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The presence of active viral infections has an impact on the prognosis of patients undergoing hematopoietic stem cell transplantation (HSCT). Nevertheless, the number of reports of cytomegalovirus infection in patients with inborn errors of immunity (IEI) who undergo HSCT is relatively low. To analyze the effect of cytomegalovirus infection acquired prior to curative treatment on patient survival in 123 children with IEI. An observational and retrospective study was performed with patients younger than 18 years diagnosed with IEI who were candidates for HSCT, gene therapy, or thymus transplantation at five hospitals in Spain between 2008 and 2019. We included 123 children, 25 infected by cytomegalovirus prior to undergoing curative treatment (20.3%). At IEI diagnosis, 24 of the patients were already infected, 21 of whom had symptomatic cytomegalovirus disease (87%), while the other three patients developed disease before undergoing curative treatment. The patients with cytomegalovirus infection had higher mortality than those without (p = 0.006). Fourteen patients developed refractory cytomegalovirus infection (56%), all of whom died, while no patients with non-refractory infection died (p = 0.001) All deaths that occurred before curative treatment and three of the five after the treatment were attributed to cytomegalovirus. Patients with refractory cytomegalovirus disease had the highest pre-HSCT mortality rate (64.3%), compared with the non-infected children and those with non-refractory cytomegalovirus disease (10.1%) (p, [Conclusion] Prevention and prompt control of cytomegalovirus infection, together with early HSCT/gene therapy, are crucial for improving the prognosis in children with IEI.

Background: In 2014, germline signal transducer and activator of transcription (STAT) 3 gain-of-function (GOF) mutations were first described to cause a novel multisystem disease of early-onset lymphoproliferation and autoimmunity. Objective: This pivotal cohort study defines the scope, natural history, treatment, and overall survival of a large global cohort of patients with pathogenic STAT3 GOF variants. Methods: We identified 191 patients from 33 countries with 72 unique mutations. Inclusion criteria included symptoms of immune dysregulation and a biochemically confirmed germline heterozygous GOF variant in STAT3. Results: Overall survival was 88%, median age at onset of symptoms was 2.3 years, and median age at diagnosis was 12 years. Immune dysregulatory features were present in all patients: lymphoproliferation was the most common manifestation (73%); increased frequencies of double-negative (CD4−CD8−) T cells were found in 83% of patients tested. Autoimmune cytopenias were the second most common clinical manifestation (67%), followed by growth delay, enteropathy, skin disease, pulmonary disease, endocrinopathy, arthritis, autoimmune hepatitis, neurologic disease, vasculopathy, renal disease, and malignancy. Infections were reported in 72% of the cohort. A cellular and humoral immunodeficiency was observed in 37% and 51% of patients, respectively. Clinical symptoms dramatically improved in patients treated with JAK inhibitors, while a variety of other immunomodulatory treatment modalities were less efficacious. Thus far, 23 patients have undergone bone marrow transplantation, with a 62% survival rate. Conclusion:: STAT3 GOF patients present with a wide array of immune-mediated disease including lymphoproliferation, autoimmune cytopenias, and multisystem autoimmunity. Patient care tends to be siloed, without a clear treatment strategy. Thus, early identification and prompt treatment implementation are lifesaving for STAT3 GOF syndrome.

[Purpose] STAT1 gain-of-function (GOF) and dominant-negative (DN) STAT3 syndromes share clinical manifestations including infectious and inflammatory manifestations. Targeted treatment with Janus-kinase (JAK) inhibitors shows promising results in treating STAT1 GOF-associated symptoms while management of DN STAT3 patients has been largely supportive. We here assessed the impact of ruxolitinib on the JAK-STAT1/3 pathway in DN STAT3 patients' cells., [Methods] Using flow cytometry, immunoblot, qPCR, and ELISA techniques, we examined the levels of basal STAT1 and phosphorylated STAT1 (pSTAT1) of cells obtained from DN STAT3, STAT1 GOF patients, and healthy donors following stimulation with type I/II interferons (IFNs) or interleukin (IL)-6. We also describe the impact of ruxolitinib on cytokine-induced STAT1 signaling in these patients., [Results] DN STAT3 and STAT1 GOF resulted in a similar phenotype characterized by increased STAT1 and pSTAT1 levels in response to IFNα (CD3+ cells) and IFNγ (CD14+ monocytes). STAT1-downstream gene expression and C-X-C motif chemokine 10 secretion were higher in most DN STAT3 patients upon stimulation compared to healthy controls. Ex vivo treatment with the JAK1/2-inhibitor ruxolitinib reduced cytokine responsiveness and normalized STAT1 phosphorylation in DN STAT3 and STAT1 GOF patient’ cells. In addition, ex vivo treatment was effective in modulating STAT1 downstream signaling in DN STAT3 patients., [Conclusion] In the absence of effective targeted treatment options for AD-HIES at present, modulation of the JAK/STAT1 pathway with JAK inhibitors may be further explored particularly in those AD-HIES patients with autoimmune and/or autoinflammatory manifestations., This work was supported by the Job Research Foundation (NY, United States); Consejería de Salud de la Junta de Andalucía (SA0051/2020 to O.N.); Agencia de Innovación y Desarrollo de Andalucía (PI-0184-2018 to P.O.), Instituto de Salud Carlos III, Madrid, Spain [Sara Borrell, CD20/00124 to P.B.L, Juan Rodés JR18/00042 to P.O, FIS PI19/01471].

[Background]: Currently, data on treatment, outcome, and prognostic factors in children with tuberculous meningitis (TBM) in Europe are limited. To date, most existing data on TBM originate from adult studies, or studies conducted in low-resource settings., [Methods]: We designed a multicenter, retrospective study involving 27 pediatric healthcare institutions in 9 European countries via an established pediatric TB research network, before and after the 2014 revision of World Health Organization (WHO) dosing recommendations., [Results]: Of 118 children, 39 (33.1%) had TBM grade 1, 68 (57.6%) grade 2, and 11 (9.3%) grade 3. Fifty-eight (49.1%) children received a standard 4-drug treatment regimen; other commonly used drugs included streptomycin, prothionamide, and amikacin. Almost half of the patients (48.3%; 56/116) were admitted to intensive care unit, with a median stay of 10 (interquartile range [IQR] 4.5–21.0) days. Of 104 children with complete outcome data, 9.6% (10/104) died, and only 47.1% (49/104) recovered fully. Main long-term sequelae included spasticity of 1 or more limbs and developmental delay both in 19.2% (20/104), and seizure disorder in 17.3% (18/104). Multivariate regression analyses identified microbiological confirmation of TBM, the need for neurosurgical intervention, and mechanical ventilation as risk factors for unfavorable outcome., [Conclusions]: There was considerable heterogeneity in the use of TB drugs in this cohort. Despite few children presenting with advanced disease and the study being conducted in a high-resource setting, morbidity and mortality were high. Several risk factors for poor outcome were identified, which may aid prognostic predictions in children with TBM in the future., TPtbnet is supported by the Deutsche Gesellschaft für Internationale Zusammenarbeit. M. Te. was supported by a Clinical Lectureship provided by the UK National Institute for Health Research (NIHR), and by a grant from the Technology Strategy Board/Innovate UK. R. B. R. is funded by an NIHR Academic Clinical Lectureship at the London School of Hygiene & Tropical Medicine (grant number CL-2018-20-001). A. N.-J. was supported by Subvencions per a la Intensificació de Facultatius Especialistes (Departament de Salut de la Generalitat de Catalunya, Programa PERIS 2016–2020; ref. SLT008/18/00193). O. N. is supported by Consejeria de Salud y Familias, Servicio Andaluz de Salud 2020 (grant number A1-0049-2020).

A unified surveillance mechanism for hand hygiene and hospital-acquired infections for pediatric wards is lacking in Europe. We managed to setup such a mechanism in 9 pediatric intensive care units in 7 European countries, using World Health Organization's definitions and common methodology which allows for benchmarking among units and countries. Median hand hygiene compliance was found high 82.3% (interquartile range 71.6-94.5%), but gaps in practices were identified.

[Introduction] Since the first description of gain of function (GOF) mutations in signal transducer and activator of transcription (STAT) 1, more than 300 patients have been described with a broad clinical phenotype including infections and severe immune dysregulation. Whilst Jak inhibitors (JAKinibs) have demonstrated benefits in several reported cases, their indications, dosing, and monitoring remain to be established., [Methods] A retrospective, multicenter study recruiting pediatric patients with STAT1 GOF under JAKinib treatment was performed and, when applicable, compared with the available reports from the literature., [Results] Ten children (median age 8.5 years (3–18), receiving JAKinibs (ruxolitinib (n = 9) and baricitinib (n = 1)) with a median follow-up of 18 months (2–42) from 6 inborn errors of immunity (IEI) reference centers were included. Clinical profile and JAKinib indications in our series were similar to the previously published 14 pediatric patients. 9/10 (our cohort) and 14/14 patients (previous reports) showed partial or complete responses. The median immune deficiency and dysregulation activity scores were 15.99 (5.2–40) pre and 7.55 (3–14.1) under therapy (p = 0.0078). Infection, considered a likely adverse event of JAKinib therapy, was observed in 1/10 patients; JAKinibs were stopped in 3/10 children, due to hepatotoxicity, pre-HSCT, and absence of response., [Conclusions] Our study supports the potentially beneficial use of JAKinibs in patients with STAT1 GOF, in line with previously published data. However, consensus regarding their indications and timing, dosing, treatment duration, and monitoring, as well as defining biomarkers to monitor clinical and immunological responses, remains to be determined, in form of international prospective multicenter studies using established IEI registries., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by the Job Research Foundation (NY, USA); the Consejería de Salud de la Junta de Andalucía (SA0051/2020 to O.N.); Agencia de Innovación y Desarrollo de Andalucía (PI-0184–2018 to P.O); Instituto de Salud Carlos III, Madrid, Spain (Sara Borrell, CD20/00124 to P.B.L, Juan Rodés JR18/00042 to P.O, FIS PI19/01471 to O.N. and P.O); the projects PI18/00223, FI19/00208, and PI21/00211 to LA, integrated in the Plan Nacional de I + D + I and co-financed by the ISCIII—Subdirección General de Evaluación y Fomento de la Investigación Sanitaria—and the Fondo Europeo de Desarrollo Regional (FEDER), by Pla Estratègic de Recerca i Innovació en Salut (PERIS), Departament de Salut, Generalitat de Catalunya (SLT006/17/ 00199 to LA), by a 2017 Leonardo Grant for Researchers and Cultural Creators, BBVA Foundation (IN[17]_BBM_CLI_0357) to LA, by a 2017 Beca de Investigación de la Sociedad Española de Inmunología Clínica Alergología y Asma Pediáatrica to LA, by a 2021 Beca de Investigación de la Sociedad Española de Inmunología Clínica, Alergología y Asma Pediátrica to ADM and by the Ministry of Health, Czech Republic (NV18-05–00162 to M.B and NV19-05–00332 to V.K).

‘Off-label’ or ‘unlicensed’ use of medicinal products are those that are prescribed outside the terms of their authorisation by the regulatory agency in a given jurisdiction (i.e. unapproved indication, age group, posology, route or schedule of administration). As the highly transmissible Omicron variant of SARS-CoV-2 becomes prevalent in the US, the EU and elsewhere, Pfizer/BioNTech announced that the results of the ongoing phase 2/3 trial (NCT04816643) assessing its BNT162b2 mRNA vaccine in 0.5–4-year-old children will be delayed to test a 3-dose regimen. A debate has emerged in the USA on whether this vaccine could be ethically prescribed to this age group of children. Whilst some commentators considered its prescription to be ethically acceptable in vulnerable kids at high risk of developing severe COVID-19,1, 2 recommendation against off-label paediatric use has been issued by the US Food and Drug Administration, American Academy of Paediatrics and Centers for Disease Control and Prevention. In addition, this latter has warned that off-label vaccine

Objective: To evaluate the efficacy of colchicine therapy in pediatric patients with PFAPA syndrome who present with an incomplete response to the standard treatment or with frequent episodes (an interval of less than 14 days between two disease flares). Methods: A multicenter cohort study of children diagnosed with PFAPA syndrome and treated with colchicine was performed in three separate hospitals located in Spain. The patients clinical and laboratory data were reviewed by accessing their medical records. Response to colchicine was evaluated after 12 months of treatment for frequency, duration, and intensity of PFAPA episodes. Results: A total of 13 children were included in our study, 43% of whom were boys. Median age of the colchicine therapy initiation was 6 years (interquartile range (IQR)=3-9.5). Following a 12-month period of colchicine therapy (median dosage of 0.02 mg/kg/day; IQR=0.02-0.03), a significant decrease in the median number of flares (median 8; IQR=7-14 vs 3; IQR=2-4; p=0.005) and the duration of disease episodes (median 4 days; IQR=3.25-5.125 vs 1 day; IQR=1-2; p=0.003) was observed. Furthermore, the highest degree of fever during disease flares was reduced from median 40ºC (IQR=39.5-40) to 38.5ºC (IQR=37.7-38.9) (p=0.002). Conclusion: Colchicine therapy decreased the frequency and intensity of PFAPA. The use of colchicine could be an effective treatment in pediatric patients with PFAPA syndrome who present with frequent or severe relapses.

[Background] A hyperinflammatory immune-mediated shock syndrome has been recognised in children exposed to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19)., [Objective] To describe typical imaging findings in children with multisystem inflammatory syndrome associated with COVID-19., [Materials and methods] During the first wave of the COVID-19 pandemic, imaging studies and clinical data from children treated for multisystem inflammatory syndrome were collected from multiple centres. Standardised case templates including demographic, biochemical and imaging information were completed by participating centres and reviewed by paediatric radiologists and paediatricians., [Results] We included 37 children (21 boys; median age 8.0 years). Polymerase chain reaction (PCR) testing was positive for SARS-CoV-2 in 15/37 (41%) children and immunoglobulins in 13/19 children (68%). Common clinical presentations were fever (100%), abdominal pain (68%), rash (54%), conjunctivitis (38%) and cough (32%). Thirty-three children (89%) showed laboratory or imaging findings of cardiac involvement. Thirty of the 37 children (81%) required admission to the intensive care unit, with good recovery in all cases. Chest radiographs demonstrated cardiomegaly in 54% and signs of pulmonary venous hypertension/congestion in 73%. The most common chest CT abnormalities were ground-glass and interstitial opacities (83%), airspace consolidation (58%), pleural effusion (58%) and bronchial wall thickening (42%). Echocardiography revealed impaired cardiac function in half of cases (51%) and coronary artery abnormalities in 14%. Cardiac MRI showed myocardial oedema in 58%, pericardial effusion in 42% and decreased left ventricular function in 25%. Twenty children required imaging for abdominal symptoms, the commonest abnormalities being free fluid (71%) and terminal ileum wall thickening (57%). Twelve children underwent brain imaging, showing abnormalities in two cases., [Conclusion] Children with multisystem inflammatory syndrome showed pulmonary, cardiac, abdominal and brain imaging findings, reflecting the multisystem inflammatory disease. Awareness of the imaging features of this disease is important for early diagnosis and treatment.

BACKGROUND Visceral leishmaniasis (VL) is an endemic in Southern Europe. However, details regarding disease burden, clinical presentations, laboratory markers, management and outcome in children are scarce. METHODS Medical records of children (

[EN] Primary immunodeficiencies (PIDs) are rare, undiagnosed and potentially fatal diseases. Clinical manifestations of PID can be fatal or leave sequelae that worsen the quality of life of patients. Traditionally, the treatment of PIDs has been largely supportive, with the exception of bone marrow transplantation and, more recently, gene therapy. The discovering of new affected pathways, the development of new molecules and biologics, and the increasing understanding of the molecular basis of these disorders have created opportunities in PIDs therapy. This document aims to review current knowledge and to provide recommendations about the diagnosis and clinical management of adults and children with PIDs based on the available scientific evidence taking in to account current practice and future challenges. A systematic review was conducted, and evidence levels based on the available literature are given for each recommendation where available., [ES] Las inmunodeficiencias primarias (IDP) son unas enfermedades raras, frecuentemente infradiagnosticadas y potencialmente fatales. Las manifestaciones clínicas de las IDP pueden ser muy graves y ocasionar secuelas que empeoran la calidad de vida de los pacientes. Tradicionalmente, el tratamiento de las IDP ha sido fundamentalmente de soporte, con excepción del trasplante de progenitores hematopoyéticos y, más recientemente, la terapia génica. El descubrimiento de nuevos mecanismos patogénicos, el desarrollo de nuevas moléculas y fármacos biológicos y los avances en el conocimiento de las bases moleculares de estas enfermedades han abierto oportunidades para el tratamiento de esta afección. El objetivo de este documento es revisar el conocimiento actual y aportar recomendaciones para el diagnóstico y el tratamiento clínico de los pacientes adultos y pediátricos con IDP basado en la evidencia científica disponible y teniendo en cuenta la actual práctica y los retos futuros. Se realizó una revisión sistemática, que justifica los niveles de evidencia para cada recomendación.

[Objective] Few data exist regarding the impact of antimicrobial stewardship programs on antifungal use. We evaluated the efficacy and safety of a comprehensive long-term antimicrobial stewardship program (ASP) focused on antifungal use., [Methods] During a 9-year period, we quarterly assessed antifungal consumption, incidence density of hospital-acquired candidemia, Candida spp. distribution, antifungal resistance, and crude death rate per 1000 occupied bed days (OBDs) of hospital-acquired candidemia. We performed segmented regression analysis of interrupted time series., [Results] A significant change in trend was observed for antifungal consumption, with a sustained reduction of -0.87% per quarter (95% confidence interval [CI], −1.36 −0.38, p < 0.001), accounting for a final reduction of −38.4%. The main reduction was produced in fluconazole, with a sustained reduction of −1.37% per quarter (95%CI, −1.96 −0.68, p, [Conclusions] This ASP has succeeded in optimizing the use of antifungal with a long-lasting reduction without increasing the incidence, neither the mortality, of hospital-acquired candidemia., The program received public funding from the Regional Health Ministry of Andalucía (Grant PI-0361-2010), which did not participate in the development of the program or the analysis of its results.

Purpose: STAT1 gain-of-function (GOF) and dominant negative (DN) STAT3 syndromes share clinical manifestations including infectious and inflammatory manifestations. Targeted treatment with Janus-kinase (JAK) inhibitors show promising results in treating STAT1 GOF-associated symptoms whilst management of DN STAT3 patients has been largely supportive. We here assessed the impact of ruxolitinib on the JAK-STAT1/3 pathway in DN STAT3 patients’ cells. Methods: Using flow cytometry, immunoblot, qPCR and ELISA techniques, we examined the levels of basal STAT1 and phosphorylated STAT1 (pSTAT1) of cells obtained from DN STAT3, STAT1 GOF patients and healthy donors following stimulation with type I/II interferons (IFNs) or interleukin (IL)-6. We also describe the impact of ruxolitinib on cytokine-induced STAT1 signaling in these patients.Results: DN STAT3 and STAT1 GOF resulted in a similar phenotype characterized by increased STAT1 and pSTAT1 levels in response to IFNα (CD3+ cells) and IFNg (CD14+ monocytes). STAT1-downstream gene expression and C-X-C motif chemokine 10 secretion were higher in most DN STAT3 patients upon stimulation compared to healthy controls. Ex vivo treatment with the JAK1/2-inhibitor ruxolitinib reduced cytokine responsiveness and normalized STAT1 phosphorylation in DN STAT3 and STAT1 GOF patient’ cells. In addition, ex vivo treatment was effective in modulating STAT1 downstream signaling in DN STAT3 patients.Conclusion: In the absence of effective targeted treatment options for AD-HIES at present, modulation of the JAK/STAT1 pathway with JAK inhibitors may be further explored particularly in those AD-HIES patients with autoimmune and/or autoinflammatory manifestations.

Introduction. Since the first description of gain of function (GOF) mutations in Signal Transducer and Activator of Transcription (STAT) 1, more than 300 patients have been described with a broad clinical phenotype including infections and severe immune dysregulation. Whilst Jak inhibitors (JAKinibs) have demonstrated benefits in several reported cases, its indications, dosing and monitoring remain to be established. Methods. A retrospective, multicenter study recruiting pediatric patients with STAT1 GOF under JAKinib treatment was performed and, when applicable, compared with the available reports from the literature. Results. Ten children (median age 8.5y (3-18), receiving JAKinibs (ruxolitinib (n=9) and baricitinib (n=1)) with a median follow-up of 18m (2-42) from 6 inborn errors of immunity (IEI) reference centers were included. Clinical profile and JAKinib indications in our series were similar to the previously published 14 pediatric patients. 9/10 (our cohort) and 14/14 patients (previous reports) showed partial or complete responses. The median immune deficiency and dysregulation activity scores were 15.99 (5.2-40) pre and 7.55 (3-14.1) under therapy (p=0.0078). Infection, considered a likely adverse event of JAKinib therapy, was observed in 1/10 patient; JAKinibs were stopped in 3/10 children, due to hepatotoxicity, pre HSCT and absence of response. Conclusions. Our study supports the potentially beneficial use of JAKinibs in patients with STAT1 GOF, in line with previously published data. However, consensus regarding their indications and timing, dosing, treatment duration and monitoring, as well as defining biomarkers to monitor clinical and immunological responses, remains to be determined, in form of international prospective multicenter studies using established IEI registries.

[Purpose] The purpose of this phase 3 study was to evaluate the efficacy, pharmacokinetics (PK), and safety of Immune Globulin Subcutaneous (Human), 20% Caprylate/Chromatography Purified (IGSC 20%) in patients with primary immunodeficiency (PI)., [Methods] Immunoglobulin treatment-experienced subjects with PI received 52 weeks of IGSC 20% given weekly at the same dose as the subject’s previous IgG regimen (DAF 1:1); the minimum dose was 100 mg/kg/week. The primary endpoint was serious bacterial infections (SBIs [null vs alternative hypothesis: SBI rate per person per year ≥ 1 vs, [Results] Sixty-one subjects (19 children [≤ 12 years], 10 adolescents [> 12–16 years], and 32 adults) were enrolled. The rate of SBIs per person per year was 0.017. The 1-sided 99% upper confidence limit was 0.036 (, [Conclusions] IGSC 20% demonstrated efficacy and good safety and tolerability in subjects with PI., This study was funded in full by Grifols.

Primary immunodeficiency diseases (PID), which are comprised of over 400 genetic disorders, occur when a component of the immune system is diminished or dysfunctional. Patients with PID who require immunoglobulin (IG) replacement therapy receive intravenous IG (IVIG) or subcutaneous IG (SCIG), each of which provides equivalent efficacy. We developed a cost-minimization model to evaluate costs of IVIG versus SCIG from the Spanish National Healthcare System perspective. The base case modeled the annual cost per patient of IVIG and SCIG for the mean doses (per current expert clinical practice) over 1 year in terms of direct (drug and administration) and indirect (lost productivity for adults and parents/guardians of pediatric patients) costs. It was assumed that all IVIG infusions were administered in a day hospital, and 95% of SCIG infusions were administered at home. Drug costs were calculated from ex-factory prices obtained from local databases minus the mandatory deduction. Costs were valued on 2018 euros. The annual modeled costs were €4,266 lower for patients with PID who received SCIG (total €14,466) compared with those who received IVIG (total €18,732). The two largest contributors were differences in annual IG costs as a function of dosage (– €1,927) and hospital administration costs (– €2,688). However, SCIG incurred training costs for home administration (€695). Sensitivity analyses for two dose-rounding scenarios were consistent with the base case. Our model suggests that SCIG may be a cost-saving alternative to IVIG for patients with PID in Spain., Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This study was funded by Shire, a Takeda company.

Background: We aimed to identify the spectrum of disease in children with COVID-19, and the risk factors for admission in paediatric intensive care units (PICUs).Methods: We conducted a multicentre, prospective study of children with SARS-CoV-2 infection in 76 Spanish hospitals. We included children with COVID-19 or multi-inflammatory syndrome (MIS-C) younger than 18 years old, attended during the first year of the pandemic.Results: We enrolled 1 200 children. A total of 666 (55.5%) were hospitalized, and 123 (18.4%) required admission to PICU. Most frequent major clinical syndromes in the cohort were: mild syndrome (including upper respiratory tract infection and flu-like syndrome, skin or mucosae problems and asymptomatic), 44.8%; bronchopulmonary syndrome (including pneumonia, bronchitis and asthma flare), 18.5%; fever without a source, 16.2%; MIS-C, 10.6%; and gastrointestinal syndrome, 10%. In hospitalized children, the proportions were: 28.5%, 25.7%, 16.5%, 19.1% and 10.2%, respectively. Risk factors associated with PICU admission were MIS-C (odds ratio [OR]: 37.5,95% CI 22.7 to 57.8), moderate or severe liver disease (OR: 9,95% CI 1.6 to 47.6), chronic cardiac disease (OR: 4.8,95% CI 1.8 to 13) and asthma or recurrent wheezing (OR: 2.8,95% CI 1.3 to 5.8). However, asthmatic children were admitted into the PICU due to MIS-C or pneumonia, not due to asthma flare. Conclusion: Hospitalized children with COVID-19 usually present as one of five major clinical phenotypes of decreasing severity. Risk factors for PICU include MIS-C, elevation of inflammation biomarkers, asthma, moderate or severe liver disease and cardiac disease.

Recently, 94 inborn errors of immunity (IEI) patients suffering from COVID-19 have been described, overall demonstrating a mild phenotype [1] although more severe disease manifestations have been suggested for patients with alterations in the interferon (IFN) signaling pathway, including auto-antibodies against type I IFN [2]. Patients with STAT1 GOF mutations show a complex and often severe phenotype, combining an increased susceptibility of fungal, (myco-) bacterial and viral infections as well as autoimmune and autoinflammatory manifestations [3]. Characteristically, in response to type I and type II IFN stimulation, these patients show STAT1 hyperphosphorylation [3, 4]. Whether in the context of SARS-CoV-2 infection, the hyperactivation of the IFN-JAK1/2-STAT1 pathway would be protective (antiviral effect) or deleterious (hyperinflammation) is unclear. Ruxolitinib (a selective JAK1/2 inhibitor) has been successfully used in STAT1 GOF patients controlling many disease manifestations [5] and also resulted in improved pulmonary function and faster recovery from lymphopenia in previously healthy individuals suffering from severe COVID-19 [6]., This work was supported by the Instituto de Salud Carlos III, Madrid (Spain) [Sara Borrell, CD20/00124 to P.B.L, Juan Rodés JR18/00042 to P.O, FIS PI19/01471 to O.N] and the Consejería de Salud, Junta Andalucía [SA0051/2020 to O.N]. A.G-V was supported by the Instituto de Salud Carlos III, cofinanced by the European Development Regional Fund (“A way to achieve Europe”), Subprograma Miguel Servet (CP19/00159).

Newborn screening for severe combined immunodeficiency using T-cell receptor excision circles allows prompt diagnosis and initiation of supportive and curative therapy thereby reducing morbidity and mortality. However, profound combined immunodeficiencies with normal numbers of nonfunctional T cells will go undetected. We present a patient with calcium release-activated calcium channel gene (ORAI1) deficiency and normal T-cell receptor excision circle numbers observed after diagnosis at the age of 14 months who suffered from disseminated fatal cytomegalovirus and Pneumocystis jirovecii infection, demonstrating a potential pitfall of the current newborn screening program.

Introduction Development of secondary haemophagocytic lymphohistiocytosis (sHLH) in the context of typhoid fever (TF) is a very rare but serious complication. Methods Description of the first pediatric case of typhoid fever acquired in a non-endemic area complicated by sHLH. A systematic literature review of sHLH in the context of TF was performed with extraction of epidemiological, clinical and laboratory data. Results The literature search revealed 17 articles (22 patients). Fifteen patients were eligible for data analysis (53.4% children). All patients had fever and pancytopenia. Transaminases and LDH were frequently elevated (46.6%). Salmonella typhi was detected mainly by blood culture (64.3%). All the patients received antibiotics whereas immunomodulation (dexamethasone) was used in two cases. Conclusions A high suspicion index for this condition is needed even in non-endemic areas. The addition of immunmodulation to standard antimicrobial therapy should be considered in selected cases.

BACKGROUND: Data on SARS-CoV-2 transmission among children living with healthcare workers (HCWs) are scarce. METHODS: A cross-sectional study was performed at a tertiary Hospital in Madrid, including children of HCW who suffered from SARS-CoV-2 infection between March and May 2020. Children underwent enzyme-linked immunosorbent serological study for detecting SARS-CoV-2 antibodies: VIRCELL IgG assay. RESULTS: One hundred thirteen children from 69 HCWs with confirmed SARS-CoV-2 infection were recruited: 47 children had positive IgG (41.6%). Children secondary attack rate was 43.7% (25% if both parents have had asymptomatic infection; 39.5% if one parent was symptomatic; and 47% when both parents had symptoms). Having a positive sibling was associated with a positive IgG result (odds ratio = 12.2; 95% confidence interval: 4.4-33.7, P < 0.001). Median age was higher in IgG positive children (P = 0.022). Children who referred anosmia presented higher IgG titles (P < 0.04). CONCLUSIONS: We observed a very high SARS-CoV-2 transmission in children of HCW during the first pandemic wave, especially when both parents were symptomatic. Having a positive sibling was associated with seroconversion, supporting the important role of family clusters in the transmission of SARS-CoV-2.

Objectives: To evaluate electrocardiogram markers to predict coronary involvement in patients with Kawasaki disease by assessing measures of ventricular repolarization parameters on the 12-lead electrocardiogram. Study design: This cross-sectional study included 180 Spanish and Japanese patients ≤14 years of age with Kawasaki disease, with or without coronary involvement, from 2011 to 2016. We manually measured the Tp-Te/QT ratio and QTc interval (with Bazett's formula) in 12-lead electrocardiogram in the acute and recovery period and explored their potential association with coronary involvement. Results: No association was found between Tp-Te/QT ratio obtained manually in V5 and V6 leads and coronary involvement in the acute (V5:0.25 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .80; V6:0.24 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .86) or the recovery (V5: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.19-0.25], P = .68; V6: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.17-0.25], P = .50) period. By contrast, QTc in V5 and V6 was significantly lower in patients with Kawasaki disease and coronary involvement in the acute period (V5: 378 ms [IQR, 364-395 ms] vs 390 ms [IQR, 371-411 ms], P = .04; V6: 377 ms [IQR, 364-392 ms] vs 390 ms [IQR, 371-410 ms], P = .01). A QTc interval of

[Background] Inherited chronic mucocutaneous candidiasis (CMC) is often caused by inborn errors of immunity, impairing the response to, or the production of IL-17A and IL-17F. About half of the cases carry STAT1 gain-of-function (GOF) mutations. Only few patients have been reported with mutations of TRAF3IP2, a gene encoding the adaptor ACT1 essential for IL-17 receptor(R) signaling. We investigated a 10-year-old girl with CMC, carrying a heterozygous variant of STAT1 and compound heterozygous variants of TRAF3IP2., [Methods] By flow cytometry, STAT1 levels and phosphorylation (CD14+) as well as IL-17A, IL-22, IFN-γ, and IL-4 production (memory CD4+ T cells) were determined. ACT1 expression and binding to IL-17RA were assessed by Western blot and co-immunoprecipitation in HEK-293T cells transfected with plasmids encoding wild-type or mutant HA-tagged ACT1 and Flag-IL-17RA. We evaluated IL-17A responses by measuring luciferase induction under a NF-κB-driven reporter system in HEK-293T cells and Gro-α secretion in fibroblasts. [Results] A STAT1 variant (c.1363G>A/p.V455I) was identified by next-generation sequencing and classified as likely non-pathogenic as functional testing revealed normal STAT1 expression and phosphorylation upon IFN-γ. We also found compound heterozygous variants (c.1325A>G/p.D451G and c.1335delA/p.K454fs11*) of TRAF3IP2. By overexpression, despite normal protein expression, and impaired (K454fs11*) or normal (D451G) interaction with IL-17RA, both mutant alleles resulted in impaired NF-κB activation. Patient's fibroblasts displayed abolished GRO-α secretion upon IL-17A stimulation. Finally, ex vivo CD4+ T cells showed increased IL-17A, IL-22, and IL-4 and normal low IFN-γ expression upon stimulation. [Conclusion] We identify novel compound heterozygous variants of TRAFP3IP2 causing autosomal recessive ACT1 deficiency in a child with CMC and provide a review of the current literature.

We conducted a multicenter clinical validity study of the Panbio coronavirus disease 2019 Antigen Rapid Test of nasopharyngeal samples in pediatric patients with coronavirus disease 2019-compatible symptoms of ≤5 days of evolution. Our study showed limited accuracy in nasopharyngeal antigen testing: overall sensitivity was 45.4%, and 99.8% of specificity, positive-predictive value was 92.5%.

Background To date, few data on paediatric COVID-19 have been published, and most reports originate from China. This study aimed to capture key data on children and adolescents with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection across Europe to inform physicians and health-care service planning during the ongoing pandemic. Methods This multicentre cohort study involved 82 participating health-care institutions across 25 European countries, using a well established research network—the Paediatric Tuberculosis Network European Trials Group (ptbnet)—that mainly comprises paediatric infectious diseases specialists and paediatric pulmonologists. We included all individuals aged 18 years or younger with confirmed SARS-CoV-2 infection, detected at any anatomical site by RT-PCR, between April 1 and April 24, 2020, during the initial peak of the European COVID-19 pandemic. We explored factors associated with need for intensive care unit (ICU) admission and initiation of drug treatment for COVID-19 using univariable analysis, and applied multivariable logistic regression with backwards stepwise analysis to further explore those factors significantly associated with ICU admission. Findings 582 individuals with PCR-confirmed SARS-CoV-2 infection were included, with a median age of 5·0 years (IQR 0·5–12·0) and a sex ratio of 1·15 males per female. 145 (25%) had pre-existing medical conditions. 363 (62%) individuals were admitted to hospital. 48 (8%) individuals required ICU admission, 25 (4%) mechanical ventilation (median duration 7 days, IQR 2–11, range 1–34), 19 (3%) inotropic support, and one ( Interpretation COVID-19 is generally a mild disease in children, including infants. However, a small proportion develop severe disease requiring ICU admission and prolonged ventilation, although fatal outcome is overall rare. The data also reflect the current uncertainties regarding specific treatment options, highlighting that additional data on antiviral and immunomodulatory drugs are urgently needed. Funding ptbnet is supported by Deutsche Gesellschaft für Internationale Zusammenarbeit.

To analyze host and pathogen factors related to disease severity of community-acquired bone and joint infections in children, a cohort of pediatric patients was prospectively recruited from 13 centers in 7 European countries. A total of 85 children were included, 11 (13%) had a severe infection. Panton-Valentine leukocidin-positive isolates were 17%, and 6% of the isolates were methicillin-resistant Staphylococcus aureus. Multivariate analysis identified Panton-Valentine leukocidin presence (adjusted odds ratio, 12.6; P = 0.01) as the only factor independently associated with severe outcome, regardless of methicillin resistance.

COACH working group.-- The paper is based on the discussion during the annual meeting of the EPI-Net project in Verona in September 2018., [Objectives] To systematically summarize the evidence on how to collect, analyse and report antimicrobial resistance (AMR) surveillance data to inform antimicrobial stewardship (AMS) teams providing guidance on empirical antibiotic treatment in healthcare settings., [Methods] The research group identified 10 key questions about the link between AMR surveillance and AMS using a checklist of 9 elements for good practice in health research priority settings and a modified 3D combined approach matrix, and conducted a systematic review of published original studies and guidelines on the link between AMR surveillance and AMS., [Results] The questions identified focused on AMS team composition; minimum infrastructure requirements for AMR surveillance; organisms, samples and susceptibility patterns to report; data stratification strategies; reporting frequency; resistance thresholds to drive empirical therapy; surveillance in high-risk hospital units, long-term care, outpatient and veterinary settings; and surveillance data from other countries. Twenty guidelines and seven original studies on the implementation of AMR surveillance as part of an AMS programme were included in the literature review., [Conclusions] The evidence summarized in this review provides a useful basis for a more integrated process of developing procedures to report AMR surveillance data to drive AMS interventions. These procedures should be extended to settings outside the acute-care institutions, such as long-term care, outpatient and veterinary. Without proper AMR surveillance, implementation of AMS policies cannot contribute effectively to the fight against MDR pathogens and may even worsen the burden of adverse events from such interventions.

Background: WHIM (Warts, Hypogammaglobulinemia, Infections, and Myelokathexis) syndrome is a rare primary immunodeficiency associated with broad cytopenia, including neutropenia. It is caused by gain-of-function mutations in C XCR4, leading to dysregulated immune cell trafficking with retention of neutrophils, lymphocytes, and monocytes in the bone marrow and in some cases, hypogammaglobulinemia. As a result, patients with WHIM syndrome have recurrent bacterial and viral infections, and unusual susceptibility to human papillomavirus infection predisposing individuals to recalcitrant warts and malignancy (McDermott D, et al. Immunol Rev. 2019;91-102). Therapeutic options are limited and do not address the underlying pathogenic mechanism of WHIM syndrome. The investigational oral CXCR4 antagonist mavorixafor directly targets the underlying cause of disease and has been shown to increase absolute neutrophil, lymphocyte, and monocyte counts, and to decrease annualized infection rate, and reduce cutaneous wart burden in a phase 2 trial of adults with WHIM syndrome (NCT03005327; Dale D, et al. Blood. 2020;136: 2994-3003). Findings from an ongoing long-term extension of this study support a sustained clinical benefit of long-term mavorixafor treatment in patients with WHIM syndrome. Here, we describe the design of a global phase 3 registrational trial evaluating the safety and efficacy of mavorixafor in WHIM syndrome in participants aged ≥12 years while reporting on preliminary baseline characteristics of the enrolled population. Methods: This phase 3 trial (4WHIM; NCT03995108) is a randomized, double-blind, placebo-controlled study with open-label extension (OLE) and planned enrollment of 18 to 28 patients from sites in Asia, Australia, Europe, Israel, and the United States. Patients aged ≥12 years with a confirmed CXCR4 mutation consistent with WHIM syndrome phenotype and a screening absolute neutrophil count (ANC) ≤400 cells/µL without clinical evidence of active systemic infection are eligible for enrollment. Patients are randomized 1:1 to receive mavorixafor (400 mg in adults, and adolescents weighing >50 kg; 200 mg in adolescents weighing ≤50 kg) or matching placebo once daily for a total of 52 weeks (≥9 patients per group). Patients who complete the randomized period or are granted early release due to recurrent infections requiring treatment (≤2 requiring hospitalization or 4 requiring intravenous antibiotic or granulocyte colony-stimulating factor) are eligible to enroll in the OLE and receive mavorixafor until commercial availability or study termination. The primary end point is the number of hours above ANC threshold of 500 cells/µL over a 24-hour period, assessed prior to treatment, and 4 times (every 3 months) over the 52-week randomized period. Secondary end points include infection rates adjudicated by a blinded, independent committee, change from baseline in cutaneous warts also with blinded assessment, number of hours above absolute lymphocyte count (ALC) of 1000 cells/µL over a 24-hour period, and patient-reported outcomes such as work/school absence and quality of life assessment using age-appropriate questionnaires. Patient Demographics and Characteristics: As of July 15 2021, the first 18 patients have enrolled from 10 countries and 15 sites. Of these, 56% are pediatric patients, 56% are males, 56% of the patients have warts, 94% have nonsense and 6% have frameshift CXCR4 mutations. All patients had severe neutropenia (ANC ≤400 cells/μL) and majority had significant lymphopenia (ALC ≤1000 cells/μL). Conclusions: Evidence supporting efficacy of current therapies in WHIM syndrome is lacking, and approved therapies targeting the underlying molecular mechanisms and hence, able to address the full clinical spectrum of this condition, are needed. The 4WHIM study is the first double-blind, placebo-controlled, randomized trial in patients with this syndrome and is an important next step in the clinical development of a novel, orally bioavailable targeted therapy for WHIM syndrome and potentially for other individuals with related cellular immunodeficiencies. This robust study will build on the findings of the phase 2 trial that suggested a clinical benefit of mavorixafor for WHIM syndrome by incorporating a broader, global population of patients observed for a longer period of time. Full phase 3 trial results are anticipated in late 2022. Disclosures Dale: X4 Pharmaceuticals: Consultancy, Honoraria, Research Funding. Azar: X4 Pharmaceuticals: Research Funding. Badolato: Angelini: Consultancy; X4 Pharmaceuticals: Consultancy; Janssen: Consultancy; SOBI (IDMC): Other. Bhandari: X4 Pharmaceuticals: Current Employment. Belschner: X4 Pharmaceuticals: Current Employment. Cadavid: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Dickerson: Bluebird Bio: Membership on an entity's Board of Directors or advisory committees. Hoffman: Zomagen: Research Funding; Novartis: Consultancy, Speakers Bureau; Takeda: Research Funding; Jecure: Research Funding. Jiang: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Kang: Cartexell: Membership on an entity's Board of Directors or advisory committees, Research Funding; Novartis Korea: Membership on an entity's Board of Directors or advisory committees, Research Funding; Amgen Korea: Membership on an entity's Board of Directors or advisory committees, Research Funding. Kulagin: Roche: Speakers Bureau; Sanofi: Speakers Bureau; Generium: Speakers Bureau; Biocad: Research Funding; Apellis: Research Funding; Alexion: Research Funding; X4 Pharmaceuticals: Research Funding; Novartis: Speakers Bureau; Johnson & Johnson: Speakers Bureau; Pfizer: Speakers Bureau. Langguth: RCPA: Membership on an entity's Board of Directors or advisory committees. MacLeod: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Sharathkumar: Amgen: Research Funding; BMS: Research Funding; Pfizer: Membership on an entity's Board of Directors or advisory committees, Research Funding; Genentech: Membership on an entity's Board of Directors or advisory committees, Research Funding; Shire: Membership on an entity's Board of Directors or advisory committees, Research Funding; X4 Pharmaceuticals: Research Funding; NIH Trials of Pediatric VTE: Membership on an entity's Board of Directors or advisory committees, Research Funding; CSL: Membership on an entity's Board of Directors or advisory committees; Bayer: Membership on an entity's Board of Directors or advisory committees. Shcherbina: X4 Pharmaceuticals: Speakers Bureau. Tang: X4 Pharmaceuticals: Current Employment, Current equity holder in publicly-traded company. Vossen: X4 Pharmaceuticals: Other: PI in WHIM Trial; Brothers of St. John: Consultancy; Austrian National Bank: Research Funding; Menarini: Honoraria; Gilead: Honoraria; Astro Pharma: Honoraria.

Background: Antibody dynamics over time after SARS-CoV-2 infection are still unclear, and data regarding children are scarce. Methods: A prospective cohort study was performed including children infected by SARS-CoV-2 between March and May 2020. Patients were categorized into 3 groups: children admitted with COVID-19, outpatient children with mild COVID-19, and seropositive children participating in a seroprevalence study among cohabitants of infected healthcare workers (HCWs). Six months after the infection, a new serological control was performed. Results: A total of 58 children were included, 50% male (median age 8.3 [IQR 2.8–13.5] years). The median time between the two serological studies was 186 (IQR 176–192) days, and 86% (48/56) of the children maintained positive IgG six months after the infection. This percentage was 100% in admitted patients and 78% among the rest of the included children (p = 0.022). The diagnoses of lower respiratory tract infection and multisystemic inflammatory syndrome were associated with persistence of IgG (p = 0.035). The children of HCWs in the seroprevalence study lost antibodies more often (p = 0.017). Initial IgG titers of the children who remained positive six months after the infection were significantly higher (p = 0.008). Conclusions: Most children infected by SARS-CoV-2 maintain a positive serological response six months after the infection. Those children who lost their IgG titer were more frequently asymptomatic or mildly symptomatic, presenting with low antibody titers after the infection.