Chronic primary systemic vasculitis (PSV) comprises a group of heterogeneous diseases that are broadly classified by affected blood vessel size, clinical traits and the presence (or absence) of ...anti-neutrophil cytoplasmic antibodies (ANCA) against proteinase 3 (PR3) and myeloperoxidase (MPO). In small vessel vasculitis (SVV), ANCA are not present in all patients, and they are rarely detected in patients with vasculitis involving medium (MVV) and large (LVV) blood vessels. Some studies have demonstrated that lysosome-associated membrane protein-2 (LAMP-2/CD107b) is a target of ANCA in SVV, but its presence and prognostic value in childhood MVV and LVV is not known. This study utilized retrospective sera and clinical data obtained from 90 children and adolescents with chronic PSV affecting small (SVV, n = 53), medium (MVV, n = 16), and large (LVV, n = 21) blood vessels. LAMP-2-ANCA were measured in time-of-diagnosis sera using a custom electrochemiluminescence assay. The threshold for seropositivity was established in a comparator cohort of patients with systemic autoinflammatory disease. The proportion of LAMP-2-ANCA-seropositive individuals and sera concentrations of LAMP-2-ANCA were assessed for associations with overall and organ-specific disease activity at diagnosis and one-year follow up. This study demonstrated a greater time-of-diagnosis prevalence and sera concentration of LAMP-2-ANCA in MVV (52.9% seropositive) and LVV (76.2%) compared to SVV (45.3%). Further, LAMP-2-ANCA-seropositive individuals had significantly lower overall, but not organ-specific, disease activity at diagnosis. This did not, however, result in a greater reduction in disease activity or the likelihood of achieving inactive disease one-year after diagnosis. The results of this study demonstrate particularly high prevalence and concentration of LAMP-2-ANCA in chronic PSV that affects large blood vessels and is seronegative for traditional ANCA. Our findings invite reconsideration of roles for autoantigens other than MPO and PR3 in pediatric vasculitis, particularly in medium- and large-sized blood vessels.
Objective
Individuals with deficiency of adenosine deaminase 2 (DADA2), a recently recognized autosomal recessive disease, present with various systemic vascular and inflammatory manifestations, ...often with young age at disease onset or with early onset of recurrent strokes. Their clinical features and histologic findings overlap with those of childhood‐onset polyarteritis nodosa (PAN), a primary “idiopathic” systemic vasculitis. Despite similar clinical presentation, individuals with DADA2 may respond better to biologic therapy than to traditional immunosuppression. The aim of this study was to screen an international registry of children with systemic primary vasculitis for variants in ADA2.
Methods
The coding exons of ADA2 were sequenced in 60 children and adolescents with a diagnosis of PAN, cutaneous PAN, or unclassifiable vasculitis (UCV), any chronic vasculitis with onset at age 5 years or younger, or history of stroke. The functional consequences of the identified variants were assessed by ADA2 enzyme assay and immunoblotting.
Results
Nine children with DADA2 (5 with PAN, 3 with UCV, and 1 with antineutrophil cytoplasmic antibody–associated vasculitis) were identified. Among them, 1 patient had no rare variants in the coding region of ADA2 and 8 had biallelic, rare variants (minor allele frequency <0.01) with a known association with DADA2 (p.Gly47Arg and p.Gly47Ala) or a novel association (p.Arg9Trp, p.Leu351Gln, and p.Ala357Thr). The clinical phenotype varied widely.
Conclusion
These findings support previous observations indicating that DADA2 has extensive genotypic and phenotypic variability. Thus, screening ADA2 among children with vasculitic rash, UCV, PAN, or unexplained, early‐onset central nervous system disease with systemic inflammation may enable an earlier diagnosis of DADA2.
Objective
There is no standardized approach to the treatment of pediatric antineutrophil cytoplasmic antibody–associated vasculitis (AAV). Because of the rarity of pediatric AAV, randomized trials ...have not been feasible. The present study of the Childhood Arthritis and Rheumatology Research Alliance (CARRA) was undertaken to establish consensus treatment plans (CTPs) for severe pediatric AAV to enable the future study of comparative effectiveness and safety.
Methods
A workgroup of CARRA members (rheumatologists and nephrologists) formed the AAV Workgroup. This group performed a literature review on existing evidence‐based treatments and guidelines for the management of AAV. They determined that the target population for CTP development was patients <18 years of age with new‐onset granulomatosis with polyangiitis (GPA), microscopic polyangiitis, or renal‐limited AAV (eosinophilic GPA was excluded), with presentation confined to those with severe disease (i.e., organ‐ or life‐threatening). Face‐to‐face consensus conferences employed nominal group techniques to identify treatment strategies for remission induction and remission maintenance, data elements to be systematically collected, and outcomes to be measured over time.
Results
The pediatric AAV Workgroup developed 2 CTPs for each of the remission induction and remission maintenance of severe AAV. A glucocorticoid‐weaning regimen for induction and maintenance, a core data set, and outcome measures were also defined. A random sample of CARRA membership voted acceptance of the CTPs for remission induction and remission maintenance, with a 94% (75 of 80) and 98% (78 of 80) approval rate, respectively.
Conclusion
Consensus methodology established standardized CTPs for treating severe pediatric AAV. These CTPs were in principle accepted by CARRA‐wide membership for the evaluation of pragmatic comparative effectiveness in a long‐term registry.
ABSTRACTKawasaki disease (KD) is one of the most common vasculitides of childhood and frequently presents to the emergency department. Although the diagnosis of KD is based on clinical criteria, ...children who do not fulfill the criteria but have sufficient supportive features of KD are diagnosed as having incomplete KD and warrant the same course of therapy as children with classic KD. The diagnosis of incomplete KD is challenging and requires a high index of suspicion. The purpose of this article is to review presenting features of incomplete KD and the diagnostic approach and management of children in the emergency department.
Abstract 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 erythematosis (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.
Regulatory T cell (Treg) therapy is a potential curative approach for a variety of immune-mediated conditions, including autoimmunity and transplantation, in which there is pathological tissue ...damage. In mice, IL-33R (ST2)-expressing Tregs mediate tissue repair by producing the growth factor amphiregulin, but whether similar tissue-reparative Tregs exist in humans remains unclear. We show that human Tregs in blood and multiple tissue types produced amphiregulin, but this was neither a unique feature of Tregs nor selectively upregulated in tissues. Human Tregs in blood, tonsil, synovial fluid, colon, and lung tissues did not express ST2, so ST2
Tregs were engineered via lentiviral-mediated overexpression, and their therapeutic potential for cell therapy was examined. Engineered ST2
Tregs exhibited TCR-independent, IL-33-stimulated amphiregulin expression and a heightened ability to induce M2-like macrophages. The finding that amphiregulin-producing Tregs have a noneffector phenotype and are progressively lost upon TCR-induced proliferation and differentiation suggests that the tissue repair capacity of human Tregs may be an innate function that operates independently from their classical suppressive function.
Abstract
Objective
The COVID-19 pandemic has disrupted healthcare delivery and clinical research worldwide, with data from areas most affected demonstrating an impact on rheumatology care. This study ...aimed to characterize the impact of the pandemic on the initial presentation of JIA and JIA-related research in Canada.
Methods
Data collected from the Canadian Alliance of Pediatric Rheumatology Investigators JIA Registry from the year pre-pandemic (11 March 2019 to 10 March 2020) was compared with data collected during the first year of the pandemic (11 March 2020 to 10 March 2021). Outcomes included time from symptom onset to first assessment, disease severity at presentation and registry recruitment. Proportions and medians were used to describe categorical and continuous variables, respectively.
Results
The median time from symptom onset to first assessment was 138 (IQR 64–365) days pre-pandemic vs 146 (IQR 83–359) days during the pandemic. The JIA category frequencies remained overall stable (44% oligoarticular JIA pre-pandemic, 46.8% pandemic), except for systemic JIA (12 cases pre-pandemic, 1 pandemic). Clinical features, disease activity (cJADAS10), disability (CHAQ) and quality of life (JAQQ) scores were similar between the two cohorts. Pre-pandemic, 225 patients were enrolled, compared with 111 in the pandemic year, with the greatest decrease from March to June 2020.
Conclusions
We did not observe the anticipated delay in time to presentation or increased severity at presentation, suggesting that, within Canada, care adapted well to provide support to new patient consults without negative impacts. The COVID-19 pandemic was associated with an initial 50% decrease in registry enrolment but has since improved.
Chronic primary vasculitis describes a group of complex and rare diseases that are characterized by blood vessel inflammation. Classification of vasculitis subtypes is based predominantly on the size ...of the involved vessels and clinical phenotype. There is a recognized need to improve classification, especially for small-to-medium sized vessel vasculitides, that, ideally, is based on the underlying biology with a view to informing treatment.
We performed RNA-Seq on blood samples from children (n = 41) and from adults (n = 11) with small-to-medium sized vessel vasculitis, and used unsupervised hierarchical clustering of gene expression patterns in combination with clinical metadata to define disease subtypes.
Differential gene expression at the time of diagnosis separated patients into two primary endotypes that differed in the expression of ~3,800 genes in children, and ~1,600 genes in adults. These endotypes were also present during disease flares, and both adult and pediatric endotypes could be discriminated based on the expression of just 20 differentially expressed genes. Endotypes were associated with distinct biological processes, namely neutrophil degranulation and T cell receptor signaling.
Phenotypically similar subsets of small-to-medium sized vessel vasculitis may have different mechanistic drivers involving innate vs. adaptive immune processes. Discovery of these differentiating immune features provides a mechanistic-based alternative for subclassification of vasculitis.
Objective
To characterize the early disease course in childhood‐onset antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV) and the 12‐month outcomes in children with AAV.
Methods
...Eligible subjects were children entered into the Pediatric Vasculitis Initiative study who were diagnosed before their eighteenth birthday as having granulomatosis with polyangiitis (Wegener's), microscopic polyangiitis, eosinophilic granulomatosis with polyangiitis (Churg‐Strauss), or ANCA‐positive pauci‐immune glomerulonephritis. The primary outcome measure was achievement of disease remission (Pediatric Vasculitis Activity Score PVAS of 0) at 12 months with a corticosteroid dosage of <0.2 mg/kg/day. Secondary outcome measures included the rates of inactive disease (PVAS of 0, with any corticosteroid dosage) and rates of improvement at postinduction (4–6 months after diagnosis) and at 12 months, presence of damage at 12 months (measured by a modified Pediatric Vasculitis Damage Index PVDI; score 0 = no damage, score 1 = one damage item present), and relapse rates at 12 months.
Results
In total, 105 children with AAV were included in the study. The median age at diagnosis was 13.8 years (interquartile range 10.9–15.8 years). Among the study cohort, 42% of patients achieved remission at 12 months, 49% had inactive disease at postinduction (4–6 months), and 61% had inactive disease at 12 months. The majority of patients improved, even if they did not achieve inactive disease. An improvement in the PVAS score of at least 50% from time of diagnosis to postinduction was seen in 92% of patients. Minor relapses occurred in 12 (24%) of 51 patients after inactive disease had been achieved postinduction. The median PVDI damage score at 12 months was 1 (range 0–6), and 63% of patients had ≥1 PVDI damage item scored as present at 12 months.
Conclusion
This is the largest study to date to assess disease outcomes in pediatric AAV. Although the study showed that a significant proportion of patients did not achieve remission, the majority of patients responded to treatment. Unfortunately, more than one‐half of this patient cohort experienced damage to various organ systems early in their disease course.
Objective
Identification of the incidence of juvenile idiopathic arthritis (JIA)–associated uveitis and its risk factors is essential to optimize early detection. Data from the Research in Arthritis ...in Canadian Children Emphasizing Outcomes inception cohort were used to estimate the annual incidence of new‐onset uveitis following JIA diagnosis and to identify associated risk factors.
Methods
Data were reported every 6 months for 2 years, then yearly to 5 years. Incidence was determined by Kaplan‐Meier estimators with time of JIA diagnosis as the reference point. Univariate log‐rank analysis identified risk factors and Cox regression determined independent predictors.
Results
In total, 1,183 patients who enrolled within 6 months of JIA diagnosis met inclusion criteria, median age at diagnosis of 9.0 years (interquartile range IQR 3.8–12.9), median follow‐up of 35.2 months (IQR 22.7–48.3). Of these patients, 87 developed uveitis after enrollment. The incidence of new‐onset uveitis was 2.8% per year (95% confidence interval 95% CI 2.0–3.5) in the first 5 years. The annual incidence decreased during follow‐up but remained at 2.1% (95% CI 0–4.5) in the fifth year, although confidence intervals overlapped. Uveitis was associated with young age (<7 years) at JIA diagnosis (hazard ratio HR 8.29, P < 0.001), positive antinuclear antibody (ANA) test (HR 3.20, P < 0.001), oligoarthritis (HR 2.45, P = 0.002), polyarthritis rheumatoid factor negative (HR 1.65, P = 0.002), and female sex (HR 1.80, P = 0.02). In multivariable analysis, only young age at JIA diagnosis and ANA positivity were independent predictors of uveitis.
Conclusion
Vigilant uveitis screening should continue for at least 5 years after JIA diagnosis, and priority for screening should be placed on young age (<7 years) at JIA diagnosis and a positive ANA test.
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