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1.
J Pediatr ; : 114189, 2024 Jul 09.
Artículo en Inglés | MEDLINE | ID: mdl-38992719

RESUMEN

OBJECTIVE: To describe for intervertebral spondylodiscitis (IS) its clinical characteristics, treatment approaches with intravenous (IV) antibiotics, and clinical implications of changes in treatment approach. STUDY DESIGN: This retrospective study included all children aged 0 through18 years diagnosed with imaging-confirmed thoracic and lumbar IS from 2000 to 2022 at a tertiary pediatric hospital. Patients with longer intravenous (IV) treatment regimen were compared with those with a shorter clinically directed IV to oral regimen. RESULTS: In all, 124 cases were included with median age 14.9 months (IQR 12.7-19.4) at diagnosis. Irritability and pain while changing diapers were common symptoms (52.4% and 49.2%, respectively). Elevated erythrocyte sedimentation rate (ESR) was the most common laboratory finding (95%, median 50 [IQR 34-64] mm/h). Elevated ESR was found in higher proportions (95%) compared with elevated CRP (76%, median 1.8 mg/dL; P< 0.001). Since implementing the shorter clinically directed IV treatment duration for patients with thoracic and lumbar IS, hospitalization duration was reduced from a median of 12 to 8 days (P =0.008) and IV treatment duration by a median of 14 to 8 days (P<0.001). Only 1(1.6%) patient in the clinically directed treatment group required re-hospitalization due to failure of therapy. Conversely, 9/124 children in the cohort suffered from IV treatment related complications; all had been treated IV for prolonged periods. CONCLUSION: Early transition to oral treatment in pediatric spondylodiscitis appears to be appropriate clinically, and shortens hospital stay and intravenous treatment duration without major negative clinical impact.

2.
Pediatr Infect Dis J ; 2024 Jul 03.
Artículo en Inglés | MEDLINE | ID: mdl-38985998

RESUMEN

BACKGROUND: The potential of hypophosphatemia (HP) to differentiate between febrile syndromes and its clinical significance in children without sepsis were not previously described. METHODS: Data were retrospectively collected of febrile children aged 3 months to 18 years, hospitalized at general pediatric wards during 2010-2019. Phosphate levels were compared between bacterial infection (BI), viral infection (VI), and Kawasaki disease (KD). Regression analyses were used to evaluate the relationship between HP and outcome. RESULTS: Of 3963 febrile children, 559 had BI, 3271 had VI, and 133 had KD. In BI compared to VI and KD, HP was more prevalent (49.2%, 19.7%, and 31.6%, respectively; P<0.001) and more severe [median (interquartile range) phosphate standard deviation score: -1.85 (2.08), -0.56 (2.08), and -1.20 (2.28), respectively; P<0.001]. In the BI group, Pi-SDS level was lower among patients with than without bacteremia (-2.33 ± 1.8 vs. -0.79 ± 1.68; P<0.001). Phosphate levels displayed discriminatory potential between bacterial and viral etiologies, with an area under the curve of 0.719 (95% CI, 0.697-0.742). Minimal phosphate standard deviation score values had a negative weak correlation with the maximal C-reactive protein levels and white blood cell count. Univariate and multivariate analyses showed an association of HP with a more severe disease course, manifested by longer hospital stay [+2.10 (95% CI, 0.75-3.46) days; P=0.003] and a higher rate of intensive care unit admission [odds ratio, 2.63 (95% CI, 1.94-3.56); P<0.001). CONCLUSIONS: Hypophosphatemia rates were highest in bacterial etiology, intermediate in KD, and lowest in viral etiology and were associated with poorer outcomes. Phosphate level may serve as a marker for ruling out a bacterial etiology.

3.
Blood ; 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38905634

RESUMEN

Neutrophils are the first line of defense against invading pathogens. Neutrophils execute and modulate immune responses by generating reactive oxygen species (ROS). Chronic Granulomatous Disease (CGD) is a primary immune deficiency disorder of phagocytes, caused by inherited mutations in the genes of the NADPH oxidase enzyme. These mutations lead to failure of ROS generation followed by recurrent bacterial and fungal infections, frequently associated with hyper-inflammatory manifestations. We report a multi-center cumulative experience in diagnosing and treating patients with CGD. From 1986 to 2021, 2,918 patients suffering from frequent infections were referred for neutrophil evaluation. Among them, 110 patients were diagnosed with CGD, 56 of Jewish ancestry, 48 of Arabic ancestry and 6 non-Jewish/non-Arabic. As opposed to other Western countries, the autosomal recessive (AR) CGD subtypes were predominant in Israel (71/110 patients). Thirty-nine patients had X-linked CGD, in most patients associated with severe infections (clinical severity score ≥3) and poor outcomes, presenting at a significantly earlier age than AR-CGD subtypes. The full spectrum of infections and hyper-inflammatory manifestations are described. Six patients had hypomorphic mutations with significantly milder phenotype, clinical severity score ≤2, and better outcomes. Hematopoietic stem cell transplantation was implemented in 39/110 patients (35.5%). Successful engraftment was achieved in 92%, with 82% long-term survival and 71% full clinical recovery. CGD is a complex disorder requiring a multi-professional team. Early identification of the genetic mutation is essential for prompt diagnosis, suitable management and prevention.

4.
J Allergy Clin Immunol ; 153(1): 330-334, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37678573

RESUMEN

BACKGROUND: Newborn screening (NBS) programs for severe combined immunodeficiency facilitate early diagnosis of severe combined immunodeficiency and promote early treatment with hematopoietic stem cell transplantation, resulting in improved clinical outcomes. Infants with congenital athymia are also identified through NBS because of severe T-cell lymphopenia. With the expanding introduction of NBS programs, referrals of athymic patients for treatment with thymus transplantation have recently increased at Great Ormond Street Hospital (GOSH) (London, United Kingdom). OBJECTIVE: We studied the impact of NBS on timely diagnosis and treatment of athymic infants with thymus transplantation at GOSH. METHODS: We compared age at referral and complications between athymic infants diagnosed after clinical presentation (n = 25) and infants identified through NBS (n = 19) who were referred for thymus transplantation at GOSH between October 2019 and February 2023. We assessed whether age at time of treatment influences thymic output at 6 and 12 months after transplantation. RESULTS: The infants referred after identification through NBS were significantly younger and had fewer complications, in particular fewer infections. All deaths occurred in the group of those who did not undergo NBS, including 6 patients before and 2 after thymus transplantation because of preexisting infections. In the absence of significant comorbidities or diagnostic uncertainties, timely treatment was achieved more frequently after NBS. Treatment when younger than age 4 months was associated with higher thymic output at 6 and 12 months after transplantation. CONCLUSION: NBS contributes to earlier recognition of congenital athymia, promoting referral of athymic patients for thymus transplantation before they acquire infections or other complications and facilitating treatment at a younger age, thus playing an important role in improving their outcomes.


Asunto(s)
Síndromes de Inmunodeficiencia , Inmunodeficiencia Combinada Grave , Lactante , Recién Nacido , Humanos , Inmunodeficiencia Combinada Grave/diagnóstico , Inmunodeficiencia Combinada Grave/terapia , Tamizaje Neonatal , Timo
6.
J Clin Immunol ; 42(7): 1535-1544, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35767111

RESUMEN

Mutations in the ARPC1B isoform component of human actin-related protein 2/3 complex have been recently associated with an inborn error of immunity characterized by combined immunodeficiency, allergies, autoinflammation, and platelet abnormalities. Currently, indications on the management of this novel disease and information on its outcome are lacking. We report the first case series of 7 children with a homozygous mutation in ARPC1B gene who underwent allogeneic-HSCT (allo-HSCT). All patients presented an early clinical onset, characterized by recurrent infections, failure to thrive and gastrointestinal bleeding episodes complicated with neonatal hemorrhagic enteritis in 3 cases, and macrophage activating syndrome in 2. Allo-HSCT was performed at the median age of 1.83 years after a myeloablative conditioning regimen in all cases. Engraftment occurred in all patients with full donor chimerism in 6 out of 7. The clinical course after engraftment was uneventful in 3 out of 7 children; 2 patients developed a grade 1-2 acute graft-versus-host disease (GvHD), and 1 patient a grade 1 chronic-GvHD. JC virus-related progressive multifocal leukoencephalopathy was diagnosed in one patient 13 months after haploidentical-HSCT and successfully managed with donor-derived viral-specific T-cell infusion. Only one patient had a fatal outcome 3 months after HSCT because of sepsis, after veno-occlusive disease, and transplant-associated microangiopathy. At a median follow-up of 19 months (range 3-110), 6 out of 7 patients are alive and disease-free. The severity of the clinical phenotype at diagnosis and the high survival rate, with limited transplant-related morbidity, strongly support the indication to allo-HSCT for patients with this diagnosis.


Asunto(s)
Complejo 2-3 Proteico Relacionado con la Actina , Trasplante de Células Madre Hematopoyéticas , Humanos , Recién Nacido , Complejo 2-3 Proteico Relacionado con la Actina/deficiencia , Supervivencia sin Enfermedad , Enfermedad Injerto contra Huésped , Acondicionamiento Pretrasplante , Lactante , Quimera por Trasplante
8.
J Allergy Clin Immunol Pract ; 10(10): 2722-2731.e9, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35487367

RESUMEN

BACKGROUND: Implementation of newborn screening (NBS) programs for severe combined immunodeficiency (SCID) have advanced the diagnosis and management of affected infants and undoubtedly improved their outcomes. Reporting long-term follow-up of such programs is of great importance. OBJECTIVE: We report a 5-year summary of the NBS program for SCID in Israel. METHODS: Immunologic and genetic assessments, clinical analyses, and outcome data from all infants who screened positive were evaluated and summarized. RESULTS: A total of 937,953 Guthrie cards were screened for SCID. A second Guthrie card was requested on 1,169 occasions (0.12%), which resulted in 142 referrals (0.015%) for further validation tests. Flow cytometry immune-phenotyping, T cell receptor excision circle measurement in peripheral blood, and expression of TCRVß repertoire for the validation of positive cases revealed a specificity and sensitivity of 93.7% and 75.9%, respectively, in detecting true cases of SCID. Altogether, 32 SCID and 110 non-SCID newborns were diagnosed, making the incidence of SCID in Israel as high as 1:29,000 births. The most common genetic defects in this group were associated with mutations in DNA cross-link repair protein 1C and IL-7 receptor α (IL-7Rα) genes. No infant with SCID was missed during the study time. Twenty-two SCID patients underwent hematopoietic stem cell transplantation, which resulted in a 91% survival rate. CONCLUSIONS: Newborn screening for SCID should ultimately be applied globally, specifically to areas with high rates of consanguineous marriages. Accumulating data from follow-up studies on NBS for SCID will improve diagnosis and treatment and enrich our understanding of immune development in health and disease.


Asunto(s)
Inmunodeficiencia Combinada Grave , ADN , Humanos , Recién Nacido , Israel/epidemiología , Tamizaje Neonatal/métodos , Receptores de Antígenos de Linfocitos T/genética , Receptores de Interleucina-7 , Inmunodeficiencia Combinada Grave/diagnóstico , Inmunodeficiencia Combinada Grave/epidemiología , Inmunodeficiencia Combinada Grave/genética
9.
Eur J Pediatr ; 181(5): 1997-2004, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35118517

RESUMEN

Diagnosis of primary complement deficiencies requires a high index of suspicion. Thus, susceptible patients are often underdiagnosed and untreated. Here, we present a multicenter experience with two novel inborn errors of the classical complement system. This is a retrospective multicenter analysis of computerized medical records of children (<18 years) admitted in the period between 2012 and 2018 at Shaare Zedek Medical Center in Jerusalem and Edmond and Lily Safra Children's Hospital, Tel-Hashomer Medical Center, in Ramat Gan, Israel. Patients were genetically diagnosed by a complementary immune workup. We identified 5 patients (3 males) from four different families harboring two novel mutations in the complement components C6-C8. Genetic mutations were identified by whole-exome sequencing or by sequencing of the coding exons of a single gene based on the findings in the immune workup. Clinical manifestations consisted of meningitis with or without meningococcemia. The immune workup demonstrated nearly absent levels of CH50, compatible with a complement pathway defect. Diagnosis delay ranged between 0 and 30 years. CONCLUSION: Awareness of risk factors for primary complement deficiencies, even at the first infectious episode, should facilitate prompt immune and genetic workup, commencing diagnosis and proper treatment for the patient and family. WHAT IS KNOWN: • Deficiencies in the classical terminal complement components increase susceptibility to invasive meningococcal infections. • Recurrent meningococcal infections mandate a diagnostic workup of the complement system. WHAT IS NEW: • Genetic workup can be utilized for prompt diagnosis of complement deficiencies. • High rates of consanguinity, even in the presence of a single meningococcal infection, should promote immune and genetic workups.


Asunto(s)
Meningitis Meningocócica , Infecciones Meningocócicas , Neisseria meningitidis , Niño , Complemento C6 , Complemento C8/genética , Proteínas del Sistema Complemento/genética , Femenino , Enfermedades por Deficiencia de Complemento Hereditario , Humanos , Masculino , Estudios Retrospectivos
10.
Pediatr Infect Dis J ; 40(11): e395-e399, 2021 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-34232922

RESUMEN

BACKGROUND: Peripheral venous catheter (PVC) is the most used vascular access device in medicine, allowing administration of intravenous fluids and medications. Known complications associated with PVC include extravasation, phlebitis and rarely bloodstream infection (BSI). Data regarding PVC-related BSI in children are lacking. Our aim was to evaluate the epidemiology, clinical and microbiologic characteristics of pediatric inpatients with PVC-related BSI. METHODS: A retrospective study was conducted in a pediatric tertiary care center. Children with BSI, admitted to general pediatric departments during 2010-2019, were identified and their medical records examined. Patients with BSI and phlebitis were further characterized and included in the analysis. We excluded patients with central venous catheters, other identified source of infection and with BSI upon admission. Data collected included patients' demographics and clinical and microbiologic characteristics. RESULTS: Twenty-seven children with PVC-related BSI were identified and included in the study, consisting of 0.2% of the total BSI cases. Patient's median age was 24 (range, 1.5-213) months, 14/27 (52%) were female and 6 (22%) were previously healthy while 21 (78%) had prior medical conditions. Sixteen (59.3%) patients had Gram-negative BSI and 6 (22.2%) Gram-positive bacteria. Polymicrobial infection occurred in 4 (14.8%) patients and Candida albicans in 1 (3.7%) patient. The most common isolated bacteria were Klebsiella spp and Staphylococcus aureus. Longer dwell-time was a predictor of Gram-negative bacteria. CONCLUSIONS: PVC-related BSI due to Gram-negative bacteria was more common than to Gram-positive bacteria. Clinicians should consider an initial broad-spectrum antibiotic coverage for PVC-related BSI in hospitalized pediatric patients.


Asunto(s)
Infecciones Relacionadas con Catéteres/microbiología , Catéteres Venosos Centrales/efectos adversos , Bacterias Gramnegativas/patogenicidad , Infecciones por Bacterias Gramnegativas/epidemiología , Hospitalización/estadística & datos numéricos , Sepsis/epidemiología , Sepsis/etiología , Adolescente , Infecciones Relacionadas con Catéteres/epidemiología , Niño , Preescolar , Infección Hospitalaria/microbiología , Femenino , Bacterias Gramnegativas/clasificación , Bacterias Gramnegativas/aislamiento & purificación , Infecciones por Bacterias Gramnegativas/etiología , Bacterias Grampositivas/clasificación , Bacterias Grampositivas/aislamiento & purificación , Humanos , Lactante , Masculino , Estudios Retrospectivos , Sepsis/microbiología , Centros de Atención Terciaria/estadística & datos numéricos
11.
Open Forum Infect Dis ; 8(3): ofab036, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33732749

RESUMEN

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted mainly via respiratory droplets. A key question in the coronavirus disease 2019 pandemic is whether SARS-CoV-2 could be transmitted via the airborne route as well. We report for the first time SARS-CoV-2 nosocomial infections despite using surgical masks and physical distancing. This report may provide possible evidence for airborne transmission of SARS-CoV-2.

13.
Pediatr Dermatol ; 37(6): 1051-1054, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32951239

RESUMEN

BACKGROUND: Chronic urticaria is defined by the presence of itchy wheals, sometimes accompanied by angioedema, lasting for at least 6 weeks. In children, most cases occur without an eliciting factor and are defined as chronic spontaneous urticaria (CSU). CSU affects up to 0.75% of children with a negative impact on quality of life and school performance. CSU is treated in adults with second-generation antihistamines, increased up to four times normal doses for second-line treatment. Omalizumab (a monoclonal antibody to IgE) may be recommended as third-line therapy. A similar protocol is used in children, yet little is known of its efficacy and safety. OBJECTIVES: To summarize our multi-center experience in treating children with recalcitrant CSU with omalizumab. METHODS: A retrospective multi-center case series conducted in 5 tertiary care centers in Israel. Patients included were children <18 years old diagnosed with recalcitrant CSU who were treated with omalizumab. Patients were followed up throughout the duration of omalizumab therapy/symptom remission. Patients' electronic medical records were used to gather data. RESULTS: Nineteen participants (11 F; 8 M) presented with CSU between ages 6 and 16.9 years. Sixteen (84%) responded to omalizumab, including children <12 years old, although two became non-responsive after 6-12 months of therapy. Another three patients (16%) were resistant to treatment, achieving remission through fourth-line (Cyclosporine A) or other therapies. CONCLUSION: Children with recalcitrant CSU, even those <12 years old, respond well to standard-dose, third-line omalizumab therapy at rates similar to adults. Yet, some cases may become non-responsive with ongoing treatment.


Asunto(s)
Antialérgicos , Urticaria Crónica , Urticaria , Adolescente , Adulto , Antialérgicos/uso terapéutico , Niño , Enfermedad Crónica , Humanos , Israel , Omalizumab/uso terapéutico , Calidad de Vida , Estudios Retrospectivos , Resultado del Tratamiento , Urticaria/tratamiento farmacológico
14.
Front Immunol ; 11: 614086, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33519822

RESUMEN

In the last few months the world has witnessed a global pandemic due to severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection causing coronavirus disease 2019 (COVID-19). Obviously, this pandemic affected individuals differently, with a significant impact on populations considered to be at high-risk. One such population, was assumed to be patients with primary genetic defect involving components or pathways of the immune system. While human immunity against COVID-19 is not fully understood, it is, so far, well documented, that both adaptive and innate cells have a critical role in protection against SARS-CoV-2. Here, we aimed to summarize the clinical and laboratory data on primary immunodeficiency (PID) patients in Israel, who were tested positive for SARS-CoV-2, in order to estimate the impact of COVID-19 on such patients. Data was collected from mid-February to end-September. During this time Israel experienced two "waves" of COVID-19 diseases; the first, from mid-February to mid-May and the second from mid-June and still ongoing at the end of data collection. A total of 20 PID patients, aged 4 months to 60 years, were tested positive for SARS-CoV-2, all but one, were detected during the second wave. Fourteen of the patients were on routine monthly IVIG replacement therapy at the time of virus detection. None of the patients displayed severe illness and none required hospitalization; moreover, 7/20 patients were completely asymptomatic. Possible explanations for the minimal clinical impact of COVID-19 pandemic observed in our PID patients include high level of awareness, extra-precautions, and even self-isolation. It is also possible that only specific immune pathways (e.g. type I interferon signaling), may increase the risk for a more severe course of disease and these are not affected in many of the PID patients. In some cases, lack of an immune response actually may be a protective measure against the development of COVID-19 sequelae.


Asunto(s)
COVID-19/complicaciones , COVID-19/epidemiología , Enfermedades de Inmunodeficiencia Primaria/complicaciones , Enfermedades de Inmunodeficiencia Primaria/epidemiología , SARS-CoV-2 , Adolescente , Adulto , Niño , Preescolar , Femenino , Evaluación del Impacto en la Salud , Humanos , Lactante , Israel/epidemiología , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Adulto Joven
15.
J Clin Immunol ; 40(1): 211-222, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31838659

RESUMEN

INTRODUCTION: Severe combined immunodeficiency (SCID) is a fatal disorder resulting from various genetic defects. In the Middle East, where consanguineous marriage is prevalent, autosomal recessive mutations in recombination-activating genes (RAG) are a leading cause of SCID. We present a large cohort of SCID patients due to RAG1 or RAG2 mutations. METHODS: Twenty-six patients with RAG1 or RAG2 deficiency, diagnosed at Sheba Medical Center, were retrospectively investigated. Clinical presentation, immunologic phenotype, genetic analysis, treatment, and outcome were analyzed. RESULTS: Majority of patients were referred from the Palestinian Authority. Most patients were males of Muslim Arab descent, 77% were born to consanguineous parents, and 65% had family history of immunodeficiency. Nearly all patients suffered from various infections before turning 2 months old, eight patients (31%) presented with Omenn and Omenn-like syndrome, and three patients (11%) had maternal engraftment. Notably, seven patients (27%) suffered from vaccine-derived infections, including a rare case of measles encephalitis. Nineteen patients underwent hematopoietic stem cell transplantation (HSCT) at a median age of 6 months, with a successful outcome for 72% of them. Genetic analysis revealed 11 different mutations (7 RAG2, 4 RAG1), two of them novel. CONCLUSIONS: Consanguineous marriages account for a genetic "founder effect." SCID is a pediatric emergency that dictates immediate precautions and curative treatment with HSCT. Due to lack of newborn screening for SCID within the Palestinian population, most patients in this cohort were diagnosed upon clinical symptoms, which led to a delayed diagnosis, harmful administration of contra-indicated live vaccines, delay in HSCT, and poor outcome.


Asunto(s)
Proteínas de Unión al ADN/genética , Proteínas de Homeodominio/genética , Proteínas Nucleares/genética , Inmunodeficiencia Combinada Grave/genética , Consanguinidad , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Humanos , Lactante , Recién Nacido , Masculino , Mutación/genética , Fenotipo , Pronóstico , Estudios Retrospectivos
16.
J Allergy Clin Immunol ; 144(3): 825-838, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30926529

RESUMEN

BACKGROUND: Thrombocytopenia is a serious issue for all patients with classical Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT) because it causes severe and life-threatening bleeding. Lentiviral gene therapy (GT) for WAS has shown promising results in terms of immune reconstitution. However, despite the reduced severity and frequency of bleeding events, platelet counts remain low in GT-treated patients. OBJECTIVE: We carefully investigated platelet defects in terms of phenotype and function in untreated patients with WAS and assessed the effect of GT treatment on platelet dysfunction. METHODS: We analyzed a cohort of 20 patients with WAS/XLT, 15 of them receiving GT. Platelet phenotype and function were analyzed by using electron microscopy, flow cytometry, and an aggregation assay. Platelet protein composition was assessed before and after GT by means of proteomic profile analysis. RESULTS: We show that platelets from untreated patients with WAS have reduced size, abnormal ultrastructure, and a hyperactivated phenotype at steady state, whereas activation and aggregation responses to agonists are decreased. GT restores platelet size and function early after treatment and reduces the hyperactivated phenotype proportionally to WAS protein expression and length of follow-up. CONCLUSIONS: Our study highlights the coexistence of morphologic and multiple functional defects in platelets lacking WAS protein and demonstrates that GT normalizes the platelet proteomic profile with consequent restoration of platelet ultrastructure and phenotype, which might explain the observed reduction of bleeding episodes after GT. These results are instrumental also from the perspective of a future clinical trial in patients with XLT only presenting with microthrombocytopenia.


Asunto(s)
Plaquetas/fisiología , Terapia Genética , Lentivirus/genética , Síndrome de Wiskott-Aldrich/sangre , Síndrome de Wiskott-Aldrich/terapia , Adolescente , Adulto , Plaquetas/ultraestructura , Niño , Preescolar , Femenino , Trasplante de Células Madre Hematopoyéticas , Humanos , Lactante , Masculino , Microscopía Electrónica de Transmisión , Fenotipo , Activación Plaquetaria , Recuento de Plaquetas , Proteína del Síndrome de Wiskott-Aldrich/metabolismo
17.
Blood ; 132(22): 2362-2374, 2018 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-30254128

RESUMEN

ARPC1B is a key factor for the assembly and maintenance of the ARP2/3 complex that is involved in actin branching from an existing filament. Germline biallelic mutations in ARPC1B have been recently described in 6 patients with clinical features of combined immunodeficiency (CID), whose neutrophils and platelets but not T lymphocytes were studied. We hypothesized that ARPC1B deficiency may also lead to cytoskeleton and functional defects in T cells. We have identified biallelic mutations in ARPC1B in 6 unrelated patients with early onset disease characterized by severe infections, autoimmune manifestations, and thrombocytopenia. Immunological features included T-cell lymphopenia, low numbers of naïve T cells, and hyper-immunoglobulin E. Alteration in ARPC1B protein structure led to absent/low expression by flow cytometry and confocal microscopy. This molecular defect was associated with the inability of patient-derived T cells to extend an actin-rich lamellipodia upon T-cell receptor (TCR) stimulation and to assemble an immunological synapse. ARPC1B-deficient T cells additionally displayed impaired TCR-mediated proliferation and SDF1-α-directed migration. Gene transfer of ARPC1B in patients' T cells using a lentiviral vector restored both ARPC1B expression and T-cell proliferation in vitro. In 2 of the patients, in vivo somatic reversion restored ARPC1B expression in a fraction of lymphocytes and was associated with a skewed TCR repertoire. In 1 revertant patient, memory CD8+ T cells expressing normal levels of ARPC1B displayed improved T-cell migration. Inherited ARPC1B deficiency therefore alters T-cell cytoskeletal dynamics and functions, contributing to the clinical features of CID.


Asunto(s)
Complejo 2-3 Proteico Relacionado con la Actina/genética , Mutación de Línea Germinal , Síndromes de Inmunodeficiencia/genética , Linfocitos T/patología , Complejo 2-3 Proteico Relacionado con la Actina/química , Femenino , Homocigoto , Humanos , Síndromes de Inmunodeficiencia/patología , Masculino , Modelos Moleculares , Linaje , Conformación Proteica , Inmunodeficiencia Combinada Grave/genética , Inmunodeficiencia Combinada Grave/patología , Linfocitos T/metabolismo
18.
Immunol Res ; 66(4): 537-542, 2018 08.
Artículo en Inglés | MEDLINE | ID: mdl-30084052

RESUMEN

Newborn screening (NBS) programs for severe combined immunodeficiency (SCID), using the TREC-based assay, have enabled early diagnosis, prompt treatment, and eventually changed the natural history of affected infants. Nevertheless, it was believed that some affected infants with residual T cell, such as patients with MHC II deficiency, will be misdiagnosed by this assay. A full immune workup and genetic analysis using direct Sanger sequencing and whole exome sequencing have been performed to a patient that was identified by the Israeli NBS program for SCID. The patient was found to have severe CD4 lymphopenia with an inverted CD4/CD8 ratio, low TREC levels in peripheral blood, abnormal response to mitogen stimulation, and a skewed T cell receptor repertoire. HLA-DR expression on peripheral blood lymphocytes was undetectable suggesting a diagnosis of MHC II deficiency. Direct sequencing of the RFX5 gene revealed a stop codon change (p. R239X, c. C715T), which could cause the patient's immune phenotype. His parents were found to be heterozygote carriers for the mutation. Whole exome sequencing could not identify other potential mutations to explain his immunodeficiency. The patient underwent successful conditioned hematopoietic stem cell transplantation from healthy matched unrelated donor and is currently well and alive with full chimerism. Infants with MHC class II deficiency can potentially be identified by the TREC-based assay NBS for SCID. Therefore, MHC II molecules (e.g., HLA-DR) measurement should be part of the confirmatory immune-phenotyping for patients with positive screening results. This will make the diagnosis of such patients straightforward.


Asunto(s)
Linfocitos T CD4-Positivos/fisiología , Antígenos HLA-DR/genética , Mutación/genética , Factores de Transcripción del Factor Regulador X/genética , Inmunodeficiencia Combinada Grave/diagnóstico , Quimerismo , Consanguinidad , Análisis Mutacional de ADN , Trasplante de Células Madre Hematopoyéticas , Humanos , Recién Nacido , Israel , Linfopenia , Masculino , Tamizaje Neonatal , Receptores de Antígenos de Linfocitos T/genética , Inmunodeficiencia Combinada Grave/genética , Inmunodeficiencia Combinada Grave/terapia , Secuenciación del Exoma
19.
J Pediatr ; 196: 154-160.e2, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29395171

RESUMEN

OBJECTIVES: To describe the prevalence, natural course, outcome, and risk factors of post-transplant de novo allergy and autoimmunity. STUDY DESIGN: A cross-sectional, cohort study of all children (<18 years) who underwent a solid-organ transplantation, between 2000 and 2012, in a single transplant center, with a follow-up period of 6 months or more post-transplant and without history of allergy or immune-mediated disorder pretransplant. RESULTS: A total of 626 eligible patients were screened, and 273 patients (160 males; 59%) met the inclusion criteria; this included 111 liver, 103 heart, 52 kidney, and 7 multivisceral recipients. Patients were followed for a median period of 3.6 years. A total of 92 (34%) patients (42 males, 46%) developed allergy or autoimmune disease after transplantation, with a high prevalence among liver (41%), heart (40%), and multivisceral (57%) transplant recipients compared with kidney recipients (4%; P < .001). Post-transplant allergies included eczema (n = 44), food allergy (22), eosinophilic gastrointestinal disease (11), and asthma (28). Autoimmunity occurred in 18 (6.6%) patients, presenting mainly as autoimmune cytopenia (n = 10). In a multivariate analysis, female sex, young age at transplantation, family history of allergy, Epstein-Barr virus infection, and elevated eosinophil count >6 months post-transplantation were associated with an increased risk for allergy or autoimmunity. Two patients (0.7%) died from autoimmune hemolytic anemia and hemophagocytic lymphohistiocytosis, and 52 episodes of post-transplant allergy, autoimmunity, and immune-mediated disorders (37%) did not improve over time. CONCLUSIONS: Allergy and autoimmunity are common in pediatric liver, heart, and multivisceral transplant recipients and pose a significant health burden. Further studies are required to clarify the mechanisms behind this post-transplant immune dysregulation.


Asunto(s)
Enfermedades Autoinmunes/etiología , Hipersensibilidad/etiología , Enfermedades del Sistema Inmune/etiología , Trasplante de Órganos/efectos adversos , Adolescente , Niño , Preescolar , Estudios Transversales , Infecciones por Virus de Epstein-Barr/complicaciones , Femenino , Estudios de Seguimiento , Hipersensibilidad a los Alimentos/complicaciones , Humanos , Sistema Inmunológico , Lactante , Masculino , Complicaciones Posoperatorias , Prevalencia , Estudios Retrospectivos , Factores de Riesgo , Resultado del Tratamiento
20.
J Allergy Clin Immunol Pract ; 6(4): 1238-1242, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29198698

RESUMEN

BACKGROUND: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a rare, potentially life-threatening delayed drug-induced hypersensitivity reaction. The most frequently reported drugs causing DRESS are aromatic antiepileptic agents. Prompt withdrawal of the offending drug and administering systemic corticosteroids is the most widely accepted and used treatment. The treatment of severe DRESS not responsive to systemic corticosteroids is uncertain. OBJECTIVE: The objective of this study was to describe a case series of pediatric patients with DRESS who were treated successfully with intravenous immunoglobulins (IVIGs). METHODS: A retrospective review of all children hospitalized in a tertiary care children's hospital with severe DRESS syndrome who received IVIG in addition to offending drug withdrawal and systemic corticosteroids during 1999-2017 is performed. RESULTS: Seven severe DRESS patients (4 males, age: 9.5 ± 5.7 years) are described. The offending drugs were antiepileptics in all but one case. Clinical findings included fever, rash, lymphadenopathy, dyspnea, anasarca, and hepatic involvement. After IVIG treatment (total dosage: 1-2 g/kg), fever resolved within a median time of 1 (range, 0-5) day, rash disappeared after 6.3 ± 1.6 days, and liver enzymes substantially improved after 3.8 ± 1.6 days. Patients were discharged 6.1 ± 2.7 days after IVIG commencement. There was no mortality. CONCLUSION: The addition of IVIG in DRESS syndrome resistant to regular drug withdrawal and systemic corticosteroid therapy may hasten disease recovery.


Asunto(s)
Síndrome de Hipersensibilidad a Medicamentos/tratamiento farmacológico , Inmunoglobulinas Intravenosas/uso terapéutico , Adolescente , Corticoesteroides/uso terapéutico , Antibacterianos/efectos adversos , Anticonvulsivantes/efectos adversos , Niño , Preescolar , Femenino , Humanos , Masculino , Resultado del Tratamiento
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