Background: Warts, Hypogammaglobulinemia, Infections, and Myelokathexis (WHIM) syndrome is a primary immunodeficiency characterized by retention of leukocytes in the bone marrow (myelokathexis), resulting in neutropenia, leukopenia, and in some cases hypogammaglobulinemia. WHIM syndrome is classically caused by gain-of-function mutations in CXCR4, with the resulting hyperactivation of the CXCR4-CXCL12 pathway. Patients diagnosed with WHIM syndrome have a heterogeneous phenotype yet typically experience recurrent sinopulmonary infections and unusual susceptibility to human papillomavirus (HPV), resulting in predisposition to warts and malignancy. There are no approved medications for WHIM syndrome. To date, all management strategies are symptomatic only, failing to address the underlying mechanism of WHIM syndrome, and are mostly ineffective for HPV infections. Mavorixafor is an investigational, oral CXCR4 antagonist that directly inhibits CXCR4-enhanced signaling in WHIM syndrome pathogenesis, and has been shown to increase white blood cell counts, decrease annualized infection rate, and reduce cutaneous warts in an open-label phase 2 clinical trial (NCT03005327) for patients with WHIM syndrome. Aims: Here, we describe the design, baseline characteristics, and status of a global phase 3, double-blind, placebo-controlled, randomized trial (4WHIM, NCT03995108) with open-label extension evaluating the safety and efficacy of mavorixafor in patients with WHIM syndrome. Methods: Eligibility for enrollment included age ≥12 years, diagnosis of WHIM syndrome, confirmed CXCR4 mutation, and absolute neutrophil count (ANC) ≤400 cells/µL without clinical evidence of active systemic infection. Patients were randomized in a 1:1 ratio to receive mavorixafor (adults, 400 mg; adolescents weighing ≤50 kg, 200mg; adolescents weighing >50 kg, 400mg) or placebo orally once daily. The primary endpoint is defined as number of hours above ANC threshold (500 cells/µL) over a 24-hour period, assessed every 3 months for 52 weeks. Secondary endpoints include the composite end point of infection and warts, infection rates and severity, change from baseline in cutaneous warts, and number of hours above absolute lymphocyte count (ALC) of ≥1000 cells/µL over a 24-hour period, and patient-reported quality-of-life assessment using age-appropriate questionnaires. Results: Enrollment for the trial has been completed, with a total of 31 patients enrolled globally. Demographics of the enrolled population include: 48% adolescents (age 12-18 years), 42% male, 71% with warts, 81% with nonsense CXCR4 mutations, and 19% with frameshift CXCR4 mutations. Mean and median ANC and ALC at screening visit were 220 cells/µL and 180 cells/µL, and 515 cells/µL and 440 cells/µL respectively. Summary/Conclusion: 4WHIM is the first double-blind, placebo-controlled, randomized trial in patients with WHIM syndrome; top-line clinical results are expected in Q4 2022. The study enrolled children (aged ≥ 12 years) and adults, all with genetically confirmed CXCR4 variants consisting of both nonsense and frameshift mutations. The patients all presented with severe neutropenia and lymphopenia and a high percentage of the patients had warts. This study represents an important next step in the development of the novel, orally bioavailable, targeted therapy mavorixafor for the treatment of patients with WHIM syndrome.

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 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 response using an NF-κB-driven luciferase reporter system in HEK-293T cells, and by measuring GRO-α secretion by fibroblasts. Results: A likely non-pathogenic STAT1 variant (c.1363G>A/p.V455I) was identified by next generation sequencing., STAT1 expression and phosphorylation upon IFN- were normal. 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 an impaired NF-κB-activation. Patient’s fibroblasts displayed abolished GRO-α secretion upon IL-17A. 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.

Background:ALPS patients show impaired generation of humoral memory for T independent antigens whereas they generate memory for self-antigens due to impaired FAS-dependent removal of autoreactive germinal center B cells. It is known that FAS signaling via caspase activation results in cell apoptosis. However, FAS ligation may also initiate or modulate non-apoptotic signaling as shown for example by its ability to activate NF-κB. Recent data implicate a regulatory role of FAS in the modulation of mTOR signaling in ALPS double-negative T cells. Moreover, a recently described C194V FAS mutation disturbs its post-translational modification leading to impaired apoptosis induction while non-apoptotic signalling is still intact. Consequently, C194V FAS protects from the autoimmune phenotype in the murine ALPS system. This supports the view that FAS may prevent autoimmunity with other mechanisms than inducing apoptosis.Objectives:We hypothesize that FAS mutations impair this modulatory signaling, leading to hyper-activation of B cells. Therefore we aim to investigate non apoptotic FAS signaling in B cells derived from healthy individuals and ALPS patients.Methods:We studied resting and activated B cells in ALPS patients in presence or absence of FAS ligand by flow cytometry analysing relevant molecules to the CD40 signaling pathway. We used mass cytometry to perform functional phenotyping of B cells isolated from secondary lymphoid organs. Proteomic studies were performed to identify potential signaling circuits and RNA sequencing to study the consequences of FAS signaling on B cell fate.Results:In CD40L activated B cells, FAS signaling results in specific modulation of the mTOR signaling pathway. This modulation is absent in ALPS derived B cells. In line with these data germinal center B cells and plasmablast from secondary lymphoid organs of ALPS patients show hyperactive mTOR signaling pathway. Proteomic studies identify a circuit that links FAS to the phosphatase PTEN via DAXX and the deubiquitinase USP7.Conclusion:We describe a new role of FAS in the regulation of B cell activation. Defects in FAS signaling in ALPS contribute to dysregulation of the mTOR signaling pathway and disturbed B cell development.Disclosure of Interests:None declared

Objectives: Inappropriate antimicrobial use favours the spread of resistance, and multidrug-resistant microorganisms (MDR) are currently of major concern. Antimicrobial stewardship programmes (ASPs) are essential for improving antibiotic use in hospitals. However, their impact on entire healthcare systems has not been thoroughly assessed. Our objective was to provide the results of an institutionally supported ASP involving 31 public hospitals in Andalusia, Spain. Methods: We designed an ecologic time-series study from 1 January 2014 to 31 December 2017. Quarterly, data on indicators were collected prospectively, and feedback reports were provided. PIRASOA is an ongoing clinically based quality-improvement programme whose key intervention is the educational interview, regular peer-to-peer interventions between advisors and prescribers to reinforce the appropriate use of antibiotics. Seventy-two indicators were monitored to measure prescribing quality (inappropriate treatments), antimicrobial consumption (defined daily doses per 1000 occupied bed-days), incidence density of MDR per 1000 occupied bed-days and crude mortality rate associated with bloodstream infections. We used Joinpoint regression software to analyse the trends. Results: The quality of antimicrobial prescribing improved markedly, and the inappropriate treatment rate was significantly lower, with quarterly percentage change (QPC) = -3.0%, p < 0.001. Total antimicrobial consumption decreased (QPC = -0.9%, p < 0.001), specifically carbapenems, amoxicillin/clavulanic acid, quinolones and antifungal agents, whereas antipseudomonal cephalosporin use increased. While the incidence of MDR showed a sustained decreasing trend (QPC = -1.8%; p 0.002), the mortality of patients with bloodstream infections remained stable (QPC = -0.2%, p 0.605). Conclusions: To date, the PIRASOA programme has succeeded in optimizing the use of antimicrobial agents and has had a positive ecologic result on bacterial resistance at level of an entire healthcare system. (C) 2019 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Seasonal influenza virus vaccination should be considered in all pediatric patients with rheumatic diseases. Few studies have addressed influenza vaccination safety and efficacy in this group. We aim to prospectively evaluate immunogenicity and safety of the trivalent inactivated influenza vaccine including A/H1N1, A/H3N2 and B strains in children with juvenile idiopathic arthritis (JIA) receiving biological therapy.

Staphylococcus aureus is the main pathogen responsible for bone and joint infections worldwide and is also capable of causing pneumonia and other invasive severe diseases. Panton-Valentine leukocidin (PVL) and methicillin-resistant S. aureus (MRSA) have been studied as factors related with severity in these infections. The aims of this study were to describe invasive community-acquired S. aureus (CA-SA) infections and to analyse factors related to severity of disease. Paediatric patients (aged 0-16 years) who had a CA-SA invasive infection were prospectively recruited from 13 centres in 7 European countries. Demographic, clinical and microbiological data were collected. Severe infection was defined as invasive infection leading to death or admission to intensive care due to haemodynamic instability or respiratory failure. A total of 152 children (88 boys) were included. The median age was 7.2 years (interquartile range, 1.3-11.9). Twenty-six (17%) of the 152 patients had a severe infection, including 3 deaths (2%). Prevalence of PVL-positive CA-SA infections was 18.6%, and 7.8% of the isolates were MRSA. The multivariate analysis identified pneumonia (adjusted odds ratio (aOR) 13.39 (95% confidence interval (CI) 4.11-43.56); p 0.008), leukopenia at admission (< 3000/mm(3)) (aOR 18.3 (95% CI 1.3-259.9); p 0.03) and PVL-positive infections (aOR 4.69 (95% CI 1.39-15.81); p 0.01) as the only factors independently associated with severe outcome. There were no differences in MRSA prevalence between severe and nonsevere cases (aOR 4.30 (95% CI 0.68- 28.95); p 0.13). Our results show that in European children, PVL is associated with more severe infections, regardless of methicillin resistance. (C) 2016 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Autosomal recessive (AR) complete Interferon-gamma Receptor1 (IFN-gamma R1) deficiency is a rare variant of Mendelian susceptibility to mycobacterial disease (MSMD). Although hematopoietic stem cell transplantation (HSCT) remains the only curative treatment, outcomes are heterogeneous; delayed engraftment and/or graft rejection being commonly observed. This case report and literature review expands the knowledge about this rare but potentially fatal pathology, providing details regarding diagnosis, antimicrobial treatment, transplant performance, and outcome that may help to guide physicians caring for patients with AR complete IFN-gamma R1 or IFN-gamma R2 deficiency. (C) 2015 Wiley Periodicals, Inc.

Uncommon microorganisms are increasingly being recognized as causative agents of paediatric infectious endocarditis (IE). We report a 4-year old girl with congenital heart disease, who suffered from 2 IE episodes secondary to Aggregatibacter aphrophilus (formerly Haemophilus aphrophilus) and Staphylococcus lugdunensis, both rarely reported pathogens in this age group. The patient was initially successfully treated with prolonged intravenous antibiotic courses, however removal of the Contegra valved conduit during the second episode was required due to recurrence of fever and development of pulmonary embolism despite completion of antibiotic therapy. A. aphrohilus is a member of the fastidious gram negative microorganisms of the HACEK group (Haemophilus spp., Aggregatibacter spp, Cardiobaterium hominis, Eikenella corrodens and Kingella kingae), that colonize the oropharynx and are a recognised cause of IE. Prognosis of children with IE due to HACEK group members varies, half of them suffering from complications and mortality rates of 10-12.5 %. Although S. lugdunensis belongs to coagulase negative staphylococci (CONS), it behaves more like S. aureus species rather than CONS. This microorganism is a well-described cause of endocarditis in adult patients, associated with high requirements of surgical procedures and mortality (42-78 %). In conclusion, paediatric IE can be caused by uncommon microorganisms associated with severe complications and potential fatality. The isolation of S. lugdunensis or A. aphrophilus in febrile patients should be considered clinically relevant and cardiac involvement must be ruled out. Those patients with proved IE will require prolonged intravenous antibiotic courses and in complicated cases surgical intervention.

Kawasaki disease (KD) is an acute, self-limited vasculitis commonly affecting children <5 years. It is the leading cause of acquired heart disease in children in developed countries and characterized by fever, bilateral non-exudative conjunctivitis, erythematous lips and oral mucosa, changes in extremities, rash and cervical lymphadenopathy. Importantly, 15–25% of untreated children will develop coronary artery aneurysms or ectasia and are at risk to suffer from myocardial infarction, sudden death, or ischemic heart disease. Incomplete or atypical KD is more common in young infants who have a higher risk to develop coronary artery aneurysms. Treatment with intravenous immunoglobulin (IVIG) in the first 10 days of illness significantly decreases the prevalence of this complication (Newburger JW et al., Circulation 2004; 110: 2747–2771). Over the last years several cases of KD associated with hemodynamic instability or Kawasaki disease shock syndrome (KDSS) have been described. (Chen PS et al., J Microbiol Immunol Infect 2015; 48: 43–50; Gámez-González LB et al., Eur J Pediatr 2013; 172: 337–342; Lin, MT et al., Pediatr Infect Dis J 2013; 161: 513–515; Dominguez SR et al., Pediatrics 2008; 122; e786–e790; Kanegaye JT et al., Pediatrics 2009; 123; e783–e789; Gatterre P et al., Intensive Care Med 2012; 38: 872–878). Here we report 3 children with KDSS requiring ICU admission and review the current literature.

The isolation of Chryseobacterium indologenes as a causative micro-organism in human diseases is rare. Risk factors for infections caused by this pathogen include very young and very old age, indwelling devices, immune suppression and recent use of broad-spectrum antibiotics. Most cases suffer from bacteraemia or nosocomial pneumonia, whilst infection of the central nervous system (CNS) is extremely rare. We present a term-born infant diagnosed prenatally with holoprosencephaly and obstructive hydrocephalus, requiring post-natal ventriculoperitoneal shunt insertion. At 6 weeks of age, he suffered from Escherichia coli meningitis, showing satisfactory clinical response with antimicrobial therapy. Aged 11 months, he suffered from hyper-drainage syndrome, resulting in the removal of the shunt system. He represented 11 days post-operatively, with low-grade fever, irritability and cerebrospinal fluid (CSF) leakage. C. indologenes from CSF was isolated and antimicrobial therapy with ceftazidime and trimethoprim-sulfamethoxazole for 3 weeks resulted in good clinical response. This is the first documented community-acquired CNS infection due to C. indologenes in an infant without concomitant indwelling device or previous antibiotic pressure.

Abnormalities in maternal folate and carbohydrate metabolism have both been shown to induce neural tube defects (NTD) in humans and animal models. However, the relationship between these two factors in the development of NTDs remains unclear. Data from mothers of children with spina bifida seen at the Unidad de Espina Bífida del Hospital Infantil Virgen del Rocío (case group) were compared to mothers of healthy children with no NTD (control group) who were randomly selected from patients seen at the outpatient ward in the same hospital. There were 25 individuals in the case group and 41 in the control group. Analysis of genotypes for the methylenetetrahydrofolate reductase (MTHFR) 677CT polymorphism in women with or without risk factors for abnormal carbohydrate metabolism revealed that mothers who were homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism were more likely to have offspring with spina bifida and high levels of homocysteine, compared to the control group. The increased incidence of NTDs in mothers homozygous for the MTHFR 677TT polymorphism and at risk of abnormal carbohydrate metabolism stresses the need for careful metabolic screening in pregnant women, and, if necessary, determination of the MTHFR 677CT genotype in those mothers at risk of developing abnormal carbohydrate metabolism.

Abstract We present the case of a 6-year-old boy diagnosed with stage III mediastinal Non Hodgkin Lymphoblastic T cell Lymphoma who suffered from catheter-related bloodstream infection (CRBI) due to Mycobacterium fortuitum whilst receiving chemotherapy. Isolation of this rare pathogen was done directly from blood culture and identification was made rapidly within 48 h using matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry as well as specific polymerase chain reaction (PCR)-reverse hybridization method. This allowed prompt directed antibiotic therapy apart from central venous catheter removal and resulted in an excellent clinical response. This case highlights the potential benefit of using MALDI-TOF mass spectrometry, a fast, cost-effective and precise methodology, in the diagnosis and subsequent management of invasive bacterial infection.

Introduction: Early diagnosis of primary immunodeficiency such as severe combined immunodeficiency (SCID) and X-linked agammaglobulinemia (XLA) improves outcome of affected infants/children. The measurement of T-cell receptor excision circles (TRECS) and kappadeleting recombination excision circles (KRECS) can identify neonates with severe T or B-cell lymphopenia.Objectives: To determine TRECS and KRECS levels from prospectively collected dried blood spot samples (DBS) and to correctly identify severe T and B-cell lymphopenia. Material and methods: Determination of TRECS and KRECS by multiplex PCR from neonates born in two tertiary hospitals in Seville between February 2014 and May 2014. PCR cut-off levels: TRECS<15 copies/mu l, KRECS<10copies/mu l, ACTB (beta-actin)>1000 copies/mu l. Internal (XLA, ataxia telangiectasia) and external (SCID) controls were included.Results: A total of 1068 out of 1088 neonates (mean GA 39 weeks (38-40) and BW 3238 g (29303520) were enrolled in the study. Mean (median, min/max) copies/mu l, were as follows: TRECS 145 (132, 8/503), KRECS 82 (71, 7/381), and ACTB 2838 (2763, 284/7710). Twenty samples (1.87%) were insufficient. Resampling was needed in one neonate (0.09%), subsequently giving a normal result. When using lower cut-offs (TRECS<8 and KRECS<4 copies/mu l), all the samples tested were normal and the internal and external controls were correctly identified.Conclusion: This is the first prospective pilot study in Spain using TRECS/KRECS/ACTB-assay, describing the experience and applicability of this method to identify severe lymphopenias. The ideal cut-off remains to be established in our population. Quality of sampling, storage and preparation need to be further improved. (C) 2014 Asociacion Espanola de Pediatria. Published by Elsevier Espana, S.L.U. All rights reserved.

El diagnóstico precoz de inmunodeficiencias primarias, como la inmunodeficiencia combinada grave (IDCG) y la agammaglobulinemia ligada al cromosoma X (ALX), mejora el pronóstico de los niños afectados. La medida de los T-cell receptor excision circles (TRECS) y kappa-deleting recombination excision circles (KRECS) puede identificar neonatos con linfopenias T y/o B graves. Cuantificar los niveles de TRECS y de KRECS de manera prospectiva a partir de muestras de sangre seca de talón para identificar de manera correcta linfopenias T y/o B. Determinación de TRECS y de KRECS mediante reacción en cadena de polimerasa multiplex en neonatos nacidos entre febrero y mayo del 2014. Los puntos de corte empleados fueron: TRECS < 15 copias/μl, KRECS < 10 copias/μl, ACTB (β-actina) > 1.000 copias/μl. Se incluyeron controles internos (ALX, ataxia) y externos (IDCG). Fueron analizadas 1.068 muestras de las 1.088 recogidas (edad gestacional media: 39 semanas [38-40]; peso al nacer medio 3.238 g [2.930-3.520]). La media (mediana, min/máx) copias/μl obtenidas fueron las siguientes; TRECS 145 (132, 8/503), KRECS 82 (71, 7/381) y ACTB 2838 (2763, 284/7710). Veinte muestras (1,87%) fueron insuficientes para el análisis. El re-test fue necesario en un neonato (0,09%), confirmándose resultados normales posteriormente. Empleando puntos de corte inferiores (TREC < 8 y KREC < 4 copias/μl), todas las muestras resultaron normales y se identificaron los controles internos y externos correctamente. Es el primer estudio prospectivo realizado en España usando el ensayo TREC/KREC/ACTB para identificar linfopenias graves. Es necesario establecer puntos de corte adecuados para nuestra población, mejorar la toma de muestras, su almacenamiento y la preparación de las mismas. Early diagnosis of primary immunodeficiency such as severe combined immunodeficiency (SCID) and X-linked agammaglobulinemia (XLA) improves outcome of affected infants/children. The measurement of T-cell receptor excision circles (TRECS) and kappa-deleting recombination excision circles (KRECS) can identify neonates with severe T or B-cell lymphopenia. To determine TRECS and KRECS levels from prospectively collected dried blood spot samples (DBS) and to correctly identify severe T and B-cell lymphopenia. Determination of TRECS and KRECS by multiplex PCR from neonates born in two tertiary hospitals in Seville between February 2014 and May 2014. PCR cut-off levels: TRECS<15 copies/μl, KRECS<10copies/μl, ACTB (β-actin)>1000 copies/μl. Internal (XLA, ataxia telangiectasia) and external (SCID) controls were included. A total of 1068 out of 1088 neonates (mean GA 39 weeks (38-40) and BW 3238 g (2930-3520) were enrolled in the study. Mean (median, min/max) copies/μl, were as follows: TRECS 145 (132, 8/503), KRECS 82 (71, 7/381), and ACTB 2838 (2763, 284/7710). Twenty samples (1.87%) were insufficient. Resampling was needed in one neonate (0.09%), subsequently giving a normal result. When using lower cut-offs (TRECS<8 and KRECS<4 copies/μl), all the samples tested were normal and the internal and external controls were correctly identified. This is the first prospective pilot study in Spain using TRECS/KRECS/ACTB-assay, describing the experience and applicability of this method to identify severe lymphopenias. The ideal cut-off remains to be established in our population. Quality of sampling, storage and preparation need to be further improved.