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.

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.

Juvenile Idiopathic Arthritis and COVID-19 Pandemic: Good Compliance With Treatment, Reluctance to Return to School.

Objective: The SARS-CoV-2 pandemic has induced an exceptional sanitary crisis, potentially having an impact on treatment continuation, for juvenile idiopathic arthritis (JIA) patients receiving immunosuppressive therapies. After national lockdowns, many patients were also concerned about their safety at school. We evaluated the impact of the pandemic on the optimal continuation of treatment and on the return to school in JIA patients. Methods: JIA patients under 18 years of age, usually treated with disease-modifying anti-rheumatic drugs (DMARDs) were prospectively included during their outpatient visit and completed a standardized questionnaire. The primary outcome was DMARD treatment modification in relation to the context of the pandemic but we also evaluated the pandemic's impact on the schooling. Results: One hundred and seventy three patients from 8 different expert centers were included between May and August 2020. Their mean age was 11.6 years (± 4.1 years), and most of them 31.2% (54/173) had a rheumatoid factor-negative polyarticular JIA. Fifty percent (86/172) were treated with methotrexate, and 72.5% (124/171) were treated with bDMARDs. DMARD treatment modification in relation to the pandemic was observed in 4.0% (7/173) of participants. 49.1% (81/165) of the patients did not return to school due to a personal/parental decision in 69.9% (55/81) of cases. Two patients were diagnosed positive for SARS-CoV-2 infection. Conclusion: This study suggests that JIA patients treated with DMARDs continued their treatment during the pandemic and were rarely affected by symptomatic COVID-19. In contrast, parents' reluctance was a major obstacle for returning to school. Therefore, more solidified school reopening strategies should be developed.

Persistent osteoarticular pain in children: early clinical and laboratory findings suggestive of acute lymphoblastic leukemia (a multicenter case-control study of 147 patients).

BACKGROUND: The aim of this study was to identify early clinical and laboratory features that distinguish acute lymphoblastic leukemia (ALL) from juvenile idiopathic arthritis (JIA) in children presenting with persistent bone or joint pain for at least 1 month. METHODS: We performed a multicenter case-control study and reviewed medical records of children who initially presented with bone or joint pain lasting for at least 1 month, all of whom were given a secondary diagnosis of JIA or ALL, in four French University Hospitals. Each patient with ALL was paired by age with two children with JIA. Logistic regression was used to compare clinical and laboratory data from the two groups. RESULTS: Forty-nine children with ALL and 98 with JIA were included. The single most important feature distinguishing ALL from JIA was the presence of hepatomegaly, splenomegaly or lymphadenopathy; at least one of these manifestations was present in 37 cases with ALL, but only in 2 controls with JIA, for an odds ratio (OR) of 154 [95%CI: 30-793] (regression coefficient: 5.0). If the presence of these findings is missed or disregarded, multivariate analyses showed that non-articular bone pain and/or general symptoms (asthenia, anorexia or weight loss) (regression coefficient: 4.8, OR 124 [95%CI: 11.4-236]), neutrophils < 2 × 109/L (regression coefficient: 3.9, OR 50 [95%CI: 4.3-58]), and platelets < 300 × 109/L (regression coefficient: 2.6, OR 14 [95%CI: 2.3-83.9]) were associated with the presence of ALL (area under the ROC curve: 0.96 [95%CI: 0.93-0.99]). CONCLUSIONS: Based on our findings we propose the following preliminary decision tree to be tested in prospective studies: in children presenting with at least 1 month of osteoarticular pain and no obvious ALL in peripheral smear, perform a bone marrow examination if hepatomegaly, splenomegaly or lymphadenopathy is present. If these manifestations are absent, perform a bone marrow examination if there is fever or elevated inflammatory markers associated with non-articular bone pain, general symptoms (asthenia, anorexia or weight loss), neutrophils < 2 × 109/L or platelets < 300 × 109/L.

The NLRP3 p.A441V Mutation in NLRP3-AID Pathogenesis: Functional Consequences, Phenotype-Genotype Correlations and Evidence for a Recurrent Mutational Event.

OBJECTIVE: To determine the molecular and cellular bases of autoinflammatory syndromes in a multigenerational French family with Muckle-Wells syndrome and in a patient originating from Portugal with familial cold autoinflammatory syndrome. METHODS: Sequencing of NLRP3 exon 3 was performed in all accessible patients. Microsatellite and whole-genome single nucleotide polymorphism genotyping was used i) to test the intrafamilial segregation of the identified variant and ii) to look for a founder effect. Functional analyses included the study of i) apoptosis-associated speck-like protein containing a CARD (ASC) speck formation in HEK293T cells (stably expressing ASC-green fluorescent protein and pro-caspase 1-FLAG) transiently expressing the wild-type or mutated NLRP3 protein, ii) levels of IL-1ß secreted from transfected THP-1 cells, and iii) inflammasome-related gene expression and cytokine secretion from monocytes isolated from patients in crisis (probands from the two families), related patients out of crisis, and from controls. RESULTS: The same heterozygous mutation (c.1322C>T, p.A441V) located in the NACHT domain, segregating with the disease within the first family, was identified in the two families. This mutation was found to be associated with different core haplotypes. NLRP3-A441V led to increased ASC speck formation and high levels of secreted IL-1ß. Monocyte inflammasome-related gene expression and cytokine secretion, which were within the normal range in patients out of crisis, were found to be differentially regulated between the two probands, correlating with their phenotypic status. CONCLUSION: These molecular and cellular findings, which indicate a recurrent mutational event, clearly demonstrate the pathogenicity of the p.A441V missense mutation in NLRP3-associated autoinflammatory disease and point to the interest of studying patients' primary cells to assess disease activity.

ADJUVITE: a double-blind, randomised, placebo-controlled trial of adalimumab in early onset, chronic, juvenile idiopathic arthritis-associated anterior uveitis.

OBJECTIVES: To assess the efficacy and safety of adalimumab on uveitis in patients with early onset, chronic, juvenile idiopathic arthritis (JIA)-associated or idiopathic anterior uveitis and an inadequate response to topical steroids and methotrexate (MTX). METHODS: Patients aged 4 years or more with ocular inflammation quantified by laser flare photometry (LFP) ≥30 photon units/ms were double-blindly randomised (1:1) to 2 groups, one treated with placebo and one with adalimumab subcutaneously at a dose of 24 mg/m2 in patients aged <13 years, 40 mg in the others, every other week. The primary outcome was response at month 2 (M2) defined as a 30% reduction of inflammation on LFP in the assessable eye with more severe baseline inflammation and no worsening on slit lamp examination. From M2 to M12, all patients received adalimumab. RESULTS: At M2, among 31 patients included in intention-to-treat analysis, there were 9/16 responders on adalimumab and 3/15 on placebo (P=0.038, Χ2 test; relative risk=2.81, 95% CI 0.94 to 8.45; risk difference: 36.3%, 95% CI 2.1 to 60.6); there was no significant difference using the Standardised Uveitis Nomenclature classification criteria of improvement. Thirty patients continued the trial after M2 and received adalimumab (open-label phase), 29 reached M12. There were seven serious adverse events none related to study treatment. CONCLUSIONS: This trial is in favour of using adalimumab in patients with early onset, chronic anterior uveitis, which is in most cases associated with JIA, in case of inadequate response to topical therapy and MTX. LFP could be a valuable tool to assess early treatment efficacy. TRIAL REGISTRATION NUMBER: NCT01385826.

Familial and syndromic lupus share the same phenotype as other early-onset forms of lupus.

OBJECTIVE: Studies of early-onset systemic lupus erythematosus (SLE) have identified monogenic forms of the disease. The primary objective of this study was to compare the clinical and laboratory features of the first patients included in the GENIAL/LUMUGENE cohort to those reported in previous publications. The secondary objective was to determine whether subgroups with a distinctive pattern of clinical and biological features are seen in predominantly genetic forms of SLE. METHODS: GENIAL/LUMUGENE is a French nationwide study of the clinical, immunological, and genetic features of juvenile-onset SLE (clinicaltrials.gov #NCT01992666). Clinical and laboratory data from the first 64 patients younger than 18 years who were included in the first part of the study were collected retrospectively. Predefined criteria were used to divide the patients into three subgroups: syndromic SLE (n=10) and familial SLE (n=12) - both presumed to have a strong genetic component - and other forms of early-onset SLE (n=42). RESULTS: The predefined criteria for identifying subgroups based on knowledge of the clinical and epidemiological features of monogenic SLE showed a significantly younger age at onset in syndromic SLE (P<0.05) and a lower frequency of joint manifestations in familial SLE. CONCLUSIONS: In this study, clinical and epidemiological data alone failed to identify a specific patient subgroup characterized by the same disease presentation or progression. This result may be related to the small sample size or indicate marked heterogeneity of juvenile-onset SLE. Genetic studies using new sequencing techniques in these patients might identify genetic factors responsible for marked phenotypic variability.

Intrafamilial variable phenotypic expression of a CIAS1 mutation: from Muckle-Wells to chronic infantile neurological cutaneous and articular syndrome.

Among hereditary inflammatory disorders, Muckle-Wells syndrome, chronic infantile neurological cutaneous and articular syndrome (CINCA), and familial cold urticaria have recently been shown to be caused by dominantly inherited mutations in the CIAS1 gene. Reports suggest that these 3 diseases result from distinct missense mutations, with very few overlapping symptoms. We describe a French family presenting an intrafamilial overlapping clinical phenotype of CINCA and Muckle-Wells syndrome, caused by a mutation in CIAS1 gene. Clinical and genetic observations suggest that Muckle-Wells syndrome, CINCA, and familial cold urticaria are various phenotypic expressions of the same disease.