Polymorphisms in Immune Response Genes in Infectious Diseases and Autoimmune Diseases

The clinical presentation of infections caused by the same micro-organism is highly diverse. This is for example demonstrated for infections with Neisseria meningitidis and respiratory syncytial virus. Some patients infected with N. meningitidis develop meningitis, while others present with sepsis or even septic shock. Moreover, only part of the individuals colonized with N. meningitidis develops clinical disease indicating a different susceptibility between individuals to develop clinical disease. The disease phenotype in respiratory syncytial virus infection varies from a common cold to severe bronchiolitis which requires mechanical ventilation.(1) A similar variation is observed in autoimmune diseases: While some patients with rheumatoid arthritis (RA) have relatively mild disease, in others joint erosion develops rather early after diagnosis. Although part of these variations in susceptibility and severity of infection is explained by, for example, age or crowding, the reasons for this variation are not completely clear. Genetic heterogeneity is thought to play a role

Circadian variation of plasminogen-activator-inhibitor-1 levels in children with meningococcal sepsis

Objective To study whether the circadian variation of plasminogen-activator-inhibitor-1 (PAI-1) levels, with high morning levels, is associated with poor outcome of children with meningococcal sepsis presenting in the morning hours. Design Retrospective analysis of prospectively collected clinical and laboratory data. Setting Single center study at Erasmus MC-Sophia Children's Hospital, Rotterdam, the Netherlands. Subjects 184 patients aged 3 weeks to 18 years with meningococcal sepsis. In 36 of these children, PAI-1 levels at admission to the PICU were measured in plasma by ELISA. Interventions None. Measurements and main results Circadian variation was studied by dividing one day in blocks of 6 hours. Patients admitted between 6:00 am and 12:00 am had increased illness severity scores and higher PAI-1 levels (n = 9, median 6912 ng/mL, IQR 5808-15600) compared to patients admitted at night (P = 0.019, n = 9, median 3546 ng/mL, IQR 1668-6118) or in the afternoon (P = 0.007, n = 7, median 4224 ng/mL, IQR 1804-5790). In 184 patients, analysis of circadian variation in relation to outcome showed more deaths, amputations and need for skin grafts in patients admitted to the PICU between 6:00 am and 12:00 am than patients admitted during the rest of the day (P = 0.009). Conclusions Circadian variation of PAI-1 levels is present in children with meningococcal sepsis and is associated with illness severity, with a peak level in the morning. Whether circadian variation is an independent risk factor for morbidity and mortality in meningococcal sepsis needs to be explored in future studies

Fever in high-risk paediatric patients presenting to European emergency departments : the perform experience

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The availability and use of diagnostic tests for the management of acute childhood infections in Europe: the protocol for a cross-sectional survey of paediatricians.

Introduction: Fever is a frequent reason of consultation in children, but correctly identifying the few febrile children with potentially severe bacterial infections is difficult. This encourages clinicians to prescribe empirical antibiotics and subject children to extensive and sometimes invasive testing. Rapid point of care tests (POCTs) are recommended internationally to reduce the use of antibiotics and medical resources. The extent of the availability and use of POCTs by paediatricians in Europe is unclear, but appears to vary widely across countries. The aim of this study is to document the availability and use of rapid POCTs for the clinical management of acute childhood infections and to identify factors associated with the variability of their adoption across Europe. Methods and analysis: The study is an online cross-sectional survey of paediatricians working in primary care and hospitals in more than 24 European countries. Participants were recruited through several European research and clinical networks Descriptive statistics will be used to describe the availability of rapid POCTs to paediatricians and the use of rapid POCTs in a clinical scenario of an infant with undifferentiated fever. Weighted regression analyses will identify factors of the availability and use of rapid POCTs across the included countries. Ethics and dissemination: Participating to this anonymous survey does not carry any risk. Ethical approval was obtained from the London School of Hygiene and Tropical Medicine Ethics Committee. The results of the survey will be presented at European paediatrics conferences and submitted for publication in peer-reviewed medical journals. This study will contribute to understanding the reasons for the variability in the adoption of rapid POCTs across different countries. The findings from this study will be useful for clinicians, health services and the industry developing and implementing rapid POCTs, particularly for the clinical management of febrile children

Association between High Levels of Blood Macrophage Migration Inhibitory Factor, Inappropriate Adrenal Response, and Early Death in Patients with Severe Sepsis

Background.Identification of new therapeutic targets remains an imperative goal to improve the morbidity and mortality associated with severe sepsis and septic shock. Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine and counterregulator of glucocorticoids, has recently emerged as a critical mediator of innate immunity and experimental sepsis, and it is an attractive new target for the treatment of sepsis. Methods.Circulating concentrations of MIF were measured in 2 clinical trial cohorts of 145 pediatric and adult patients who had severe sepsis or septic shock caused predominantly by infection with Neisseria meningitidis or other gram-negative bacteria, to study the kinetics of MIF during sepsis, to analyze the interplay between MIF and other mediators of sepsis or stress hormones (adrenocorticotropic hormone and cortisol), and to determine whether MIF is associated with patient outcome. Results.Circulating concentrations of MIF were markedly elevated in 96% of children and adults who had severe sepsis or septic shock, and they remained elevated for several days. MIF levels were correlated with sepsis severity scores, presence of shock, disseminated intravascular coagulation, urine output, blood pH, and lactate and cytokine levels. High levels of MIF were associated with a rapidly fatal outcome. Moreover, in meningococcal sepsis, concentrations of MIF were positively correlated with adrenocorticotropic hormone levels and negatively correlated with cortisol levels and the cortisol : adrenocorticotropic hormone ratio, suggesting an inappropriate adrenal response to sepsis. Conclusions.MIF is markedly and persistently up-regulated in children and adults with gram-negative sepsis and is associated with parameters of disease severity, with dysregulated pituitary-adrenal function in meningococcal sepsis, and with early deat

Polymorphisms in the glucocorticoid receptor gene that modulate glucocorticoid sensitivity are associated with rheumatoid arthritis

Introduction: The glucocorticoid receptor (GR) plays an important regulatory role in the immune system. Four polymorphisms in the GR gene are associated with differences in glucocorticoid (GC) sensitivity; the minor alleles of the polymorphisms N363 S and BclI are associated with relative hypersensitivity to GCs, while those of the polymorphisms ER22/23EK and 9β are associated with relative GC resistance. Because differences in GC sensitivity may influence immune effector functions, we examined whether these polymorphisms are associated with the susceptibility to develop Rheumatoid Arthritis (RA) and RA disease severity.Methods: The presence of GR polymorphisms was assessed in healthy controls (n = 5033), and in RA patients (n = 368). A second control group (n = 532) was used for confirmation of results. In RA patients, the relationship between GR polymorphisms and disease severity was examined.Results: Carriers of the N363 S and BclI minor alleles had a lower risk of developing RA: odds ratio (OR) = 0.55 (95% confidence interval (CI) 0.32-0.96, P = 0.032) and OR = 0.73 (95% CI 0.58-0.91, P = 0.006), respectively. In contrast, 9β minor allele carriers had a higher risk of developing RA: OR = 1.26 (95% CI 1.00-1.60, P = 0.050). For ER22/23EK minor allele carriers a trend to an increased risk OR = 1.42 (95% CI 0.95-2.13, P = 0.086) was found. All ER22/23EK carriers (32/32) had erosive disease, while only 77% (259/336) of the non-carriers did (P = 0.008). In addition, ER22/23EK carriers were treated more frequently with anti-tumor necrosis factor-alpha (TNFα) therapy (P < 0.05).Conclusions: The minor alleles of the 9β and ER22/23EK polymorphisms seem to be associated with increased predisposition to develop RA. Conversely, the minor alleles of the N363 S and BclI polymorphisms are associated with reduced susceptibility to develop RA. These opposite associations suggest that constitutionally determined GC resistance may predispose to development of auto-immunity, at least in RA, and vice versa

A Novel Framework for Phenotyping Children With Suspected or Confirmed Infection for Future Biomarker Studies

Copyright © 2021 Nijman, Oostenbrink, Moll, Casals-Pascual, von Both, Cunnington, De, Eleftheriou, Emonts, Fink, van der Flier, de Groot, Kaforou, Kohlmaier, Kuijpers, Lim, Maconochie, Paulus, Martinon-Torres, Pokorn, Romaine, Calle, Schlapbach, Smit, Tsolia, Usuf, Wright, Yeung, Zavadska, Zenz, Levin, Herberg, Carrol and the PERFORM consortium (Personalized Risk assessment in febrile children to optimize Real-life Management across the European Union).Background: The limited diagnostic accuracy of biomarkers in children at risk of a serious bacterial infection (SBI) might be due to the imperfect reference standard of SBI. We aimed to evaluate the diagnostic performance of a new classification algorithm for biomarker discovery in children at risk of SBI. Methods: We used data from five previously published, prospective observational biomarker discovery studies, which included patients aged 0– <16 years: the Alder Hey emergency department (n = 1,120), Alder Hey pediatric intensive care unit (n = 355), Erasmus emergency department (n = 1,993), Maasstad emergency department (n = 714) and St. Mary's hospital (n = 200) cohorts. Biomarkers including procalcitonin (PCT) (4 cohorts), neutrophil gelatinase-associated lipocalin-2 (NGAL) (3 cohorts) and resistin (2 cohorts) were compared for their ability to classify patients according to current standards (dichotomous classification of SBI vs. non-SBI), vs. a proposed PERFORM classification algorithm that assign patients to one of eleven categories. These categories were based on clinical phenotype, test outcomes and C-reactive protein level and accounted for the uncertainty of final diagnosis in many febrile children. The success of the biomarkers was measured by the Area under the receiver operating Curves (AUCs) when they were used individually or in combination. Results: Using the new PERFORM classification system, patients with clinically confident bacterial diagnosis (“definite bacterial” category) had significantly higher levels of PCT, NGAL and resistin compared with those with a clinically confident viral diagnosis (“definite viral” category). Patients with diagnostic uncertainty had biomarker concentrations that varied across the spectrum. AUCs were higher for classification of “definite bacterial” vs. “definite viral” following the PERFORM algorithm than using the “SBI” vs. “non-SBI” classification; summary AUC for PCT was 0.77 (95% CI 0.72–0.82) vs. 0.70 (95% CI 0.65–0.75); for NGAL this was 0.80 (95% CI 0.69–0.91) vs. 0.70 (95% CI 0.58–0.81); for resistin this was 0.68 (95% CI 0.61–0.75) vs. 0.64 (0.58–0.69) The three biomarkers combined had summary AUC of 0.83 (0.77–0.89) for “definite bacterial” vs. “definite viral” infections and 0.71 (0.67–0.74) for “SBI” vs. “non-SBI.” Conclusion: Biomarkers of bacterial infection were strongly associated with the diagnostic categories using the PERFORM classification system in five independent cohorts. Our proposed algorithm provides a novel framework for phenotyping children with suspected or confirmed infection for future biomarker studies.publishersversionPeer reviewe

Development and validation of a prediction model for invasive bacterial infections in febrile children at European Emergency Departments : MOFICHE, a prospective observational study

Funding Information: Funding This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 668303. The research was supported by the National Institute for Health Research Biomedical Research Centres at Imperial College London, Newcastle Hospitals NHS Foundation Trust and Newcastle University. Publisher Copyright: © 2021 Archives of Disease in ChildhoodObjectives: To develop and cross-validate a multivariable clinical prediction model to identify invasive bacterial infections (IBI) and to identify patient groups who might benefit from new biomarkers. Design: Prospective observational study. Setting: 12 emergency departments (EDs) in 8 European countries. Patients: Febrile children aged 0-18 years. Main outcome measures: IBI, defined as bacteraemia, meningitis and bone/joint infection. We derived and cross-validated a model for IBI using variables from the Feverkidstool (clinical symptoms, C reactive protein), neurological signs, non-blanching rash and comorbidity. We assessed discrimination (area under the receiver operating curve) and diagnostic performance at different risk thresholds for IBI: sensitivity, specificity, negative and positive likelihood ratios (LRs). Results: Of 16 268 patients, 135 (0.8%) had an IBI. The discriminative ability of the model was 0.84 (95% CI 0.81 to 0.88) and 0.78 (95% CI 0.74 to 0.82) in pooled cross-validations. The model performed well for the rule-out threshold of 0.1% (sensitivity 0.97 (95% CI 0.93 to 0.99), negative LR 0.1 (95% CI 0.0 to 0.2) and for the rule-in threshold of 2.0% (specificity 0.94 (95% CI 0.94 to 0.95), positive LR 8.4 (95% CI 6.9 to 10.0)). The intermediate thresholds of 0.1%-2.0% performed poorly (ranges: sensitivity 0.59-0.93, negative LR 0.14-0.57, specificity 0.52-0.88, positive LR 1.9-4.8) and comprised 9784 patients (60%). Conclusions: The rule-out threshold of this model has potential to reduce antibiotic treatment while the rule-in threshold could be used to target treatment in febrile children at the ED. In more than half of patients at intermediate risk, sensitive biomarkers could improve identification of IBI and potentially reduce unnecessary antibiotic prescriptions.publishersversionPeer reviewe

Diversity in the emergency care for febrile children in Europe : A questionnaire study

Publisher Copyright: © © Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.Objective To provide an overview of care in emergency departments (EDs) across Europe in order to interpret observational data and implement interventions regarding the management of febrile children. Design and setting An electronic questionnaire was sent to the principal investigators of an ongoing study (PERFORM (Personalised Risk assessment in Febrile illness to Optimise Real-life Management), www.perform2020.eu) in 11 European hospitals in eight countries: Austria, Germany, Greece, Latvia, the Netherlands, Slovenia, Spain and the UK. Outcome measures The questionnaire covered indicators in three domains: local ED quality (supervision, guideline availability, paper vs electronic health records), organisation of healthcare (primary care, immunisation), and local factors influencing or reflecting resource use (availability of point-of-care tests, admission rates). Results Reported admission rates ranged from 4% to 51%. In six settings (Athens, Graz, Ljubljana, Riga, Rotterdam, Santiago de Compostela), the supervising ED physicians were general paediatricians, in two (Liverpool, London) these were paediatric emergency physicians, in two (Nijmegen, Newcastle) supervision could take place by either a general paediatrician or a general emergency physician, and in one (München) this could be either a general paediatrician or a paediatric emergency physician. The supervising physician was present on site in all settings during office hours and in five out of eleven settings during out-of-office hours. Guidelines for fever and sepsis were available in all settings; however, the type of guideline that was used differed. Primary care was available in all settings during office hours and in eight during out-of-office hours. There were differences in routine immunisations as well as in additional immunisations that were offered; immunisation rates varied between and within countries. Conclusion Differences in local, regional and national aspects of care exist in the management of febrile children across Europe. This variability has to be considered when trying to interpret differences in the use of diagnostic tools, antibiotics and admission rates. Any future implementation of interventions or diagnostic tests will need to be aware of this European diversity.Peer reviewe