Dissemination of a Pediatric Musculoskeletal POCUS Scoring System via Virtual Education: A Proof-of-Concept Study.

Point of care pediatric musculoskeletal POCUS scanning and scoring protocols for childhood arthritis have emerged in recent years. However, pediatric musculoskeletal POCUS curricula in rheumatology fellowship programs are limited due to availability of trained faculty and resources. This proof-of-concept study investigated the effectiveness of educational methods for a pediatric musculoskeletal POCUS scoring protocol among fellows and physicians of differing subspecialties. Educational methods assessed included recorded videos and virtual review sessions. Effectiveness was assessed by calculating interrater reliability for the musculoskeletal POCUS scoring systems using the intra-class correlation coefficient (ICC). Following training sessions, participants then underwent scoring exercise(s) until the goal of an excellent ICC ≥ 0.75 was reached. Four participants completed two rounds of virtual education, review, and scoring sessions. Excellent interrater reliability was achieved for most views. This proof-of-concept study demonstrated virtual education covering advanced concepts of pediatric musculoskeletal POCUS provides a knowledge base for physicians from different subspecialties and various experience.

Comparison of disease phenotypes and mechanistic insight on causal variants in patients with DADA2.

BACKGROUND: Deficiency of adenosine deaminase 2 (DADA2) results in heterogeneous manifestations including systemic vasculitis and red cell aplasia. The basis of different disease phenotypes remains incompletely defined. OBJECTIVE: We sought to further delineate disease phenotypes in DADA2 and define the mechanistic basis of ADA2 variants. METHODS: We analyzed the clinical features and ADA2 variants in 33 patients with DADA2. We compared the transcriptomic profile of 14 patients by bulk RNA sequencing. ADA2 variants were expressed experimentally to determine impact on protein production, trafficking, release, and enzymatic function. RESULTS: Transcriptomic analysis of PBMCs from DADA2 patients with the vasculitis phenotype or pure red cell aplasia phenotype exhibited similar upregulation of TNF, type I interferon, and type II interferon signaling pathways compared with healthy controls. These pathways were also activated in 3 asymptomatic individuals with DADA2. Analysis of ADA2 variants, including 7 novel variants, showed different mechanisms of functional disruption including (1) unstable transcript leading to RNA degradation; (2) impairment of ADA2 secretion because of retention in the endoplasmic reticulum; (3) normal expression and secretion of ADA2 that lacks enzymatic function; and (4) disruption of the N-terminal signal peptide leading to cytoplasmic localization of unglycosylated protein. CONCLUSIONS: Transcriptomic signatures of inflammation are observed in patients with different disease phenotypes, including some asymptomatic individuals. Disease-associated ADA2 variants affect protein function by multiple mechanisms, which may contribute to the clinical heterogeneity of DADA2.

Inflammatory biomarkers in COVID-19-associated multisystem inflammatory syndrome in children, Kawasaki disease, and macrophage activation syndrome: a cohort study.

BACKGROUND: Multisystem inflammatory syndrome in children (MIS-C) is a potentially life-threatening hyperinflammatory syndrome that occurs after primary SARS-CoV-2 infection. The pathogenesis of MIS-C remains undefined, and whether specific inflammatory biomarker patterns can distinguish MIS-C from other hyperinflammatory syndromes, including Kawasaki disease and macrophage activation syndrome (MAS), is unknown. Therefore, we aimed to investigate whether inflammatory biomarkers could be used to distinguish between these conditions. METHODS: We studied a prospective cohort of patients with MIS-C and Kawasaki disease and an established cohort of patients with new-onset systemic juvenile idiopathic arthritis (JIA) and MAS associated with systemic JIA (JIA-MAS), diagnosed according to established guidelines. The study was done at Cincinnati Children's Hospital Medical Center (Cincinnati, OH, USA). Clinical and laboratory features as well as S100A8/A9, S100A12, interleukin (IL)-18, chemokine (C-X-C motif) ligand 9 (CXCL9), and IL-6 concentrations were assessed by ELISA and compared using parametric and non-parametric tests and receiver operating characteristic curve analysis. FINDINGS: Between April 30, 2019, and Dec 14, 2020, we enrolled 19 patients with MIS-C (median age 9·0 years [IQR 4·5-15·0]; eight [42%] girls and 11 [58%] boys) and nine patients with Kawasaki disease (median age 2·0 years [2·0-4·0]); seven [78%] girls and two [22%] boys). Patients with MIS-C and Kawasaki disease had similar S100 proteins and IL-18 concentrations but patients with MIS-C were distinguished by significantly higher median concentrations of the IFNγ-induced CXCL9 (1730 pg/mL [IQR 604-6300] vs 278 pg/mL [54-477]; p=0·038). Stratifying patients with MIS-C by CXCL9 concentrations (high vs low) revealed differential severity of clinical and laboratory presentation. Compared with patients with MIS-C and low CXCL9 concentrations, more patients with high CXCL9 concentrations had acute kidney injury (six [60%] of ten vs none [0%] of five), altered mental status (four [40%] of ten vs none [0%] of five), shock (nine [90%] of ten vs two [40%] of five), and myocardial dysfunction (five [50%] of ten vs one [20%] of five); these patients also had higher concentrations of systemic inflammatory markers and increased severity of cytopenia and coagulopathy. By contrast, patients with MIS-C and low CXCL9 concentrations resembled patients with Kawasaki disease, including the frequency of coronary involvement. Elevated concentrations of S100A8/A9, S100A12, and IL-18 were also useful in distinguishing systemic JIA from Kawasaki disease with high sensitivity and specificity. INTERPRETATION: Our findings show MIS-C is distinguishable from Kawasaki disease primarily by elevated CXCL9 concentrations. The stratification of patients with MIS-C by high or low CXCL9 concentrations provides support for MAS-like pathophysiology in patients with severe MIS-C, suggesting new approaches for diagnosis and management. FUNDING: Cincinnati Children's Research Foundation, National Institute of Arthritis and Musculoskeletal and Skin Diseases/National Institutes of Health, the Deutsche Forschungsgemeinschaft, and The Jellin Family Foundation.

S100 proteins, cytokines, and chemokines as tear biomarkers in children with juvenile idiopathic arthritis-associated uveitis.

PURPOSE: Biomarkers for juvenile idiopathic arthritis-associated uveitis (JIA-U) are needed. We aimed to measure inflammatory biomarkers in tears as a non-invasive method to identify biomarkers of uveitis activity. METHODS: Tears were collected from children with JIA-U (n=20) and pediatric controls (n=20) using Schirmer strips. S100A8, A9, A12, IL-18, IL-8, IP-10, MCP-1, RANTES, and sICAM-1 were measured by ELISA and Luminex assays. Levels of biomarkers were compared between children with JIA-U and controls, and active and inactive JIA-U. RESULTS: IL-8, sICAM-1, and S100A12 levels were similar between JIA-U and controls, but differed by activity. Active JIA-U had significantly increased S100A12 compared to inactive JIA-U (mean 27,722.5 pg/ML (SE 1.3) vs. 5,937.2 (1.3), p=0.002), IL-8 (73.5 [1.2] vs. 36.2 [1.2], p=0.009), and sICAM-1 (15,822.7 [1.2) vs. 8,778.0 [1.6], p=0.024). CONCLUSION: We detected inflammatory biomarkers non-invasively in tears of children with JIA-U. IL-8, sICAM-1, and S100A12 are potential biomarkers for uveitis activity.

Improving quick and accurate diagnosis of childhood JIA-uveitis from a pediatric rheumatology perspective.

INTRODUCTION: Juvenile idiopathic arthritis (JIA) is the most common pediatric rheumatic disease associated with uveitis. JIA-associated uveitis (JIA-U) is typically asymptomatic, chronic, and can lead to sight-threatening complications. This review will provide approaches to improve the diagnosis and outcomes of children with JIA-U. AREAS COVERED: We will provide updates on risk factors for uveitis onset and ocular complications, improvements in the ophthalmic screening schedule for uveitis detection, and potential strategies to advance the diagnosis and monitoring of JIA-U using advanced ophthalmic imaging and diagnostic equipment and laboratory biomarkers. EXPERT OPINION: There is a lack of high-quality research in JIA-U and few randomized controlled trials, underscoring the urgent need for further studies in this population. Early uveitis diagnosis combined with timely and appropriate treatment can improve visual outcomes. Improved knowledge of uveitis pathogenesis, risk factors for uveitis onset, measurement of uveitis outcomes, and optimal treatment are crucial.

Loss- or Gain-of-Function Mutations in ACOX1 Cause Axonal Loss via Different Mechanisms.

ACOX1 (acyl-CoA oxidase 1) encodes the first and rate-limiting enzyme of the very-long-chain fatty acid (VLCFA) ß-oxidation pathway in peroxisomes and leads to H2O2 production. Unexpectedly, Drosophila (d) ACOX1 is mostly expressed and required in glia, and loss of ACOX1 leads to developmental delay, pupal death, reduced lifespan, impaired synaptic transmission, and glial and axonal loss. Patients who carry a previously unidentified, de novo, dominant variant in ACOX1 (p.N237S) also exhibit glial loss. However, this mutation causes increased levels of ACOX1 protein and function resulting in elevated levels of reactive oxygen species in glia in flies and murine Schwann cells. ACOX1 (p.N237S) patients exhibit a severe loss of Schwann cells and neurons. However, treatment of flies and primary Schwann cells with an antioxidant suppressed the p.N237S-induced neurodegeneration. In summary, both loss and gain of ACOX1 lead to glial and neuronal loss, but different mechanisms are at play and require different treatments.

Update on the treatment and outcome of systemic lupus erythematous in children.

PURPOSE OF REVIEW: Provide an update of studies published in last 2 years on the outcomes and therapies in childhood-onset systemic lupus erythematous (cSLE). RECENT FINDINGS: Additional evidence has been provided about the benefits of universal hydroxychloroquine in SLE patients, although antimalarial maculopathy may be more prevalent than previously thought. Recent studies support lower glucocorticoid doses than used in the past may provide comparable therapeutic benefits, and cSLE patients can mount adequate immunogenic response and sustain long-term seroprotective titers when vaccinated. Long-term studies of adults with cSLE confirmed that damage accrual increases with disease duration. Cardiovascular disease, renal transplants, replacement arthroplasties, and myocardial infarctions occur between 20 and 40 years of age. Higher prednisone doses predicted higher damage trajectory and antimalarial exposure was protective. There were no prospective clinical trials published in pediatric patients with cSLE, but positive results from phase II trials with bariticinib and ustekinumab in adult SLE may raise the expectation that these drugs could be beneficial when used in cSLE. SUMMARY: The dire need for more clinical trials and licensed medications for cSLE persist as well as decreasing damage accrual.

Cerebrospinal Fluid Cytokines Correlate With Aseptic Meningitis and Blood-Brain Barrier Function in Neonatal-Onset Multisystem Inflammatory Disease: Central Nervous System Biomarkers in Neonatal-Onset Multisystem Inflammatory Disease Correlate With Central Nervous System Inflammation.

OBJECTIVE: To evaluate proinflammatory cytokines and leukocyte subpopulations in the cerebrospinal fluid (CSF) and blood of patients with neonatal-onset multisystem inflammatory disease (NOMID) after treatment, and to compare inflammatory cytokines in the CSF and blood in 6 patients treated with 2 interleukin-1 (IL-1) blockers-anakinra and canakinumab. METHODS: During routine follow-up visits between December 2011 and October 2013, we immunophenotyped the CSF of 17 pediatric NOMID patients who were treated with anakinra, and analyzed CSF cytokine levels in samples obtained at baseline and at 3-5-year follow-up visits and compared them to samples from healthy controls. RESULTS: CSF levels of IL-6, interferon-γ-inducible 10-kd protein (IP-10/CXCL10), and IL-18 and monocyte and granulocyte counts significantly decreased with anakinra treatment but did not normalize to levels in the controls, even in patients fulfilling criteria for clinical remission. CSF IL-6 and IL-18 levels significantly correlated with measures of blood-brain barrier function, specifically CSF protein (r = 0.75 and r = 0.81, respectively) and albumin quotient (r = 0.79 and r = 0.68, respectively). When patients were treated with canakinumab versus anakinra, median CSF white blood cell counts and IL-6 levels were significantly higher with canakinumab treatment (10.2 cells/mm3 versus 3.7 cells/mm3 and 150.7 pg/ml versus 28.5 pg/ml, respectively) despite similar serum cytokine levels. CONCLUSION: CSF leukocyte subpopulations and cytokine levels significantly improve with optimized IL-1 blocking treatment, but do not normalize. The correlation of CSF IL-6, IP-10/CXCL10, and IL-18 levels with clinical laboratory measures of inflammation and blood-brain barrier function suggests that they may have a role as biomarkers in central nervous system (CNS) inflammation. The difference in inhibition of CSF biomarkers between 2 IL-1 blocking agents, anakinra and canakinumab, suggests differences in efficacy in the intrathecal compartment, with anakinra being more effective. Our data indicate that intrathecal immune responses shape CNS inflammation and should be assessed in addition to blood markers.

A 24-month open-label study of canakinumab in neonatal-onset multisystem inflammatory disease.

OBJECTIVE: To study efficacy and safety of escalating doses of canakinumab, a fully human anti-IL-1ß monoclonal antibody in the severe cryopyrin-associated periodic syndrome, neonatal-onset multisystem inflammatory disease (NOMID). METHODS: 6 patients were enrolled in this 24-month, open-label phase I/II study. All underwent anakinra withdrawal. The initial subcutaneous canakinumab dose was 150 mg (or 2 mg/kg in patients ≤40 kg) or 300 mg (or 4 mg/kg) with escalation up to 600 mg (or 8 mg/kg) every 4 weeks. Full remission was remission of patient-reported clinical components and measures of systemic inflammation and CNS inflammation. Hearing, vision and safety were assessed. Primary endpoint was full remission at month 6. RESULTS: All patients flared after anakinra withdrawal, and symptoms and serum inflammatory markers improved with canakinumab. All patients required dose escalation to the maximum dose. At month 6, none had full remission, although 4/6 achieved inflammatory remission, based on disease activity diary scores and normal C-reactive proteins. None had CNS remission; 5/6 due to persistent CNS leucocytosis. At the last study visit, 5/6 patients achieved inflammatory remission and 4/6 had continued CNS leucocytosis. Visual acuity and field were stable in all patients, progressive hearing loss occurred in 1/10 ears. Adverse events (AEs) were rare. One serious AE (abscess due to a methicillin-resistant Staphylococcus aureus infection) occurred. CONCLUSIONS: Canakinumab at the studied doses improves symptoms and serum inflammatory features of NOMID, although low-grade CNS leukocytosis in four patients and headaches in one additional patient persisted. Whether further dose intensifications are beneficial in these cases remains to be assessed. CLINICALTRIALSGOV IDENTIFIER: NCT00770601.