Uncovering the hidden socioeconomic impact of juvenile idiopathic arthritis and paving the way for other rare childhood diseases: an international, cross-disciplinary, patient-centered approach (PAVE Consortium).

BACKGROUND: Juvenile idiopathic arthritis (JIA) refers to a heterogeneous group of rheumatic conditions in children. Novel drugs have greatly improved disease outcomes; however, outcomes are impacted by limited awareness of the importance of early diagnosis and adequate treatment, and by differences in access across health systems. As a result, patients with JIA continue to be at risk for short- and long-term morbidity, as well as impacts on virtually all aspects of life of the child and family. MAIN BODY: Literature on the socioeconomic burden of JIA is largely focused on healthcare costs, and the impact of JIA on patients, families, and communities is not well understood. High quality evidence on the impact of JIA is needed to ensure that patients are receiving necessary support, timely diagnostics, and adequate treatment, and to inform decision making and resource allocation. This commentary introduces the European Joint Programme on Rare Diseases: Producing an Arthritis Value Framework with Economic Evidence: Paving the Way for Rare Childhood Diseases (PAVE) project, which will co-develop a patient-informed value framework to measure the impact of JIA on individuals and on society. With a patient-centered approach, fundamental to PAVE is the involvement of three patient advocacy organizations from Canada, Israel, and Europe, as active research partners co-designing all project phases and ensuring robust patient and family engagement. The framework will build on the findings of projects from six countries: Canada, Germany, Switzerland, Spain, Israel, and Belgium, exploring costs, outcomes (health, well-being), and unmet needs (uveitis, mental health, equity). CONCLUSION: This unique international collaboration will combine evidence on costs (from family to societal), outcomes (clinical, patient and family outcomes), and unmet needs, to co-design and build a framework with patients and families to capture the full impact of JIA. The framework will support the development of high-quality evidence, encompassing economic and clinical considerations, unmet needs, and patient perspectives, to inform equitable resource allocation, health system planning, and quality of care better aligned with the needs of children with JIA, their families, and communities. Knowledge gained from this novel approach may pave the way forward to be applied more broadly to other rare childhood diseases.

Validation of the EQ-5D-Y-5L parent-proxy version among children with juvenile idiopathic arthritis.

OBJECTIVES: Juvenile idiopathic arthritis (JIA) is the most common type of arthritis among children. It can cause joint pain and permanent physical damage, which affects mobility and daily activities. The EQ-5D-Y-3L self-report version has been validated in JIA, but the validity of EQ-5D-Y-5L remains unknown. We examined the psychometric properties of the EQ-5D-Y-5L parent-proxy version among children with JIA. METHODS: We used data from the Understanding Childhood Arthritis Network Canadian-Dutch collaboration study cohort, including patients with new-onset JIA, and those starting or stopping biologics. Clinical data and the parent-proxy version of the childhood health assessment questionnaire (CHAQ) and EQ-5D-Y-5L were collected. We evaluated the ceiling and floor effect; convergent and divergent validity using Spearman's rank correlation; known-group validity using one-way ANOVA (Analysis of Variance) and effect size; and informativity using Shannon's evenness index. RESULTS: 467 patient visits representing 407 patients were analyzed. The EQ-5D-Y-5L had no ceiling/floor effect. The EQ-5D-Y-5L showed good convergent (e.g., EQ-5D-Y-5L pain/discomfort dimension vs. CHAQ pain index (Spearman's r = 0.74, 95% confidence interval (C.I.): 0.69-0.79)), divergent (e.g., EQ-5D-Y-5L pain/discomfort dimension vs. CHAQ eating dimension (Spearman's r = 0.19, 95% C.I.: 0.09-0.29)) and known-group validity (e.g., mean EQ-5D-Y-5L level summary score for patients with inactive versus active disease status, 6.34 vs. 10.52 (p < 0.001, effect size = 1.20 (95% C.I.: 0.95-1.45)). Shannon's evenness index ranged from 0.52 to 0.88, suggesting most dimensions had relatively even distributions. CONCLUSIONS: In this patient sample, EQ-5D-Y-5L parent-proxy version exhibited construct validity and informativity, suggesting the EQ-5D-Y-5L can be used to measure the quality of life of children with JIA.

Juvenile idiopathic arthritis is the most common type of arthritis affecting children. It can cause pain and permanent physical damage to joints and affects mobility and daily activities. While there is no cure yet, new therapies like biologics are effective. However, biologics are expensive and can have side effects. To decide when is the best time to use these biologics, we need to understand their cost and impact on patients. EQ-5D-Y-5L is a common tool to measure how the disease affects a patient's life. It is unclear whether EQ-5D-Y-5L works well for patients with juvenile idiopathic arthritis. In this study, we compared the EQ-5D-Y-5L to another tool that measures how the illness impacts functional ability. We looked to see if the EQ-5D-Y-5L could tell the difference between children who were more or less sick. We also assessed whether the EQ-5D-Y-5L has the ability to describe patients with different severity in health status. This study indicates that the EQ-5D-Y-5L is a good tool to measure the health of patients with juvenile idiopathic arthritis. Findings from this study support the use of the EQ-5D-Y-5L among this patient population in future clinical trials and research studies.

Autologous haematopoiesis stem cell transplantation (AHSCT) for treatment-refractory autoimmune diseases in children.

OBJECTIVES: To evaluate the long-term effectiveness and safety of autologous haematopoiesis stem cell transplantation (AHSCT) for severe, refractory autoimmune diseases in paediatric patients. METHODS: A single-centre study of consecutive children and adolescents with refractory autoimmune diseases undergoing AHSCT was performed. Demographics, clinical, laboratory features, pre-AHSCT medications, disease activity and functional status were captured. The primary outcome was progression-free survival, secondary outcomes included overall survival, disease-specific treatment responses, disease activity at the last follow-up and AHSCT safety. RESULTS: The study included seven patients: two systemic sclerosis, one pansclerotic morphoea, one eosinophilic fasciitis, one juvenile dermatomyositis and two patients with systemic juvenile idiopathic arthritis; four women, three men median age at AHSCT of 10 years (7-19), median follow-up post-AHSCT of 17 years. Median progression-free survival and overall survival was 4.2 years (95% CI: 0.98 to 8.3) and 17 years (95% CI: 11.8 to 22.1), respectively. Progression-free survival rates at 1 and 2 years post-AHSCT were 100% and 77%, respectively. All children survived. All patients are in clinical remission, only four require ongoing immunotherapy. SAFETY: Three experienced infections, including HHV6, Candida and Ralstonia sepsis; one developed a systemic inflammatory response syndrome; two new onset secondary autoimmune diseases including autoimmune haemolytic anaemia, Graves' disease and one was found to have a breast fibroadenoma. Treatment toxicity: one cyclophosphamide-associated transient renal failure and pericardial effusion, one patient with amenorrhoea/infertility. CONCLUSIONS: AHSCT was an effective and safe approach for children and adolescents with treatment-refractory autoimmune diseases. The indication and timing of transplantation requires a careful consideration and a multidisciplinary approach.

Refining Treat-to-Target (T2T) strategies in Cryopyrin-Associated Periodic Syndromes (CAPS): The role of inflammatory markers.

OBJECTIVES: Cryopyrin-Associated Periodic Syndromes (CAPS) encompasses a spectrum of Interleukin-1 (IL-1) driven systemic diseases with dramatic individual and societal burden. The study aimed to identify parameters and instruments to refine real-life Treat-to-Target (T2T) strategies and control CAPS disease activity. METHODS: A single-centre, longitudinal study of consecutive children and adults diagnosed with CAPS and treated with anti-IL-1 therapy was performed. Demographics, clinical phenotype and NLRP3 gene variants in addition to serial inflammatory markers and Physician and Patient/Parent Global Assessments (PGA/PPGA) were captured. Effectiveness of anti-IL-1 T2T strategies and factors associated with therapy escalation were determined. RESULTS: A total of 54 CAPS patients with 759 follow-up visits were included; 31/54 (57%) were children; the median follow-up was 108 months (12-620). The moderate CAPS phenotype was present in 89%; overall 59% had pathogenic/likely pathogenic NLRP3 variants. Therapy adjustments were documented in 50/759 visits including 35 therapy escalations and 15 reductions; 74% of the therapy escalation visits were for children. At time of visit, 63% showed moderate, 37% severe clinical disease activity. Inflammatory markers remained largely normal. Significant improvement was observed in both PGA/PPGA throughout the study (p< 0.01). At the last follow-up, 96% of patients achieved remission. CONCLUSION: Guidance for refining real-life T2T strategies in CAPS cohorts can be drawn from serial assessments of PGA and PPGA reliably reflecting changes in disease activity. Individual parameters including age and NLRP3 gene variants are important predictors, while the sensitivity of inflammatory markers is limited due to the confounding anti-IL-1 therapy.

Real-World Biomarkers for Pediatric Takayasu Arteritis.

Childhood-onset Takayasu arteritis (TA) is a rare, heterogeneous disease with limited diagnostic markers. Our objective was to identify and classify all candidates for biomarkers of TA diagnosis in children reported in the literature. A systematic literature review (PRISMA) of MEDLINE, EMBASE, Wiley Cochrane Library, ClinicalTrias.gov, and WHO ICTRP for articles related to TA in the pediatric age group between January 2000 and August 2023 was performed. Data on demographics, clinical features, laboratory measurements, diagnostic imaging, and genetic analysis were extracted. We identified 2026 potential articles, of which 52 studies (81% case series) met inclusion criteria. A total of 1067 TA patients were included with a peak onset between 10 and 15 years. Childhood-onset TA predominantly presented with cardiovascular, constitutional, and neurological symptoms. Laboratory parameters exhibited a low sensitivity and specificity. Imaging predominantly revealed involvement of the abdominal aorta and renal arteries, with magnetic resonance angiography (MRA) being the preferred imaging modality. Our review confirms the heterogeneous presentation of childhood-onset TA, posing significant challenges to recognition and timely diagnosis. Collaborative, multinational efforts are essential to better understand the natural course of childhood-onset TA and to identify accurate biomarkers to enhance diagnosis and disease management, ultimately improving patient outcomes.

Optimized Treatment of Interleukin (IL-1)-Mediated Autoinflammatory Diseases: Impact of Disease Activity-Based Treatment Adjustments.

Background: Effective control of disease activity in Interleukin-1 autoinflammatory diseases (IL-1 AID) is crucial to prevent damage. The aim was to longitudinally analyze the impact of protocolized disease activity-based treatment adjustments in a real-life cohort. Methods: A single-center study of consecutive children with IL-1 AID followed between January 2016 and December 2019 was performed. Demographics, phenotypes, genotypes, inflammatory markers, physician (PGA), and patient/parent (PPGA) global assessment were captured. Disease activity and treatment changes were assessed. The impact of distinct parameters on disease activity trajectories was analyzed. Results: A total of 56 children were included, median follow-up was 2.1 years reflecting 361 visits. Familial Mediterranean Fever was the most common IL-1 AID. At the first visit, 68% of the patients had moderate/severe disease activity. Disease activity-based treatment adjustments were required in 28/56 children (50%). At last follow-up, 79% had a well-controlled disease. Both PGA and PPGA decreased significantly over time (p < 0.001; p < 0.017, respectively), however, both differed statistically at last visit (p < 0.001). Only PGA showed a significant estimated mean decrease across all IL-1 AID over time. Conclusions: Disease activity-based treatment adjustments can effectively refine treat-to-target strategies, enable personalized precision health approaches, and improve outcomes in children with IL-1 AID.

Non-invasive biomarkers of disease activity and organ damage in ANCA-associated vasculitis: a systematic review.

BACKGROUND: In anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), histopathological assessment of affected tissue is often necessary for diagnosis and assessment of disease extent. There is a requirement for validated non-invasive biomarkers to avoid the need for serial tissue biopsies. METHODS: A systematic review of scientific databases from 2012 until present was performed to identify studies fulfilling the inclusion criteria. Studies were assessed for quality using the Strengthening the Reporting of Observational Studies in Epidemiology checklist for cohort, case-control and cross-sectional studies and the Risk of Bias Assessment tool for Non-randomised Studies, or the Cochrane Risk of Bias tool 2.0 for randomised controlled trials. A descriptive synthesis of the data for non-invasive (blood-based or urinary) biomarkers of AAV-related disease activity and organ damage was performed. RESULTS: Twenty-two high quality studies were included. These articles reported the value of blood-based and urinary biomarkers including anti-neutrophil cytoplasmic antibodies, immune cells, complement factors, gene expression profiles, cytokines, chemokines and other proteins in the assessment of disease activity and/or organ damage in patients with AAV. Many of these biomarkers involve the alternative complement pathway, neutrophil activation and macrophage activation. CONCLUSION: This is the first contemporary systematic review synthesising the value of non-invasive biomarkers of AAV-related disease activity and organ damage. The incorporation of individual markers in combined biomarker profiles might enhance clinical decision-making. Many unmet needs were identified; few studies involve oeosinophilic granulomatosis with polyangiitis and patients with childhood-onset AAV. Further validation of the candidate biomarkers is warranted in large prospective studies to bridge the existing knowledge gaps and apply precision health to systemic vasculitis.

Long-Term Efficacy and Safety of Canakinumab in Patients With Tumor Necrosis Factor Receptor-Associated Periodic Syndrome: Results From a Phase III Trial.

OBJECTIVE: We aimed at assessing efficacy, safety, and tolerability of canakinumab in patients with tumor necrosis factor receptor-associated periodic syndrome (TRAPS) during a 72-week long-term, open-label extension of the CLUSTER study. METHODS: Patients received open-label canakinumab 150 or 300 mg, either every 4 weeks (q4w) or every 8 weeks, with up-titration permitted after on-treatment flares (maximum dose: 300 mg q4w). Efficacy assessments included physician global assessment of disease activity, number of flares, and serum C-reactive protein (CRP) and serum amyloid A protein (SAA) levels. Adverse events were also reported. Results are described for the overall population and according to the cumulative dose of canakinumab adjusted for body weight (<36 mg/kg or ≥36 mg/kg). RESULTS: Of 53 patients entering the final phase (epoch 4) of CLUSTER, 51 completed the treatment. At the end of epoch 4, >94% of patients achieved no or minimal disease activity. Most patients had either no (69.8%) or one flare (24.5%), whereas at baseline, the median number of flares was 9.0 per year. Median CRP levels remained at <10 mg/L. Median SAA concentrations were largely unchanged, with medians of 11.5 mg/L and 14.5 mg/L in the <36 mg/kg and ≥36 mg/kg groups, respectively, at the end of the study. No unexpected safety findings were identified. CONCLUSION: Control of disease activity, with low flare incidence, was maintained with long-term canakinumab treatment in patients with TRAPS during the 72-week final epoch of the CLUSTER study, with no new safety findings.

Quantifying hospital-associated costs, and accompanying travel costs and productivity losses, before and after withdrawing tumour necrosis factor-alfa inhibitors in juvenile idiopathic arthritis.

OBJECTIVE: To quantify differences in hospital-associated costs, and accompanying travel costs and productivity losses, before and after withdrawing TNFi in JIA patients. METHODS: Retrospective analysis of prospectively collected data from electronic medical records of paediatric JIA patients treated with TNFi, which were either immediately discontinued, spaced (increased treatment interval) or tapered (reduced subsequent doses). Costs of hospital-associated resource use (consultations, medication, radiology procedures, laboratory testing, procedures under general anaesthesia, hospitalisation) and associated travel costs and productivity losses were quantified during clinically inactive disease until TNFi withdrawal (pre-withdrawal period) and compared with costs during the first and second year after withdrawal initiation (first and second year post-withdrawal). RESULTS: Fifty-six patients were included of whom 26 immediately discontinued TNFi, 30 spaced and zero tapered. Mean annual costs were €9,165/patient on active treatment (pre-withdrawal) and decreased significantly to €5,063/patient (-44.8%) and €6,569/patient (-28.3%) in the first and second year post-withdrawal, respectively (p< 0.05). Of these total annual costs, travel costs plus productivity losses were €834/patient, €1,180/patient, and €1,320/patient, in the three periods respectively. Medication comprised 80.7%, 61.5% and 72.4% of total annual costs in the pre-withdrawal, first, and second year post-withdrawal period, respectively. CONCLUSION: In the first two years after initiating withdrawal, the total annual costs are decreased compared with the pre-withdrawal period. However, cost reductions were lower in the second year compared with the first year post-withdrawal, primarily due to restarting or intensifying biologics. To support biologic withdraw decisions, future research should assess the full long-term societal cost impacts, and include all biologics.

Neuroimaging Scoring Tools to Differentiate Inflammatory Central Nervous System Small-Vessel Vasculitis: A Need for Artificial Intelligence/Machine Learning?-A Scoping Review.

Neuroimaging has a key role in identifying small-vessel vasculitis from common diseases it mimics, such as multiple sclerosis. Oftentimes, a multitude of these conditions present similarly, and thus diagnosis is difficult. To date, there is no standardized method to differentiate between these diseases. This review identifies and presents existing scoring tools that could serve as a starting point for integrating artificial intelligence/machine learning (AI/ML) into the clinical decision-making process for these rare diseases. A scoping literature review of EMBASE and MEDLINE included 114 articles to evaluate what criteria exist to diagnose small-vessel vasculitis and common mimics. This paper presents the existing criteria of small-vessel vasculitis conditions and mimics them to guide the future integration of AI/ML algorithms to aid in diagnosing these conditions, which present similarly and non-specifically.

A decade of progress in juvenile idiopathic athritis treatments and outcomes in Canada: results from ReACCh-Out and the CAPRI registry.

OBJECTIVE: To assess changes in juvenile idiopathic arthritis (JIA) treatments and outcomes in Canada, comparing a 2005-2010 and a 2017-2021 inception cohorts. METHODS: Patients enrolled within three months of diagnosis in the Research in Arthritis in Canadian Children Emphasizing Outcomes (ReACCh-Out) and the Canadian Alliance of Pediatric Rheumatology Investigators Registry (CAPRI) cohorts were included. Cumulative incidences of drug starts and outcome attainment within 70 weeks of diagnosis were compared with Kaplan Meier survival analysis and multivariable Cox regression. RESULTS: The 2005-2010 and 2017-2021 cohorts included 1128 and 721 patients, respectively. JIA category distribution and baseline clinical juvenile idiopathic arthritis disease activity (cJADAS10) scores at enrolment were comparable. By 70 weeks, 6% of patients (95% CI 5, 7) in the 2005-2010 and 26% (23, 30) in the 2017-2021 cohort had started a biologic DMARD (bDMARD), and 43% (40, 47) and 60% (56, 64) had started a conventional DMARD (cDMARD), respectively. Outcome attainment was 64% (61, 67) and 83% (80, 86) for Inactive disease (Wallace criteria), 69% (66, 72) and 84% (81, 87) for minimally active disease (cJADAS10 criteria), 57% (54, 61) and 63% (59, 68) for pain control (<1/10), and 52% (47, 56) and 54% (48, 60) for a good health-related quality of life. CONCLUSION: Although baseline disease characteristics were comparable in the 2005-2010 and 2017-2021 cohorts, cDMARD and bDMARD use increased with a concurrent increase in minimally active and inactive disease. Improvements in parent and patient reported outcomes were smaller than improvements in disease activity.

Withdrawing biologics in non-systemic JIA: what matters to pediatric rheumatologists?

OBJECTIVE: Approximately one third of children with JIA receive biologic therapy, but evidence on biologic therapy withdrawal is lacking. This study aims to increase our understanding of whether and when pediatric rheumatologists postpone a decision to withdraw biologic therapy in children with clinically inactive non-systemic JIA. METHODS: A survey containing questions about background characteristics, treatment patterns, minimum treatment time with biologic therapy, and 16 different patient vignettes, was distributed among 83 pediatric rheumatologists in Canada and the Netherlands. For each vignette, respondents were asked whether they would withdraw biologic therapy at their minimum treatment time, and if not, how long they would continue biologic therapy. Statistical analysis included descriptive statistics, logistic and interval regression analysis. RESULTS: Thirty-three pediatric rheumatologists completed the survey (40% response rate). Pediatric rheumatologists are most likely to postpone the decision to withdraw biologic therapy when the child and/or parents express a preference for continuation (OR 6.3; p < 0.001), in case of a flare in the current treatment period (OR 3.9; p = 0.001), and in case of uveitis in the current treatment period (OR 3.9; p < 0.001). On average, biologic therapy withdrawal is initiated 6.7 months later when the child or parent prefer to continue treatment. CONCLUSION: Patient's and parents' preferences were the strongest driver of a decision to postpone biologic therapy withdrawal in children with clinically inactive non-systemic JIA and prolongs treatment duration. These findings highlight the potential benefit of a tool to support pediatric rheumatologists, patients and parents in decision making, and can help inform its design.

Paediatric inflammatory multisystem syndrome in Canada: population-based surveillance and role of SARS-CoV-2 linkage.

BACKGROUND: Paediatric inflammatory multisystem syndrome (PIMS) is a rare condition temporally associated with SARS-CoV-2 infection. Using national surveillance data, we compare presenting features and outcomes among children hospitalized with PIMS by SARS-CoV-2 linkage, and identify risk factors for intensive care (ICU). METHODS: Cases were reported to the Canadian Paediatric Surveillance Program by a network of >2800 pediatricians between March 2020 and May 2021. Patients with positive versus negative SARS-CoV-2 linkages were compared, with positive linkage defined as any positive molecular or serologic test or close contact with confirmed COVID-19. ICU risk factors were identified with multivariable modified Poisson regression. RESULTS: We identified 406 children hospitalized with PIMS, including 49.8% with positive SARS-CoV-2 linkages, 26.1% with negative linkages, and 24.1% with unknown linkages. The median age was 5.4 years (IQR 2.5-9.8), 60% were male, and 83% had no comorbidities. Compared to cases with negative linkages, children with positive linkages experienced more cardiac involvement (58.8% vs. 37.4%; p < 0.001), gastrointestinal symptoms (88.6% vs. 63.2%; p < 0.001), and shock (60.9% vs. 16.0%; p < 0.001). Children aged ≥6 years and those with positive linkages were more likely to require ICU. CONCLUSIONS: Although rare, 30% of PIMS hospitalizations required ICU or respiratory/hemodynamic support, particularly those with positive SARS-CoV-2 linkages. IMPACT: We describe 406 children hospitalized with paediatric inflammatory multisystem syndrome (PIMS) using nationwide surveillance data, the largest study of PIMS in Canada to date. Our surveillance case definition of PIMS did not require a history of SARS-CoV-2 exposure, and we therefore describe associations of SARS-CoV-2 linkages on clinical features and outcomes of children with PIMS. Children with positive SARS-CoV-2 linkages were older, had more gastrointestinal and cardiac involvement, and hyperinflammatory laboratory picture. Although PIMS is rare, one-third required admission to intensive care, with the greatest risk amongst those aged ≥6 years and those with a SARS-CoV-2 linkage.

What matters most to pediatric rheumatologists in deciding whether to discontinue biologics in a child with juvenile idiopathic arthritis? A best-worst scaling survey.

OBJECTIVES: Care for JIA patients has been transformed in the biologics era; however, biologics carry important (although rare) risks and are costly. Flares after biological withdrawal are seen frequently, yet there is little clinical guidance to identify which patients in clinical remission can safely have their biologic discontinued (by stopping or tapering). We examined what characteristics of the child or their context are important to pediatric rheumatologists when making the decision to discuss withdrawal of biologics. METHODS: We conducted a survey including a best-worst scaling (BWS) exercise in pediatric rheumatologists who are part of the UCAN CAN-DU network to assess the relative importance of 14 previously identified characteristics. A balanced incomplete block design was used to generate choice tasks. Respondents evaluated 14 choice sets of 5 characteristics of a child with JIA and identified for each set which was the most and least important in the decision to offer withdrawal. Results were analyzed using conditional logit regression. RESULTS: Fifty-one (out of 79) pediatric rheumatologists participated (response rate 65%). The three most important characteristics were how challenging it was to achieve remission, history of established joint damage, and time spent in remission. The three least important characteristics were history of temporomandibular joint involvement, accessibility of biologics, and the patient's age. CONCLUSIONS: These findings give quantitative insight about factors important to pediatric rheumatologists' decision-making about biologic withdrawal. In addition to high quality clinical evidence, further research is needed to understand the perspective of patients and families to inform shared decision-making about biologic withdrawal for JIA patients with clinically inactive disease. Key Points ● What is already known on this topic-there is limited clinical guidance for pediatric rheumatologists in making decisions about biologic withdrawal for patients with juvenile idiopathic arthritis who are in clinical remission. ● What this study adds-this study quantitatively examined what characteristic of the child in clinical remission, or of their context, are most important to pediatric rheumatologists in deciding whether to offer withdrawal of biologics. ● How this study might affect research, practice or policy-understanding of these characteristics can provide useful information to other pediatric rheumatologists in making their decisions, and may guide areas to focus on for future research.

Developing a Framework of Cost Elements of Socioeconomic Burden of Rare Disease: A Scoping Review.

BACKGROUND AND OBJECTIVE: Rare diseases place a significant burden on patients, families, the healthcare system, and society. Evidence on the socioeconomic burden of rare disease is limited and mostly reflects diseases where treatments are available. We developed a framework encompassing recommended cost elements for studies of the socioeconomic burden of rare diseases. METHODS: A scoping review, conducted in five databases (Cochrane Library, EconLit, Embase, MEDLINE, and APA PsycINFO), identified English language publications from 2000 to 2021 presenting frameworks developed for determining, measuring or valuing costs for rare or chronic diseases. Cost elements were extracted and used to develop a literature-informed framework. Structured feedback was gathered from experts in rare diseases, health economics/health services, and policy research to revise the framework. RESULTS: Of 2990 records identified, eight papers were included and informed our preliminary framework; three focused on rare disease and five on chronic disease. Following expert input, we developed a framework consisting of nine cost categories (inpatient, outpatient, community, healthcare products/goods, productivity/education, travel/accommodation, government benefits, family impacts, and other), with several cost elements within each category. Our framework includes unique costs, added from the expert feedback, including genetic testing to inform treatment, use of private laboratories or out-of-country testing, family involvement in foundations and organizations, and advocacy costs for special access programs. CONCLUSIONS: Our work is the first to identify a comprehensive list of cost elements for rare disease for use by researchers and policy makers to fully capture socioeconomic burden. Use of the framework will increase the quality and comparability of future studies. Future work should focus on measuring and valuing these costs through onset, diagnosis, and post-diagnosis.

Distinct phenotypes of multisystem inflammatory syndrome in children: a cohort study.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a severe disease with an unpredictable course and a substantial risk of cardiogenic shock. Our objectives were to (a) compare MIS-C phenotypes across the COVID-19 pandemic, (b) identify features associated with intensive care need and treatment with biologic agents. METHODS: Youth aged 0-18 years, fulfilling the World Health Organization case definition of MIS-C, and admitted to the Alberta Children's Hospital during the first four waves of the COVID-19 pandemic (May 2020-December 2021) were included in this cohort study. Demographic, clinical, biochemical, imaging, and treatment data were captured. RESULTS: Fifty-seven MIS-C patients (median age 6 years, range 0-17) were included. Thirty patients (53%) required intensive care. Patients in the third or fourth wave (indicated as phase 2 of the pandemic) presented with higher peak ferritin (µg/l, median (IQR) = 1134 (409-1806) vs. 370 (249-629), P = 0.001), NT-proBNP (ng/l, median (IQR) = 12,217 (3013-27,161) vs. 3213 (1216-8483), P = 0.02) and D-dimer (mg/l, median (IQR) = 4.81 (2.24-5.37) vs. 2.01 (1.27-3.34), P = 0.004) levels, and higher prevalence of liver enzyme abnormalities (n(%) = 17 (68) vs. 11 (34), P = 0.02), hypoalbuminemia (n(%) = 24 (100) vs. 25 (81), P = 0.03) and thrombocytopenia (n(%) 18 (72) vs. 11 (34), P = 0.007) compared to patients in the first two waves (phase 1). These patients had a higher need of non-invasive/mechanical ventilation (n(%) 4 (16) vs. 0 (0), P = 0.03). Unsupervised clustering analyses classified 47% of the patients in the correct wave and 74% in the correct phase of the pandemic. NT-proBNP was the only significant contributor to the need for intensive care in all applied multivariate regression models. Treatment with biologic agents was significantly associated with peak CRP (mg/l (median, IQR = 240.9 (132.9-319.4) vs. 155.8 (101.0-200.7), P = 0.02) and ferritin levels (µg/l, median (IQR) = 1380 (509-1753) vs. 473 (280-296)). CONCLUSIONS: MIS-C patients in a later stage of the pandemic displayed a more severe phenotype, reflecting the impact of distinct SARS-CoV-2 variants. NT-proBNP emerged as the most crucial feature associated with intensive care need, underscoring the importance of monitoring.

Association Between HLA-DPB1 and Antineutrophil Cytoplasmic Antibody-Associated Vasculitis in Children.

OBJECTIVE: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare, life-threatening inflammation of blood vessels that can affect both adults and children. Compared to adult-onset disease, AAV is especially rare in children, with an annual prevalence of 0.5-6.4 cases per million children. The etiology of AAV remains largely unknown, and both environmental and genetic factors are likely involved. The present study was undertaken to explore the genetic susceptibility factors recently identified in adult patients, including HLA-DP and HLA-DQ, in pediatric patients. METHODS: We performed a genome-wide association study of pediatric AAV in patients of European ancestry (n = 63 AAV cases, n = 315 population-matched controls). RESULTS: We identified a significant genetic association between pediatric AAV and the HLA-DPB1*04:01 allele (P = 1.5 × 10-8 , odds ratio [OR] 3.5), with a stronger association observed in children with proteinase 3-ANCA positivity than in children with myeloperoxidase-ANCA positivity. Among the HLA alleles, the HLA-DPB1*04:01 allele was the most highly associated with AAV, although not significantly, in a follow-up adult AAV cohort (P = 2.6 × 10-4 , OR 0.4). T cell receptor and interferon signaling pathways were also shown to be enriched in the pediatric AAV cohort. CONCLUSION: The HLA-DPB1 locus showed an association with pediatric AAV, as similarly shown previously in adult AAV. Despite the difference in the age of onset, these findings suggest that childhood- and adult-onset vasculitis share a common genetic predisposition. The identification of genetic variants contributing to AAV is an important step to improved classification tools and treatment strategies.

Pharmacological treatment patterns in patients with juvenile idiopathic arthritis in the Netherlands: a real-world data analysis.

OBJECTIVE: To investigate medication prescription patterns among children with JIA, including duration, sequence and reasons for medication discontinuation. METHODS: This study is a single-centre, retrospective analysis of prospective data from the electronic medical records of JIA patients receiving systemic therapy aged 0-18 years between 1 April 2011 and 31 March 2019. Patient characteristics (age, gender, JIA subtype) and medication prescriptions were extracted and analysed using descriptive statistics, Sankey diagrams and Kaplan-Meier survival methods. RESULTS: Over a median of 4.2 years follow-up, the 20 different medicines analysed were prescribed as monotherapy (n = 15) or combination therapy (n = 48 unique combinations) among 236 patients. In non-systemic JIA, synthetic DMARDs were prescribed to almost all patients (99.5%), and always included MTX. In contrast, 43.9% of non-systemic JIA patients received a biologic DMARD (mostly adalimumab or etanercept), ranging from 30.9% for oligoarticular persistent ANA-positive JIA, to 90.9% for polyarticular RF-positive JIA. Among systemic JIA, 91.7% received a biologic DMARD (always including anakinra). When analysing medication prescriptions according to their class, 32.6% involved combination therapy. In 56.8% of patients, subsequent treatment lines were initiated after unsuccessful first-line treatment, resulting in 68 unique sequences. Remission was the most common reason for DMARD discontinuation (44.7%), followed by adverse events (28.9%) and ineffectiveness (22.1%). CONCLUSION: This paper reveals the complexity of pharmacological treatment in JIA, as indicated by: the variety of mono- and combination therapies prescribed, substantial variation in medication prescriptions between subtypes, most patients receiving two or more treatment lines, and the large number of unique treatment sequences.

Resource use and disease severity of children hospitalized for COVID-19 versus multisystem inflammatory syndrome in children (MIS-C) in Canada.

Background: Direct comparisons of paediatric hospitalizations for acute coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) can inform health system planning. We describe the absolute and relative hospital burden of acute paediatric COVID-19 and MIS-C in Canada. Methods: This national prospective study was conducted via the Canadian Paediatric Surveillance Program from March 2020-May 2021. Children younger than 18 years old and hospitalized for acute COVID-19 or MIS-C were included in the analysis. Outcomes included supplemental oxygen (low-flow oxygen or high-flow nasal cannula), ventilation (non-invasive or conventional mechanical), vasopressors, paediatric intensive care unit (PICU) admission, or death. Adjusted risk differences (aRD) and 95% confidence intervals (CI) were calculated to identify factors associated with each diagnosis. Results: Overall, we identified 330 children hospitalized for acute COVID-19 (including five deaths) and 208 hospitalized for MIS-C (including zero deaths); PICU admission was required for 49.5% of MIS-C hospitalizations versus 18.2% of acute COVID-19 hospitalizations (aRD 20.3; 95% CI, 9.9-30.8). Resource use differed by age, with children younger than one year hospitalized more often for acute COVID-19 (aRD 43.4% versus MIS-C; 95% CI, 37.7-49.1) and more children 5-11 years hospitalized for MIS-C (aRD 38.9% vs. acute COVID-19; 95% CI, 31.0-46.9). Conclusion: While there were more hospitalizations and deaths from acute paediatric COVID-19, MIS-C cases were more severe, requiring more intensive care and vasopressor support. Our findings suggest that both acute COVID-19 and MIS-C should be considered when assessing the overall burden of severe acute respiratory syndrome coronavirus 2 in hospitalized children.

Central nervous system manifestations of monogenic autoinflammatory disorders and the neurotropic features of SARS-CoV-2: Drawing the parallels.

Central nervous system (CNS) involvement in monogenic autoinflammatory disorders (AID) is increasingly recognized and can be life threatening. Therefore, a low threshold to consider CNS disease should be maintained in patients with systemic inflammation. Hyperinflammation is also a key feature of severe acute COVID-19 and post COVID-19 entities such as multisystem inflammatory syndrome in children. Like AID, COVID-19 patients can present with severe CNS involvement. The impact of COVID-19 on AID and CNS involvement in particular is still obscure, nevertheless dreaded. In the current review, we synthesize the spectrum of CNS manifestations in monogenic AID. We explore common pathophysiological and clinical features of AID and COVID-19. Moreover, we assess the impact of immune dysregulation associated with SARS-CoV-2 infections and post COVID-19 hyperinflammation in AID. The striking commonalities found between both disease entities warrant caution in the management of AID patients during the current pandemic.