Eric Bywaters and Barbara Ansell: Founders of Modern Pediatric Rheumatology.

Eric Bywaters and Barbara Ansell were, without doubt, two of the giants in the field of Rheumatology. With their keen clinical observations and their visionary development of a dedicated multidisciplinary program focusing on diagnosis, treatment, and research, they are remembered as the founders of the modern specialty of Pediatric Rheumatology.

Higher concentrations of vitamin D in Canadian children with juvenile idiopathic arthritis compared to healthy controls are associated with more frequent use of vitamin D supplements and season of birth.

A number of studies have demonstrated that patients with autoimmune disease have lower levels of vitamin D prompting speculation that vitamin D might suppress inflammation and immune responses in children with juvenile idiopathic arthritis (JIA).  The objective of this study was to compare vitamin D levels in children with JIA at disease onset with healthy children. We hypothesized that children and adolescents with JIA have lower vitamin D levels than healthy children and adolescents. Data from a Canadian cohort of children with new-onset JIA (n= 164, data collection 2007-2012) were compared to Canadian Health Measures Survey (CHMS) data (n=4027, data collection 2007-2011). We compared 25-hydroxy vitamin D (25(OH)D) concentrations with measures of inflammation, vitamin D supplement use, milk intake, and season of birth. Mean 25(OH)D level was significantly higher in patients with JIA (79 ± 3.1 nmol/L) than in healthy controls (68 ± 1.8 nmol/L P <.05). Patients with JIA more often used vitamin D containing supplements (50% vs. 7%; P <.05). The prevalence of 25(OH)D deficiency (<30 nmol/L) was 6% for both groups. Children with JIA with 25(OH)D deficiency or insufficiency (<50 nmol/L) had higher C-reactive protein levels. Children with JIA were more often born in the fall and winter compared to healthy children. In contrast to earlier studies, we found vitamin D levels in Canadian children with JIA were higher compared to healthy children and associated with more frequent use of vitamin D supplements. Among children with JIA, low vitamin D levels were associated with indicators of greater inflammation.

Clinical and psychosocial stress factors are associated with decline in physical activity over time in children with juvenile idiopathic arthritis.

BACKGROUND: Physical activity (PA) patterns in children with juvenile idiopathic arthritis (JIA) over time are not well described. The aim of this study was to describe associations of physical activity (PA) with disease activity, function, pain, and psychosocial stress in the 2 years following diagnosis in an inception cohort of children with juvenile idiopathic arthritis (JIA). METHODS: In 82 children with newly diagnosed JIA, PA levels, prospectively determined at enrollment, 12 and 24 months using the Physical Activity Questionnaire for Children (PAQ-C) and Adolescents (PAQ-A) raw scores, were evaluated in relation to disease activity as reflected by arthritis activity (Juvenile Arthritis Disease Activity Score (JADAS-71)), function, pain, and psychosocial stresses using a linear mixed model approach. Results in the JIA cohort were compared to normative Pediatric Bone Mineral Accrual Study data derived from healthy children using z-scores. RESULTS: At enrollment, PA z-score levels of study participants were lower than those in the normative population (median z-score - 0.356; p = 0.005). At enrollment, PA raw scores were negatively associated with the psychosocial domain of the Juvenile Arthritis Quality of Life Questionnaire (r = - 0.251; p = 0.023). There was a significant decline in PAQ-C/A raw scores from baseline (median and IQR: 2.6, 1.4-3.1) to 24 months (median and IQR: 2.1, 1.4-2.7; p = 0.003). The linear mixed-effect model showed that PAQ-C/A raw scores in children with JIA decreased as age, disease duration, and ESR increased. The PAQ-C/A raw scores of the participants was also negatively influenced by an increase in disease activity as measured by the JADAS-71 (p <  0.001). CONCLUSION: Canadian children with newly diagnosed JIA have lower PA levels than healthy children. The decline in PA levels over time was associated with disease activity and higher disease-specific psychosocial stress.

Soluble Low-density Lipoprotein Receptor-related Protein 1 in Juvenile Idiopathic Arthritis.

OBJECTIVES: This study aimed to expand knowledge about soluble low-density lipoprotein receptor-related protein 1 (sLRP1) in juvenile idiopathic arthritis (JIA) by determining associations of sLRP1 levels in nonsystemic JIA patients with clinical and inflammatory biomarker indicators of disease activity. METHODS: Plasma sLRP1 and 44 inflammation-related biomarkers were measured at enrollment and 6 months later in a cohort of 96 newly diagnosed Canadian patients with nonsystemic JIA. Relationships between sLRP1 levels and indicators of disease activity and biomarker levels were analyzed at both visits. RESULTS: At enrollment, sLRP1 levels correlated negatively with age and active joint counts. Children showed significantly higher levels of sLRP1 than adolescents (mean ranks: 55.4 and 41.9, respectively; P = 0.02). Participants with 4 or fewer active joints, compared to those with 5 or more active joints, had significantly higher sLRP1 levels (mean ranks: 56.2 and 40.7, respectively; P = 0.006). At enrollment, considering the entire cohort, sLRP1 correlated negatively with the number of active joints (r = -0.235, P = 0.017). In the entire cohort, sLRP1 levels at enrollment and 6 months later correlated with 13 and 6 pro- and antiinflammatory biomarkers, respectively. In JIA categories, sLRP1 correlations with inflammatory markers were significant in rheumatoid factor-negative polyarticular JIA, oligoarticular JIA, enthesitis-related arthritis, and psoriatic arthritis at enrollment. Higher sLRP1 levels at enrollment increased the likelihood of absence of active joints 6 months later. CONCLUSION: Plasma sLRP1 levels correlate with clinical and biomarker indicators of short-term improvement in JIA disease activity, supporting sLRP1 as an upstream biomarker of potential utility for assessing JIA disease activity and outcome prediction.

Long-term outcomes and disease course of children with juvenile idiopathic arthritis in the ReACCh-Out cohort: a two-centre experience.

OBJECTIVE: To assess long-term outcomes of children with JIA diagnosed in the biologic era. METHODS: Chart review of patients prospectively enrolled in the Research in Arthritis in Canadian Children Emphasizing Outcomes inception cohort at two Canadian centres. Inactive disease and remission were defined according to Wallace criteria. RESULTS: We included 247 of 254 (97%) eligible patients diagnosed 2005-10. At the last follow-up visit at a median age of 16.9 years, 47% were in remission off medications, 25% in remission on medications and 27% had active disease; 51% were on at least one anti-rheumatic medication (22% on biologics). Patients with systemic JIA had the highest frequency of remission off medications (70%) and patients with RF-positive polyarthritis had the lowest (18%) (P <0.05 by Fisher's exact test). Among 99 patients with oligoarthritis at enrolment, 14 (14%) had an oligoarthritis extended course. Forty-five patients (18%) had at least one erosion or joint space narrowing in X-rays or MRI, and two (0.8%) required joint replacement. CONCLUSION: Relative to historical cohorts, this study suggests a reduction in JIA permanent damage, a more favourable prognosis for systemic JIA and a lower progression to oligoarthritis extended category. However, in an era of biologic therapy, one in four patients with JIA still enter adulthood with active disease and one in two still on treatment.

Associations of clinical and inflammatory biomarker clusters with juvenile idiopathic arthritis categories.

OBJECTIVE: To identify discrete clusters comprising clinical features and inflammatory biomarkers in children with JIA and to determine cluster alignment with JIA categories. METHODS: A Canadian prospective inception cohort comprising 150 children with JIA was evaluated at baseline (visit 1) and after six months (visit 2). Data included clinical manifestations and inflammation-related biomarkers. Probabilistic principal component analysis identified sets of composite variables, or principal components, from 191 original variables. To discern new clinical-biomarker clusters (clusters), Gaussian mixture models were fit to the data. Newly-defined clusters and JIA categories were compared. Agreement between the two was assessed using Kruskal-Wallis analyses and contingency plots. RESULTS: Three principal components recovered 35% (three clusters) and 40% (five clusters) of the variance in patient profiles in visits 1 and 2, respectively. None of the clusters aligned precisely with any of the seven JIA categories but rather spanned multiple categories. Results demonstrated that the newly defined clinical-biomarker lustres are more homogeneous than JIA categories. CONCLUSION: Applying unsupervised data mining to clinical and inflammatory biomarker data discerns discrete clusters that intersect multiple JIA categories. Results suggest that certain groups of patients within different JIA categories are more aligned pathobiologically than their separate clinical categorizations suggest. Applying data mining analyses to complex datasets can generate insights into JIA pathogenesis and could contribute to biologically based refinements in JIA classification.

Clinical and associated inflammatory biomarker features predictive of short-term outcomes in non-systemic juvenile idiopathic arthritis.

OBJECTIVE: To identify early predictors of disease activity at 18 months in JIA using clinical and biomarker profiling. METHODS: Clinical and biomarker data were collected at JIA diagnosis in a prospective longitudinal inception cohort of 82 children with non-systemic JIA, and their ability to predict an active joint count of 0, a physician global assessment of disease activity of ≤1 cm, and inactive disease by Wallace 2004 criteria 18 months later was assessed. Correlation-based feature selection and ReliefF were used to shortlist predictors and random forest models were trained to predict outcomes. RESULTS: From the original 112 features, 13 effectively predicted 18-month outcomes. They included age, number of active/effused joints, wrist, ankle and/or knee involvement, ESR, ANA positivity and plasma levels of five inflammatory biomarkers (IL-10, IL-17, IL-12p70, soluble low-density lipoprotein receptor-related protein 1 and vitamin D), at enrolment. The clinical plus biomarker panel predicted active joint count = 0, physician global assessment ≤ 1, and inactive disease after 18 months with 0.79, 0.80 and 0.83 accuracy and 0.84, 0.83, 0.88 area under the curve, respectively. Using clinical features alone resulted in 0.75, 0.72 and 0.80 accuracy, and area under the curve values of 0.81, 0.78 and 0.83, respectively. CONCLUSION: A panel of five plasma biomarkers combined with clinical features at the time of diagnosis more accurately predicted short-term disease activity in JIA than clinical characteristics alone. If validated in external cohorts, such a panel may guide more rationally conceived, biologically based, personalized treatment strategies in early JIA.

Complexity in unclassified auto-inflammatory disease: a case report illustrating the potential for disease arising from the allelic burden of multiple variants.

BACKGROUND: Despite recent advances in the diagnosis and understanding of many autoinflammatory diseases, there are still a great number of patients with phenotypes that do not fit any clinically- and/or genetically-defined disorders. CASE PRESENTATION: We describe a fourteen-year-old boy who presented at two and a half years of age with recurrent febrile episodes. Over the course of the disease, the episodes increased in frequency and severity, with new signs and symptoms continuing to appear. Most importantly, these included skin changes, splenomegaly and transaminitis. Only partial control of the disease was achieved with anti-IL-1 therapy. Extensive investigation showed generalized inflammation without immune deficiency, with increased levels of serum amyloid A and several pro-inflammatory cytokines including interferon-γ, as well as an increased type I interferon score. Exome sequence analysis identified P369S and R408Q variants in the MEFV innate immunity regulator, pyrin (MEFV) gene and T260 M and T320 M variants in the NLR family pyrin domain containing 12 (NLRP12) gene. CONCLUSION: Patients with unclassified and/or unexplained autoinflammatory syndromes present diagnostic and therapeutic challenges and collectively form a substantial part of every cohort of patients with autoinflammatory diseases. Therefore, it is important to acquire their full genomic profile through whole exome and/or genome sequencing and present their cases to a broader audience, to facilitate characterization of similar patients. A critical mass of well-characterized cases will lead to improved diagnosis and informed treatment.

Toward New Classification Criteria for Juvenile Idiopathic Arthritis: First Steps, Pediatric Rheumatology International Trials Organization International Consensus.

OBJECTIVE: To revise the current juvenile idiopathic arthritis (JIA) International League of Associations for Rheumatology (ILAR) classification criteria with an evidence-based approach, using clinical and routine laboratory measures available worldwide, to identify homogeneous clinical groups and to distinguish those forms of chronic arthritis typically seen only in children from the childhood counterpart of adult diseases. METHODS: The overall project consists of 4 steps. This work represents Step 1, a Delphi Web-based consensus and Step 2, an international nominal group technique (NGT) consensus conference for the new provisional Pediatric Rheumatology International Trials Organization JIA classification criteria. A future large data collection of at least 1000 new-onset JIA patients (Step 3) followed by analysis and NGT consensus (Step 4) will provide data for the evidence-based validation of the JIA classification criteria. RESULTS: In Step 1, three Delphi rounds of interactions were implemented to revise the 7 ILAR JIA categories. In Step 2, forty-seven questions with electronic voting were implemented to derive the new proposed criteria. Four disorders were proposed: (a) systemic JIA; (b) rheumatoid factor-positive JIA; (c) enthesitis/spondylitis-related JIA; and (d) early-onset antinuclear antibody-positive JIA. The other forms were gathered under the term "others." These will be analyzed during the prospective data collection using a list of descriptors to see whether the clustering of some of them could identify homogeneous entities. CONCLUSION: An international consensus was reached to identify different proposed homogeneous chronic disorders that fall under the historical term JIA. These preliminary criteria will be formally validated with a dedicated project.

Growth and weight gain in children with juvenile idiopathic arthritis: results from the ReACCh-Out cohort.

BACKGROUND: With modern treatments, the effect of juvenile idiopathic arthritis (JIA) on growth may be less than previously reported. Our objective was to describe height, weight and body mass index (BMI) development in a contemporary JIA inception cohort. METHODS: Canadian children newly-diagnosed with JIA 2005-2010 had weight and height measurements every 6 months for 2 years, then yearly up to 5 years. These measurements were used to calculate mean age- and sex-standardized Z-scores, and estimate prevalence and cumulative incidence of growth impairments, and the impact of disease activity and corticosteroids on growth. RESULTS: One thousand one hundred forty seven children were followed for median 35.5 months. Mean Z-scores, and the point prevalence of short stature (height < 2.5th percentile, 2.5% to 3.4%) and obesity (BMI > 95th percentile, 15.8% to 16.4%) remained unchanged in the whole cohort. Thirty-three children (2.9%) developed new-onset short stature, while 27 (2.4%) developed tall stature (>97.5th percentile). Children with systemic arthritis (n = 77) had an estimated 3-year cumulative incidence of 9.3% (95%CI: 4.3-19.7) for new-onset short stature and 34.4% (23-49.4) for obesity. Most children (81.7%) received no systemic corticosteroids, but 1 mg/Kg/day prednisone-equivalent maintained for 6 months corresponded to a drop of 0.64 height Z-scores (0.56-0.82) and an increase of 0.74 BMI Z-scores (0.56-0.92). An increase of 1 in the 10-cm physician global assessment of disease activity maintained for 6 months corresponded to a drop of 0.01 height Z-scores (0-0.02). CONCLUSIONS: Most children in this modern JIA cohort grew and gained weight as children in the general population. About 1 in 10 children who had systemic arthritis, uncontrolled disease and/or prolonged corticosteroid use, had increased risk of growth impairment.

The importance of considering monogenic causes of autoimmunity: A somatic mutation in KRAS causing pediatric Rosai-Dorfman syndrome and systemic lupus erythematosus.

OBJECTIVES: Clinicians need to be aware of the growing list of defined monogenic etiologies of autoimmune diseases. This is particularly relevant when evaluating children, as these rare monogenic forms of autoimmunity tend to present very early in life. METHODS AND RESULTS: By harnessing the transformative power of next generation sequencing, we made the unifying diagnosis of RAS-associated autoimmune leukoproliferative disease (RALD), caused by the somatic gain-of-function p.G13C KRAS mutation, in a boy with the seemingly unrelated immune dysregulatory conditions of Rosai-Dorfman and systemic lupus erythematosus (SLE). CONCLUSIONS: This case expands our understanding of the clinical phenotypes associated with the extremely rare condition of RALD, and emphasizes the importance of always considering the possibility of a monogenic cause for autoimmunity, particularly when the disease manifestations begin early in life and do not follow a typical clinical course.

A Family History of Psoriasis in a First-degree Relative in Children with JIA: to Include or Exclude?

OBJECTIVE: To determine the consequences of disregarding first-degree relatives with psoriasis (FRP) as a classification criterion in juvenile idiopathic arthritis (JIA). METHODS: Criteria were examined in children from a prospective cohort with unclassified and psoriatic JIA. RESULTS: FRP was the most common reason children were unclassified (57/85, 67%); all 57 children could be classified if FRP were disregarded as an exclusion criterion. FRP was a necessary inclusion criterion to classify 11/77 (14.3%) children with psoriatic JIA. CONCLUSION: Eliminating FRP as an exclusion criterion, but keeping it as an inclusion criterion in psoriatic JIA simplifies classification, though it is unclear whether the resulting classification would be better.

The risk and nature of flares in juvenile idiopathic arthritis: results from the ReACCh-Out cohort.

OBJECTIVE: To describe probabilities and characteristics of disease flares in children with juvenile idiopathic arthritis (JIA) and to identify clinical features associated with an increased risk of flare. METHODS: We studied children in the Research in Arthritis in Canadian Children emphasizing Outcomes (ReACCh-Out) prospective inception cohort. A flare was defined as a recurrence of disease manifestations after attaining inactive disease and was called significant if it required intensification of treatment. Probability of first flare was calculated with Kaplan-Meier methods, and associated features were identified using Cox regression. RESULTS: 1146 children were followed up a median of 24 months after attaining inactive disease. We observed 627 first flares (54.7% of patients) with median active joint count of 1, physician global assessment (PGA) of 12 mm and duration of 27 weeks. Within a year after attaining inactive disease, the probability of flare was 42.5% (95% CI 39% to 46%) for any flare and 26.6% (24% to 30%) for a significant flare. Within a year after stopping treatment, it was 31.7% (28% to 36%) and 25.0% (21% to 29%), respectively. A maximum PGA >30 mm, maximum active joint count >4, rheumatoid factor (RF)-positive polyarthritis, antinuclear antibodies (ANA) and receiving disease-modifying antirheumatic drugs (DMARDs) or biological agents before attaining inactive disease were associated with increased risk of flare. Systemic JIA was associated with the lowest risk of flare. CONCLUSIONS: In this real-practice JIA cohort, flares were frequent, usually involved a few swollen joints for an average of 6 months and 60% led to treatment intensification. Children with a severe disease course had an increased risk of flare.

The outcomes of juvenile idiopathic arthritis in children managed with contemporary treatments: results from the ReACCh-Out cohort.

OBJECTIVE: To describe clinical outcomes of juvenile idiopathic arthritis (JIA) in a prospective inception cohort of children managed with contemporary treatments. METHODS: Children newly diagnosed with JIA at 16 Canadian paediatric rheumatology centres from 2005 to 2010 were included. Kaplan-Meier survival curves for each JIA category were used to estimate probability of ever attaining an active joint count of 0, inactive disease (no active joints, no extraarticular manifestations and a physician global assessment of disease activity <10 mm), disease remission (inactive disease >12 months after discontinuing treatment) and of receiving specific treatments. RESULTS: In a cohort of 1104 children, the probabilities of attaining an active joint count of 0 exceeded 78% within 2 years in all JIA categories. The probability of attaining inactive disease exceeded 70% within 2 years in all categories, except for RF-positive polyarthritis (48%). The probability of discontinuing treatment at least once was 67% within 5 years. The probability of attaining remission within 5 years was 46-57% across JIA categories except for polyarthritis (0% RF-positive, 14% RF-negative). Initial treatment included joint injections and non-steroidal anti-inflammatory drugs for oligoarthritis, disease-modifying antirheumatic drugs (DMARDs) for polyarthritis and systemic corticosteroids for systemic JIA. CONCLUSIONS: Most children with JIA managed with contemporary treatments attain inactive disease within 2 years of diagnosis and many are able to discontinue treatment. The probability of attaining remission within 5 years of diagnosis is about 50%, except for children with polyarthritis.

What matters most for patients, parents, and clinicians in the course of juvenile idiopathic arthritis? A qualitative study.

OBJECTIVE: To assess which clinical features are most important for patients, parents, and clinicians in the course of juvenile idiopathic arthritis (JIA). METHODS: Forty-nine people participated in 6 audience-specific focus group discussions and 112 reciprocal interviews in 3 Canadian cities. Participants included youth with JIA, experienced English- and French-speaking parents, novice parents (<6 mos since diagnosis), pediatric rheumatologists, and allied health professionals. Participants discussed the importance of 34 JIA clinical features extracted from medical literature. Transcripts and interview reports underwent qualitative analysis to establish relative priorities for each group. RESULTS: Most study participants considered medication requirements, medication side effects, pain, participant-defined quality of life, and active joints as high priority clinical features of JIA. Active joint count was the only American College of Rheumatology core variable accorded high or medium priority by all groups. Rheumatologists and allied health professionals considered physician global assessment as high priority, but it had very low priority for patients and parents. The parent global assessment was considered high priority by clinicians, medium to high by parents, and low by patients. Child Health Assessment Questionnaire scores were considered low priority by patients and parents, and moderate or high by clinicians. The number of joints with limited motion was given low to very low priority by all groups. Parents gave high priority to arthritis flares. CONCLUSION: If our findings are confirmed, medication requirements, medication side effects, pain, participant-defined quality of life, and active joint counts should figure prominently in describing the course of JIA.