Clinical spectrum and outcome of Takayasu's arteritis in children.

OBJECTIVES: We aimed to compare clinical spectrum and outcome between adults and children with Takayasu's arteritis (TAK) in a European population. METHODS: We made a nationwide retrospective observational study between 1988 and 2019. All adult patients met the ACR diagnostic criteria for TAK and all children met the EULAR/PRINTO/PRES criteria for paediatric TAK. RESULTS: We identified 46 children and 389 adults with TAK. The male to female ratio was 34/46 (0.74) in the paediatric group compared to 241/274 (0.88) in the adult group (P<0.05). Children presented with significantly more systemic symptoms; i.e., fever (P<0.05), fatigue (P<0.001), weight loss (P<0.001), abdominal pain (P<0.05), and myalgia (P<0.05) while adults had more upper limb claudication (P<0.01). Topography of the lesions differed significantly between the two groups: adults had more damage at the cerebral vasculature (P<0.01), upper and lower limbs (P<0.001) while children had more kidney lesions (P<0.05). Children TAK had more frequent (P<0.01) and higher (P<0.001) biological inflammation than adults. Children received higher dose-weight of corticosteroids (P=0.001) and less biotherapy (P<0.010) at diagnosis. Relapses (P<0.05) and death (8.6% vs 4.9%) were more frequent in children TAK than in adults. CONCLUSION: Paediatric TAK seems more severe than adult TAK. Therefore, paediatrics patients may require closer monitoring and systemic use of biological treatment.

Functional diversity of NLRP3 gain-of-function mutants associated with CAPS autoinflammation.

NLRP3-associated autoinflammatory disease is a heterogenous group of monogenic conditions caused by NLRP3 gain-of-function mutations. The poor functional characterization of most NLRP3 variants hinders diagnosis despite efficient anti-IL-1 treatments. Additionally, while NLRP3 is controlled by priming and activation signals, gain-of-functions have only been investigated in response to priming. Here, we characterize 34 NLRP3 variants in vitro, evaluating their activity upon induction, priming, and/or activation signals, and their sensitivity to four inhibitors. We highlight the functional diversity of the gain-of-function mutants and describe four groups based on the signals governing their activation, correlating partly with the symptom severity. We identify a new group of NLRP3 mutants responding to the activation signal without priming, associated with frequent misdiagnoses. Our results identify key NLRP3 residues controlling inflammasome activity and sensitivity to inhibitors, and antagonistic mechanisms with broader efficacy for therapeutic strategies. They provide new insights into NLRP3 activation, an explanatory mechanism for NLRP3-AID heterogeneity, and original tools for NLRP3-AID diagnosis and drug development.

Accurate diagnosis of acute hemorrhagic edema of infancy: a French multicenter observational study.

The purpose of the study is to highlight clinical signs that are either suggestive of or against the diagnosis of AHEI to improve diagnosis and management. The medical records of children under 3 years old diagnosed with AHEI were retrospectively reviewed. Clinical data and photographs were reviewed by three independent experts, and the cases were classified as probable, doubtful, or unclear AHEI. Of the 69 cases of children diagnosed with AHEI included in 22 centers, 40 were classified as probable, 22 as doubtful, and 7 as unclear. The median age of patients with probable AHEI was 11 months [IQR 9-15], and they were in overall good condition (n = 33/40, 82.5%). The morphology of the purpura was targetoid in 75% of cases (n = 30/40) and ecchymotic in 70% of cases (n = 28/40) and affected mostly the legs (n = 39/40, 97%), the arms (n = 34/40, 85%), and the face (n = 33/40, 82.5%). Edema was observed in 95% of cases and affected mostly the hands (n = 36/38, 95%) and feet (n = 28/38, 74%). Pruritus was absent in all patients with probable AHEI and described for 6/21 with doubtful AHEI (29%). AHEI was the original diagnosis in only 24 patients (n = 24/40, 60%). The major differential diagnoses were purpura fulminans and urticaria multiforme.  Conclusion: AHEI, which the diagnosis is made on clinical findings, is often misdiagnosed. Purpuric lesions localized on the face/ears, arms/forearms, and thighs/legs with edema of the hands without pruritus in a young child with a good overall condition are highly suggestive of AHEI. What is Known: •Acute hemorrhagic edema of infancy (AHEI) is a cutaneous leukocytoclastic vasculitis affecting children under 3 years old. •Appropriate diagnosis is important to distinguish this benign disease from more serious diseases to avoid investigations and treatments, iatrogenic harm and unnecessary follow-up. What is New: •AHEI is an uncommon disorder often misdiagnosed by pediatricians and dermatologists. •Purpuric lesions localized on the face/ears, arms/forearms, and thighs/legs with edema of the hands without pruritus in an infant with a good overall condition are highly suggestive of AHEI.

Mutations in the B30.2 and the central helical scaffold domains of pyrin differentially affect inflammasome activation.

Familial Mediterranean Fever (FMF) is the most common monogenic autoinflammatory disorder. FMF is caused by mutations in the MEFV gene, encoding pyrin, an inflammasome sensor. The best characterized pathogenic mutations associated with FMF cluster in exon 10. Yet, mutations have been described along the whole MEFV coding sequence. Exon 10 encodes the B30.2 domain of the pyrin protein, but the function of this human-specific domain remains unclear. Pyrin is an inflammasome sensor detecting RhoA GTPase inhibition following exposure to bacterial toxins such as TcdA. Here, we demonstrate that the B30.2 domain is dispensable for pyrin inflammasome activation in response to this toxin. Deletion of the B30.2 domain mimics the most typical FMF-associated mutation and confers spontaneous inflammasome activation in response to pyrin dephosphorylation. Our results indicate that the B30.2 domain is a negative regulator of the pyrin inflammasome that acts independently from and downstream of pyrin dephosphorylation. In addition, we identify the central helical scaffold (CHS) domain of pyrin, which lies immediately upstream of the B30.2 domain as a second regulatory domain. Mutations affecting the CHS domain mimic pathogenic mutations in the B30.2 domain and render the pyrin inflammasome activation under the sole control of the dephosphorylation. In addition, specific mutations in the CHS domain strongly increase the cell susceptibility to steroid catabolites, recently described to activate pyrin, in both a cell line model and in monocytes from genotype-selected FMF patients. Taken together, our work reveals the existence of two distinct regulatory regions at the C-terminus of the pyrin protein, that act in a distinct manner to regulate positively or negatively inflammasome activation. Furthermore, our results indicate that different mutations in pyrin regulatory domains have different functional impacts on the pyrin inflammasome which could contribute to the diversity of pyrin-associated autoinflammatory diseases.

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.

Cryopyrin-associated periodic syndrome: a treatable genetic inflammatory condition.

A 20-year-old man presented with recurrent subdural haemorrhages on a background of progressive sensorineural hearing loss, juvenile idiopathic arthritis and intracranial hypertension of unknown cause. His mother had a similar previous history. They both had a persistently mildly elevated serum C reactive protein. Repeat lumbar punctures identified persistently elevated intracranial pressure and mild pleocytosis. A dural biopsy showed necrotising pachymeningitis with granulomatous vasculitis. The underlying cause in both patients was a cryopyrin-associated periodic syndrome. We discuss its varied phenotype and how clinicians need to be aware of this treatable genetic condition to facilitate early treatment and to prevent accumulation of disability.

Therapeutic alliance is associated to treatment adherence in children with juvenile idiopathic arthritis.

OBJECTIVES: Therapeutic alliance (TA) is the agreement between caregiver and patient during the care process. Therapeutic adherence is a major issue for the management of Juvenile Idiopathic Arthritis (JIA) requiring child's strong ability to follow treatments. The aim of this study was to evaluate the relationship between TA and adherence in patients with JIA. METHODS: Observational, cross-sectional, multicenter study. Children, with JIA, aged 8-16, were included. Children, parents and physicians completed the Helping Alliance Questionnaire (HAQ-CP) for assessing TA. Adherence was measured using the Child/Parent Adherence Report Questionnaire (CARQ & PARQ). Demographic data, disease characteristics, current treatments and social environment were collected. The univariate relationship between TA and adherence, was studied by Pearson correlation coefficient. The multivariate analysis used a multiple linear regression model. RESULTS: A total of 119 patients were included: 68.9% girls, mean age (SD) 12.4 (2.9) years, disease duration 73.1 (48.2) months. JIA was in remission (52%), in low activity (32%) and active (16%). TA scores were high (≥80/100) for children, parents and physicians. HAQCP was highly correlated with CARQ (r=0.31; P<0.001) PARQ (r=0.37; P<0.001). In univariate analysis, disease activity (P<0.05), place of residence (P<0.01) and family status (P<0.01) were associated with child's TA. In multivariate analysis, only the place of residence (P<0.001) and the family status (P<0.05) remained associated with TA. CONCLUSION: TA strongly influences therapeutic adherence and therefore may be important for treatment effectiveness.

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.

Mosaicism in autoinflammatory diseases: Cryopyrin-associated periodic syndromes (CAPS) and beyond. A systematic review.

Autoinflammatory diseases (AIDs) are conditions related to defective regulation of the innate immune system. Sanger sequencing of the causative genes has long been the reference for confirming the diagnosis. However, for many patients with a typical AID phenotype, the genetic cause remains unknown. A pioneering study in 2005 demonstrated mosaicism in patients with cryopyrin-associated periodic syndromes (CAPS); the authors found somatic mosaicism in 69% of their cohort of Sanger-negative CAPS patients. We aim to address the extent to which mosaicism contributes to the etiology of AIDs and its impact on phenotype. We retrieved English-language publications reporting mosaicism in AIDs by querying PubMed with no restriction on date and we surveyed French reference centers. We provide a comprehensive clinical and genetic picture of mosaicism in AIDs. We estimate that the proportion of CAPS-like patients presenting mosaicism ranges from 0.5% to 19%. We also discuss the possible links between the proportion of mutated alleles and various clinical features. This review reevaluates the contribution of mosaic DNA variants in CAPS. Mosaicism may be more common than anticipated in other AIDs. No significant difference was demonstrated between variant allele frequency and clinical phenotype. Such knowledge has implications for the development of guidelines for genetic diagnosis, genetic counseling of affected families and effective patient care.

Conventional radiography in juvenile idiopathic arthritis: Joint recommendations from the French societies for rheumatology, radiology and paediatric rheumatology.

BACKGROUND: Juvenile idiopathic arthritis (JIA) can cause structural damage. However, data on conventional radiography (CR) in JIA are scant. OBJECTIVE: To provide pragmatic guidelines on CR in each non-systemic JIA subtype. METHODS: A multidisciplinary task force of 16 French experts (rheumatologists, paediatricians, radiologists and one patient representative) formulated research questions on CR assessments in each non-systemic JIA subtype. A systematic literature review was conducted to identify studies providing detailed information on structural joint damage. Recommendations, based on the evidence found, were evaluated using two Delphi rounds and a review by an independent committee. RESULTS: 74 original articles were included. The task force developed four principles and 31 recommendations with grades ranging from B to D. The experts felt strongly that patients should be selected for CR based on the risk of structural damage, with routine CR of the hands and feet in rheumatoid factor-positive polyarticular JIA but not in oligoarticular non-extensive JIA. CONCLUSION: These first pragmatic recommendations on CR in JIA rely chiefly on expert opinion, given the dearth of scientific evidence. CR deserves to be viewed as a valuable tool in many situations in patients with JIA. KEY POINTS: • CR is a valuable imaging technique in selected indications. • CR is routinely recommended for peripheral joints, when damage risk is high. • CR is recommended according to the damage risk, depending on JIA subtype. • CR is not the first-line technique for imaging of the axial skeleton.

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.

Musculoskeletal symptoms in patients with cryopyrin-associated periodic syndromes: a large database study.

OBJECTIVE: To determine the type and frequency of musculoskeletal symptoms at onset and during followup of cryopyrin-associated periodic syndromes (CAPS). METHODS: We retrospectively recorded the articular and muscular symptoms of patients with CAPS followed up in French hospitals. Data were presented as frequencies or the median (range), and patient groups were compared using chi-square test, Fisher's exact test, and Mann-Whitney test. RESULTS: The study included 133 patients (33 children), 20 with familial cold autoinflammatory syndrome, 88 with Muckle-Wells syndrome, 22 with chronic infantile neurologic, cutaneous, articular syndrome, and 3 with unclassified CAPS. The median age was 35 years (range 0-78 years) at the time of the study, 1 year (range 0-41 years) at symptom onset, and 23 years (range 0-58 years) at diagnosis. The disease was sporadic in 17% of the patients. Cutaneous symptoms predominated at onset (77%), followed by articular symptoms (30%). The p.Thr348Met and p.Arg260Trp NLRP3 mutations were significantly associated with the presence and absence of articular symptoms at onset, respectively. During followup, 86% of the patients had musculoskeletal symptoms, 88% had arthralgia, and 58% had arthritis, but only 9% had joint destruction. Tendinopathies occurred in 21.5% of the patients, tender points in 16.5%, and myalgia in 33%. Only 3 patients had typical knee deformities. Radiographs were rarely obtained. Except for bone deformities, osteoarticular symptoms occurred at similar frequencies in the different CAPS phenotypes. CONCLUSION: Joint manifestations were frequent in all CAPS phenotypes. Bone deformities were rare. Musculoskeletal manifestations varied within given families but tended to worsen over time.

Prevalence and incidence of juvenile idiopathic arthritis: a systematic review.

OBJECTIVES: To conduct a systematic literature review on incidence and prevalence of juvenile idiopathic arthritis and to estimate these figures in Europe for 2010. METHODS: Articles on incidence or prevalence of juvenile idiopathic arthritis were searched in Medline. Pooled incidence and prevalence were calculated overall, by gender, age, classification and arthritis categories. We used the available age and gender pooled rates to standardize the incidence and prevalence on the 2010 European population and estimate the number of cases in Europe in 2010. RESULTS: Forty-three articles (33 on incidence, 29 on prevalence) were included. Incidence rates varied from 1.6 to 23 and prevalence from 3.8 to 400/100,000. Pooled incidence and prevalence were higher for girls (10.0 [9.4-10.7] and 19.4 [18.3-20.6]/100,000) than boys (5.7 [5.3-6.2] and 11.0 [10.2-11.9]/100,000). Oligoarthritis was the most frequent form (pooled incidence rate 3.7 [3.5-3.9] and prevalence 16.8 [15.9-17.7]/100,000). The direct standardized incidence rate was 8.2 [7.5-9.0] and prevalence 70.2 [62.9-78.1]/100,000. In Europe in 2010, the estimated number of incident cases was 6896 [5481-8578] and 59,175 [44,256-76,983] prevalent cases. CONCLUSIONS: Incidence and prevalence varied greatly among published reports of juvenile idiopathic arthritis, which may be explained by methodological issues, classification used, and time. Estimating the number of affected children can be useful, especially with the new treatment possibilities.

Abatacept improves health-related quality of life, pain, sleep quality, and daily participation in subjects with juvenile idiopathic arthritis.

OBJECTIVE: To assess health-related quality of life (HRQOL) in abatacept-treated children/adolescents with juvenile idiopathic arthritis (JIA). METHODS: In this phase III, double-blind, placebo-controlled trial, subjects with active polyarticular course JIA and an inadequate response/intolerance to ≥1 disease-modifying antirheumatic drug (including biologics) received abatacept 10 mg/kg plus methotrexate (MTX) during the 4-month open-label period (period A). Subjects achieving the American College of Rheumatology Pediatric 30 criteria for improvement (defined "responders") were randomized to abatacept or placebo (plus MTX) in the 6-month double-blind withdrawal period (period B). HRQOL assessments included 15 Child Health Questionnaire (CHQ) health concepts plus the physical (PhS) and psychosocial summary scores (PsS), pain (100-mm visual analog scale), the Children's Sleep Habits Questionnaire, and a daily activity participation questionnaire. RESULTS: A total of 190 subjects from period A and 122 from period B were eligible for analysis. In period A, there were substantial improvements across all of the CHQ domains (greatest improvement was in pain/discomfort) and the PhS (8.3 units) and PsS (4.3 units) with abatacept. At the end of period B, abatacept-treated subjects had greater improvements versus placebo in all domains (except behavior) and both summary scores. Similar improvement patterns were seen with pain and sleep. For participation in daily activities, an additional 2.6 school days/month and 2.3 parents' usual activity days/month were gained in period A responders with abatacept, and further gains were made in period B (1.9 versus 0.9 [P = 0.033] and 0.2 versus -1.3 [P = 0.109] school days/month and parents' usual activity days/month, respectively, in abatacept- versus placebo-treated subjects). CONCLUSION: Improvements in HRQOL were observed with abatacept, providing real-life tangible benefits to children with JIA and their parents/caregivers.

Efficacy of etanercept for the treatment of juvenile idiopathic arthritis according to the onset type.

OBJECTIVE: To assess the efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), and to assess the tolerance of these patients to etanercept. METHODS: All JIA patients with active chronic polyarthritis, who were first treated with etanercept between November 1999 and June 2001 in 18 French centers because of poor response or intolerance to methotrexate, were included in this open-label, prospective, multicenter study. A standardized questionnaire was sent to the treating physicians. We assessed the validated international core-set score for JIA activity every 3 months and performed an intent-to-treat analysis. We also compared the risk of treatment failure in patients defined as having systemic-onset, oligoarticular-onset, or polyarticular-onset JIA. RESULTS: Sixty-one patients were enrolled and were followed up for a median of 13 months. Treatment had to be stopped in 1 patient who became pregnant and in 12 patients due to severe side effects, including neurologic or psychiatric disorders, retrobulbar optic neuropathy, major weight gain, severe infection, cutaneous vasculitis with systemic symptoms, hemorrhagic diarrhea, uveitis flare, and pancytopenia. All of these side effects disappeared after discontinuation of etanercept. Crohn's disease was subsequently diagnosed in 1 child. Scores improved by > or =30% in 73% of patients after 3 months, but this proportion decreased to 39% after 12 months. The response rate was significantly lower in patients with systemic-onset JIA than in those with oligoarticular- or polyarticular-onset JIA. CONCLUSION: Treatment of JIA with etanercept may be associated with a wide spectrum of severe side effects. Although most patients initially respond to etanercept, this initial response is not always followed by sustained improvement over longer periods of time. In addition, the higher rate of treatment failure in the group with systemic-onset JIA indicates that these patients in particular may require alternative treatments.

Validation of the French version of the Childhood Health Assessment Questionnaire (CHAQ) in juvenile idiopathic arthritis.

OBJECTIVES: To translate, cross-culturally adapt, and validate the functional disability tool Childhood Health Assessment Questionnaire (CHAQ), a variant of the Health Assessment Questionnaire (HAQ), in children with juvenile idiopathic arthritis (JIA). CHILDREN AND METHODS: The disability index is the mean of the scores on the eight domains of the CHAQ and can range from 0 (no disability) to 3 (maximum disability). The CHAQ was first translated into French and adapted, then validated in a multicenter cross-sectional study in 306 children with JIA (systemic onset, 23%; polyarticular onset, 22%; extended oligoarticular subtype, 25%; and persistent oligoarticular subtype, 30%). RESULTS: Overall CHAQ scores discriminated between the four JIA subtypes (systemic: 1.1 +/- 0.9; polyarticular: 0.8 +/- 0.7, extended oligoarticular 0.8 +/- 0.7, and persistent oligoarticular: 0.4 +/- 0.5 [P < 0.0001]). Reproducibility evaluated by test-retest at a 7-day interval was excellent (intraclass coefficient, 0.91), as was agreement between the Parent's and Children's versions of the questionnaire (intraclass coefficient, 0.89). Significant correlations were found between the overall CHAO score and variables reflecting disease severity (joint counts, physician's and parent's global assessments, and erythrocyte sedimentation rate), indicating excellent convergent validity of the tool. CONCLUSION: The French version of the CHAQ displays good psychometric characteristics, although its sensitivity to change remains to be established. The French version of the CHAO should prove useful in international studies and can be expected to be helpful for monitoring individual patients with JIA.