C-terminal variants in CDC42 drive type I interferon-dependent autoinflammation in NOCARH syndrome reversible by ruxolitinib.

C-terminal variants in CDC42 encoding cell division control protein 42 homolog underlie neonatal-onset cytopenia, autoinflammation, rash, and hemophagocytic lymphohistiocytosis (NOCARH). Pyrin inflammasome hyperactivation has been shown to contribute to disease pathophysiology. However, mortality of NOCARH patients remains high despite inflammasome-focused treatments. Here, we demonstrate in four NOCARH patients from three families that cell-intrinsic activation of type I interferon (IFN) is a previously unrecognized driver of autoinflammation in NOCARH. Our data show that aberrant innate immune activation is caused by sensing of cytosolic nucleic acids released from mitochondria, which exhibit disturbances in integrity and dynamics due to CDC42 dysfunction. In one of our patients, treatment with the Janus kinase inhibitor ruxolitinib led to complete remission, indicating that inhibition of type I IFN signaling may have an important role in the management of autoinflammation in patients with NOCARH.

Multisystem inflammatory syndrome in children during the COVID-19 waves: data from the Juvenile Inflammatory Rheumatism cohort.

Introduction: Multisystem inflammatory syndrome in children (MIS-C) is a new condition that first appeared in children and adolescents during the COVID-19 pandemic. We aimed to describe the diagnostic course, clinical and biological manifestations, and treatment of MIS-C during the first three COVID-19 waves. Methods: We extracted patient data from the Juvenile Inflammatory Rheumatism (JIR) cohort. We analyzed data for patients meeting the World Health Organization diagnostic criteria for MIS-C from the start of the COVID-19 pandemic from March 2020 to June 30, 2021. We then compared data for patients in wave one to those in waves two and three. Results: We identified 136 patients with MIS-C. The median age decreased but not significantly during the waves, from 9.9 years to 7.3 years (p = 0.105). Boys represented 52.2% (n = 71) of patients, and 46% (n = 41) of patients originated from sub-Saharan Africa (p < 0.001). Patients presented less diarrhea (p = 0.004), respiratory distress (p < 0.001), and myocarditis (p < 0.001) with progressive waves. Biological inflammation also decreased, namely, C-reactive protein level (p < 0.001), neutrophil count (p = 0.004), and albumin level (p < 0.001). Patients received more corticosteroids (p < 0.001) and required less ventilation support (p < 0.01) and less inotrope treatment (p < 0.001) in the later waves. The duration of hospitalization gradually decreased (p < 0.001), as did critical care unit admissions (p = 0.002). Conclusion: Over the three COVID-19 waves, with a change in the management of MIS-C, children in the JIR cohort in France showed a less severe disease course, in particular, a greater use of corticosteroids. This observation may reflect the impact of both improved management and different SARS-CoV-2 variant.

Factors associated with poor prognosis of hip arthritis in juvenile idiopathic arthritis: Data from the JIR cohort.

OBJECTIVES: Hip involvement remains a predictor of severe juvenile idiopathic arthritis (JIA) course and carries a high risk of disability. This study aims to determine the factors of poor prognosis of hip involvement in patients with JIA and to assess the treatment response. METHODS: This is a multicenter observational cohort study. Patients were selected from the JIR Cohort database. Hip involvement was defined as clinically suspected and confirmed by an imaging tool. Follow-up data were collected during 5 years. RESULTS: Among the 2223 patients with JIA, 341(15%) patients had hip arthritis. Male gender, enthesitis-related arthritis, and North African origin were factors associated with hip arthritis. Hip inflammation was associated with disease activity parameters during the first year, particularly Physician Global Assessment, joint count, and inflammatory marks. Structural hip progression was associated with early onset of the disease, a longer time to diagnosis, geographic origin, and JIA subtypes. Anti-TNF therapy was found to be the only treatment able to effectively reduce structural damage progression. CONCLUSION: The early onset diagnostic delay, origin, and systemic subtype of JIA predict a poor prognosis of hip arthritis in children with JIA. The use of anti-TNF was associated with a better structural prognosis.

Individual and environmental determinants associated with longer times to access pediatric rheumatology centers for patients with juvenile idiopathic arthritis, a JIR cohort study.

BACKGROUND: Despite guidelines, poor access to appropriate care for juvenile idiopathic arthritis (JIA) patients remains a global issue. Prompt referral to a pediatric rheumatology (PR) center and effective care is known to be critical for changing the natural history of the disease and improving long-term prognosis. This project assesses socio-economic factors of delayed referral to a pediatric rheumatologist (PRst) for JIA patients in France and Switzerland within the Juvenile Inflammatory Rheumatism (JIR) Cohort. METHODS: All patients diagnosed with JIA, presenting at one center of the JIRcohort in France or Switzerland with additional data on referral pathway were included. Patient characteristics at first visit to the PR center, dates of visits to healthcare providers during referral, and parent characteristics were extracted from the JIRcohort database. RESULTS: Two hundred fifty children were included. The overall median time to first PR assessment was 2.4 months [1.3; 6.9] and ranged widely across the JIA subtypes, from 1.4 months [0.6; 3.8] for children with systemic juvenile idiopathic arthritis (sJIA) to 5.3 months [2.0; 19.1] for children with enthesitis-related arthritis (ERA). A diagnosis of ERA and an appointment with an orthopedist during the referral pathway were significantly associated with a longer time before the first PR visit (hazard ratio HR 0.50 [95% CI: 0.29; 0.84]) and HR 0.68 [95% CI: 0.49; 0.93], respectively) in multivariable analysis. Having a mother with a post-graduate educational attainment level was tendentially associated with a shorter time before the first PR visit, (HR 1.32 [95% CI: 0.99; 1.78]). CONCLUSIONS: Time to first PRst visit was most often short compared to other studies and close to the British recommendations. However, this time remained too long for many patients. We observed no social inequities in access to a PRst, but we show the need to improve effective pathway and access to a PR center for JIA patients.

Joint involvement in Noonan syndrome. A retrospective paediatric descriptive study.

OBJECTIVES: Noonan syndrome is a rare genetic disorder characterized mainly by congenital heart disease, occasional intellectual disability, and varied orthopaedic, rheumatological and haematologic anomalies. Despite potentially serious functional consequences, joint involvement has been rarely studied in the literature. Our objective was to perform a retrospective study evaluating the prevalence and characteristics of joint involvement in Noonan syndrome. METHODS: We recorded articular symptoms, including their type and frequency, in patients with Noonan syndrome followed up in French hospitals. Patients were included if the diagnosis was confirmed before the age of 20 based on the van der Burgt criteria or genetic analysis. Data are presented as frequencies or medians (ranges), and patient groups were compared using chi-square or Fisher tests. RESULTS: Seventy-one patients were included from 4 centres. The average age was 12.5 years (range: 2-36). Musculoskeletal pain was found in 18 patients (25%) and joint stiffness in 10 (14%) located in the wrists, elbows, ankles, knees and hips, which was usually bilateral. Only one destructive form was described (multiple villonodular synovitis and a giant cell lesion of the jaw). There were no cases of systemic lupus erythaematosus (SLE) or other autoimmune arthritis. Raynaud's phenomenon was observed in 3 patients. Only 50% of joint complaints led to additional exploration. SOS1 mutations (P<0.05) and treatment with growth hormone (GH) (P<0.05) were the only factors significantly related to musculoskeletal pain. Patients treated with GH did not have more SOS1 mutations. Patients experiencing pain were not more likely to experience stiffness, joint hypermobility, or coagulation abnormalities. CONCLUSION: Joint manifestations were frequent in Noonan syndrome, predominant in large joints, and rarely explored. Multiple villonodular synovitis is characteristic but rare. Auto-immune disorders were not described in this cohort. A more multidisciplinary approach could be recommended for the early detection of possibly disabling rheumatologic manifestations.

Real-Life Indications of Interleukin-1 Blocking Agents in Hereditary Recurrent Fevers: Data From the JIRcohort and a Literature Review.

Background: Interleukin (IL)-1 inhibitors represent the main treatment in patients with colchicine-resistant/intolerant familial Mediterranean fever (crFMF), mevalonate kinase deficiency (MKD), and tumor necrosis factor receptor-associated periodic syndrome (TRAPS). However, the reasons for the use of IL-1 inhibitors in these diseases are still not completely clarified. Objective: Identify real-life situations that led to initiating anakinra or canakinumab treatment in hereditary recurrent fevers (HRFs), combining data from an international registry and an up-to-date literature review. Patients and Methods: Data were extracted from the JIRcohort, in which clinical information (demographic data, treatment, disease activity, and quality of life) on patients with FMF, MKD, and TRAPS was retrospectively collected. A literature search was conducted using Medline, EMBASE, and Cochrane databases. Results: Complete data of 93 patients with HRF (53.8% FMF, 31.2% MKD, and 15.1% TRAPS) were analyzed. Data from both the registry and the literature review confirmed that the main reasons for use of IL-1 blockers were the following: failure of previous treatment (n = 57, 61.3% and n = 964, 75.3%, respectively), persistence of disease activity with frequent attacks (n = 44, 47.3% and n = 1,023, 79.9%) and/or uncontrolled inflammatory syndrome (n = 46, 49.5% and n = 398, 31.1%), severe disease complication or associated comorbidities (n = 38, 40.9% and n = 390, 30.4%), and worsening of patients' quality of life (n = 36, 38.7% and n = 100, 7,8%). No reasons were specified for 12 (16.4%) JIRcohort patients and 154 (12%) patients in the literature. Conclusion: In the absence of standardized indications for IL-1 inhibitors in crFMF, MKD, and TRAPS, these results could serve as a basis for developing a treat-to-target strategy that would help clinicians codify the therapeutic escalation with IL-1 inhibitors.

Etanercept concentration and immunogenicity do not influence the response to Etanercept in patients with juvenile idiopathic arthritis.

OBJECTIVE: To investigate the relationship of clinical response of Juvenile Idiopathic Arthritis (JIA) to etanercept (ETN) with ETN levels, and the presence of anti-drug antibodies to ETN (ADAb). METHODS: Prospective study of JIA patients under 18 years old. Clinical and pharmacological data were collected at two visits. JIA clinical inactivity and activity were assessed according to the Wallace criteria and to the Juvenile Arthritis Disease Activity Score (JADAS). ETN and ADAb serum levels assessments were determined using ELISA-based assays. RESULTS: 126 patients were enrolled. The median duration of ETN treatment at inclusion was 569 days (range 53-2340). ADAb were undetectable (<10 ng/ml) in 171/218 (78%) samples and were > 25 ng/mL in 2/218 samples. No significant relationship between ETN concentration and the clinical inactivity status and JIA activity was found using either univariate logistic regression or multiple logistic regression analysis, adjusted on one individual descriptors, time since diagnosis, time of sampling, use of corticosteroids or methotrexate and classification of JIA. No correlation was found between the remission status and the detection of ADAb. CONCLUSION: This study did not demonstrate any correlation between JIA activity and circulating ETN levels in a large population of patients with JIA previously treated with ETN for at least 1.5 months. As described for adults, our study confirms that ETN is marginally immunogenic in pediatric patients. These results do not support the clinical usefulness of a monitoring of ADAb or ETN concentrations for the management of this group of JIA patients if they fail to achieve clinical inactive disease.

Single amino acid charge switch defines clinically distinct proline-serine-threonine phosphatase-interacting protein 1 (PSTPIP1)-associated inflammatory diseases.

BACKGROUND: Hyperzincemia and hypercalprotectinemia (Hz/Hc) is a distinct autoinflammatory entity involving extremely high serum concentrations of the proinflammatory alarmin myeloid-related protein (MRP) 8/14 (S100A8/S100A9 and calprotectin). OBJECTIVE: We sought to characterize the genetic cause and clinical spectrum of Hz/Hc. METHODS: Proline-serine-threonine phosphatase-interacting protein 1 (PSTPIP1) gene sequencing was performed in 14 patients with Hz/Hc, and their clinical phenotype was compared with that of 11 patients with pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. PSTPIP1-pyrin interactions were analyzed by means of immunoprecipitation and Western blotting. A structural model of the PSTPIP1 dimer was generated. Cytokine profiles were analyzed by using the multiplex immunoassay, and MRP8/14 serum concentrations were analyzed by using an ELISA. RESULTS: Thirteen patients were heterozygous for a missense mutation in the PSTPIP1 gene, resulting in a p.E250K mutation, and 1 carried a mutation resulting in p.E257K. Both mutations substantially alter the electrostatic potential of the PSTPIP1 dimer model in a region critical for protein-protein interaction. Patients with Hz/Hc have extremely high MRP8/14 concentrations (2045 ± 1300 µg/mL) compared with those with PAPA syndrome (116 ± 74 µg/mL) and have a distinct clinical phenotype. A specific cytokine profile is associated with Hz/Hc. Hz/Hc mutations altered protein binding of PSTPIP1, increasing interaction with pyrin through phosphorylation of PSTPIP1. CONCLUSION: Mutations resulting in charge reversal in the y-domain of PSTPIP1 (E→K) and increased interaction with pyrin cause a distinct autoinflammatory disorder defined by clinical and biochemical features not found in patients with PAPA syndrome, indicating a unique genotype-phenotype correlation for mutations in the PSTPIP1 gene. This is the first inborn autoinflammatory syndrome in which inflammation is driven by uncontrolled release of members of the alarmin family.

A new mutation in the C-SH2 domain of PTPN11 causes Noonan syndrome with multiple giant cell lesions.

Noonan syndrome (NS), an autosomal dominant multisystem disorder, is caused by the dysregulation of the RAS-MAPK pathway and is characterized by short stature, heart defects, pectus excavatum, webbed neck, learning problems, cryptorchidism and facial dysmorphism. We here present the clinical and molecular characterization of a family with NS and multiple giant cell lesions (MGCLs). The proband is a 12-year-old girl with NS and MGCL. Her mother shows typical NS without MGCL. Whole-exome sequencing of the girl, her mother and her healthy maternal grand parents revealed a previously unobserved mutation in exon 5 of the PTPN11 gene (c.598 A>T; p.N200Y), transmitted from the mother to the proband. As no other modification in the RAS-MAPK pathway genes as related to Rasopathies was detected in the proband, this report demonstrates for the first time that a unique mutation affecting this, otherwise unaffected signaling route, can cause both NS and NS/MGCL in the same family. This observation further confirms that NS/MGCL is not a distinct entity but rather that MGCL represents a rare complication of NS. Moreover, the localization of the p.N200Y mutation suggests an alternative molecular mechanism for the excessive phosphatase activity of the PTPN11-encoded protein.

Evaluation of health related quality of life in children with immune thrombocytopenia with the PedsQL™ 4.0 Generic Core Scales: a study on behalf of the pays de Loire pediatric hematology network.

BACKGROUND: Immune thrombocytopenia (ITP) is a childhood disorder that is often life-altering for children and their parents. Health related quality of life (HRQL) has never been chronologically monitored in children with ITP. We initiated a prospective study to assess HRQL from diagnosis to six months and define factors that influence this outcome in children with ITP. METHODS: 73 children with acute ITP aged from 2 to 18 years were prospectively enrolled in the study. According to the presence of bleeding, they were or were not given a 4-day course of corticosteroid treatment. The PedsQL™ 4.0 Generic Core Scale was completed by children and parents upon their inclusion in the study and 6 months after diagnosis. RESULTS: Over the six month period, quality of life improved in terms of their global, physical and psychosocial well-being for 54.5%, 35.6% and 36.2% of patients respectively. This improvement is clinically relevant compared to scores at diagnosis, corresponding at least to a minimal clinically important difference (MCID). Factors such as sex, age, platelet count, bleeding scores, bone marrow aspiration and persistence of ITP at 6 months were not significantly associated with HRQL scores. However, preceding viral infection was identified to have an impact on HRQL. CONCLUSIONS: This first longitudinal study assessing HRQL in children with ITP reveals a global improvement in PedSQL™ 4.0. However, these results should be considered with caution since our data also confirm that self-report HRQL scores are not influenced by any analyzed biologic or clinical parameters. Others tools, such as Kids' ITP Tools, would probably be required to assess the HRQL of this population. TRIAL REGISTRATION: Trial registration clinical trials.gov Identifier: NCT00331357.

Progressive polyepiphyseal dysplasia with arthropathy: a distinct disorder from idiopathic juvenile arthritis and pseudorheumatoid dysplasia?

Juvenile idiopathic arthritis is an inflammatory disease with various onset-forms which can sometimes be difficult to distinguish from genetic inflammatory/rheumatoid-like osteoarthropathies. In this report, we describe two boys with severe chronic arthralgia, stiffness and swelling of joints, motor weakness and joints contractures evolving despite immunosuppressive treatments and for whom all biological and molecular exams failed to identify a prompt diagnosis. Some findings also overlap with pseudorheumatoid dysplasia but WISP3 gene molecular analysis failed to identify any mutation for both patients. Therefore, we propose that these boys show a clinical entity distinct from the actually known genetic inflammatory/rheumatoid-like osteoarthropathies.