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

Soluble urokinase plasminogen activator receptor (suPAR) in children with obesity or type 1 diabetes as a marker of endothelial dysfunction: a cross-sectional study

Pediatric obesity and type 1 diabetes mellitus (T1DM) represent two common chronic diseases associated with chronic inflammation, endothelial dysfunction and long-term complications. The aim of the present study was to assess the possible diagnostic and prognostic value of soluble urokinase plasminogen activator receptor (suPAR), a marker of inflammation and impaired endothelial function, in children with the diseases. In this cross-sectional study, children and adolescents with T1DM (N = 41) or obesity (N = 37), aged < 18 years old, and without proteinuria were included, together with children of similar age and without evident morbidity that served as controls (N = 42). Serum samples were obtained during standard outpatient follow up and the urokinase-type plasminogen activator receptor (suPAR) concentrations were measured using a commercially available sandwich ELISA kit (DUP00, R&D systems). Clinical and biochemical indices that were also assessed include body mass index (BMI) z-score, Tanner stages, glycosylated haemoglobin (HbA1c), fasting lipid profile and serum creatinine. Mean serum suPAR levels were significantly higher in patients with obesity compared to patients with T1DM and controls, while children with T1DM had similar suPAR levels to controls. Also, serum suPAR levels showed a negative correlation with age (Spearman rho -0.359, p < 0.001) and serum creatinine levels (Spearman rho -0.334, p = 0.005), and a positive correlation with BMI z-score (Spearman rho 0.354, p = 0.009) in the whole cohort.  Conclusion: Serum suPAR may be a useful predictive marker of inflammation or endothelial dysfunction for children with obesity and T1DM, as well as a promising therapeutic target. Further studies are needed in order to clarify whether the reported differences in suPAR levels could reflect a greater impairment of the inflammation status and endothelial function in children with obesity compared to children with T1DM. What is Known: • Paediatric obesity and type 1 diabetes are characterised by chronic inflammation and metabolic dysregulation. • Urokinase plasminogen activator receptor (uPAR) has been proposed as a useful biomarker for chronic inflammation and cardiovascular risk in adults. What is New: • Serum suPAR levels were increased in children and adolescents with obesity compared to those with T1DM and healthy controls; thus, obesity may affect the inflammatory status and endothelial function to a higher degree than T1DM during childhood. • Serum suPAR may serve as a diagnostic and predictive marker of inflammation and endothelial dysfunction for children and adolescents with obesity and T1DM.

Advances in sepsis biomarkers

Sepsis, a dysregulated host immune response to an infectious agent, significantly increases morbidity and mortality for hospitalized patients worldwide. This chapter reviews (1) the basic principles of infectious diseases, pathophysiology and current definition of sepsis, (2) established sepsis biomarkers such lactate, procalcitonin and C-reactive protein, (3) novel, newly regulatory-cleared/approved biomarkers, such as assays that evaluate white blood cell properties and immune response molecules, and (4) emerging biomarkers and biomarker panels to highlight future directions and opportunities in the diagnosis and management of sepsis.

Eosinophil Cell Count Predicts Mortality in the Intensive Care Unit after Return of Spontaneous Circulation

BACKGROUND

Eosinophils constitute 1%-5% of peripheral blood leukocytes, less in the presence of acute infections (referred to as eosinopenia). Studies indicate that eosinopenia can be used as a prognostic predictor for chronic obstructive pulmonary disease exacerbation, sepsis, or acute myocardial infarction disease. There are only a few studies about predicting mortality in emergency departments and intensive care units (ICUs). Prognostic studies about patients in ICUs are generally carried out using different scoring systems. We aimed to analyze if the eosinophil count can estimate the prognosis among non-traumatic patients who underwent cardiopulmonary resuscitation and were hospitalized in ICU thereafter.

METHODS

The data were evaluated of 865 non-traumatic adult patients (>18 years of age) who were admitted with cardiopulmonary arrest or developed cardiopulmonary arrest during clinical follow-ups. Admission venous blood sample tests, complete blood count, and biochemical laboratory results were recorded. Arterial blood gas results were also evaluated. The mean results of the recorded laboratory results were compared between the surviving and non-surviving patients groups.

RESULTS

There was a significant difference between the two groups in regard to platelet, eosinophil count, pH, PaO₂, SaO₂, and HCO₃^- (P<0.001 for all). In the multiple linear regression analysis, eosinophil counts were found to be an independent factor (odds ratio=0.03, 95% confidence interval 0.33-0.56, P<0.001) associated with the mortality after cardiopulmonary resuscitation.

CONCLUSION

Because admission eosinophil counts can be measured easily, they are inexpensive biomarkers that can be used for predicting the prognosis among the patients who have return of spontaneous circulation and are treated in ICUs.

Biomarkers in pediatric sepsis: a review of recent literature

Sepsis remains the leading cause of death in infants and children worldwide. Prompt diagnosis and monitoring of infection is pivotal to guide therapy and optimize outcomes. No single biomarker has so far been identified to accurately diagnose sepsis, monitor response and predict severity. We aimed to assess existing evidence of available sepsis biomarkers, and their utility in pediatric population. C-reactive protein and procalcitonin remain the most extensively evaluated and used biomarkers. However, biomarkers related to endothelial damage, vasodilation, oxidative stress, cytokines/chemokines and cell bioproducts have also been identified, often with regard to the site of infection and etiologic pathogen; still, with controversial utility. A multi-biomarker model driven by genomic tools could establish a personalized approach in future disease management.

Levels of Soluble Urokinase Plasminogen Activator Receptor in Pediatric Lower Respiratory Tract Infections

Background: Lower respiratory tract infections (LTRIs) are the most common cause of pediatric emergency department visits and are associated with significant morbidity and mortality. The aim of this study was to evaluate the soluble urokinase plasminogen activator receptor (suPAR) levels in pediatric patients with LRTIs and to investigate the correlation of suPAR with disease severity. Methods: This is a prospective case-control study of children with LTRIs. Demographic data, diagnoses, vital signs, disease severity scores, length of hospital stay, laboratory findings, and viral polymerase chain reaction results for nasopharyngeal aspirates were recorded. Blood samples for suPAR were collected and assessed by enzyme-linked immunosorbent assay. Results: There were 94 patients with LTRIs and 32 children in the control group. Patients were further subdivided into 2 groups based on diagnosis of acute bronchiolitis (n: 31, 33%) or pneumonia (n: 63, 67%). The median levels of suPAR were significantly higher in patients with LTRIs than in healthy controls (4.3 and 3.5 ng/mL, respectively; P = 0.003). There was an association between suPAR levels and disease severity in pneumonia patients. suPAR values were higher in patients with severe pneumonia than mild pneumonia (5.5 and 3.6 ng/mL, respectively; P < 0.001). Conclusion: We have shown that suPAR levels increased in patients with LTRIs and suPAR values were higher in patients with severe pneumonia than mild pneumonia. Further studies with large case series are needed to clarify the role of suPAR levels in children with LTRIs.

Soluble urokinase-type plasminogen activator receptor as a biomarker of treatment response in childhood tuberculosis

Background

Childhood tuberculosis (TB) is a major health problem worldwide, especially in developing countries. In 2015, there are estimated 950,000 cases of childhood TB. Since most TB in children is paucibacillary, this gives rise not only to problem in diagnosing but also in monitoring the response to anti-TB treatment as well. Soluble urokinase-type plasminogen activator receptor (suPAR), a glycosylphosphatidylinositol-linked membrane protein of various cells of immune system, is one of the potential biomarkers to be used in the management of TB. The objective of this study is to study the decrease of serum suPAR level after anti-TB treatment in children with TB and its association with patient characteristics.

Methods

We conducted a prospective study on children suspected of having TB due to a history of contact with active TB case and symptoms such as coughing, fever, and enlarged lymph nodes. The diagnosis of TB is established by history, physical examination including anthropometric examination. Tuberculin skin test using PPD RT-23 and interferon-gamma releasing assay with Quantiferon TB-Gold Plus was performed. Chest X-rays were read by two independent radiologists. Microbiological examination was performed using microscopic examination and Xpert MTB/RIF. The level of suPAR before and after anti-TB treatment was examined with the Elisa method.

Results

There was no significant difference of serum suPAR levels before and after anti-TB treatment (mean 0.71 [standard deviation 0.585] ng/mL; P = 0.072). There was no association between ages (P = 0.112), nutritional status (P = 0.228), diagnosis of pulmonary or extrapulmonary TB (P = 0.956), and radiological feature (P = 0.810) with serum suPAR levels decrease.

Conclusion

There is no suPAR serum level decrease 2 months after treatment with anti-TB and there is no association with age, nutritional status, pulmonary or extrapulmonary TB diagnosis, and radiological feature.

Prognostic Value of High-Sensitivity C-Reactive Protein, Procalcitonin and Pancreatic Stone Protein in Pediatric Sepsis

Background

To investigate the prognostic value of procalcitonin (PCT), high-sensitivity C-reactive protein (hs-CRP), and pancreatic stone protein (PSP) in children with sepsis.

Material/Methods

A total of 214 patients with sepsis during hospitalization were enrolled. Serum levels of PCT, hs-CRP, and PSP were measured on day 1 of hospitalization and the survival rates of children were recorded after a follow-up of 28 days. Pearson’s correlation analysis was conducted to test the association of PCT, hs-CRP, and PSP with pediatric critical illness score (PCIS). Logistic regression models were used to analyze the risk factors contributing to patients’ death. The AUC was used to determine the value of PCT, hs-CRP, and PSP in the prognosis of patients with sepsis.

Results

The expression of PCT, hs-CRP, and PSP in the dying patients was higher than in the surviving patients (p<0.001). Pearson’s correlation analysis showed that serum PCT, hs-CRP, and PSP levels were negatively correlated with PCIS (p<0.001). Multivariate logistic regression revealed that PCT, hs-CRP, and PSP were independent risk factors for the prognosis of patients with sepsis (p<0.001). ROC analysis showed the AUC values of PCT, hs-CRP, and PSP were 0.83 (95% CI, 0.77–0.88), 0.76 (95% CI, 0.70–0.82), and 0.73 (95% CI, 0.67–0.79), respectively. The combined AUC value of PCT, hs-CRP, and PSP, was 0.92 (95% CI, 0.87–0.95), which was significantly increased compared with PCT, hs-CRP, or PSP (p<0.001).

Conclusions

The combination of serum PCT, hs-CRP, and PSP represents a promising biomarker of risk, and is a useful clinical tool for risk stratification of children with sepsis.

Usefulness of soluble urokinase plasminogen activator receptor (suPAR) as an inflammatory biomarker in obese children

OBJECTIVE

Soluble urokinase plasminogen activator receptor (suPAR) has emerged as a relatively new biomarker that reflects increased inflammatory status and been associated with cardiovascular risk. We wanted to investigate the predictive value and usefulness of suPAR as an inflammatory biomarker in obese children.

METHODS AND RESULTS

Of the total 136 participants, 76 (36 male, 40 female) were in obese group and 60 (24 male, 36 female) were in control group. The median age was 12.05 (6.16-17.30) years old for obese group, and 12.83 (8.00-16.75) years old for control group. Obese children had statistically significantly higher heart rate, systolic and diastolic blood pressure, EAT and LV mass than control group (p<0.01). The median suPAR level in obese group was not statistically different than in control group (0.54 vs. 0.59, p=0.26). The median hsCRP level in obese group was found statistically significantly higher than in control group (1.97 vs. 0.41, p<0.01). A significant positive correlation between hsCRP and BMI in the obese participants was found (r=0.45, p<0.01), but not a relationship between suPAR and BMI (r=-0.21, p>0.05).

CONCLUSION

Our research did not demonstrate the usefulness of suPAR as an inflammatory biomarker and a predictive value for future atherosclerosis in obese children. Further studies with larger sample size are required to determine whether suPAR is useful as an inflammatory biomarker in childhood obesity.