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1.
Pediatr Rheumatol Online J ; 17(1): 61, 2019 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-31462263

RESUMO

BACKGROUND: Despite the increased use of rituximab in treating pediatric patients with autoimmune diseases in the last decade, there are limited data on rituximab safety in those subjects who have a developing immune system. The objective of this study is to determine the prevalence of hypogammaglobulinemia in children with autoimmune disease receiving rituximab within the first three years of treatment in the pediatric rheumatology clinic at a tertiary care center. METHODS: We conducted a retrospective chart review of 63 pediatric subjects who received rituximab for the treatment of their autoimmune disease. Immunoglobulin gamma (IgG) levels, immunosuppressive medication and the need for immunoglobulin replacement therapy were evaluated. Hypogammaglobulinemia was defined as a serum IgG level less than two standard deviations below the mean for age-matched healthy controls. RESULTS: Twenty-eight patients (44%) were found to have hypogammaglobulinemia. Hypogammaglobulinemia occurred within the first six months of rituximab treatment in the majority of patients (22 out of 28). The occurrence of hypogammaglobulinemia varied based on the rituximab indication: 46% pediatric Systemic Lupus Erythematosus (SLE), 71% autoimmune CNS disease, 60% ANCA vasculitis, and 12% in the miscellaneous group. Autoimmune CNS disease had more severe hypogammaglobulinemia, more persistent and was associated with more frequent or severe infections. Three patients with autoimmune CNS disease and one with SLE were given IgG replacement therapy to prevent recurrent or severe infections. CONCLUSIONS: The prevalence of hypogammaglobulinemia in rituximab treated children with autoimmune disease seems to be higher than published data for adults, especially for children with autoimmune CNS disease. The onset of hypogammaglobulinemia is usually within six months of initiation of rituximab therapy. We recommend: 1) obtaining an IgG level prior to starting rituximab; 2) close monitoring for hypogammaglobulinemia after the use of rituximab in pediatric patients and 3) early institution of immunoglobulin replacement therapy if patients develop recurrent infections.

2.
Arthritis Rheumatol ; 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31403247

RESUMO

OBJECTIVE: Neutrophils are key immune cells participating in host defense through several mechanisms, including the formation of neutrophil extracellular traps (NETs). The role of neutrophils in juvenile dermatomyositis (JDM) is not known. METHODS: Electron microscopy was used to identify neutrophils in tissue. NETs were also imaged using fluorescence microscopy, and quantified by an MPO-DNA ELISA in plasma from healthy children (n=20), disease controls (n=29), JDM patients (n=66), and JDM patients with history of calcifications (n=20). Clinical data included disease activity scores and complement C4 levels. Levels of immune complexes (ICs) and calprotectin were analyzed by ELISA. RESULTS: Using electron microscopy, neutrophils were found to infiltrate affected muscle tissue, engulfing deposited calcium crystals. Uptake of the crystals led to neutrophil activation (p<0.01) and subsequent PI3K- and NADPH oxidase-dependent, but PAD4-independent NET formation, which contained mitochondrial DNA (p<0.05) as confirmed in vivo and in vitro (p<0.001, and p<0.01). Peripheral NET levels were associated with calcinosis (p=0.01), ICs (p=0.008), and IL-8 levels (p=0.004). JDM children had an impaired NET clearance (p=0.01), associated with autoantibody profiles, including MDA-5 (p=0.005), and depressed complement C4 levels (r=-0.72, p=0.002). Further, JDM children had evidence of neutrophil activation, with elevated levels of peroxidase activity (p=0.02) and calprotectin (p<0.01), associated with disease activity (p=0.007), and dyslipidemia (OR 4.7, p<0.05). CONCLUSIONS: Our investigation reports novel mechanisms of both calcium crystal-mediated neutrophil activation and cell death in JDM pathophysiology. Targeting this pathway may reduce the frequency and extent of calcinosis, as well as prevent long-term development of co-morbidities, including atherosclerosis.

3.
Ann Rheum Dis ; 78(7): 996-1002, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31138531

RESUMO

OBJECTIVES: Idiopathic inflammatory myopathies (IIM) are a spectrum of rare autoimmune diseases characterised clinically by muscle weakness and heterogeneous systemic organ involvement. The strongest genetic risk is within the major histocompatibility complex (MHC). Since autoantibody presence defines specific clinical subgroups of IIM, we aimed to correlate serotype and genotype, to identify novel risk variants in the MHC region that co-occur with IIM autoantibodies. METHODS: We collected available autoantibody data in our cohort of 2582 Caucasian patients with IIM. High resolution human leucocyte antigen (HLA) alleles and corresponding amino acid sequences were imputed using SNP2HLA from existing genotyping data and tested for association with 12 autoantibody subgroups. RESULTS: We report associations with eight autoantibodies reaching our study-wide significance level of p<2.9×10-5. Associations with the 8.1 ancestral haplotype were found with anti-Jo-1 (HLA-B*08:01, p=2.28×10-53 and HLA-DRB1*03:01, p=3.25×10-9), anti-PM/Scl (HLA-DQB1*02:01, p=1.47×10-26) and anti-cN1A autoantibodies (HLA-DRB1*03:01, p=1.40×10-11). Associations independent of this haplotype were found with anti-Mi-2 (HLA-DRB1*07:01, p=4.92×10-13) and anti-HMGCR autoantibodies (HLA-DRB1*11, p=5.09×10-6). Amino acid positions may be more strongly associated than classical HLA associations; for example with anti-Jo-1 autoantibodies and position 74 of HLA-DRB1 (p=3.47×10-64) and position 9 of HLA-B (p=7.03×10-11). We report novel genetic associations with HLA-DQB1 anti-TIF1 autoantibodies and identify haplotypes that may differ between adult-onset and juvenile-onset patients with these autoantibodies. CONCLUSIONS: These findings provide new insights regarding the functional consequences of genetic polymorphisms within the MHC. As autoantibodies in IIM correlate with specific clinical features of disease, understanding genetic risk underlying development of autoantibody profiles has implications for future research.

4.
JCI Insight ; 3(22)2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30429375

RESUMO

Juvenile dermatomyositis (JDM) is a debilitating pediatric autoimmune disease manifesting with characteristic rash and muscle weakness. To delineate signaling abnormalities in JDM, mass cytometry was performed with PBMCs from treatment-naive JDM patients and controls. NK cell percentages were lower while frequencies of naive B cells and naive CD4+ T cells were higher in JDM patients than in controls. These cell frequency differences were attenuated with cessation of active disease. A large number of signaling differences were identified in treatment-naive JDM patients compared with controls. Classification models incorporating feature selection demonstrated that differences in phospholipase Cγ2 (PLCγ2) phosphorylation comprised 10 of 12 features (i.e., phosphoprotein in a specific immune cell subset) distinguishing the 2 groups. Because NK cells represented 5 of these 12 features, further studies focused on the PLCγ2 pathway in NK cells, which is responsible for stimulating calcium flux and cytotoxic granule movement. No differences were detected in upstream signaling or total PLCγ2 protein levels. Hypophosphorylation of PLCγ2 and downstream mitogen-activated protein kinase-activated protein kinase 2 were partially attenuated with cessation of active disease. PLCγ2 hypophosphorylation in treatment-naive JDM patients resulted in decreased calcium flux. The identification of dysregulation of PLCγ2 phosphorylation and decreased calcium flux in NK cells provides potential mechanistic insight into JDM pathogenesis.

5.
Steroids ; 140: 159-166, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30352204

RESUMO

Glucocorticoids are standard of care for many chronic inflammatory conditions, including juvenile dermatomyositis (JDM) and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We sought to define pharmacodynamic biomarkers of therapeutic efficacy and safety concerns of glucocorticoid treatment for these two disorders. Previous proteomic profiling of patients with Duchenne muscular dystrophy (DMD) and inflammatory bowel disease (IBD) treated with glucocorticoids identified candidate biomarkers for efficacy and safety concerns of glucocorticoids. Serial serum samples from patients with AAV (n = 30) and JDM (n = 12) were obtained during active disease, and after treatment with glucocorticoids. For AAV, 8 of 11 biomarkers of the anti-inflammatory response to glucocorticoids were validated (P-value ≤0.05; CD23, macrophage-derived cytokine, interleukin-22 binding protein, matrix metalloproteinase-12, T lymphocyte surface antigen Ly9, fibrinogen gamma chain, angiopoietin-2 [all decreased], and protein C [increased]), as were 5 of 7 safety biomarkers (P-value ≤0.05; afamin, matrix metalloproteinase-3, insulin growth factor binding protein-5, angiotensinogen, leptin [all increased]). For JDM, 10 of 11 efficacy biomarkers were validated (P-value ≤0.05; all proteins except fibrinogen gamma chain) and 6 of 7 safety biomarkers (P-value ≤0.05; AAV proteins plus growth hormone binding protein). The identified efficacy biomarkers may be useful as objective outcome measures for early phase proof-of-concept studies when assessing novel anti-inflammatory drugs in JDM and AAV, and likely in other inflammatory disorders. Similarly, safety biomarkers may also be helpful assessing toxicity of alternatives to glucocorticoids.

7.
Ann Rheum Dis ; 77(2): 241-250, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29084729

RESUMO

OBJECTIVES: This study aimed to develop consensus on an internationally agreed dataset for juvenile dermatomyositis (JDM), designed for clinical use, to enhance collaborative research and allow integration of data between centres. METHODS: A prototype dataset was developed through a formal process that included analysing items within existing databases of patients with idiopathic inflammatory myopathies. This template was used to aid a structured multistage consensus process. Exploiting Delphi methodology, two web-based questionnaires were distributed to healthcare professionals caring for patients with JDM identified through email distribution lists of international paediatric rheumatology and myositis research groups. A separate questionnaire was sent to parents of children with JDM and patients with JDM, identified through established research networks and patient support groups. The results of these parallel processes informed a face-to-face nominal group consensus meeting of international myositis experts, tasked with defining the content of the dataset. This developed dataset was tested in routine clinical practice before review and finalisation. RESULTS: A dataset containing 123 items was formulated with an accompanying glossary. Demographic and diagnostic data are contained within form A collected at baseline visit only, disease activity measures are included within form B collected at every visit and disease damage items within form C collected at baseline and annual visits thereafter. CONCLUSIONS: Through a robust international process, a consensus dataset for JDM has been formulated that can capture disease activity and damage over time. This dataset can be incorporated into national and international collaborative efforts, including existing clinical research databases.

8.
RMD Open ; 3(1): e000385, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28955482

RESUMO

The study aimed to document the utility of the absolute number of natural killer cells as a biomarker in paediatric orbital myositis (OM). Extracted data from four children with OM included demographics, laboratory values, imaging and treatment response. Stored sera (-80°C) were tested for IgG4 levels in three cases and antibody to Coxsackie B in two cases. Their first symptom was at 14.4±1.2 years (mean±SD). At diagnosis three had creatine phosphokinase (CPK) of 97.3±44.2, aldolase of 8.5±2.8 (n=2), alanine aminotransferase (ALT) of 13±2.8 (n=2) and aspartate aminotransferase (AST) of 21.3±2.9. IG4 level was 87.7±66 (normal=8-89 mg/dL); two sera (patients 1and4) were positive (>1:8 dilution) for anti-Coxsackievirus antigen B5. The CD3-CD16+CD56+ natural killer absolute count was 96.7±28.7 (lower limit of normal=138), increasing to 163±57.2 with disease resolution in three patients. The fourth patient was followed elsewhere. CT showed involvement of bilateral superior oblique, lateral rectus or the left medial rectus muscles. Treatment included intravenous methylprednisolone, methotrexate (n=2) and other immunosuppressants. Paediatric OM disease activity was associated with initially low absolute CD3-CD16+CD56+ natural killer cell counts, which normalised with improvement. We speculate (1) infection, such as Coxsackie B virus, may be associated with paediatric OM; and (2) the absolute count of circulating CD3-CD16+CD56+ natural killer lymphocytes may serve as a biomarker to guide medical therapy.

9.
Pediatr Rheumatol Online J ; 15(1): 42, 2017 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-28514969

RESUMO

OBJECTIVE: A pilot study to determine endothelial progenitor cells (EPC) number in children with Juvenile Dermatomyositis (JDM). METHODS: After obtaining informed consent, the EPC number from 34 fasting children with definite/probable JDM at various stages of therapy-initially untreated, active disease on medication and clinically inactive, off medication-was compared with 13 healthy fasting pediatric controls. The EPC number was determined by fluorescence activated cell sorting (FACS), CD34+/VEGFR2+/CD45dim-, and assessed in conjunction with clinical variables: disease activity scores (DAS), duration of untreated disease (DUD), TNF-α allelic polymorphism (A/G) at the promoter region of -308, number of nailfold capillary end row loop (ERL) and von Willebrand factor antigen (vWF:Ag). Correlations of the EPC numbers with the clinical and demographic variables, including DAS Skin (DAS SK), DAS Weakness (DAS WK), DAS Total Score, DUD, Cholesterol, triglycerides, High-Density Lipoprotein (HDL) and Low-Density Lipoprotein (LDL), and ERL were calculated using the Pearson correlation coefficient. Tests of associations of EPC with gender (boy vs girl), TNF-α-308A allele (GA/AA vs GG), vWF:Ag (categorized by specific ABO type) as normal/abnormal were performed, using two-sample T- tests. RESULTS: The EPC number for JDM was not significantly different from the healthy controls and was not associated with any of the clinical or cardiovascular risk factors tested. CONCLUSION: The EPC for JDM were in the normal range, similar to adults with DM. These data support the concept that the normal EPC numbers in DM/JDM, irrespective of age, differs from adult PM, where they are decreased, perhaps reflecting a different pathophysiology.


Assuntos
Contagem de Células , Dermatomiosite/sangue , Células Progenitoras Endoteliais/citologia , Adolescente , Estudos de Casos e Controles , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Lactente , Masculino , Projetos Piloto
10.
Rheumatology (Oxford) ; 56(8): 1342-1347, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28444299

RESUMO

Objective: The aim was to assess environmental factors associated with disease flare in juvenile and adult dermatomyositis (DM). Methods: An online survey of DM patients from the USA and Canada examined smoking, sun exposure, infections, medications, vaccines, stressful life events and physical activity during the 6 months before flares, or in the past 6 months in patients without flares. Differences were evaluated by χ 2 and Fisher's exact tests, and significant univariable results were examined in multivariable logistic regression. Residential locations before flare were correlated with the National Weather Service UV index. Results: Of 210 participants (164 juvenile and 46 adult DM), 134 (63.8%) experienced a disease flare within 2 years of the survey. Subjects more often reported disease flare after sun exposure [odds ratio (OR) = 2.0, P = 0.03], although use of photoprotective measures did not differ between those with and without flare. Urinary tract infections (OR = 16.4, P = 0.005) and gastroenteritis (OR = 3.2, P = 0.04) were more frequent in the preceding 6 months in those who flared. Subjects who flared recently used NSAIDS (OR = 3.0, P = 0.0003), blood pressure medicines (OR = 3.5, P = 0.049) or medication for depression or mood changes (OR = 12.9, P = 0.015). Moving to a new house (OR = 10.3, P = 0.053) was more common in those who flared. Only sun exposure (OR = 2.2) and NSAIDs (OR = 1.9) were significant factors in multivariable analysis. Conclusion: Certain classes of environmental agents that have been associated with the initiation of DM, including sun exposure and medications, may also play a role in disease flares.


Assuntos
Dermatomiosite/patologia , Progressão da Doença , Acontecimentos que Mudam a Vida , Luz Solar/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/efeitos adversos , Anti-Hipertensivos/efeitos adversos , Canadá , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Dermatomiosite/complicações , Feminino , Gastroenterite/etiologia , Humanos , Lactente , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Razão de Chances , Psicotrópicos/efeitos adversos , Inquéritos e Questionários , Estados Unidos , Infecções Urinárias/etiologia , Adulto Jovem
11.
Pediatr Rheumatol Online J ; 14(1): 64, 2016 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-27894310

RESUMO

BACKGROUND: Dystrophic calcifications may occur in patients with J uvenile Idiopathic Inflammatory Myopathy (JIIM) as well as other connective tissue and metabolic diseases, but a reliable method of measuring the volume of these calcifications has not been established. The purpose of this study is to determine the feasibility of low dose, limited slice, Computed Tomography (CT) to measure objectively in-situ calcification volumes in patients with JIIM over time. METHODS: Ten JIIM patients (eight JDM, two Overlap) with calcifications were prospectively recruited over a 2-year period to undergo two limited, low dose, four-slice CT scans. Calculation of the volume of calcifications used a CT post processing workstation. Additional patient data included: Disease Activity Scores (DAS), Childhood Myositis Assessment Scale (CMAS), myositis specific antibodies (MSA), and the TNFα-308 promoter region A/G polymorphism. Statistical analysis utilized the Pearson correlation coefficient, the paired t-test and descriptive statistics. RESULTS: Ten JIIM, mean age 14.54 ± 4.54 years, had a duration of untreated disease of 8.68 ± 5.65 months  MSA status: U1RNP (1), PM-Scl (1), Ro (1, 4 indeterminate), p155/140 (2), MJ (3), Mi-2 indeterminate (1), negative (3). 4/8 JDM (50%) were TNF-α-308 A+. Overall, the calcification volumes tended to decrease from the first to the second CT study by 0.5 cm3 (from 2.79 ± 1.98 cm3 to 2.29 ± 2.25 cm3). The average effective radiation dose was 0.007 ± 0.002, 0.010 ± 0.005, and 0.245 mSv for the upper extremity, lower extremity and chest, respectively (compared to a standard chest x-ray-- 0.02mSV effective dosage). CONCLUSION: We conclude: 1) the limited low dose CT technique provides objective data about volume of the calcifications in JIIM; 2) measuring the volume of calcifications in an extremity is associated with minimal radiation exposure; 3) This method may be useful to evaluate the efficacy of therapies for JIIM dystrophic calcification.


Assuntos
Calcinose/diagnóstico por imagem , Miosite/diagnóstico por imagem , Adolescente , Calcinose/patologia , Criança , Estudos de Viabilidade , Feminino , Humanos , Masculino , Miosite/patologia , Projetos Piloto , Doses de Radiação , Tomografia Computadorizada por Raios X/métodos , Adulto Jovem
12.
Ann Rheum Dis ; 75(8): 1558-66, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26362759

RESUMO

OBJECTIVES: The idiopathic inflammatory myopathies (IIMs) are a heterogeneous group of rare autoimmune diseases characterised by muscle weakness and extramuscular manifestations such as skin rashes and interstitial lung disease. We genotyped 2566 IIM cases of Caucasian descent using the Immunochip; a custom array covering 186 established autoimmune susceptibility loci. The cohort was predominantly comprised of patients with dermatomyositis (DM, n=879), juvenile DM (JDM, n=481), polymyositis (PM, n=931) and inclusion body myositis (n=252) collected from 14 countries through the Myositis Genetics Consortium. RESULTS: The human leucocyte antigen (HLA) and PTPN22 regions reached genome-wide significance (p<5×10(-8)). Nine regions were associated at a significance level of p<2.25×10(-5), including UBE2L3, CD28 and TRAF6, with evidence of independent effects within STAT4. Analysis of clinical subgroups revealed distinct differences between PM, and DM and JDM. PTPN22 was associated at genome-wide significance with PM, but not DM and JDM, suggesting this effect is driven by PM. Additional suggestive associations including IL18R1 and RGS1 in PM and GSDMB in DM were identified. HLA imputation confirmed that alleles HLA-DRB1*03:01 and HLA-B*08:01 of the 8.1 ancestral haplotype (8.1AH) are most strongly associated with IIM, and provides evidence that amino acids within the HLA, such as HLA-DQB1 position 57 in DM, may explain part of the risk in this locus. Associations with alleles outside the 8.1AH reveal differences between PM, DM and JDM. CONCLUSIONS: This work represents the largest IIM genetic study to date, reveals new insights into the genetic architecture of these rare diseases and suggests different predominating pathophysiology in different clinical subgroups.


Assuntos
Antígenos HLA/genética , Miosite/genética , Alelos , Autoimunidade/genética , Estudos de Casos e Controles , Dermatomiosite/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Miosite/imunologia , Polimorfismo de Nucleotídeo Único , Polimiosite/genética , Proteína Tirosina Fosfatase não Receptora Tipo 22/genética , Locos de Características Quantitativas , Fatores de Risco
13.
J Rheumatol ; 43(1): 161-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26628598

RESUMO

OBJECTIVE: To identify differentially expressed microRNA (miRNA) in muscle biopsies (MBx) from 15 untreated children with juvenile dermatomyositis (JDM) compared with 5 controls. METHODS: Following MBx miRNA profiling, differentially expressed miRNA and their protein targets were validated by quantitative real-time PCR (qRT-PCR) and immunological assay. The association of miRNA-10a and miRNA-10b with clinical data was evaluated, including Disease Activity Score (DAS), von Willebrand factor antigen (vWF:Ag), nailfold capillary end row loops, duration of untreated disease, and tumor necrosis factor (TNF)-α-308A allele. RESULTS: In JDM, 16/362 miRNA were significantly differentially expressed [false discovery rate (FDR) < 0.05]. Among these, miRNA-10a was the most downregulated miRNA in both FDR and ranking of fold change: miRNA-10a = -2.27-fold, miRNA-10b = -1.80-fold. Decreased miRNA-10a and miRNA-10b expressions were confirmed using q RT-PCR: -4.16 and -2.59 fold, respectively. The qRT-PCR documented that decreased miRNA-10a expression was related to increased vascular cell adhesion molecule 1 in 13 of these JDM cases (correlation -0.67, p = 0.012), unlike miRNA-10b data (not significant). Concurrent JDM plasma contained increased levels of interleukin (IL) 6 (p = 0.0363), IL-8 (p = 0.0005), TNF-α (p = 0.0011), and monocyte chemoattractant proteins 1 (p = 0.0139). Decreased miRNA-10a, but not miRNA-10b, was associated with the TNF-α-308A allele (p = 0.015). In the 15 JDM, a trend of association of miRNA-10a (but not miRNA-10b) with vWF:Ag and DAS was observed. CONCLUSION: MiRNA-10a downregulation is an important element in untreated JDM muscle pathophysiology. We speculate that muscle miRNA expression in adult dermatomyositis differs from muscle miRNA expression in untreated childhood JDM.


Assuntos
Dermatomiosite/genética , Dermatomiosite/patologia , Regulação da Expressão Gênica/imunologia , Mediadores da Inflamação/metabolismo , MicroRNAs/genética , Biópsia por Agulha , Estudos de Casos e Controles , Criança , Pré-Escolar , Citocinas/metabolismo , Dermatomiosite/terapia , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Humanos , Biópsia Guiada por Imagem , Imuno-Histoquímica , Imagem por Ressonância Magnética/métodos , Masculino , Reação em Cadeia da Polimerase em Tempo Real/métodos , Valores de Referência , Amostragem , Índice de Gravidade de Doença
14.
PLoS One ; 10(3): e0121707, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25826270

RESUMO

There is growing evidence and a consensus in the field that most pediatric brain tumors originate from stem cells, of which radial glial cells constitute a subtype. Here we show that orthotopic transplantation of human radial glial (RG) cells to the subventricular zone of the 3rd ventricle--but not to other transplantation sites--of the brain in immunocompromised NOD-SCID mice, gives rise to tumors that have the hallmarks of CNS primitive neuroectodermal tumors (PNETs). The resulting mouse model strikingly recapitulates the phenotype of PNETs. Importantly, the observed tumorigenic transformation was accompanied by aspects of an epithelial to mesenchymal transition (EMT)-like process. It is also noteworthy that the tumors are highly invasive, and that they effectively recruit mouse endothelial cells for angiogenesis. These results are significant for several reasons. First, they show that malignant transformation of radial glial cells can occur in the absence of specific mutations or inherited genomic alterations. Second, they demonstrate that the same radial glial cells may either give rise to brain tumors or differentiate normally depending upon the microenvironment of the specific region of the brain to which the cells are transplanted. In addition to providing a prospect for drug screening and development of new therapeutic strategies, the resulting mouse model of PNETs offers an unprecedented opportunity to identify the cancer driving molecular alterations and the microenvironmental factors that are responsible for committing otherwise normal radial glial cells to a malignant phenotype.


Assuntos
Transplante de Células , Tumores Neuroectodérmicos Primitivos/patologia , Neuroglia/citologia , Microambiente Tumoral , Animais , Linhagem Celular Tumoral , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID
15.
Arthritis Care Res (Hoboken) ; 66(5): 783-7, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24127327

RESUMO

OBJECTIVE: To evaluate the efficacy of etanercept in patients with juvenile dermatomyositis (DM) refractory to standard treatment. METHODS: Nine patients with juvenile DM prospectively received etanercept 0.4 mg/kg subcutaneous twice weekly concurrently with baseline medications for 12 weeks. Patients were reevaluated 12 weeks (week 24) after stopping etanercept. Outcome measures included a validated Disease Activity Score (DAS), serum muscle enzymes, Childhood Myositis Assessment Scale (CMAS), and nailfold capillaroscopy (NFC). RESULTS: Six patients completed all visits; 2 patients completed through week 12 and 1 patient stopped after the fifth etanercept dose due to marked worsening of a rash. At week 12, 7 patients had a mild decrease in DAS and 1 patient noted worsening of the DAS. At week 24, 1 patient remained stable, 2 patients had worsening of the DAS, and 3 patients had improvement of the DAS (1 patient with inactive disease), including the patient who worsened while receiving etanercept. This patient and the patient who stopped (worsening rash) both had the tumor necrosis factor α (TNFα) 308A allele. There was a trend of worsening NFC at week 12, while at week 24 improvement of NFC was noted. There was no appreciable change in serum muscle enzymes or CMAS throughout the study. CONCLUSION: In this trial of patients with refractory juvenile DM, etanercept did not demonstrate appreciable improvement and some patients noted worsening of disease. Caution should be taken when recommending TNF receptor inhibitors to patients with active symptoms of juvenile DM, and close followup is warranted. Further investigation of the interaction of the TNFα-308A polymorphism and type I interferon is needed to define the mechanism of TNF blockade in juvenile DM.


Assuntos
Dermatomiosite/diagnóstico , Dermatomiosite/tratamento farmacológico , Imunoglobulina G/uso terapêutico , Imunossupressores/uso terapêutico , Receptores do Fator de Necrose Tumoral/uso terapêutico , Adolescente , Adulto , Criança , Etanercepte , Feminino , Humanos , Masculino , Projetos Piloto , Estudos Prospectivos
16.
Arthritis Rheum ; 65(12): 3239-47, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23983088

RESUMO

OBJECTIVE: To identify new genetic associations with juvenile and adult dermatomyositis (DM). METHODS: We performed a genome-wide association study (GWAS) of adult and juvenile DM patients of European ancestry (n = 1,178) and controls (n = 4,724). To assess genetic overlap with other autoimmune disorders, we examined whether 141 single-nucleotide polymorphisms (SNPs) outside the major histocompatibility complex (MHC) locus, and previously associated with autoimmune diseases, predispose to DM. RESULTS: Compared to controls, patients with DM had a strong signal in the MHC region consisting of GWAS-level significance (P < 5 × 10(-8)) at 80 genotyped SNPs. An analysis of 141 non-MHC SNPs previously associated with autoimmune diseases showed that 3 SNPs linked with 3 genes were associated with DM, with a false discovery rate (FDR) of <0.05. These genes were phospholipase C-like 1 (PLCL1; rs6738825, FDR = 0.00089), B lymphoid tyrosine kinase (BLK; rs2736340, FDR = 0.0031), and chemokine (C-C motif) ligand 21 (CCL21; rs951005, FDR = 0.0076). None of these genes was previously reported to be associated with DM. CONCLUSION: Our findings confirm the MHC as the major genetic region associated with DM and indicate that DM shares non-MHC genetic features with other autoimmune diseases, suggesting the presence of additional novel risk loci. This first identification of autoimmune disease genetic predispositions shared with DM may lead to enhanced understanding of pathogenesis and novel diagnostic and therapeutic approaches.


Assuntos
Doenças Autoimunes/genética , Dermatomiosite/genética , Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Grupo com Ancestrais do Continente Europeu/genética , Feminino , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade
17.
Arthritis Rheum ; 65(9): 2424-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23740815

RESUMO

OBJECTIVE: To evaluate serum interferon-α (IFNα) activity in the context of autoantibody profiles in patients with juvenile dermatomyositis (JDM). METHODS: Sera from 36 patients with JDM were analyzed. Autoantibody profiles were determined by probing microarrays, which were fabricated with ∼80 distinct autoantigens, with serum and a Cy3-conjugated secondary antibody. Arrays were scanned and analyzed to determine antigen reactivity. Serum IFNα activity was measured using a functional reporter cell assay. Sera were assayed alone or in combination with cellular material released from necrotic U937 cells to stimulate peripheral blood mononuclear cells from healthy donors in vitro, and IFNα production in culture was measured by a dissociation-enhanced lanthanide fluoroimmunoassay (DELFIA). RESULTS: Reactivity against at least 1 of 41 autoantigens on the microarray, including Ro 52, Ro 60, La, Sm, and RNP, was observed in 75% of the serum samples from patients with JDM. IFNα activity was detected in 7 samples by reporter cell assay. The reporter cell assay showed a significant association of reactivity against Ro, La, Sm, and proliferating cell nuclear antigen with serum IFNα activity (P = 0.005). Significance Analysis of Microarrays (SAM) identified increased reactivity against Sm, RNP, Ro 52, U1-C, and Mi-2 in these sera. Sixteen samples induced IFNα production as measured by DELFIA, and there was a significant association of reactivity against Ro, La, Sm, and RNP with the induction of IFNα by serum and necrotic cell material (P = 0.034). SAM identified increased reactivity against Ro 60 in these sera. CONCLUSION: These data support the hypothesis that nucleic acid-associated autoantibodies, including the Ro/La and Sm/RNP complexes, may stimulate the production of active IFNα in children with JDM.


Assuntos
Autoanticorpos/análise , Autoantígenos/imunologia , Dermatomiosite/imunologia , Interferon-alfa/imunologia , Adolescente , Autoanticorpos/sangue , Autoanticorpos/imunologia , Criança , Dermatomiosite/sangue , Feminino , Humanos , Interferon-alfa/sangue , Masculino , Ribonucleoproteína Nuclear Pequena U1/imunologia , Ribonucleoproteínas/imunologia , Proteínas Centrais de snRNP/imunologia
18.
Arthritis Care Res (Hoboken) ; 65(10): 1697-701, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23666925

RESUMO

OBJECTIVE: To test 4-year-olds, using 14 maneuvers of the Childhood Myositis Assessment Scale (CMAS), comparing healthy children with those with juvenile dermatomyositis (DM). METHODS: Healthy 4-year-olds (n = 28) completed the CMAS. Their scores were compared with children with juvenile DM (n = 18) who had a muscle Disease Activity Score (DAS-M) of 0. RESULTS: The healthy children achieved a mean ± SD CMAS score of 46.6 ± 2.3 (interquartile range 46-47). There were no significant differences between boys and girls, and the scores were not significantly associated with height or weight. The greatest variation involved items that assessed endurance. Item 1, neck raise, yielded a mean ± SD score of 28.2 ± 19.3 seconds, with a mean ± SD CMAS score of 2.5 ± 0.9 (maximum score 5). Item 3, leg lift, yielded a mean ± SD score of 55.5 ± 37.3 seconds, with a mean ± SD CMAS score of 3.1 ± 1.1 (maximum score 5). Item 5, sit-ups maneuver, yielded a mean ± SD score of 5.3 ± 1.1 sit-ups. Almost identical data were obtained for the 18 treated children with juvenile DM who had normal strength on the DAS-M. CONCLUSION: Healthy children ages 4 years do not achieve the total CMAS score of 52 attained by older children. Both boys and girls were remarkably consistent, with a mean CMAS score of 46.6. Children ages 4 years with juvenile DM with a DAS-M of 0 also achieved a CMAS score of 46.6. We conclude that half of 4-year-old children achieve a mean CMAS score of 46 or 47, not a total CMAS score of 52, suggesting that weakness may be overdiagnosed in 4-year-olds with an inflammatory myopathy.


Assuntos
Dermatomiosite/diagnóstico , Músculo Esquelético/fisiopatologia , Exame Físico , Fatores Etários , Estudos de Casos e Controles , Pré-Escolar , Dermatomiosite/fisiopatologia , Dermatomiosite/terapia , Feminino , Humanos , Masculino , Força Muscular , Debilidade Muscular , Resistência Física , Projetos Piloto , Valor Preditivo dos Testes , Estudos Prospectivos , Recuperação de Função Fisiológica , Valores de Referência , Reprodutibilidade dos Testes
19.
Arthritis Care Res (Hoboken) ; 65(9): 1424-31, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23568855

RESUMO

OBJECTIVE: To determine the association of decreased lung function in children with idiopathic inflammatory myopathies (IIMs) with specific clinical parameters. METHODS: This study of 38 children ages 6-23 years diagnosed with definite/probable IIM evaluated the association of myositis-specific/-associated antibodies (MSAs/MAAs), duration of untreated disease at diagnosis, Disease Activity Score for muscle (DAS-M), muscle-derived enzymes (aldolase, lactate dehydrogenase [LDH], aspartate transaminase, and creatine phosphokinase [CPK]), neopterin and von Willebrand factor antigen, and the Childhood Myositis Assessment Scale (CMAS) scores with data from pulmonary function testing (PFT). RESULTS: Impaired PFTs were defined as total lung capacity (TLC) or diffusing capacity for carbon monoxide (DLCO) of <80% predicted. The PFTs documented that 37% of the children (14 of 38) had either decreased TLC or decreased DLCO; 5% (2 of 38) had both. Children with decreased TLC alone (7 [18%] of 38) were older both at the time of PFT and diagnosis, had anti-Jo-1 and anti-Scl-70 antibody, and had elevated levels of CPK and neopterin. Children with decreased DLCO alone (5 [13%] of 38) had a shorter duration of untreated disease at diagnosis, had higher DAS-M and total DAS, were positive for anti-Ro and anti-PL-12, had increased LDH, and had elevated levels of neopterin and aldolase, with low CMAS scores for items 1, 3, 10, 11, and 14. CONCLUSION: Assessment of PFTs in children with IIMs should be considered, since more than one-third of patients were found to be impaired. The presence of MSAs/MAAs, an elevated serum neopterin level (mean ± SD 12.4 ± 9.6 nmoles/liter, normal value <10.5), older age at diagnosis, and shorter duration of untreated disease at diagnosis suggest the presence of potential lung pathology.


Assuntos
Miosite/patologia , Miosite/fisiopatologia , Testes de Função Respiratória/métodos , Adolescente , Criança , Estudos Transversais , Feminino , Humanos , Masculino , Miosite/epidemiologia , Testes de Função Respiratória/normas , Estudos Retrospectivos , Capacidade Pulmonar Total/fisiologia , Adulto Jovem
20.
Arthritis Rheum ; 64(10): 3478-85, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22674142

RESUMO

OBJECTIVE: To determine the effect of methylation alteration in inflamed muscles from children with juvenile dermatomyositis (DM) and other idiopathic inflammatory myopathies (IIMs). METHODS: Magnetic resonance imaging-directed diagnostic muscle biopsies yielded samples from 20 children with juvenile DM, which were used for genome-wide DNA methylation profiling, as were muscle biopsy samples from 4 healthy controls. Bisulfite treatment followed by pyrosequencing confirmed methylation status in juvenile DM and other IIMs. Immunohistochemistry defined localization and expression levels of WT1. RESULTS: Comparison of genome-wide DNA methylation profiling between juvenile DM muscle and normal control muscle revealed 27 genes with a significant methylation difference between the groups. These genes were enriched with transcription factors and/or cell cycle regulators and were unrelated to duration of untreated disease. Six homeobox genes were among them; ALX4, HOXC11, HOXD3, and HOXD4 were hypomethylated, while EMX2 and HOXB1 were hypermethylated. WT1 was significantly hypomethylated in juvenile DM (Δß = -0.41, P < 0.001). Bisulfite pyrosequencing verification in samples from 56 patients with juvenile DM confirmed the methylation alterations of these genes. Similar methylation alterations were observed in juvenile polymyositis (n = 5) and other IIMs (n = 9). Concordant with the other findings, WT1 protein was increased in juvenile DM muscle, with average positive staining of 11.6%, but was undetectable in normal muscle (P < 0.001). CONCLUSION: These results suggest that affected muscles of children with juvenile DM and IIMs have the capacity to be repaired, and that homeobox and WT1 genes are epigenetically marked to facilitate this repair process, potentially suggesting new avenues of therapeutic intervention.


Assuntos
Dermatomiosite/genética , Genes Homeobox/genética , Músculo Esquelético/metabolismo , Proteínas WT1/genética , Criança , Pré-Escolar , Dermatomiosite/metabolismo , Dermatomiosite/patologia , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Masculino , Metilação , Músculo Esquelético/patologia , Proteínas WT1/metabolismo
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