Proinflammatory cytokines, fibrinolytic system enzymes, and biochemical indices in children with infectious para-pneumonic effusions

Diagnostic value of soluble biomarkers for parapneumonic pleural effusion

Parapneumonic pleural effusion (PPE) is a common complication in patients with pneumonia. Timely and accurate diagnosis of PPE is of great value for its management. Measurement of biomarkers in circulating and pleural fluid have the advantages of easy accessibility, short turn-around time, objectiveness and low cost and thus have utility for PPE diagnosis and stratification. To date, many biomarkers have been reported to be of value for the management of PPE. Here, we review the values of pleural fluid and circulating biomarkers for the diagnosis and stratification PPE. The biomarkers discussed are C-reactive protein, procalcitonin, presepsin, soluble triggering receptor expressed on myeloid cells 1, lipopolysaccharide-binding protein, inflammatory markers, serum amyloid A, soluble urokinase plasminogen activator receptor, matrix metalloproteinases, pentraxin-3 and cell-free DNA. We found that none of the available biomarkers has adequate performance for diagnosing and stratifying PPE. Therefore, further work is needed to identify and validate novel biomarkers, and their combinations, for the management of PPE.

Role of procalcitonin in diagnosis of community acquired pneumonia in Children

Background

The role of serum Procalcitonin (PCT) in adults in diagnosis of Community acquired pneumonia (CAP) is well established, however, role in pediatric CAP remains controversial.

Objectives

The objective of this study was to investigate the utility of serum procalcitonin in differentiating bacterial community-acquired lower respiratory tract infection from non-bacterial respiratory infection in children; radiologically confirmed pneumonia was used as the reference. In addition, we assessed the utility of adding the PCT assay to the clinical criteria for diagnosis of pneumonia.

Study design

Subanalysis of a larger prospective,multicentriccohort study.

Participants

Children, 2 months to 59 months of age, attending paediatric OPD of 5 urban tertiary care hospitals, suffering from acute respiratory infection (ARI).

Intervention

Detailed clinical history and examination findings of enrolled children were recorded on predesigned case record form. Samples for PCT were obtained at admission and were measured centrally at the end of the study except for one site using VIDAS® B.R.A.H.M.S PCT kit (Biomerieux SA, France).

Outcomes

Sensitivity and specificity of procalcitonin for diagnosis of radiologically confirmed pneumonia.

Results

Serum Procalcitonin was measured in 370 patients; median (IQR) age of these children being 12 (7, 22) months, 235 (63.5%) were boys. The median (IQR) serum procalcitonin concentration was 0.1(0.05, 0.4) ng/mL.Sensitivity and specificity of raised PCT (> 0.5 ng/mL) for pneumonia as per any CXR abnormalities were 29.7% and87.5%,(P < 0.001) respectively. Raised PCT was also significantly associated with consolidation (34.5%,79.2%,P < 0.02)and pleural effusion(54.6%,79%,P < 001). Adding PCT to the existing clinical criteria of WHO did not improve the sensitivity for diagnosis of pneumonia. PCT was significantly higher in children with severe pneumonia.

Conclusion

Positive PCT (> 0.5 ng/mL) is significantly associated with radiographic pneumonia but not with pneumonia based on WHO criteria.However, it can act as a surrogate marker for severe pneumonia.

Effect of Prehospital Antibiotic Therapy on Clinical Outcome and Pathogen Detection in Children With Parapneumonic Pleural Effusion/Pleural Empyema

BACKGROUND

Parapneumonic pleural effusion and pleural empyema (PPE/PE) are complications of community-acquired pneumonia. The objective of this study was to analyze prehospital antibiotic therapy (PH-ABT) of children with PPE/PE and investigate its effects on clinical outcome and pathogen detection.

METHODS

Prospective nationwide active surveillance in Germany between October 2010 and June 2018. Children and adolescents <18 years of age with pneumonia-associated PE or PPE requiring drainage or with persistence of PPE/PE >7 days were included.

RESULTS

A total of 1724 children with PPE/PE were reported, of whom 556 children (32.3% of 1719 with available data) received PH-ABT. Children with PH-ABT had a shorter median hospital length of stay (15 vs. 18 days, P < 0.001), a longer time from onset of symptoms until hospital discharge (25 vs. 23 days, P = 0.002), a lower rate of intensive care unit admission (58.3% vs. 64.4%, P = 0.015) and fewer infectious complications (5.9% vs. 10.0%; P = 0.005). Bacterial pathogens in blood or pleural fluid culture were detected in 597 (34.5%) of 1513 children. Positive culture results were less frequent in children with than without PH-ABT (81/466 [17.4%] vs. 299/1005 [29.8%]; P < 0.001), whereas detection rates in pleural fluid samples by polymerase chain reaction were similar (91/181 [50.3%] vs. 220/398 [55.3%]; P = 0.263).

CONCLUSIONS

In children with PPE/PE, PH-ABT significantly reduced the overall rate of bacterial pathogen detection by culture, but not by polymerase chain reaction. PH-ABT was associated with a lower rate of infectious complications but did not affect the overall duration of disease. We therefore speculate that the duration of PPE/PE is mainly a consequence of an infection-induced inflammatory process, which can only partially be influenced by antibiotic treatment.

Inflammatory mediators in various molecular pathways involved in the development of pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a type of interstitial lung disease (ILD) that is marked by scarring of lung tissue, ultimately leading to respiratory failure. The survival rate of IPF is disappointing and to date demonstrates a clinical quandary. The exact etiology of the disease remains under discussion. According to the recent hypothesis, inflammatory mediators cause severe damage to the alveolar epithelium leading to the impairment of the alveolar structure. The role of inflammation in the development of the IPF has been controversial for years. There are two schools of thought regarding the role of inflammation. One group of researchers claims that cell death and fibroblast dysfunction are the primary causes and inflammation is just a secondary cause of IPF. The other group claims inflammation to be the primary cause. Studies using human subjects have also reported inflammation as a critical element in IPF. Inflammatory cytokinesserve amajor rolein commencing theinflammatoryresponse in the lungs. Several cytokines are reported to be involved in different molecular mechanisms underlying IPF, someof which alsocontribute additionally by acting as growth factors. The present review addressed to explore the contribution of various inflammatory cytokines, growth factors, and various other inflammatory molecules activating the major molecular pathways involved during the development of IPF.

Systemic cytokines/chemokines associated to radiographic abnormalities in pneumonia in children

Community-acquired pneumonia (CAP) diagnosis remains a challenge in paediatrics. Chest radiography is considered gold standard for definition of pneumonia, however no previous study assessed the relationship between immune response and radiographic-confirmed-pneumonia. We assessed association between cytokines/chemokines levels and radiographic abnormalities in children with CAP. Children < 5-years-old hospitalized with CAP were investigated in a prospective study at the Federal University of Bahia Hospital, Brazil. On admission, clinical data and biological samples were collected to investigate 20 aetiological agents and determine serum cytokines/chemokines levels; chest radiographs were performed. Among 158 patients, radiographic diagnosis of pneumonia was confirmed in 126(79.7%) and 17(10.8%) had pleural effusion. Viral, bacterial and pneumococcal infection were detected in 80(50.6%), 78(49.4%) and 37(23.4%) cases. By comparing the median concentrations of serum cytokines/chemokines between children with or without pleural effusion, interleukin(IL)-6 was higher (26.6[18.6-103.7] vs 3.0[0.0-19.8]; p < 0.001) among those with pleural effusion; and between children with or without radiographic-confirmed-pneumonia, IL-6 was higher in the first subgroup (4.5[0.0-23.4] vs 0.0[0.0-3.6]; p = 0.02) after having excluded cases with pleural effusion. Stratified analyses according to aetiology showed IL-6 increase in the radiographic-confirmed-pneumonia subgroup inside the pneumococcal infection (28.2[5.9-64.1] vs 0.0[0.0-0.0]; p = 0.03) subgroup. By multivariable analysis, with IL-6 as dependent variable, pneumococcal infection and pleural effusion showed independent association with IL-6 elevation [respective OR: 5.071 (95%CI = 2.226-11.548; p < 0.001) and 13.604 (95%CI = 3.463-53.449; p = 0.0001)]. Considering the cases without pleural effusion, the area under the curve of IL-6 to predict pneumococcal infection was 0.76 (95%CI = 0.66-0.86; p < 0.001). IL-6 increase is a potential biomarker of pneumococcal infection among children with CAP without pleural effusion upon admission.

Phase 1 trial of intrapleural LTI-01; single chain urokinase in complicated parapneumonic effusions or empyema

BACKGROUND

Current dosing of intrapleural fibrinolytic therapy (IPFT) in adults with complicated parapneumonic effusion (CPE) / empyema is empiric, as dose-escalation trials have not previously been conducted. We hypothesized that LTI-01 (scuPA), which is relatively resistant to PA inhibitor-1 (PAI-1), would be well-tolerated.

METHODS

This was an open-label, dose-escalation trial of LTI-01 IPFT at 50,000-800,000 IU daily for up to 3 days in adults with loculated CPE/empyema and failed pleural drainage. The primary objective was to evaluate safety and tolerability, and secondary objectives included assessments of processing and bioactivity of scuPA in blood and pleural fluid (PF), and early efficacy.

RESULTS

LTI-01 was well tolerated with no bleeding, treatment-emergent adverse events or surgical referrals (n=14 subjects). uPA antigen increased in PFs at 3 hours after LTI-01 (p<0.01) but not in plasma. PF saturated active PAI-1, generated PAI-1-resistant bioactive complexes, increased PA and fibrinolytic activities and D-dimers. There was no systemic fibrinogenolysis, nor increments in plasma D-dimer. Decreased pleural opacities occurred in all but one subject. Both subjects receiving 800,000 IU required two doses to relieve pleural sepsis, with two other subjects similarly responding at lower doses.

CONCLUSION

LTI-01 IPFT was well-tolerated at these doses with no safety concerns. Bioactivity of LTI-01 IPFT was confirmed, limited to PFs where its processing simulated that previously reported in preclinical studies. Preliminary efficacy signals including reduction of pleural opacity were observed.

Metabolomics Reveals Anaerobic Bacterial Fermentation and Hypoxanthine Accumulation for Fibrinous Pleural Effusions in Children with Pneumonia

Fibrin formation in infectious parapneumonic effusion (IPE) characterizes complicated parapneumonic effusion and is important for providing guidelines for the management of IPEs that require aggressive interventions. We aim to identify metabolic mechanisms associated with bacterial invasion, inflammatory cytokines, and biochemical markers in cases of fibrinous infectious pleural effusions in children with pneumonia. Pleural fluid metabolites were determined by ¹H nuclear magnetic resonance spectroscopy. Metabolites that contributed to the separation between fibrinous and nonfibrinous IPEs were identified using supervised partial least squares discriminant analysis ( Q²/ R² = 0.84; P_permutation < 0.01). IL-1β in the inflammatory cytokines and glucose in the biochemical markers were significantly correlated with 11 and 9 pleural fluid metabolites, respectively, and exhibited significant overlaps. Four metabolites, including glucose, lactic acid, 3-hydroxybutyric acid, and hypoxanthine, were significantly correlated with plasminogen activator inhibitor type 1 in the fibrinolytic system enzymes. Metabolic pathway analysis revealed that anaerobic bacterial fermentation with increased lactic acid and butyric acid via glucose consumption and adenosine triphosphate hydrolysis with increased hypoxanthine appeared to be associated with fibrinous IPE. Our results demonstrate that an increase in lactic acid anaerobic fermentation and hypoxanthine accumulation under hypoxic conditions are associated with fibrin formation in IPE, representing advanced pleural inflammatory progress in children with pneumonia.

Transforming growth factor beta1 (TGF-ß1) levels in a rat model of induced pleural empyema

PURPOSE

To evaluate the concentration of transforming growth factor beta 1 (TGFB1) levels in a rat pleural effusion obtained by inoculation of intrapleural bacteria or turpentine through thoracentesis.

METHODS

Thirty-Nine Wistar rats were divided into three groups: Staphylococcus aureus (SA, n = 17); Streptococcus pneumoniae (SP, n = 12); and turpentine (control, n = 10). Pleural fluid was collected through ultrasound-guided thoracentesis 12 h, 24 h, and 36 h after instillation of bacteria or turpentine. Levels of TGFB1 were measured in pleural fluid.

RESULTS

At 12 h, mean TGFB1concentrations were 5.3450 pg/mL in the SA group, 5.3449 pg/mL in the SP group, and 5.3450 pg/mL in controls. At 24 h, they were 4.6700 pg/mL in the SA group, 4.6700 pg/mL in the SP group, and 4.6700 pg/mL in controls. At 36 h, they were 4.6699 pg/mL in the SA group and in control. No difference was observed among the groups in mean TGFB1concentration (p = 0.12); however, a significant intragroup reduction in mean TGFB1 was observed between 12 and 24 h (p < 0.01).

CONCLUSION

The transforming growth factor beta 1 concentrations were not useful as a diagnostic tool or an early marker of infected pleural effusion.

Differences Between Radiologically Confirmed Pneumonia With and Without Pleural Fluid in Hospitalized Children Younger Than 5 Years in Southern Israel

We compared demographic and clinical characteristics of pneumonia with and without pleural fluid (PF and Pn, respectively) in hospitalized children younger than 5 years in southern Israel, between 2002 and 2011. Overall, 108 PF and 5811 Pn episodes were recorded. Children with PF were older. Prematurity (6.6% vs 14.0%) and asthma (9.9% vs 23.5%) were less common in PF. Mean temperature and saturation were higher in PF while hemoglobin and sodium levels were lower in PF compared with Pn. Nasal washes were obtained in 30.6% and 39.9% of PF and Pn episodes, respectively, with respiratory syncytial virus identified more commonly in Pn (24.2% vs 42.3%). Streptococcus pneumoniae was identified in 5.2% and 0.9% of blood cultures in PF and Pn, respectively. In conclusion, PF differed from Pn in demographic and clinical characteristics, possibly due to differences in etiology. Although both diseases are considered bacterial, a high proportion of viral etiology was found in both, especially in Pn.

Dose dependency of outcomes of intrapleural fibrinolytic therapy in new rabbit empyema models

The incidence of empyema (EMP) is increasing worldwide; EMP generally occurs with pleural loculation and impaired drainage is often treated with intrapleural fibrinolytic therapy (IPFT) or surgery. A number of IPFT options are used clinically with empiric dosing and variable outcomes in adults. To evaluate mechanisms governing intrapleural fibrinolysis and disease outcomes, models of Pasteurella multocida and Streptococcus pneumoniae were generated in rabbits and the animals were treated with either human tissue (tPA) plasminogen activator or prourokinase (scuPA). Rabbit EMP was characterized by the development of pleural adhesions detectable by chest ultrasonography and fibrinous coating of the pleura. Similar to human EMP, rabbits with EMP accumulated sizable, 20- to 40-ml fibrinopurulent pleural effusions associated with extensive intrapleural organization, significantly increased pleural thickness, suppression of fibrinolytic and plasminogen-activating activities, and accumulation of high levels of plasminogen activator inhibitor 1, plasminogen, and extracellular DNA. IPFT with tPA (0.145 mg/kg) or scuPA (0.5 mg/kg) was ineffective in rabbit EMP (n = 9 and 3 for P. multocida and S. pneumoniae, respectively); 2 mg/kg tPA or scuPA IPFT (n = 5) effectively cleared S. pneumoniae-induced EMP collections in 24 h with no bleeding observed. Although intrapleural fibrinolytic activity for up to 40 min after IPFT was similar for effective and ineffective doses of fibrinolysin, it was lower for tPA than for scuPA treatments. These results demonstrate similarities between rabbit and human EMP, the importance of pleural fluid PAI-1 activity, and levels of plasminogen in the regulation of intrapleural fibrinolysis and illustrate the dose dependency of IPFT outcomes in EMP.

Metabolomic Profiling of Infectious Parapneumonic Effusions Reveals Biomarkers for Guiding Management of Children with Streptococcus pneumoniae Pneumonia

Metabolic markers in biofluids represent an attractive tool for guiding clinical management. The aim of this study was to identify metabolic mechanisms during the progress of pleural infection in children with Streptococcus pneumoniae pneumonia. Forty children diagnosed with pneumococcal pneumonia were enrolled and analysis of pleural fluid metabolites categorized by complicated parapneumonic effusions (CPE) and non-CPE was assessed by using ¹H-NMR spectroscopy. Multivariate statistical analysis including principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) were performed. Metabolites identified were studied in relation to subsequent intervention procedures by receiver operating characteristic (ROC) curve analysis. Ten metabolites significantly different between CPE and non-CPE were identified. A significantly lower level of glucose for glycolysis was found in CPE compared to non-CPE. Six metabolites involving bacterial biosynthesis and three metabolites involving bacterial fermentation were significantly higher in CPE compared to non-CPE. Glucose and 3-hydroxybutyric acid were the metabolites found to be useful in discriminating from receiving intervention procedures. Metabolic profiling of pleural fluid using ¹H-NMR spectroscopy provides direct observation of bacterial metabolism in the progress of pneumococcal pneumonia. An increase in the metabolism of butyric acid fermentation of glucose could potentially lead to the need of aggressive pleural drainage.

Best vaccination practice and medically attended injection site events following deltoid intramuscular injection

Analysis of medically attended injection site events data provides a vehicle to appreciate the inadequacies of vaccination practice for deltoid intramuscular injection and to develop best practice procedures. These data can be divided into 3 groups; nerve palsies, musculoskeletal injuries and cutaneous reactions and reflect inappropriate site of injection, needle over or under penetration, local sepsis and vascular complications. The aim of this review is to formulate best vaccination practice procedures for deltoid intramuscular injection of vaccines through the collation and analysis of medically attended injection site events.

The value of total protein in guiding management of infectious parapneumonic effusion by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

BACKGROUND/PURPOSE

Infectious parapneumonic effusion (PE) contains proteins originating from circulation as well as proteins locally released by inflammatory pulmonary cells. The purpose of this study was to investigate the value of total protein analysis in guiding management of infectious PE by using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

METHODS

Fifty-seven children with pneumonia followed by PE were consecutively enrolled into our study. Protein profiles generated by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry after fractionating samples with functionalized magnetic beads (C8) were used for differentiating complicated PE (CPE) from non-CPE. A training set was used to generate classification models and the clinical efficacy of these models in detecting CPE and the need for intervention was then evaluated in an independent set.

RESULTS

The MS spectra derived from PE were analyzed, and classification models were constructed in the training set. A total of 123 mass/charge (m/z) values were identified and 23 m/z values which were significant with p < 0.05 were used as classifiers. An optimized genetic algorithm model containing enforced selection of three significant downregulated m/z values (2127, 2232, and 2427) was able to classify CPE with 100% positive predictive value and predict the need of aggressive therapeutic intervention with 77% positive predictive value.

CONCLUSION

A diagnostic model construction comprising three potential biomarkers can predict CPE and need for surgical intervention rapidly and precisely. Pleural fluid proteins downregulated during the progression of pneumonia could potentially guide the management of infectious PE.

Increased production of interleukin-10 in children with Down syndrome upon ex vivo stimulation with Streptococcus pneumoniae

BACKGROUND

Children with Down syndrome (DS) have an increased susceptibility to infections, due to altered humoral and/or cellular immunity. The aim of the study was to determine the cytokine production in whole blood of children with DS upon stimulation with heat-killed Streptococcus pneumoniae and lipopolysaccharide (LPS), in comparison with their healthy siblings.

METHODS

Whole blood of 61 children with DS and 57 of their healthy siblings was stimulated with 200 ng/ml LPS and 4 × 10(7) colony-forming units/ml S. pneumoniae during 6, 24, and 48 h. Concentrations of pro- and anti-inflammatory cytokines, tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, IL-12p70, and IL-10 were determined at all time points.

RESULTS

Children with DS show an increased IL-10 production upon stimulation with S. pneumoniae compared to their healthy siblings. At most time points, no significant differences were seen in cytokine production upon stimulation with LPS.

CONCLUSION

Children with DS may be prone to a severe course of pneumococcal pneumonia, because of an increased anti-inflammatory response.

Diagnostic value of proinflammatory interleukins in parapneumonic effusions

Pleural effusion appears in approximately 40% of patients with pneumonia. Given that microbiology results are often negative, its diagnosis is frequently based on clinical criteria. Our study consisted of 266 patients, divided into infectious (n = 34), tuberculous (n = 54), paraneoplastic (n = 63), miscellaneous exudates (n = 53), and transudates (n = 62). Interleukin (IL)-6, IL-8, and IL-1beta were measured in the pleural fluid and serum of all patients, as well as the different cell populations in the pleural fluid. Analysis of the receiver operating characteristic curves of the different ILs in pleural fluid for the diagnosis of parapneumonic/empyematous effusion showed IL-6 with a sensitivity of 38.2% and specificity of 97.4%, IL-8 with a sensitivity of 73.5% and specificity of 65.1%, IL-1beta with a sensitivity of 55.6% and specificity of 91.3%, and total neutrophil count in pleural fluid (PNEU) with a sensitivity of 62.9% and specificity of 91.1%. The combination of IL-1beta and PNEU improved the yield, with a sensitivity of 75.7% and a specificity of 83.1%.

Decreased proinflammatory cytokines production in children with complicated parapneumonic pleural effusion after intrapleural fibrinolytic treatment

Intrapleural fibrinolytic therapy (IFT) provides clinical benefit in the treatment of complicated pleural parapneumonic effusion (CPE). Whether IFT influences the proinflammatory cytokines production and fibrinlytic activity is currently unclear. Therefore, we collected pleural effusion samples from CPE patients with IFT (study group) and patients without IFT (control group). A membrane human inflammatory cytokines array kit was used to compare the difference of targeted cytokine production between these two groups. Enzyme-linked immunosorbent assay (ELISA) methods were used for quantitative analysis of targeted cytokines and fibrinolytic enzymes. The results showed there were no significant differences between the study (n = 16) and control (n = 14) groups in patients' demographic data. After fibrinolytic therapy, the patients in the study group had significant lower plasminogen activator inhibitor (PAI) level (732.36+/-254.09 ng/mL vs 1,509.36+/-1,340.11 ng/mL, p<0.05) and higher urokinase plasminogen activator (u-PA) level (75.56+/-41.70 ng/mL vs 6.87+/-5.07 ng/mL, p<0.05) than they did before treatment. Moreover, the tissue inhibitors of metalloproteinase-2 (TIMP-2) (1,560.03+/-403.49 pg/mL vs 3,686.45+/-1,263.83 pg/mL, p<0.05) and inflammatory chemokine, regulated on activation normal T-cell expressed and secreted/chemokine (C-C motif) ligand 5 (RANTES), (293.58+/-212.93 pg/mL vs 749.27+/-53.79 pg/mL, p<0.05), were also significantly lower in the study group after fibrinolytic therapy, but not in the control group. In conclusion, intrapleural fibrinolytic treatment with urokinase could enhance fibrinolytic activity and decrease TIMP-2 and RANTES production.

Clinical practice: treatment of childhood empyema

INTRODUCTION

The incidence of empyema in children is increasing. Adequate knowledge of treatment modalities is therefore essential for every pediatrician. At the university hospital of Leuven, the incidence per 100,000 admissions increased from 40 in 1993 to 120 in 2005. The treatment of choice, however, is still a matter of debate. This is mainly due to the scarcity of prospective randomized trials in children but is further complicated by the absence of uniform terminology. This review starts with clarifying definitions of empyema and complicated versus noncomplicated parapneumonic effusion. The place of different imaging techniques--ultrasound, chest X-ray, computerized tomography and magnetic resonance imaging--is illustrated. All treatment steps are evaluated starting with antibiotic choices, duration of i.v. and oral antibiotics, pleural fluid analysis, indications for chest drain placement, and fibrinolysis. As to the surgical interventions, there is at present insufficient evidence that early surgery is superior to noninvasive medical treatment. Therefore, video-assisted thoracoscopy cannot be advised as general first-line therapy.

CONCLUSION

Since the pathogenicity of empyema is a dynamic process, therapeutic strategy must be decided based on empyema stage and clinical experience. Each referral center should agree on a diagnostic and therapeutic flowchart based on current evidence and local expertise. The flow chart outlined for our center is presented.