Genomic risk scores for juvenile idiopathic arthritis and its subtypes.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is an autoimmune disease and a common cause of chronic disability in children. Diagnosis of JIA is based purely on clinical symptoms, which can be variable, leading to diagnosis and treatment delays. Despite JIA having substantial heritability, the construction of genomic risk scores (GRSs) to aid or expedite diagnosis has not been assessed. Here, we generate GRSs for JIA and its subtypes and evaluate their performance. METHODS: We examined three case/control cohorts (UK, US-based and Australia) with genome-wide single nucleotide polymorphism (SNP) genotypes. We trained GRSs for JIA and its subtypes using lasso-penalised linear models in cross-validation on the UK cohort, and externally tested it in the other cohorts. RESULTS: The JIA GRS alone achieved cross-validated area under the receiver operating characteristic curve (AUC)=0.670 in the UK cohort and externally-validated AUCs of 0.657 and 0.671 in the US-based and Australian cohorts, respectively. In logistic regression of case/control status, the corresponding odds ratios (ORs) per standard deviation (SD) of GRS were 1.831 (1.685 to 1.991) and 2.008 (1.731 to 2.345), and were unattenuated by adjustment for sex or the top 10 genetic principal components. Extending our analysis to JIA subtypes revealed that the enthesitis-related JIA had both the longest time-to-referral and the subtype GRS with the strongest predictive capacity overall across data sets: AUCs 0.82 in UK; 0.84 in Australian; and 0.70 in US-based. The particularly common oligoarthritis JIA also had a GRS that outperformed those for JIA overall, with AUCs of 0.72, 0.74 and 0.77, respectively. CONCLUSIONS: A GRS for JIA has potential to augment clinical JIA diagnosis protocols, prioritising higher-risk individuals for follow-up and treatment. Consistent with JIA heterogeneity, subtype-specific GRSs showed particularly high performance for enthesitis-related and oligoarthritis JIA.

The DNA methylation landscape of CD4+ T cells in oligoarticular juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is presumed to be driven by an adverse combination of genes and environment. Epigenetic processes, including DNA methylation, act as a conduit through which the environment can regulate gene activity. Altered DNA methylation has been associated with adult autoimmune rheumatic diseases such as rheumatoid arthritis, but studies are lacking for paediatric autoimmune rheumatic diseases including JIA. Here, we performed a genome-scale case-control analysis of CD4+ T cell DNA methylation from 56 oligoarticular JIA (oJIA) cases and 57 age and sex matched controls using Illumina HumanMethylation450 arrays. DNA methylation at each array probe was tested for association with oJIA using RUV (Remove Unwanted Variation) together with a moderated t-test. Further to this 'all-inclusive' analysis, we stratified by age at diagnosis (≤6yrs, >6yrs) and by sex as potential sources of heterogeneity. Following False Discovery Rate (FDR) adjustment, no probes were associated with oJIA in the all-inclusive, >6yrs-diagnosed, or sex-stratified analyses, and only one probe was associated with oJIA in the ≤6yrs-diagnosed analysis. We attempted technical validation and replication of 14 probes (punadj<0.01) at genes of known/potential relevance to disease. At VPS53, we demonstrated a regional shift towards higher methylation in oJIA (all-inclusive) compared to controls. At REEP3, where polymorphism has been previously associated with JIA, we demonstrated higher DNA methylation in male oJIA compared to male controls. This is the most comprehensive JIA case-control analysis of DNA methylation to date. While we have generated some evidence of altered methylation in oJIA, substantial differences are not apparent in CD4+ T cells. This may indicate a lesser relevance of DNA methylation levels in childhood, compared to adult, rheumatic disease.

Variants in CXCR4 associate with juvenile idiopathic arthritis susceptibility.

BACKGROUND: Juvenile idiopathic arthritis (JIA) is the most common chronic rheumatic disease among children, the etiology of which involves a strong genetic component, but much of the underlying genetic determinants still remain unknown. Our aim was to identify novel genetic variants that predispose to JIA. METHODS: We performed a genome-wide association study (GWAS) and replication in a total of 1166 JIA cases and 9500 unrelated controls of European ancestry. Correlation of SNP genotype and gene expression was investigated. Then we conducted targeted resequencing of a candidate locus, among a subset of 480 cases and 480 controls. SUM test was performed to evaluate the association of the identified rare functional variants. RESULTS: The CXCR4 locus on 2q22.1 was found to be significantly associated with JIA, peaking at SNP rs953387. However, this result is subjected to subpopulation stratification within the subjects of European ancestry. After adjusting for principal components, nominal significant association remained (p < 10(-4)). Because of its interesting known function in immune regulation, we carried out further analyses to assess its relationship with JIA. Expression of CXCR4 was correlated with CXCR4 rs953387 genotypes in lymphoblastoid cell lines (p = 0.014) and T-cells (p = 0.0054). In addition, rare non-synonymous and stop-gain sequence variants in CXCR4, putatively damaging for CXCR4 function, were significantly enriched in JIA cases (p = 0.015). CONCLUSION: Our results suggest the association of CXCR4 variants with JIA, implicating that this gene may be involved in the pathogenesis of autoimmune disease. However, because this locus is subjected to population stratification within the subjects of European ancestry, additional replication is still necessary for this locus to be considered a true risk locus for JIA. This cell-surface chemokine receptor has already been targeted in other diseases and may serve as a tractable therapeutic target for a specific subset of pediatric arthritis patients with additional replication and functional validation of the locus.

Sex bias in paediatric autoimmune disease - Not just about sex hormones?

Autoimmune diseases affect up to 10% of the world's population, and approximately 80% of those affected are female. The majority of autoimmune diseases occur more commonly in females, although some are more frequent in males, while others show no bias by sex. The mechanisms leading to sex biased disease prevalence are not well understood. However, for adult-onset autoimmune disease, at least some of the cause is usually ascribed to sex hormones. This is because levels of sex hormones are one of the most obvious physiological differences between adult males and females, and their impact on immune system function is well recognised. While for paediatric-onset autoimmune diseases a sex bias is not as common, there are several such diseases for which one sex predominates. For example, the oligoarticular subtype of juvenile idiopathic arthritis (JIA) occurs in approximately three times more girls than boys, with a peak age of onset well before the onset of puberty, and at a time when levels of androgen and oestrogen are low and not strikingly different between the sexes. Here, we review potential explanations for autoimmune disease sex bias with a particular focus on paediatric autoimmune disease, and biological mechanisms outside of sex hormone differences.

Case mix in paediatric rheumatology: implications for training in Australia.

BACKGROUND: Despite a move towards the provision of specialist training in Australia in settings that extend beyond the public hospital system, formal comparisons of case mix between public and private specialty clinics have rarely been performed. It is therefore unclear for many specialties how well training in one setting prepares trainees for practice in the other. AIMS: This study aims to compare the case mix of paediatric rheumatology patients seen in public and private settings and the referral sources of patients in each. METHODS: An audit of all new patients seen in the public and private paediatric rheumatology clinics on campus at Royal Children's Hospital between June 2009 and January 2011. Data related to demographics, primary diagnosis, referral source and location seen were abstracted and compared. RESULTS: Eight hundred and seventy-six new patients were seen during the period of interest. Of these, 429 patients (48.9%) were seen in private clinics. The commonest diagnostic categories for both type of clinics were non-inflammatory musculoskeletal pain/orthopaedic conditions (public 39.4%, private 33.6%) followed by juvenile idiopathic arthritis (public 16.6%, %, private 18.6%), other skin/soft tissue disorders (public 8.7%, private 9.6%) and pain syndromes (public 4.9%, private 11.4%). Patients with haematological and vasculitic disorders were predominantly seen in public clinics. The commonest source of referrals to both clinics was general practitioners (public 40.6%, private 53.1%). CONCLUSION: The case mix in private paediatric rheumatology clinics closely mirrors that of public clinics at our centre. Training in either setting would provide sufficient case-mix exposure to prepare trainees for practice in the other.

Identification of Novel Loci Shared by Juvenile Idiopathic Arthritis Subtypes Through Integrative Genetic Analysis.

OBJECTIVE: Juvenile idiopathic arthritis (JIA) is the most common chronic immune-mediated joint disease among children and encompasses a heterogeneous group of immune-mediated joint disorders classified into 7 subtypes according to clinical presentation. However, phenotype overlap and biologic evidence suggest a shared mechanistic basis between subtypes. This study was undertaken to systematically investigate shared genetic underpinnings of JIA subtypes. METHODS: We performed a heterogeneity-sensitive genome-wide association study encompassing a total of 1,245 JIA cases (classified into 7 subtypes) and 9,250 controls, followed by fine-mapping of candidate causal variants at each genome-wide significant locus, functional annotation, and pathway and network analysis. We further identified candidate drug targets and drug repurposing opportunities by in silico analyses. RESULTS: In addition to the major histocompatibility complex locus, we identified 15 genome-wide significant loci shared between at least 2 JIA subtypes, including 10 novel loci. Functional annotation indicated that candidate genes at these loci were expressed in diverse immune cell types. CONCLUSION: This study identified novel genetic loci shared by JIA subtypes. Our findings identified candidate mechanisms underlying JIA subtypes and candidate targets with drug repurposing opportunities for JIA treatment.

High levels of psychosocial distress among Australian frontline healthcare workers during the COVID-19 pandemic: a cross-sectional survey.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has had a profound and prolonged impact on healthcare services and healthcare workers. AIMS: The Australian COVID-19 Frontline Healthcare Workers Study aimed to investigate the severity and prevalence of mental health issues, as well as the social, workplace and financial disruptions experienced by Australian healthcare workers during the COVID-19 pandemic. METHODS: A nationwide, voluntary, anonymous, single timepoint, online survey was conducted between 27 August and 23 October 2020. Individuals self-identifying as frontline healthcare workers in secondary or primary care were invited to participate. Participants were recruited through health organisations, professional associations or colleges, universities, government contacts and national media. Demographics, home and work situation, health and psychological well-being data were collected. RESULTS: A total of 9518 survey responses were received; of the 9518 participants, 7846 (82.4%) participants reported complete data. With regard to age, 4110 (52.4%) participants were younger than 40 years; 6344 (80.9%) participants were women. Participants were nurses (n=3088, 39.4%), doctors (n=2436, 31.1%), allied health staff (n=1314, 16.7%) or in other roles (n=523, 6.7%). In addition, 1250 (15.9%) participants worked in primary care. Objectively measured mental health symptoms were common: mild to severe anxiety (n=4694, 59.8%), moderate to severe burnout (n=5458, 70.9%) and mild to severe depression (n=4495, 57.3%). Participants were highly resilient (mean (SD)=3.2 (0.66)). Predictors for worse outcomes on all scales included female gender; younger age; pre-existing psychiatric condition; experiencing relationship problems; nursing, allied health or other roles; frontline area; being worried about being blamed by colleagues and working with patients with COVID-19. CONCLUSIONS: The COVID-19 pandemic is associated with significant mental health symptoms in frontline healthcare workers. Crisis preparedness together with policies and practices addressing psychological well-being are needed.

Possible environmental determinants of juvenile idiopathic arthritis.

Like other autoimmune diseases, including adult RA, risk of developing juvenile idiopathic arthritis (JIA) is thought to be determined by a complex combination of genetic and environmental factors. Although some predisposing JIA genes are now being identified, research aimed at identifying environmental influences lags behind most other autoimmune conditions. Here we review research to date, from which some evidence has been generated to support a role for breastfeeding, infection and maternal smoking in determining JIA risk. We also propose further hypotheses worthy of testing, based on knowledge acquired for other autoimmune diseases. These include the role of vitamin D and sun exposure, and the role of early-life infection ('the hygiene hypothesis') in determining risk. Finally, we discuss future directions including practical study designs to more comprehensively test hypotheses and provide new insight into this important area of research.

Association of Increased Sun Exposure Over the Life-course with a Reduced Risk of Juvenile Idiopathic Arthritis.

Cutaneous sun exposure is an important determinant of circulating vitamin D. Both sun exposure and vitamin D have been inversely associated with risk of autoimmune disease. In juvenile idiopathic arthritis (JIA), low circulating vitamin D appears common, but disease-related behavioral changes may have influenced sun exposure. We therefore aimed to determine whether predisease sun exposure is associated with JIA. Using validated questionnaires, we retrospectively measured sun exposure for 202 Caucasian JIA case-control pairs born in Victoria Australia, matched for birth year and time of recruitment. Measures included maternal sun exposure at 12 weeks of pregnancy and child sun exposure across the life-course prediagnosis. We converted exposure to UVR dose and looked for case-control differences using logistic regression, adjusting for potential confounders. Higher cumulative prediagnosis UVR exposure was associated with reduced risk of JIA, with a clear dose-response relationship (trend P = 0.04). UVR exposure at 12 weeks of pregnancy was similarly inversely associated with JIA (trend P = 0.011). Associations were robust to sensitivity analyses for prediagnosis behavioral changes, disease duration and knowledge of the hypothesis. Our data indicate that lower UVR exposure may increase JIA risk. This may be through decreased circulating vitamin D, but prospective studies are required to confirm this.

Establishing an Updated Core Domain Set for Studies in Juvenile Idiopathic Arthritis: A Report from the OMERACT 2018 JIA Workshop.

OBJECTIVE: The current Juvenile Idiopathic Arthritis (JIA) Core Set used in randomized controlled trials (RCT) and longitudinal observational studies (LOS) was developed without the input of patients/parents. At the Outcome Measures in Rheumatology (OMERACT) 2016, a special interest group voted to reconsider the core set, incorporating broader input. We describe subsequent work culminating in an OMERACT 2018 plenary and consensus voting. METHODS: Candidate domains were identified through literature review, qualitative surveys, and online discussion boards (ODB) held with patients with JIA and parents in Australia, Italy, and the United States. A Delphi process with parents, patients, healthcare providers, researchers, and regulators served to edit the domain list and prioritize candidate domains. After the presentation of results, OMERACT workshop participants voted, with consensus set at > 70%. RESULTS: Participants in ODB were 53 patients with JIA (ages 15-24 yrs) and 55 parents. Three rounds of Delphi considering 27 domains were completed by 190 (response rate 85%), 201 (84%), and 182 (77%) people, respectively, from 50 countries. There was discordance noted between domains prioritized by patients/parents compared to others. OMERACT conference voting approved domains for JIA RCT and LOS with 83% endorsement. Mandatory domains are pain, joint inflammatory signs, activity limitation/physical function, patient's perception of disease activity (overall well-being), and adverse events. Mandatory in specific circumstances: inflammation/other features relevant to specific JIA categories. CONCLUSION: Following the OMERACT methodology, we developed an updated JIA Core Domain Set. Next steps are to identify and systematically evaluate best outcome measures for these domains.

Evidence for Updating the Core Domain Set of Outcome Measures for Juvenile Idiopathic Arthritis: Report from a Special Interest Group at OMERACT 2016.

OBJECTIVE: The current Juvenile Idiopathic Arthritis (JIA) Core Set was developed in 1997 to identify the outcome measures to be used in JIA clinical trials using statistical and consensus-based techniques, but without patient involvement. The importance of patient/parent input into the research process has increasingly been recognized over the years. An Outcome Measures in Rheumatology (OMERACT) JIA Core Set Working Group was formed to determine whether the outcome domains of the current core set are relevant to those involved or whether the core set domains should be revised. METHODS: Twenty-four people from the United States, Canada, Australia, and Europe, including patient partners, formed the working group. Guided by the OMERACT Filter 2.0 process, we performed (1) a systematic literature review of outcome domains, (2) a Web-based survey (142 patients, 343 parents), (3) an idea-generation study (120 parents), (4) 4 online discussion boards (24 patients, 20 parents), and (5) a Special Interest Group (SIG) activity at the OMERACT 13 (2016) meeting. RESULTS: A MEDLINE search of outcome domains used in studies of JIA yielded 5956 citations, of which 729 citations underwent full-text review, and identified additional domains to those included in the current JIA Core Set. Qualitative studies on the effect of JIA identified multiple additional domains, including pain and participation. Twenty-one participants in the SIG achieved consensus on the need to revise the entire JIA Core Set. CONCLUSION: The results of qualitative studies and literature review support the need to expand the JIA Core Set, considering, among other things, additional patient/parent-centered outcomes, clinical data, and imaging data.

A survey of national and multi-national registries and cohort studies in juvenile idiopathic arthritis: challenges and opportunities.

BACKGROUND: To characterize the existing national and multi-national registries and cohort studies in juvenile idiopathic arthritis (JIA) and identify differences as well as areas of potential future collaboration. METHODS: We surveyed investigators from North America, Europe, and Australia about existing JIA cohort studies and registries. We excluded cross-sectional studies. We captured information about study design, duration, location, inclusion criteria, data elements and collection methods. RESULTS: We received survey results from 18 studies, including 11 national and 7 multi-national studies representing 37 countries in total. Study designs included inception cohorts, prevalent disease cohorts, and new treatment cohorts (several of which contribute to pharmacosurveillance activities). Despite numerous differences, the data elements collected across the studies was quite similar, with most studies collecting at least 5 of the 6 American College of Rheumatology core set variables and the data needed to calculate the 3-variable clinical juvenile disease activity score. Most studies were collecting medication initiation and discontinuation dates and were attempting to capture serious adverse events. CONCLUSION: There is a wide-range of large, ongoing JIA registries and cohort studies around the world. Our survey results indicate significant potential for future collaborative work using data from different studies and both combined and comparative analyses.

Sibling Exposure and Risk of Juvenile Idiopathic Arthritis.

OBJECTIVE: Susceptibility to juvenile idiopathic arthritis (JIA) is presumed to be determined by both genes and environment. However, the environmental factors remain largely unknown. The hygiene hypothesis suggests that exposure to siblings, as a marker of exposure to microbes in early life, may protect against the development of later immune disorders. Some prior evidence suggests this may also be true for JIA. The present study was undertaken to test this hypothesis in detail. METHODS: We conducted a comprehensive analysis of the role of sibling exposure in JIA risk within the Childhood Arthritis Risk Factor Identification Study JIA case-hospital control sample (302 cases and 676 controls) from Victoria, Australia. RESULTS: We found that, compared to being an only child, having any siblings was protective against JIA, with an adjusted odds ratio (OR) of 0.46 (95% confidence interval [95% CI] 0.28-0.74) (P = 0.001). The protective association appeared to increase with increasing number of siblings (e.g., for ≥3 siblings, adjusted OR 0.25 [95% CI 0.13-0.48], P < 0.001). A protective association of siblings was also observed when we considered cumulative sibling years by age 6 (e.g., for ≥3 years of exposure versus no exposure, adjusted OR 0.49 [95% CI 0.30-0.79], P = 0.003). We also compared cases to a second control sample (n = 341) collected from the community and weighted to represent the child population of Victoria. Data remained supportive of an association between sibling exposure and protection against JIA, particularly for exposure to younger siblings. CONCLUSION: Increased exposure to siblings is associated with a reduced risk of disease in our sample. This suggests that increased microbial exposure in childhood may confer protection against the development of JIA.

DNA methylation at IL32 in juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is the most common autoimmune rheumatic disease of childhood. We recently showed that DNA methylation at the gene encoding the pro-inflammatory cytokine interleukin-32 (IL32) is reduced in JIA CD4+ T cells. To extend this finding, we measured IL32 methylation in CD4+ T-cells from an additional sample of JIA cases and age- and sex-matched controls, and found a reduction in methylation associated with JIA consistent with the prior data (combined case-control dataset: 25.0% vs 37.7%, p = 0.0045). Further, JIA was associated with reduced IL32 methylation in CD8+ T cells (15.2% vs 25.5%, p = 0.034), suggesting disease-associated changes to a T cell precursor. Additionally, we measured regional SNPs, along with CD4+ T cell expression of total IL32, and the γ and ß isoforms. Several SNPs were associated with methylation. Two SNPs were also associated with JIA, and we found evidence of interaction such that methylation was only associated with JIA in minor allele carriers (e.g. rs10431961 p(interaction) = 0.011). Methylation at one measured CpG was inversely correlated with total IL32 expression (Spearman r = -0.73, p = 0.0009), but this was not a JIA-associated CpG. Overall, our data further confirms that reduced IL32 methylation is associated with JIA, and that SNPs play an interactive role.

Epistasis amongst PTPN2 and genes of the vitamin D pathway contributes to risk of juvenile idiopathic arthritis.

Juvenile idiopathic arthritis (JIA) is a leading cause of childhood-onset disability. Although epistasis (gene-gene interaction) is frequently cited as an important component of heritability in complex diseases such as JIA, there is little compelling evidence that demonstrates such interaction. PTPN2, a vitamin D responsive gene, is a confirmed susceptibility gene in JIA, and PTPN2 has been suggested to interact with vitamin D pathway genes in type 1 diabetes. We therefore, tested for evidence of epistasis amongst PTPN2 and the vitamin D pathway genes GC, VDR, CYP24A1, CYP2R1, and DHCR7 in two independent JIA case-control samples (discovery and replication). In the discovery sample (318 cases, 556 controls), we identified evidence in support of epistasis across six gene-gene combinations (e.g., GC rs1155563 and PTPN2 rs2542151, ORint=0.45, p=0.00085). Replication was obtained for three of these combinations. That is, for GC and PTPN2, CYP2R1 and VDR, and VDR and PTPN2, similar epistasis was observed using the same SNPs or correlated proxies in an independent JIA case-control sample (1008 cases, 9287 controls). Using SNP data imputed across a 4 MB region spanning each gene, we obtained highly significant evidence for epistasis amongst all 6 gene-gene combinations identified in the discovery sample (p-values ranging from 5.6×10(-9) to 7.5×10(-7)). This is the first report of epistasis in JIA risk. Epistasis amongst PTPN2 and vitamin D pathway genes was both demonstrated and replicated.

Genetic sharing and heritability of paediatric age of onset autoimmune diseases.

Autoimmune diseases (AIDs) are polygenic diseases affecting 7-10% of the population in the Western Hemisphere with few effective therapies. Here, we quantify the heritability of paediatric AIDs (pAIDs), including JIA, SLE, CEL, T1D, UC, CD, PS, SPA and CVID, attributable to common genomic variations (SNP-h(2)). SNP-h(2) estimates are most significant for T1D (0.863±s.e. 0.07) and JIA (0.727±s.e. 0.037), more modest for UC (0.386±s.e. 0.04) and CD (0.454±0.025), largely consistent with population estimates and are generally greater than that previously reported by adult GWAS. On pairwise analysis, we observed that the diseases UC-CD (0.69±s.e. 0.07) and JIA-CVID (0.343±s.e. 0.13) are the most strongly correlated. Variations across the MHC strongly contribute to SNP-h(2) in T1D and JIA, but does not significantly contribute to the pairwise rG. Together, our results partition contributions of shared versus disease-specific genomic variations to pAID heritability, identifying pAIDs with unexpected risk sharing, while recapitulating known associations between autoimmune diseases previously reported in adult cohorts.

Meta-analysis of shared genetic architecture across ten pediatric autoimmune diseases.

Genome-wide association studies (GWASs) have identified hundreds of susceptibility genes, including shared associations across clinically distinct autoimmune diseases. We performed an inverse χ(2) meta-analysis across ten pediatric-age-of-onset autoimmune diseases (pAIDs) in a case-control study including more than 6,035 cases and 10,718 shared population-based controls. We identified 27 genome-wide significant loci associated with one or more pAIDs, mapping to in silico-replicated autoimmune-associated genes (including IL2RA) and new candidate loci with established immunoregulatory functions such as ADGRL2, TENM3, ANKRD30A, ADCY7 and CD40LG. The pAID-associated single-nucleotide polymorphisms (SNPs) were functionally enriched for deoxyribonuclease (DNase)-hypersensitivity sites, expression quantitative trait loci (eQTLs), microRNA (miRNA)-binding sites and coding variants. We also identified biologically correlated, pAID-associated candidate gene sets on the basis of immune cell expression profiling and found evidence of genetic sharing. Network and protein-interaction analyses demonstrated converging roles for the signaling pathways of type 1, 2 and 17 helper T cells (TH1, TH2 and TH17), JAK-STAT, interferon and interleukin in multiple autoimmune diseases.

Independent confirmation of juvenile idiopathic arthritis genetic risk loci previously identified by immunochip array analysis.

BACKGROUND: Our understanding of the genetic factors underlying juvenile idiopathic arthritis (JIA) is growing, but remains incomplete. Recently, a number of novel genetic loci were reported to be associated with JIA at (or near) genome-wide significance in a large case-control discovery sample using the Immunochip genotyping array. However, independent replication of findings has yet to be performed. We therefore attempted to replicate these newly identified loci in the Australian CLARITY JIA case-control sample. FINDINGS: Genotyping was successfully performed on a total of 404 JIA cases (mean age 6.4 years, 68% female) and 676 healthy child controls (mean age 7.1 years, 42% female) across 19 SNPs previously associated with JIA. We replicated a significant association (p < 0.05, odds ratio (OR) in a direction consistent with the previous report) for seven loci, six replicated for the first time--C5orf56-IRF1 (rs4705862), ERAP2-LNPEP (rs27290), PRR5L (rs4755450), RUNX1 (rs9979383), RUNX3 (rs4648881), and UBE2L3 (rs2266959). CONCLUSIONS: We have carried out the first independent replication of association for six genes implicated in JIA susceptibility. Our data significantly strengthens the evidence that these loci harbor true disease associated variants. Thus, this study makes an important contribution to the growing body of international data that is revealing the genetic risk landscape of JIA.

Out-of-clinic patient communication in paediatric rheumatology: the extent and nature of demand.

BACKGROUND: Traditional funding models for public paediatric rheumatology care are typically based on providing medical services for a defined number of clinics per week. Anecdotally there is significant demand by patients and families for out-of-clinic communication with care providers and services provided under traditional funding models may not meet this need. Our aim was to determine the extent and nature of this 'hidden' demand in a tertiary paediatric rheumatology centre. METHODS: Communication data and diagnoses were extracted from the Rheumatology service database at our centre for the period 1/1/2009 to 31/12/2011. Clinical activity data over the same time were obtained from hospital clinic databases. RESULTS: There were 5672 instances of communication with 749 patients/families over 3 years, (mean 7.3/weekday). This increased over time in parallel with clinical activity. 41% of clinic patients sought communication with the team out of clinic hours. 58% were telephone calls, 36% emails and 6% letters. The communication topics were for advice, results or general updates (28%), medication queries (24%), appointment/admission coordination (20%), disease flare or other disease events (14%), psychosocial, school or transition issues (6%) and miscellaneous queries (8%). Of the most frequent communicators, those with juvenile idiopathic arthritis were the majority (85%). The remainder had other chronic inflammatory conditions. CONCLUSIONS: The communication and support needs of patients with chronic rheumatic diseases and their families extend beyond that which can be provided in the clinic environment. It is essential that funding for paediatric rheumatology services allows for staffing sufficient to meet this need.

Independent replication analysis of genetic loci with previous evidence of association with juvenile idiopathic arthritis.

BACKGROUND: Over the last five years, there have been numerous reports of association of juvenile idiopathic arthritis with single nucleotide polymorphisms (SNPs) at various loci outside the major histocompatibility complex (MHC) region. However, the majority of these association findings have been generated using a limited number of international cohorts, and thus there is benefit in further independent replication. To address this, we examined a total of 56 SNPs in 42 non-MHC gene regions previously reported to be associated with JIA, in the ChiLdhood Arthritis Risk factor Identification sTudY (CLARITY), a new Australian collection of cases and healthy child controls. FINDINGS: Genotyping was performed on a total of 324 JIA cases (mean age 9.7 years, 67.3% female) and 568 controls (mean age 7.8 years, 40.7% female). We demonstrated clear evidence for replication of association of JIA with SNPs in or around c12orf30, c3orf1, PTPN22, STAT4, and TRAF1-C5, confirming the involvement of these loci in disease risk. Further, we generated evidence supportive of replication of association of JIA with loci containing AFF3, CD226, MBL2, PSTPIP1, and RANTES (CCL5). These results were robust to sensitivity analyses for ethnicity. CONCLUSION: We have provided valuable independent data as to the underlying genetic architecture of this understudied pediatric autoimmune disease, further confirming five loci outside the MHC, and supporting a role for a further five loci in determining disease risk.