (26%) versus without (74%) epicardial endothelial dysfunction. Patients' characteristics and resting coronary hemodynamics were not significantly different between those with (62%) and those without (38%) mircovascular endothelial dysfunction. Patients with mircovascular endothelial dysfunction demonstrated local coronary su PAR production versus su PAR extraction in patients with normal microvascular function (median 25.8 [interquartile range 121.6, -23.7] versus -12.7 [52.0, -74.8] ng/min, P=0.03). Patients with epicardial endothelial dysfunction had higher median coronary PAI -1 production rates compared with those with normal epicardial endothelial function (1224.7 [12 940.7, -1915.4] versus -187.4 [4444.7, -4535.8] ng/min, P=0.03). Conclusions su PAR is released in coronary circulation of patients with mircovascular endothelial dysfunction and extracted in those with normal microvascular function. Cross-coronary PAI -1 release is higher in humans with epicardial endothelial dysfunction.

Predicting Mortality in African Americans With Type 2 Diabetes Mellitus: Soluble Urokinase Plasminogen Activator Receptor, Coronary Artery Calcium, and High-Sensitivity C-Reactive Protein

BACKGROUND

Type 2 diabetes mellitus is a major risk factor for cardiovascular disease; however, outcomes in individual patients vary. Soluble urokinase plasminogen activator receptor (suPAR) is a bone marrow-derived signaling molecule associated with adverse cardiovascular and renal outcomes in many populations. We characterized the determinants of suPAR in African Americans with type 2 diabetes mellitus and assessed whether levels were useful for predicting mortality beyond clinical characteristics, coronary artery calcium (CAC), and high-sensitivity C-reactive protein (hs-CRP).

METHODS AND RESULTS

We measured plasma suPAR levels in 500 African Americans with type 2 diabetes mellitus enrolled in the African American-Diabetes Heart Study. We used Kaplan-Meier curves and Cox proportional hazards models adjusting for clinical characteristics, CAC, and hs-CRP to examine the association between suPAR and all-cause mortality. Last, we report the change in C-statistics comparing the additive values of suPAR, hs-CRP, and CAC to clinical models for prediction of mortality. The suPAR levels were independently associated with female sex, smoking, insulin use, decreased kidney function, albuminuria, and CAC. After a median 6.8-year follow-up, a total of 68 deaths (13.6%) were recorded. In a model incorporating suPAR, CAC, and hs-CRP, only suPAR was significantly associated with mortality (hazard ratio 2.66, 95% confidence interval 1.63-4.34). Addition of suPAR to a baseline clinical model significantly improved the C-statistic for all-cause death (Δ0.05, 95% confidence interval 0.01-0.10), whereas addition of CAC or hs-CRP did not.

CONCLUSIONS

In African Americans with type 2 diabetes mellitus, suPAR was strongly associated with mortality and improved risk discrimination metrics beyond traditional risk factors, CAC and hs-CRP. Studies addressing the clinical usefulness of measuring suPAR concentrations are warranted.

Evaluation of Urokinase Plasminogen Activator Receptor, Soluble Urokinase Plasminogen Activator Receptor, and β1 Integrin in Patients with Hodgkin's Lymphoma

Background:

The objective of this study is to indicate the role of urokinase plasminogen activator receptor (uPAR), soluble uPAR (suPAR), and β1 integrin in tumor growth and invasion of lymph nodes from Hodgkin's lymphoma (HL) patients.

Materials and Methods:

In this study, 25 lymph nodes from HL patients were analyzed for the expression of β1 integrin and uPAR on mononuclear cells using two-color flow cytometry and immunohistochemical analysis. Moreover, the levels of suPAR in the serum samples of HL patients were measured and compared with 32 healthy controls.

Results:

Flowcytometry and immunohistochemical results indicated no significant association of uPAR expression with tumor size, different stages, or different histological subtypes of HL; however, an increased expression of β1 integrin was detected in the advanced stages of HL. Higher expression of β1 integrin was detected in nodular sclerosis compared to lymphocyte predominant. No significant difference was observed between the serum levels of suPAR in patients with different stages of HL and healthy controls. Moreover, the levels of suPAR were significantly higher in nodular sclerosis in comparison with other subtypes.

Conclusions:

This study showed that the levels of suPAR and β1 integrin varied between different histological subtypes of HL. Although uPAR may play only a minor role in the growth and metastasis of lymphoma, β1 integrin may be important in predicting prognosis and metastasis in HL.

Elevated Soluble Urokinase Plasminogen Activator Receptor and Proenkephalin Serum Levels Predict the Development of Acute Kidney Injury after Cardiac Surgery

Acute kidney injury (AKI) develops in up to 40% of patients after cardiac surgery. The soluble urokinase plasminogen activator receptor (suPAR) has been identified as a biomarker for incident chronic kidney disease (CKD). Proenkephalin (proENK) also has been shown to be a biomarker for renal dysfunction. We hypothesized that pre-surgery suPAR and proENK levels might predict AKI in patients undergoing cardiac surgery. Consecutive patients (n = 107) undergoing elective cardiac surgery were studied prospectively. Clinical data, laboratory parameters, suPAR and proENK serum levels were assessed before operation, after operation and days one and four post-operatively. A total of 21 (19.6%) patients developed AKI within the first four days after elective surgery. Serum levels of suPAR and proENK, but not of creatinine, were significantly higher before surgery in these patients compared to those patients without AKI. This difference remained significant for suPAR, if patients with or without AKI were matched for risk factors (hypertension, diabetes, CKD). If cardiac surgery patients with pre-existing CKD (n = 10) were excluded, only pre-operative suPAR but not proENK serum levels remained significantly elevated in patients with subsequent AKI. Thus, our findings indicate that suPAR may be a predictive biomarker for AKI in the context of cardiac surgery, even in patients without underlying CKD.

Effects of Acute Exercise on Circulating Soluble Form of the Urokinase Receptor in Patients With Major Depressive Disorder

Inflammation has been proposed to play a role in the generation of depressive symptoms. Previously, we demonstrated that patients with major depressive disorder (MDD) have increased plasma levels of the soluble form of the urokinase receptor (suPAR), a marker for low-grade inflammation. The aim of this study was to test the hypothesis that acute exercise would induce inflammatory response characterized by increased suPAR and elucidate whether patients with MDD display altered levels of suPAR in response to acute exercise. A total of 17 patients with MDD and 17 controls were subjected to an exercise challenge. Plasma suPAR (P-suPAR) was analyzed before, during, and after exercise. There was a significantly higher baseline P-suPAR in the patients with MDD, and the dynamic changes of P-suPAR during the exercise were significantly lower in the patients with MDD, compared with the controls. This study supports the hypothesis that an activation of systemic inflammatory processes, measured as elevated P-suPAR, is involved in the pathophysiology of depression. The study concludes that P-suPAR is influenced by acute exercise, most likely due to release from activated neutrophils.

The Clinical Value of Soluble Urokinase Plasminogen Activator Receptor (suPAR) Levels in Autoimmune Connective Tissue Disorders

The assessment of the general inflammatory condition of patients with autoimmune connective tissue disorders (ACTD) is a major challenge. The use of traditional inflammatory markers including CRP-levels and erythrocyte sedimentation rate (ESR) is limited by several preanalytical factors and their low specificities. Soluble urokinase plasminogen activator receptor (suPAR) is one of the novel candidate markers that is increasingly used in immune mediated disorders. In our studies we compared suPAR levels of patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and ankylosing spondylitis with those of healthy controls. suPAR provided valuable clinical information on disease activity in RA, SLE and SSc. We identified a subgroup of remitted RA patients, who presented still clinical symptoms of inflammatory activity which correlated to high plasma suPAR (while ESR and CRP were normal). In SLE we established specific suPAR cut-off values that support the discrimination between patients with high and those with moderate SLE activity. In patients with SSc suPAR correlated with objective measures of lung and other complications. In the majority of ACTDs including SLE, SSc or RA, suPAR is seemingly a good biomarker that would provide valuable clinical information. However, before the introduction of this novel parameter in laboratory repertoire important issues should be elucidated. These include the establishment of appropriate and disease specific cutoff values, clarification of interfering preanalytical values and underlying conditions and declaration of age- and gender-specific reference ranges.

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.

Analysis of soluble urokinase plasminogen activator receptor in multiple myeloma for predicting prognosis

Multiple myeloma is a type of malignancy, which affects the plasma cells of the bone marrow. Recent studies have found that malignant plasma cells may express urokinase plasminogen activator (uPA) and uPA receptor (uPAR), and that initiation of proteolytic events by this system contributes to the process of invasion and destruction of the bone marrow. Studies have also suggested that the level of the soluble form of uPAR (suPAR) may act as a marker for prognosis in patients with multiple myeloma, and that there is an association between uPAR/suPAR expression, and clinical characteristics, efficacy of treatment in disease control and patient survival. In order to investigate this, the present study used flow cytometry to detect the monoclonal antibodies associated with multiple myeloma, specifically, uPAR (CD87), CD56 and CD38. Patients with multiple myeloma were divided into the following groups: The effective groups (remission and stable disease) and the ineffective group (progressive disease). suPAR expression in the effective groups was 257.6±32.47 pg/ml and 331.0±99.80 pg/ml respectively, which was not significantly different from that of the normal control group (P>0.05). By contrast, the suPAR level in the invalid group was 562.2±291.0 pg/ml, which was significantly different from the levels in the normal control group (P<0.01) and the effective groups (P<0.05). suPAR levels were positively correlated with disease stage (P<0.01), renal function (P<0.05), C-reactive protein (P<0.005), β2-microglobulin (P<0.001), extramedullary involvement (P<0.001), chromosome 13 deletion (P<0.01) and survival >2 years (P<0.01). They were was negatively correlated with hemoglobin concentration. No correlation was observed between uPAR expression and suPAR levels. The present study also indicated that the stage of disease and suPAR expression were independent factors, which predicted survival of <2 years. In conclusion, high suPAR expression appears to predict disease progression, a shortened survival period and early extramedullary infiltration.

A case report of adrenocorticotropic hormone to treat recurrent focal segmental glomerular sclerosis post-transplantation and biomarker monitoring

Background: Recurrent focal segmental glomerular sclerosis (rFSGS) in renal transplant recipients (RTR) is difficult to predict and treat. Early rFSGS is likely from circulating factors and preformed antibodies.

Methods: We present the case of a 23-year-old white man who presented with rFSGS and acute renal failure, requiring dialysis 9-months after a 1-haplotype matched living-related transplant. We retrospectively analyzed serum samples from various clinical stages for rFSGS biomarkers: serum glomerular albumin permeability (P_alb), soluble urokinase-type plasminogen activator receptor (suPAR) serum level with suPAR-β3 integrin signaling on human podocytes, and angiotensin II type I receptor-antibody (AT1R-Ab) titer.

Results: All biomarkers were abnormal at 1-year pre-transplant prior to initiation of dialysis and at the time of transplant. After initiation of hemodialysis, β3 integrin activity on human podocytes, in response to patient serum, as well as AT1R-Ab were further elevated. At the time of biopsy-proven recurrence, all biomarkers were abnormally high. One week after therapy with aborted plasmapheresis (secondary to intolerance), and high dose steroids, the P_alb and suPAR-β3 integrin activity remained significantly positive. After 12-weeks of treatment with high-dose steroids, rituximab, and galactose, the patient remained hemodialysis-dependent. Three-months after his initial presentation, we commenced adrenocorticotropic hormone (ACTH, Acthar^® Gel), 80 units subcutaneously twice weekly. Four-weeks later, he was able to discontinue dialysis. After 8-months of maintenance ACTH therapy, his serum creatinine stabilized at 1.79 mg/dL with <1 g of proteinuria.

Conclusion: ACTH therapy was associated with improvement in renal function within 4 weeks. The use of rFSGS biomarkers may aid in predicting development of rFSGS.

Soluble urokinase plasminogen activator receptor levels are elevated and associated with complications in patients with type 1 diabetes

OBJECTIVES

Soluble urokinase plasminogen activator receptor (suPAR) is a marker of inflammation and endothelial dysfunction. We investigated the associations between suPAR and diabetes, including diabetes duration and complications, in patients with type 1 diabetes.

DESIGN, SETTING AND SUBJECTS

From 2009 to 2011, 667 patients with type 1 diabetes and 51 nondiabetic control subjects were included in a cross-sectional study at Steno Diabetes Center, Gentofte, Denmark. suPAR levels were measured with an enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

The investigated diabetic complications were cardiovascular disease (CVD: previous myocardial infarction, revascularisation, peripheral arterial disease and stroke), autonomic dysfunction (heart rate variability during deep breathing <11 beats min(-1) ), albuminuria [urinary albumin excretion rate (UAER) ≥30 mg/24 h] or a high degree of arterial stiffness (pulse wave velocity ≥10 m s(-1) ). Analyses were adjusted for gender, age, systolic blood pressure, estimated glomerular filtration rate, UAER, glycated haemoglobin (HbA1c ), total cholesterol, body mass index, C-reactive protein, antihypertensive treatment and smoking.

RESULTS

Soluble urokinase plasminogen activator receptor levels were lower in control subjects versus all patients, in control subjects versus normoalbuminuric patients (UAER <30 mg/24 h), in normoalbuminuric patients with short (<10 years) versus long diabetes duration and were increased with degree of albuminuria (adjusted P < 0.001 for all). Furthermore, suPAR levels were higher in patients with versus without CVD (n = 144; 21.3%), autonomic dysfunction (n = 369; 59.2%), albuminuria (n = 357; 53.1%) and a high degree of arterial stiffness (n = 298; 47.2%) (adjusted P ≤ 0.024). The adjusted odds ratio (95% confidence interval) values per 1 ln unit increase in suPAR were as follows: 2.5 (1.1-5.7) for CVD: 2.7 (1.2-6.2) for autonomic dysfunction; 3.8 (1.3-10.9) for albuminuria and 2.5 (1.1-6.1) for a high degree of arterial stiffness (P ≤ 0.039).

CONCLUSION

The suPAR level is higher in patients with type 1 diabetes and is associated with diabetes duration and complications independent of other risk factors. suPAR is a potential novel risk marker for the management of diabetes.

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.

Diagnostic value of suPAR in differentiating noncardiac pleural effusions from cardiac pleural effusions

INTRODUCTION

Soluble urokinase plasminogen activator receptor (suPAR) is a newly discovered inflammatory biomarker. suPAR has not been previously studied in differentiating noncardiac pleural effusion (PF) from cardiac PF. The aim of our study was to assess the diagnostic value of suPAR in PF.

METHODS

The concentration of PF-suPAR was measured by a commercialized enzyme-linked immunosorbent assay in a prospective cohort of 74 patients with PF, 18 patients with PF due to cardiac failure (CF) and 56 patients with noncardiac PF. The area under the curve quantified the overall diagnostic accuracy of the tests.

RESULTS

The median pleural fluid suPAR level was found as 23 (5.4-102.8) ng/mL. The median PF-suPAR level in CF was significantly lower than that of noncardiac effusions [11.8 (5.4-28.9) ng/mL vs 26.7 (8.2-102.8) ng/mL, respectively, P < 0.001]. The area under the receiver operating characteristic curve was 0.878 (95% confidence interval: 0795-0.962, P < 0.001) for noncardiac pleural fluid suPAR. The sensitivity, specificity and positive predictive value of PF-suPAR for noncardiac effusions at the cutoff level of ≥17.6 n/mL was 88%, 83% and 94%, respectively. The suPAR level in PF was found to correlate with all of the biochemical parameters of PF.

CONCLUSIONS

suPAR is a potential new marker for the discrimination between cardiac and noncardiac PF.

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.

Life-long endurance exercise in humans: circulating levels of inflammatory markers and leg muscle size

Human aging is associated with a loss of skeletal muscle and an increase in circulating inflammatory markers. It is unknown whether endurance training (Tr) can prevent these changes. Therefore we studied 15 old trained (O-Tr) healthy males and, for comparison, 12 old untrained (O-Un), 10 Young-Tr (Y-Tr) and 12 Young-Un (Y-Un). Quadriceps size, VO2 peak, CRP, IL-6, TNF-α and its receptors, suPAR, lipid profile, leucocytes and glucose homeostasis were measured. Tr was associated with an improved insulin profile (p<0.05), and lower leucocyte (p<0.05) and triglyceride levels (p<0.05), independent of age. Aging was associated with poorer glucose control (p<0.05), independent of training. The age-related changes in waist circumference, VO2 peak, cholesterol, LDL, leg muscle size, CRP and IL-6 were counteracted by physical activity (p<0.05). A significant increase in suPAR with age was observed (p<0.05). Most importantly, life-long endurance exercise was associated with a lower level of the inflammatory markers CRP and IL-6 (p<0.05), and with a greater thigh muscle area (p<0.05), compared to age-matched untrained counterparts. These findings in a limited group of individuals suggest that regular physical endurance activity may play a role in reducing some markers of systemic inflammation, even within the normal range, and in maintaining muscle mass with aging.

Soluble urokinase plasminogen activator receptor levels reflect organ damage in systemic lupus erythematosus

Assessments of disease activity and organ damage in systemic lupus erythematosus (SLE) remain challenging because of the lack of reliable biomarkers and disease heterogeneity. Ongoing inflammation can be difficult to distinguish from permanent organ damage caused by previous flare-ups or medication side effects. Circulating soluble urokinase plasminogen activator receptor (suPAR) has emerged as a potential marker of inflammation and disease severity, and an outcome predictor in several disparate conditions. This study was done to evaluate suPAR as a marker of disease activity and organ damage in SLE. Sera from 100 healthy donors and 198 patients with SLE fulfilling the 1982 American College of Rheumatology classification criteria and/or the Fries criteria were analyzed for suPAR by enzyme immunoassay. Eighteen patients with varying degree of disease activity were monitored longitudinally. Disease activity was assessed by the SLE disease activity index 2000 and the physician's global assessment. Organ damage was evaluated by the Systemic Lupus International Collaborating Clinics/American College of Rheumatology damage index (SDI). Compared with healthy control subjects, serum suPAR levels were elevated significantly in patients with SLE. No association was recorded regarding suPAR levels and SLE disease activity in cross-sectional or consecutive samples. However, a strong association was observed between suPAR and SDI (P < 0.0005). Considering distinct SDI domains, renal, neuropsychiatric, ocular, skin, and peripheral vascular damage had a significant effect on suPAR levels. This study is the first to demonstrate an association between serum suPAR and irreversible organ damage in SLE. Further studies are warranted to evaluate suPAR and other biomarkers as predictors of evolving organ damage.

The Prognostic Value of suPAR Compared to Other Inflammatory Markers in Patients with Severe Sepsis

It has been suggested that soluble urokinase plasminogen activator (suPAR) can be used as a marker of disease severity and risk of mortality in sepsis. The aim with the present study was to compare plasma levels of suPAR in patients with severe sepsis to control subjects and correlate it with the level of inflammatory activation, severity and mortality. Samples were collected from 27 sepsis patients at the intensive care unit (ICU), Lund, Sweden; 90-day mortalities were registered. The suPAR level was significantly elevated in sepsis patients compared to controls, but not significantly higher in nonsurvivors than survivors. Plasma levels of suPAR did correlate weakly with the SOFA score and myeloperoxidase (MPO) but not with CRP, PCT, IL-6 or IL-10 in patients with severe sepsis. The weak correlation between suPAR and other inflammatory markers might suggest that suPAR reflects general activation of the immune system rather than exerting inflammatory actions.