A multi-platform approach to identify a blood-based host protein signature for distinguishing between bacterial and viral infections in febrile children (PERFORM) : a multi-cohort machine learning study

Copyright © 2023 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.BACKGROUND: Differentiating between self-resolving viral infections and bacterial infections in children who are febrile is a common challenge, causing difficulties in identifying which individuals require antibiotics. Studying the host response to infection can provide useful insights and can lead to the identification of biomarkers of infection with diagnostic potential. This study aimed to identify host protein biomarkers for future development into an accurate, rapid point-of-care test that can distinguish between bacterial and viral infections, by recruiting children presenting to health-care settings with fever or a history of fever in the previous 72 h. METHODS: In this multi-cohort machine learning study, patient data were taken from EUCLIDS, the Swiss Pediatric Sepsis study, the GENDRES study, and the PERFORM study, which were all based in Europe. We generated three high-dimensional proteomic datasets (SomaScan and two via liquid chromatography tandem mass spectrometry, referred to as MS-A and MS-B) using targeted and untargeted platforms (SomaScan and liquid chromatography mass spectrometry). Protein biomarkers were then shortlisted using differential abundance analysis, feature selection using forward selection-partial least squares (FS-PLS; 100 iterations), along with a literature search. Identified proteins were tested with Luminex and ELISA and iterative FS-PLS was done again (25 iterations) on the Luminex results alone, and the Luminex and ELISA results together. A sparse protein signature for distinguishing between bacterial and viral infections was identified from the selected proteins. The performance of this signature was finally tested using Luminex assays and by calculating disease risk scores. FINDINGS: 376 children provided serum or plasma samples for use in the discovery of protein biomarkers. 79 serum samples were collected for the generation of the SomaScan dataset, 147 plasma samples for the MS-A dataset, and 150 plasma samples for the MS-B dataset. Differential abundance analysis, and the first round of feature selection using FS-PLS identified 35 protein biomarker candidates, of which 13 had commercial ELISA or Luminex tests available. 16 proteins with ELISA or Luminex tests available were identified by literature review. Further evaluation via Luminex and ELISA and the second round of feature selection using FS-PLS revealed a six-protein signature: three of the included proteins are elevated in bacterial infections (SELE, NGAL, and IFN-γ), and three are elevated in viral infections (IL18, NCAM1, and LG3BP). Performance testing of the signature using Luminex assays revealed area under the receiver operating characteristic curve values between 89·4% and 93·6%. INTERPRETATION: This study has led to the identification of a protein signature that could be ultimately developed into a blood-based point-of-care diagnostic test for rapidly diagnosing bacterial and viral infections in febrile children. Such a test has the potential to greatly improve care of children who are febrile, ensuring that the correct individuals receive antibiotics. FUNDING: European Union's Horizon 2020 research and innovation programme, the European Union's Seventh Framework Programme (EUCLIDS), Imperial Biomedical Research Centre of the National Institute for Health Research, the Wellcome Trust and Medical Research Foundation, Instituto de Salud Carlos III, Consorcio Centro de Investigación Biomédica en Red de Enfermedades Respiratorias, Grupos de Refeencia Competitiva, Swiss State Secretariat for Education, Research and Innovation.Peer reviewe

Guideline adherence in febrile children below 3 months visiting European Emergency Departments : an observational multicenter study

Funding Information: This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No. 848196. 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. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health. For the remaining authors, no sources of funding were declared. The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Publisher Copyright: © 2022, The Author(s).Febrile children below 3 months have a higher risk of serious bacterial infections, which often leads to extensive diagnostics and treatment. There is practice variation in management due to differences in guidelines and their usage and adherence. We aimed to assess whether management in febrile children below 3 months attending European Emergency Departments (EDs) was according to the guidelines for fever. This study is part of the MOFICHE study, which is an observational multicenter study including routine data of febrile children (0–18 years) attending twelve EDs in eight European countries. In febrile children below 3 months (excluding bronchiolitis), we analyzed actual management compared to the guidelines for fever. Ten EDs applied the (adapted) NICE guideline, and two EDs applied local guidelines. Management included diagnostic tests, antibiotic treatment, and admission. We included 913 children with a median age of 1.7 months (IQR 1.0–2.3). Management per ED varied as follows: use of diagnostic tests 14–83%, antibiotic treatment 23–54%, admission 34–86%. Adherence to the guideline was 43% (374/868) for blood cultures, 29% (144/491) for lumbar punctures, 55% (270/492) for antibiotic prescriptions, and 67% (573/859) for admission. Full adherence to these four management components occurred in 15% (132/868, range 0–38%), partial adherence occurred in 56% (484/868, range 35–77%). Conclusion: There is large practice variation in management. The guideline adherence was limited, but highest for admission which implies a cautious approach. Future studies should focus on guideline revision including new biomarkers in order to optimize management in young febrile children.What is Known:• Febrile children below 3 months have a higher risk of serious bacterial infections, which often leads to extensive diagnostics and treatment.• There is practice variation in management of young febrile children due to differences in guidelines and their usage and adherence.What is New:• Full guideline adherence is limited, whereas partial guideline adherence is moderate in febrile children below 3 months across Europe.• Guideline revision including new biomarkers is needed to improve management in young febrile children.publishersversionPeer reviewe

Emergency medical services utilisation among febrile children attending emergency departments across Europe : an observational multicentre study

Funding Information: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 848196. CT received an additional funding from Stichting Erasmus Trustfonds. 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. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, or the Department of Health. For the remaining authors, no sources of funding were declared. The funding sources had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication. Publisher Copyright: © 2023, The Author(s).Children constitute 6–10% of all patients attending the emergency department (ED) by emergency medical services (EMS). However, discordant EMS use in children occurs in 37–61% with fever as an important risk factor. We aimed to describe EMS utilisation among febrile children attending European EDs. This study is part of an observational multicentre study assessing management and outcome in febrile children up to 18 years (MOFICHE) attending twelve EDs in eight European countries. Discordant EMS use was defined as the absence of markers of urgency including intermediate/high triage urgency, advanced diagnostics, treatment, and admission in children transferred by EMS. Multivariable logistic regression analyses were performed for the association between (1) EMS use and markers of urgency, and (2) patient characteristics and discordant EMS use after adjusting all analyses for the covariates age, gender, visiting hours, presenting symptoms, and ED setting. A total of 5464 (15%, range 0.1–42%) children attended the ED by EMS. Markers of urgency were more frequently present in the EMS group compared with the non-EMS group. Discordant EMS use occurred in 1601 children (29%, range 1–59%). Age and gender were not associated with discordant EMS use, whereas neurological symptoms were associated with less discordant EMS use (aOR 0.2, 95%CI 0.1–0.2), and attendance out of office hours was associated with more discordant EMS use (aOR 1.6, 95%CI 1.4–1.9). Settings with higher percentage of self-referrals to the ED had more discordant EMS use (p < 0.05). Conclusion: There is large practice variation in EMS use in febrile children attending European EDs. Markers of urgency were more frequently present in children in the EMS group. However, discordant EMS use occurred in 29%. Further research is needed on non-medical factors influencing discordant EMS use in febrile children across Europe, so that pre-emptive strategies can be implemented. What is Known: •Children constitute around 6–10% of all patients attending the emergency department by emergency medical services. •Discordant EMS use occurs in 37–61% of all children, with fever as most common presenting symptom for discordant EMS use in children. What is New: •There is large practice variation in EMS use among febrile children across Europe with discordance EMS use occurring in 29% (range 1–59%), which was associated with attendance during out of office hours and with settings with higher percentage of self-referrals to the ED. •Future research is needed focusing on non-medical factors (socioeconomic status, parental preferences and past experience, healthcare systems, referral pathways, out of hours services provision) that influence discordant EMS use in febrile children across Europe.Peer reviewe

Klīnisko pazīmju kopuma, vecāku un ārstu intuitīvā novērtējuma nozīme smagu bakteriālu infekciju diagnostikā bērniem ar drudzi. Promocijas darbs

The Doctoral Thesis was developed at Rīga Stradiņš University, Latvia. Defence: at the public session of the Promotion Council of Clinical Medicine on 2nd September, 2022 at 15.00 in Hippocrates Lecture Theatre, Dzirciema Street 16 and online via Zoom platform.Fever is one of the main reasons for visits to paediatric emergency departments (ED). Although in most cases the underlying cause is self-limiting viral infections, 4 to 25 % of children visiting ED with fever develop serious bacterial infections (SBI), which are significant causes of childhood mortality, even in developed countries. Due to high number of patients visiting ED with febrile illness, rapid discrimination between children with and without possible SBI is challenging.This study aimed to improve early recognition of SBI in children who present to ED by assessing the diagnostic value of clinical signs at presentation, clinician’s non-analytical reasoning, defined as “gut feeling” of serious illness and “sense of reassurance”, and parental concern of different / more severe illness. Based on these variables, derivation and external validation of two clinical prediction models (CPMs) for SBI was performed, and the performance of a CPM based on clinical variables alone was compared to a model integrating clinical features together with variables of non-analytical reasoning. The models were derived from a dataset of 517 febrile patients presenting to the ED of Children’s Clinical University Hospital (CCUH) in Riga, and externally validated in a dataset of 188 patients prospectively enrolled in six regional hospitals in Latvia.While the prognostic value of clinician’s “gut feeling” as an independent variable for diagnosing SBI was limited, “sense of reassurance” was significantly predictive of absence of SBI, and the performance of the CPM 2 integrating the non-analytical variables with clinical features was superior in both derivation (Receiver Operating Characteristic curve (ROC) Area Under Curve (AUC) 0.783, 95 % confidence interval (CI) 0.727–0.839) and validation cohorts (ROC AUC 0.752, 95 % CI 0.674–0.830), when compared to the performance of the CPM 1, which was based solely on clinical variables (ROC AUC in derivation population 0.738, 95 % CI 0.688–0.788, in validation population 0.677, 95 % CI 0.586–0.767). Both CPMs had moderate ability to predict SBI in febrile children presenting to ED and acceptable performance in the validation cohort. A scoring system based on the superior prediction model was created to distinguish between patients with high or low risk of SBI, as well as to identify patients in diagnostic “grey area”, in which the severity of manifestations of SBI and mild infections overlapped. Contrary to studies in primary care performed in other European countries, parental concern was not significantly predictive of SBI. Elements of fever-related anxiety were identified as factors influencig the level of parental concern and urging parents to present to healthcare early. A qualitative interview study including 34 parents of patients enrolled in derivation cohort revealed existing misconceptions regarding the possible negative effects of fever, which often were a result of unfulfilled educational and emotional needs when caring for a febrile child. This study suggests that educational intervention is necessary to reduce “fever phobia” in parents and to improve the diagnostic reliability of parental concern.This Thesis is a part of EU Horizon 2020 project “Personalised Risk assessment in febrile illness to optimise Real-life Management across the European Union” (PERFORM) (EU Grant Agreement No. 668303

Diagnostic Value of Clinical Presentation, Parental Concern, and Clinician’s Non-Analytical Reasoning in Identifying Serious Bacterial Infections in Febrile Children. Summary of the Doctoral Thesis

Promocijas darbs izstrādāts Rīgas Stradiņa universitātē, Latvijā. Aizstāvēšana: klīniskās medicīnas promocijas padomes atklātā sēdē 2022. gada 2. septembrī 15.00 Hipokrāta auditorijā, Rīgas Stradiņa universitātē, Dzirciema iela 16, kā arī tiešsaistes platformā Zoom.Drudzis bērniem ir viens no biežākajiem palīdzības meklēšanas iemesliem Neatliekamās palīdzības nodaļā. Lai gan visbiežāk drudzi izraisa pašlimitējošas vīrusu infekcijas, 4 līdz 25 % gadījumu bērniem, kuri vērsušies Neatliekamās palīdzības nodaļā ar drudzi, tiek diagnosticētas smagas bakteriālas infekcijas (SBI), kas joprojām ir viens no biežākajiem bērnu mirstības cēloņiem arī attīstītajās valstīs. Ātra febrilu pacientu ar iespējamu SBI atpazīšana ir nozīmīgs izaicinājums klīnicistiem lielās pacientu plūsmas Neatliekamās palīdzības nodaļā dēļ. Šī pētījuma mērķis bija uzlabot agrīnu SBI atpazīšanu bērniem ar drudzi, kuri vēršas pēc palīdzības Neatliekamās palīdzības nodaļā, izvērtējot dažādu klīnisko pazīmju, klīnicista intuitīvā novērtējuma (“gut feeling”) par iespējamu smagu saslimšanu, klīnicista intuitīvā novērtējuma par iespējamu pašlimitējošu saslimšanu (“sense of reassurance”), kā arī vecāku bažu par atšķirīgi / smagāk noritošu saslimšanu bērnam (parental concern) diagnostisko vērtību. Balstoties uz minētajiem faktoriem kā mainīgajiem, tika izveidoti un validēti divi klīniskie paredzēšanas modeļi. Modeļa, kurā iekļauti tikai klīniskie parametri, efektivitāte tika salīdzināta ar otra modeļa, kurā tika iekļauti klīnicista instinktu raksturojošie parametri, efektivitāti SBI atpazīšanā. Modeļi tika izveidoti, balsoties uz 517 prospektīvi iekļautu pacientu klīnisko informāciju, kuri pēc palīdzības vērsās Bērnu klīniskās universitātes slimnīcas (BKUS) Neatliekamās palīdzības nodaļā. Rezultāti tika validēti, balstoties uz datiem, kas iegūti no 188 prospektīvi iekļautu pacientu populācijas, kuri pēc palīdzības bija vērsušies sešās Latvijas reģionālajās slimnīcās.Lai gan klīnicista intuitīvā novērtējuma (“gut feeling”) par iespējamu smagu saslimšanu prognostiskā vērtība SBI atpazīšanā bija ierobežota, klīnicista intuitīvais novērtējums par iespējamu pašlimitējošu saslimšanu “sense of reassurance” bija nozīmīgs prognostisks rādītājs SBI neesamībai. Modelis, kurā klīnicista instinktu raksturojošie mainīgie tika integrēti kopā ar klīniskajām pazīmēm, efektīvāk atpazina SBI gan izveides (receiver operating characteristic curve (ROC) area under curve (AUC) 0,783, 95 % ticamības intervāls (TI) 0,727–0,839), gan validācijas populācijās (ROC AUC 0,752, 95 % TI 0,674–0,830), salīdzinot ar modeli, kurā tika iekļauti tikai klīniskie parametri (ROC AUC izveides populācijā – 0,738, 95 % TI 0,688–0,788, validācijas populācijā – 0,677, 95 % TI 0,586–0,767). Abiem modeļiem bija mērena efektivitāte SBI atpazīšanā drudža pacientiem, kuri vērsās pēc palīdzības Neatliekamās palīdzības nodaļā. Pamatojoties uz efektīvāko modeli, tika izveidota uz punktiem balstīta drudža pacientu vērtēšanas sistēma, kas vienkāršoja pacientu ar augstu vai zemu SBI risku atpazīšanu, kā arī nodalīja daļu pacientu tā sauktajā diagnostikas pelēkajā zonā, kurā SBI un vieglāk noritošu infekciju klīnisko izpausmju smagums bija līdzīgs. Atšķirībā no citu Eiropas valstu pētījumu rezultātiem primārās aprūpes līmenī vecāku bažu par atšķirīgi / smagāk noritošu saslimšanu prognostiskā vērtība SBI atpazīšanā pētījuma populācijā bija zema. Vecāku bažu līmeni ietekmēja satraukums, ko izraisīja drudzis bērnam jeb tā dēvētā drudža fobija, kas savukārt mudināja vecākus drudža gadījumā bērnam vērsties pēc palīdzības agrīni. Kvalitatīvā pētījumā, balstoties uz 34 vecāku intervijām, kuru bērni tika iekļauti BKUS kohortā, tika noskaidrots, ka vecākiem pastāv mīti par drudža iespējamu kaitīgu ietekmi uz bērna organismu. Šo nepareizo, uz pierādījumiem nebalstīto pieņēmumu saglabāšanos nereti veicināja nepietiekams klīnicistu skaidrojums par bērnu ar drudzi aprūpi, kā arī emocionālā atbalsta trūkums no medicīnas personāla puses, vecākiem rūpējoties par bērnu, kas slims ar drudzi. Pētījums parāda, ka “drudža fobijas” mazināšanai un vecāku bažu kā klīniskā rādītāja precizitātes uzlabošanai nepieciešama plašāka vecāku izglītošana par to, kā izvērtēt un aprūpēt bērnu ar drudzi.Promocijas darbs izstrādāts ES iniciatīvas Horizon 2020 projekta “Personalised Risk assessment in febrile illness to optimise Real-life Management across the European Union” (PERFORM) ietvaros (ES granta Nr. 668303

Klīnisko pazīmju kopuma, vecāku un ārstu intuitīvā novērtējuma nozīme smagu bakteriālu infekciju diagnostikā bērniem ar drudzi. Promocijas darba kopsavilkums

The Doctoral Thesis was developed at Rīga Stradiņš University, Latvia. Defence: at the public session of the Promotion Council of Clinical Medicine on 2nd September, 2022 at 15.00 in Hippocrates Lecture Theatre, Dzirciema Street 16 and online via Zoom platform.Fever is one of the main reasons for visits to paediatric emergency departments (ED). Although in most cases the underlying cause is self-limiting viral infections, 4 to 25 % of children visiting ED with fever develop serious bacterial infections (SBI), which are significant causes of childhood mortality, even in developed countries. Due to high number of patients visiting ED with febrile illness, rapid discrimination between children with and without possible SBI is challenging.This study aimed to improve early recognition of SBI in children who present to ED by assessing the diagnostic value of clinical signs at presentation, clinician’s non-analytical reasoning, defined as “gut feeling” of serious illness and “sense of reassurance”, and parental concern of different / more severe illness. Based on these variables, derivation and external validation of two clinical prediction models (CPMs) for SBI was performed, and the performance of a CPM based on clinical variables alone was compared to a model integrating clinical features together with variables of non-analytical reasoning. The models were derived from a dataset of 517 febrile patients presenting to the ED of Children’s Clinical University Hospital (CCUH) in Riga, and externally validated in a dataset of 188 patients prospectively enrolled in six regional hospitals in Latvia.While the prognostic value of clinician’s “gut feeling” as an independent variable for diagnosing SBI was limited, “sense of reassurance” was significantly predictive of absence of SBI, and the performance of the CPM 2 integrating the non-analytical variables with clinical features was superior in both derivation (Receiver Operating Characteristic curve (ROC) Area Under Curve (AUC) 0.783, 95 % confidence interval (CI) 0.727–0.839) and validation cohorts (ROC AUC 0.752, 95 % CI 0.674–0.830), when compared to the performance of the CPM 1, which was based solely on clinical variables (ROC AUC in derivation population 0.738, 95 % CI 0.688–0.788, in validation population 0.677, 95 % CI 0.586–0.767). Both CPMs had moderate ability to predict SBI in febrile children presenting to ED and acceptable performance in the validation cohort. A scoring system based on the superior prediction model was created to distinguish between patients with high or low risk of SBI, as well as to identify patients in diagnostic “grey area”, in which the severity of manifestations of SBI and mild infections overlapped. Contrary to studies in primary care performed in other European countries, parental concern was not significantly predictive of SBI. Elements of fever-related anxiety were identified as factors influencig the level of parental concern and urging parents to present to healthcare early. A qualitative interview study including 34 parents of patients enrolled in derivation cohort revealed existing misconceptions regarding the possible negative effects of fever, which often were a result of unfulfilled educational and emotional needs when caring for a febrile child. This study suggests that educational intervention is necessary to reduce “fever phobia” in parents and to improve the diagnostic reliability of parental concern.This Thesis is a part of EU Horizon 2020 project “Personalised Risk assessment in febrile illness to optimise Real-life Management across the European Union” (PERFORM) (EU Grant Agreement No. 668303

Impact of infection on proteome-wide glycosylation revealed by distinct signatures for bacterial and viral pathogens

Mechanisms of infection and pathogenesis have predominantly been studied based on differential gene or protein expression. Less is known about posttranslational modifications, which are essential for protein functional diversity. We applied an innovative glycoproteomics method to study the systemic proteome-wide glycosylation in response to infection. The protein site-specific glycosylation was characterized in plasma derived from well-defined controls and patients. We found 3862 unique features, of which we identified 463 distinct intact glycopeptides, that could be mapped to more than 30 different proteins. Statistical analyses were used to derive a glycopeptide signature that enabled significant differentiation between patients with a bacterial or viral infection. Furthermore, supported by a machine learning algorithm, we demonstrated the ability to identify the causative pathogens based on the distinctive host blood plasma glycopeptide signatures. These results illustrate that glycoproteomics holds enormous potential as an innovative approach to improve the interpretation of relevant biological changes in response to infection

Emergency medical services utilisation among febrile children attending emergency departments across Europe: an observational multicentre study

Abstract Children constitute 6–10% of all patients attending the emergency department (ED) by emergency medical services (EMS). However, discordant EMS use in children occurs in 37–61% with fever as an important risk factor. We aimed to describe EMS utilisation among febrile children attending European EDs. This study is part of an observational multicentre study assessing management and outcome in febrile children up to 18 years (MOFICHE) attending twelve EDs in eight European countries. Discordant EMS use was defined as the absence of markers of urgency including intermediate/high triage urgency, advanced diagnostics, treatment, and admission in children transferred by EMS. Multivariable logistic regression analyses were performed for the association between (1) EMS use and markers of urgency, and (2) patient characteristics and discordant EMS use after adjusting all analyses for the covariates age, gender, visiting hours, presenting symptoms, and ED setting. A total of 5464 (15%, range 0.1–42%) children attended the ED by EMS. Markers of urgency were more frequently present in the EMS group compared with the non-EMS group. Discordant EMS use occurred in 1601 children (29%, range 1–59%). Age and gender were not associated with discordant EMS use, whereas neurological symptoms were associated with less discordant EMS use (aOR 0.2, 95%CI 0.1–0.2), and attendance out of office hours was associated with more discordant EMS use (aOR 1.6, 95%CI 1.4–1.9). Settings with higher percentage of self-referrals to the ED had more discordant EMS use (p &lt; 0.05).  Conclusion: There is large practice variation in EMS use in febrile children attending European EDs. Markers of urgency were more frequently present in children in the EMS group. However, discordant EMS use occurred in 29%. Further research is needed on non-medical factors influencing discordant EMS use in febrile children across Europe, so that pre-emptive strategies can be implemented. What is Known: •Children constitute around 6–10% of all patients attending the emergency department by emergency medical services. •Discordant EMS use occurs in 37–61% of all children, with fever as most common presenting symptom for discordant EMS use in children. What is New: •There is large practice variation in EMS use among febrile children across Europe with discordance EMS use occurring in 29% (range 1–59%), which was associated with attendance during out of office hours and with settings with higher percentage of self-referrals to the ED. •Future research is needed focusing on non-medical factors (socioeconomic status, parental preferences and past experience, healthcare systems, referral pathways, out of hours services provision) that influence discordant EMS use in febrile children across Europe. </jats:p