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Idiopathic inflammatory myopathies; Genome Miopatías inflamatorias idiopáticas; Genoma Miopaties inflamatòries idiopàtiques; Genoma Objective The idiopathic inflammatory myopathies (IIMs) are heterogeneous diseases thought to be initiated by immune activation in genetically predisposed individuals. We imputed variants from the ImmunoChip array using a large reference panel to fine-map associations and identify novel associations in IIM. Methods We analyzed 2,565 Caucasian IIM patient samples collected through the Myositis Genetics Consortium (MYOGEN) and 10,260 ethnically matched control samples. We imputed 1,648,116 variants from the ImmunoChip array using the Haplotype Reference Consortium panel and conducted association analysis on IIM and clinical and serologic subgroups. Results The HLA locus was consistently the most significantly associated region. Four non-HLA regions reached genome-wide significance, SDK2 and LINC00924 (both novel) and STAT4 in the whole IIM cohort, with evidence of independent variants in STAT4, and NAB1 in the polymyositis (PM) subgroup. We also found suggestive evidence of association with loci previously associated with other autoimmune rheumatic diseases (TEC and LTBR). We identified more significant associations than those previously reported in IIM for STAT4 and DGKQ in the total cohort, for NAB1 and FAM167A-BLK loci in PM, and for CCR5 in inclusion body myositis. We found enrichment of variants among DNase I hypersensitivity sites and histone marks associated with active transcription within blood cells. Conclusion We found novel and strong associations in IIM and PM and localized signals to single genes and immune cell types. Supported by the Intramural Research Program, National Institute of Environmental Health Sciences, NIH. Dr. Lundberg's work was supported by grants from the Swedish Research Council and Stockholm Regional Council (ALF). Dr. Vencovsky's work was supported by the Czech Ministry of Health–Conceptual Development of Research Organization (award 00023728) (Institute of Rheumatology). Drs. Hanna and Machado's work were supported by the NIHR University College London Hospitals Biomedical Research Centre. Drs. De Bleecker and De Paepe's work were supported by the European Reference Network for Rare Neuromuscular Diseases (ERN EURO-NMD). Dr. Wedderburn's work was supported by Versus Arthritis (awards 21593 and 21552), the Wellcome trust (award 085860), Myositis UK, the Cure JM Foundation, the Remission Charity, and the NIHR Biomedical research Centre at GOSH. Dr. Chinoy's work was supported by the Medical Research Council UK (award MR/N003322/1), Myositis UK, and the NIHR Manchester Biomedical Research Centre Funding Scheme. Dr. Lamb's work was supported by the Medical Research Council UK (award MR/N003322/1) and Myositis UK.

Aim Juvenile idiopathic inflammatory myopathies have been recently reclassified into clinico‐serological subgroups. Myopathological correlates of the subgroups are incompletely understood. Methods We studied muscle biopsies from 101 children with clinically and serologically defined juvenile idiopathic inflammatory myopathies from the UK JDM Cohort and Biomarker Study by applying the international JDM score tool, myopathological review and C5b‐9 complement analysis. Results Autoantibody data were available for 90/101 cases with 18/90 cases positive for anti‐TIF1γ, 15/90 anti‐NXP2, 11/90 anti‐MDA5, 5/90 anti‐Mi2 and 6/90 anti‐PmScl. JDM biopsy severity scores were consistently low in the anti‐MDA5 group, high in the anti‐Mi2 group, and widely distributed in the other groups. Biopsies were classified histologically as perifascicular atrophy (22/101), macrophage‐rich necrosis (6/101), scattered necrosis (2/101), clustered necrosis (2/101), inflammatory fibre invasion (2/101), chronic myopathic change (1/101), diffuse endomysial macrophage infiltrates (40/101) and minimal change (24/101). MDA5 cases segregated with the minimal change group and showed no capillary C5b‐9‐deposition. The Mi2 group displayed high severity scores and a tendency towards sarcolemmal complement deposition. NXP2 and TIF1γ groups showed a variety of pathologies with a high proportion of diffuse endomysial macrophage infiltrates and a high proportion of capillary C5b‐9 deposition. Conclusion We have shown that juvenile idiopathic inflammatory myopathies have a spectrum of histopathological phenotypes and show distinct complement attack complex deposition patterns. Both correlate in some cases with the serological subtypes. Most cases do not show typical histological features associated with dermatomyositis (e.g. perifascicular atrophy). In contrast, more than half show relatively mild histopathological changes.

BACKGROUND: Anti-Signal Recognition Particle associated myopathy is a clinically and histopathologically distinct subgroup of Juvenile Idiopathic Inflammatory Myositis, which is under-recognised in children and fails to respond to conventional first line therapies. We present three cases where remission was successfully induced using combination therapy with intensive rehabilitation.CASE PRESENTATIONS: Three new patients are reported. All 3 cases presented with profound, rapid-onset, proximal myopathy and markedly raised CK, but no rash. Histology revealed a destructive myopathy characterized by scattered atrophic and necrotic fibres with little or no inflammatory infiltrate. All 3 patients responded to induction with cyclophosphamide, IVIG and rituximab, in conjunction with intensive physiotherapy and methotrexate as the maintenance agent. Our patients regained near-normal strength (MMT > 70/80), in contrast with the current literature where >50% of cases reported severe residual weakness. A literature search on paediatric anti-SRP myositis was performed to June 2016; PubMed was screened using a combination of the following terms: signal recognition particle, autoantibodies, antibodies, myositis, muscular diseases, skeletal muscle, childhood, paediatric, juvenile. Articles in a foreign language were excluded. Nine case studies were found.CONCLUSION: This paper supports the hypothesis that anti-SRP myositis is distinct from other JIIM. It is an important differential to JDM and should be considered where there is severe weakness without rash or if highly elevated muscle enzymes (CK > 10,000 U/l) are found. Early identification is essential to initiate aggressive medical and physical therapy. Greater international collaboration and long-term follow-up data is needed to establish the most effective treatment strategy for this rare group of patients.

Objectives:Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases, comprising seven categories. Genetic data could potentially be used to help redefine JIA categories and improve the current classification system. The human leukocyte antigen (HLA) region is strongly associated with JIA. Fine-mapping of the region was performed to look for similarities and differences in HLA associations between the JIA categories and define correspondences with adult inflammatory arthritides. Methods:Dense genotype data from the HLA region, from the Immunochip array for 5,043 JIA cases and 14,390 controls, was used to impute SNPs, HLA classical alleles and amino acids. Bivariate analysis was performed to investigate genetic correlation between the JIA categories. Conditional analysis was used to identify additional effects within the region. Comparison of the findings with those in adult inflammatory arthritic diseases was performed.ResultsWe identified category-specific associations and have demonstrated for the first time that rheumatoid factor negative polyarticular JIA and oligoarticular JIA are genetically similar in their HLA associations. We also observe that each JIA category potentially has an adult counterpart. The RF-positive polyarthritis association at HLA-DRB1 amino acid at position 13 mirrors the association in adult seropositive rheumatoid arthritis (RA). Interestingly, the combined oligoarthritis and RF-negative polyarthritis dataset shares the same association with adult seronegative RA. ConclusionsThe findings suggest the value of using genetic data in helping to classify the categories of this heterogeneous disease. Mapping JIA categories to adult counterparts could enable shared knowledge of disease pathogenesis and etiology and facilitate transition from paediatric to adult services.

Objectives Juvenile idiopathic arthritis (JIA) is a heterogeneous group of diseases, comprising seven categories. Genetic data could potentially be used to help redefine JIA categories and improve the current classification system. The human leucocyte antigen (HLA) region is strongly associated with JIA. Fine-mapping of the region was performed to look for similarities and differences in HLA associations between the JIA categories and define correspondences with adult inflammatory arthritides. Methods Dense genotype data from the HLA region, from the Immunochip array for 5043 JIA cases and 14 390 controls, were used to impute single-nucleotide polymorphisms, HLA classical alleles and amino acids. Bivariate analysis was performed to investigate genetic correlation between the JIA categories. Conditional analysis was used to identify additional effects within the region. Comparison of the findings with those in adult inflammatory arthritic diseases was performed. Results We identified category-specific associations and have demonstrated for the first time that rheumatoid factor (RF)-negative polyarticular JIA and oligoarticular JIA are genetically similar in their HLA associations. We also observe that each JIA category potentially has an adult counterpart. The RF-positive polyarthritis association at HLA-DRB1 amino acid at position 13 mirrors the association in adult seropositive rheumatoid arthritis (RA). Interestingly, the combined oligoarthritis and RF-negative polyarthritis dataset shares the same association with adult seronegative RA. Conclusions The findings suggest the value of using genetic data in helping to classify the categories of this heterogeneous disease. Mapping JIA categories to adult counterparts could enable shared knowledge of disease pathogenesis and aetiology and facilitate transition from paediatric to adult services. This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See: http://creativecommons.org/licenses/by/4.0/

Background: Although Methotrexate (MTX) is one of the most commonly prescribed disease-modifying drugs in JIA no questionnaire exists that assesses the knowledge of parents about this drug. A 60-item questionnaire was recently developed to measure rheumatoid arthritis (RA) patients’ knowledge about MTX; the Methotrexate in Rheumatoid Arthritis Knowledge Test (MiRAK; Ciciriello et al. (Arthritis Rheum 62:10–1009, 2010)). This study aimed to adapt the MiRAK for parents of children with JIA.\ud \ud Methods: Adaption of the MiRAK involved: 1) email consultations with clinicians working in the field of paediatric rheumatology (Panel 1) to ascertain the potential adaptations of the MiRAK from a clinical perspective, 2) synthesis of clinicians’ suggestions by a panel of experts, researchers and MiRAK developers (Panel 2) to reach consensus on which items needed to be modified and create a draft Methotrexate in Juvenile Idiopathic Arthritis Knowledge Test (MiJIAK), 3) a review of the draft by 5 parents of children with JIA (Panel 3) using the cognitive ‘think-aloud’ method, 4) a second consultation with Panel 2 to review parents’ suggestions and determine the final items.\ud \ud Results: A total of 9 items remained unchanged, e.g. “Methotrexate is effective at relieving joint stiffness”, 19 were deemed inappropriate in the paediatric setting and deleted, e.g. “It is safe to become pregnant 3 weeks after methotrexate has been stopped”, 32 underwent editorial changes largely to indicate that the questionnaire was about the children with JIA, e.g. “If you forget to give a dose of Methotrexate, you can still take it the next day” became “If your child misses a dose of Methotrexate, they can still take it the next day”, and 1 new item was added. A new 42-item questionnaire was produced and was found to be well understood by parents of children with JIA.\ud \ud Conclusions: The systematic modification of the MiRAK, a patient-centred MTX knowledge questionnaire, has generated a comprehensive new questionnaire for use in the JIA setting. The wide consultation process, including cognitive testing, has ensured the tool is both relevant and acceptable to clinicians and will therefore be a valuable addition in understanding the parents’ perspective of this treatment in JIA.

Background: Research on adult patients with chronic illness has shown that their illness beliefs are associated with patient reported outcomes. There is limited research focusing on the illness and treatment beliefs of parents of ill children. The aim of this study was to discern if treatment success, as measured by the ACR Pediatric (Ped) criteria has an impact upon parents’ beliefs about their child’s illness and treatment.\ud \ud Methods: The data of 157 mothers and 75 fathers was used in this cross-sectional study. Parents were asked to complete a series of questionnaires including the Illness Perception Questionnaire Revised (IPQ-R) and the Treatment Representation Inventory (TRI). Parents of children, who reached the ACR Ped 70 level of improvement in arthritis were compared to parents of non-responders using Chi-Square Tests and ANOVAs.\ud \ud Results: A number of significant differences in parents’ illness perceptions were found. Mothers of non-responders had a stronger belief in the unpredictable nature of the arthritis (p = 0.01) and mothers of ACR Ped 70 responders showed a stronger belief in their ability to control the arthritis (p = 0.03). Fathers of ACR Pediatric 70 responders had a stronger belief in their child’s understanding of the arthritis (p = 0.01) and in the arthritis being an acute condition (p = 0.03). Only one significant difference was found in parents’ treatment representations. Mothers of ACR Ped 70 responders had a stronger belief in the ability of the treatment to cure the arthritis. The means of the scale assessing the value of treatment were high for all mothers and fathers. Other treatment and illness beliefs were in the mid-range reflecting uncertain beliefs.\ud \ud Conclusions: With the exception of mothers’ beliefs in the ability of the treatment to cure the arthritis, no differences were found in the treatment beliefs between parents of ACR Ped 70 responders and parents of non-responders. This suggests that with exception of beliefs in cure, the treatment success is not generally reflected in parents’ treatment beliefs. However, treatment success influenced a number of parents’ beliefs about their child’s illness. These differences were all in the expected direction. Notably, on a number of the scales mothers and fathers consistently showed a degree of uncertainty in their beliefs about their child’s illness and treatment, regardless of treatment success. This uncertainty may reflect the fact that currently there is no cure for JIA. Illness uncertainty has been found to be positively associated with negative psychological outcomes in patients with chronic illness. The findings in this study suggest that parents of children with JIA may require additional support to deal with the uncertainty in relation to their child’s illness and treatment.

Background: Campylobacter jejuni is the most prevalent cause of bacterial gastroenteritis worldwide. Despite the significant health burden this infection presents, molecular understanding of C. jejuni-mediated disease pathogenesis remains poorly defined. Here, we report the characterisation of the early, innate immune response to C. jejuni using an ex-vivo human gut model of infection. Secondly, impact of bacterial-driven dendritic cell activation on T-cell mediated immunity was also sought.Methodology: Healthy, control paediatric terminal ileum or colonic biopsy tissue was infected with C. jejuni for 8-12 hours. Bacterial colonisation was followed by confocal microscopy and mucosal innate immune responses measured by ELISA. Marked induction of IFN gamma with modest increase in IL-22 and IL-17A was noted. Increased mucosal IL-12, IL-23, IL-1 beta and IL-6 were indicative of a cytokine milieu that may modulate subsequent T-cell mediated immunity. C. jejuni-driven human monocyte-derived dendritic cell activation was followed by analyses of T cell immune responses utilising flow cytometry and ELISA. Significant increase in Th-17, Th-1 and Th-17/Th-1 double-positive cells and corresponding cytokines was observed. The ability of IFN gamma, IL-22 and IL-17 cytokines to exert host defence via modulation of C. jejuni adhesion and invasion to intestinal epithelia was measured by standard gentamicin protection assay.Conclusions: Both innate and adaptive T cell-immunity to C. jejuni infection led to the release of IFN gamma, IL-22 and IL-17A; suggesting a critical role for this cytokine triad in establishing host anti-microbial immunity during the acute and effectors phase of infection. In addition, to their known anti-microbial functions; IL-17A and IL-17F reduced the number of intracellular C. jejuni in intestinal epithelia, highlighting a novel aspect of how IL-17 family members may contribute to protective immunity against C. jejuni.