Publications by authors named "Margarida Guedes"

Background: Systemic autoinflammatory diseases (SAID) are monogenic and polygenic inherited conditions characterized by dysregulation of the innate immune system.

Objective: We aimed to characterize the clinical features of patients with SAID.

Methods: This study was a retrospective chart review on the clinical and genetic features of the pediatric population with SAID observed from 1998 to 2020 in our center.

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Background: Rheumatic diseases are associated with an increase in overall risks of tuberculosis (TB). The aim of this study was to evaluate the frequency of TB and the frequency of latent TB infection (LTBI), in clinical practice, for juvenile idiopathic arthritis (JIA) patients from high and low risk of TB incidence endemic countries.

Methods: This is an international, multicenter, cross-sectional, observational study of data collection from Brazil and Registry of Portugal at REUMA.

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Accumulation of human CD21 B cells in peripheral blood is a hallmark of chronic activation of the adaptive immune system in certain infections and autoimmune disorders. The molecular pathways underpinning the development, function, and fate of these CD21 B cells remain incompletely characterized. Here, combined transcriptomic and chromatin accessibility analyses supported a prominent role for the transcription factor T-bet in the transcriptional regulation of these T-betCD21 B cells.

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. Granulomatosis with polyangiitis (GPA) is a rare disease in pediatric age. We report two cases with distinct presentations.

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Objective: To investigate the relationship between body mass index (BMI) and disease activity in patients with Juvenile Idiopathic Arthritis (JIA).

Methods: Patients with JIA, aged ≤18 years, registered at the Rheumatic Diseases Portuguese Register (Reuma.pt) in Portugal and Brazil were included.

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Zinc is an essential element, a cofactor of many enzymes, and performs catalytic, structural and regulatory functions. Once in the gastrointestinal tract, zinc can interact with food constituents. Phytic acid, the major phosphorus storage in plants, limits zinc availability from animal feeds due to the formation of insoluble complexes with phytates.

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Background: JIA-associated uveitis (JIAU) is a serious, sight-threatening disease with significant long-term complications and risk of blindness, even with improved contemporary treatments. The MIWGUC was set up in order to propose specific JIAU activity and response items and to validate their applicability for clinical outcome studies.

Methods: The group consists of 8 paediatric rheumatologists and 7 ophthalmologists.

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Biallelic loss-of-function (LOF) mutations of the NCF4 gene, encoding the p40phox subunit of the phagocyte NADPH oxidase, have been described in only 1 patient. We report on 24 p40phox-deficient patients from 12 additional families in 8 countries. These patients display 8 different in-frame or out-of-frame mutations of NCF4 that are homozygous in 11 of the families and compound heterozygous in another.

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ANCA-positive systemic vasculitides, rare in paediatric age, present multiorganic involvement. A female teenager presented with a history of subglottic stenosis diagnosed at the age of 12. From the investigation carried out, we highlight hematoproteinuria and negative ANCAs.

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Chronic granulomatous disease (CGD) is a primaryimmunodeficiency disorder that affects the phagocyticcells of the innate immune system. It is characterizedby recurrent or persistent infections with granulomaformation. Lupus-like lesions have been reported incarriers of CGD and less frequently, in patients withCGD.

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Objectives: Assess the effectiveness and safety of biologic therapy as well as predictors of response at 1 year of therapy, retention rate in biologic treatment and predictors of drug discontinuation in JIA patients in the Portuguese register of rheumatic diseases.

Methods: We prospectively collected patient and disease characteristics from patients with JIA who started biological therapy. Adverse events were collected during the follow-up period.

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Pulmonary haemosiderosis is characterised by chronic alveolar haemorrhage, which can lead to serious cardiorespiratory complications. Although considered idiopathic in most patients, there are many possible aetiologies. We present a case of an 18-year-old woman with pulmonary haemosiderosis since 4 years of age, with an inconclusive initial study, who was treated with systemic corticosteroids and hydroxychloroquine until the age of 12 years, and azathioprine since then.

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Aims: Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by mutations in the phagocyte reactive oxygen species (ROS)-producing NOX2 enzyme complex and characterized by recurrent infections associated with hyperinflammatory and autoimmune manifestations. A translational, comparative analysis of CGD patients and the corresponding ROS-deficient Ncf1(m1J) mutated mouse model was performed to reveal the molecular pathways operating in NOX2 complex deficient inflammation.

Results: A prominent type I interferon (IFN) response signature that was accompanied by elevated autoantibody levels was identified in both mice and humans lacking functional NOX2 complex.

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Unlabelled: Kawasaki disease (KD) is an acute, self-limiting, idiopathic form of vasculitis. The preventive effect of early therapy on coronary artery aneurysms, the hallmark of the disease, is well established. The spectrum of complication includes not only cardiac involvement but also central nervous system lesions.

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Autosomal recessive interleukin-1 receptor-associated kinase (IRAK)-4 and myeloid differentiation factor (MyD)88 deficiencies impair Toll-like receptor (TLR)- and interleukin-1 receptor-mediated immunity. We documented the clinical features and outcome of 48 patients with IRAK-4 deficiency and 12 patients with MyD88 deficiency, from 37 kindreds in 15 countries.The clinical features of IRAK-4 and MyD88 deficiency were indistinguishable.

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MyD88 is a key downstream adapter for most Toll-like receptors (TLRs) and interleukin-1 receptors (IL-1Rs). MyD88 deficiency in mice leads to susceptibility to a broad range of pathogens in experimental settings of infection. We describe a distinct situation in a natural setting of human infection.

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The cytokines controlling the development of human interleukin (IL) 17--producing T helper cells in vitro have been difficult to identify. We addressed the question of the development of human IL-17--producing T helper cells in vivo by quantifying the production and secretion of IL-17 by fresh T cells ex vivo, and by T cell blasts expanded in vitro from patients with particular genetic traits affecting transforming growth factor (TGF) beta, IL-1, IL-6, or IL-23 responses. Activating mutations in TGFB1, TGFBR1, and TGFBR2 (Camurati-Engelmann disease and Marfan-like syndromes) and loss-of-function mutations in IRAK4 and MYD88 (Mendelian predisposition to pyogenic bacterial infections) had no detectable impact.

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The authors present the case of a child with severe idiopathic pulmonary hemosiderosis who after having begun treatment with hydroxychloroquine had a significant and lasting improvement. The efficacy of this therapeutic is pointed out. They also report the occurrence of clinical exacerbation, with hemoptysis, after receiving an influenza vaccine.

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Interstitial lung disease includes a group of chronic diseases characterized by alterations in alveolar walls and loss of functional alveolar-capillary units. These are rare diseases in children, mostly with an unknown cause and associated with a high morbidity and mortality due to insufficient therapeutic effectiveness. The authors report a case of a previously healthy 3 years old child who presented with wheezing and severe respiratory insufficiency following a respiratory infection.

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