Antiphospholipid syndrome in children.

Antiphospholipid syndrome (APS) in children is a rare disease associated with significant morbidity and mortality. In comparison with APS in adults, pediatric APS has a more severe presentation with frequent recurrences of thrombotic events and a higher probability of life-threatening catastrophic APS. Nonthrombotic manifestations are also more common in the pediatric age group and can precede thrombosis. New classification criteria have been introduced recently and have not yet been assessed in pediatric patients with APS. In addition to anticoagulation drugs, other novel therapies have emerged including the use of B cell and complement inhibitors, especially in catastrophic APS. The purpose of this review is to provide a broad overview of aPL-related clinical manifestations in pediatric patients based on the analysis of published cohorts and data from the international pediatric APS registry. We also aim to illustrate APS in infants caused by transplacentally transferred maternal aPL, which is very rarely associated with acute thrombotic events in the perinatal period and more frequently with long-term neurodevelopmental abnormalities.

Development of the 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria, Phase III-D Report: Multi Criteria Decision Analysis.

BACKGROUND: The 2023 ACR/EULAR Antiphospholipid Syndrome (APS) Classification Criteria development, aiming to identify patients with high likelihood of APS for research, employed a four-phase methodology. Phase I and II resulted in 27 proposed candidate criteria, organized into laboratory and clinical domains. Here, we summarize the last stage of Phase III efforts employing a consensus-based multi-criteria decision analysis (MCDA) to weigh candidate criteria and identify an APS classification threshold score. METHODS: We evaluated 192 unique, international real-world cases referred for "suspected APS" with a wide range of APS manifestations. Using proposed candidate criteria, subcommittee members rank-ordered 20 representative cases from highly unlikely to highly likely APS. During an in-person meeting, the subcommittee refined definitions and participated in an MCDA exercise to identify relative weights of candidate criteria. Using consensus decisions and pairwise criteria comparisons, 1000Minds™ software assigned criteria weights, and we rank ordered 192 cases by their additive scores. A consensus-based threshold score for APS classification was set. RESULTS: Pre-meeting evaluation of 20 representative cases demonstrated variability in APS assessment. MCDA resolved 81 pairwise decisions; relative weights identified domain item hierarchy. After assessing 192 cases by weights and additive scores, the Steering Committee reached consensus that APS classification should require separate clinical and laboratory scores, rather than a single aggregate score, to ensure high specificity. CONCLUSION: Using MCDA, candidate criteria preliminary weights were determined. Unlike other disease classification systems using a single aggregate threshold score, separate clinical and laboratory domain thresholds were incorporated into the new APS classification criteria.

Serological response after COVID-19 infection compared to vaccination against COVID-19 in children with autoimmune rheumatic diseases.

BACKGROUND: Paediatric patients with autoimmune rheumatic diseases (pARD) have a dysregulated immune system, so infections present a major threat to them. To prevent severe COVID-19 infections we aimed to vaccinate them as soon as possible. Studies have shown that the BNT162b2 vaccine is safe, effective, and immunogenic, however, in a short observation period, only. METHODS: The main objective was to compare the serological response between three groups of pARD: after SARS-CoV-2 infection, after vaccination against COVID-19 with two doses of the BNT162b2 vaccine, and after experiencing both events. Data on demographics, diagnosis, therapy, and serology (anti-SARS-CoV-2 IgG/IgA) were collected from March 2020 to April 2022. For statistical analysis ANOVA, Mann-Whitney U test, Chi-square test and Fisher's exact test were applied. To compare adverse events (AE) after vaccination we included a control group of healthy adolescents. RESULTS: We collected data from 115 pARD; from 92 after infection and 47 after vaccination. Twenty-four were included in both groups. Serological data were available for 47 pARD after infection, 25 after vaccination, and 21 after both events. Serological response was better after vaccination and after both events compared to after infection only. No effect of medication on the antibody levels was noted. The safety profile of the vaccine was good. Systemic AE after the first dose of the vaccine were more common in healthy adolescents compared to pARD. In the observation period of 41.3 weeks, 60% of vaccinated pARD did not experience a symptomatic COVID-19 infection. CONCLUSIONS: IgG and IgA anti-SARS-CoV-2 levels were higher after vaccination and after both events compared to after infection only. Six months after vaccination we observed an increase in antibody levels, suggesting that pARD had been exposed to SARS-CoV-2 but remained asymptomatic. TRIAL REGISTRATION: The study was approved by the Medical Ethics Committee of the Republic of Slovenia (document number: 0120-485/2021/6).

The HyperPed-COVID international registry: Impact of age of onset, disease presentation and geographical distribution on the final outcome of MIS-C.

OBJECTIVES: The aim of the study was to establish an international multicenter registry to collect data on patients with Multisystem Inflammatory Syndrome in Children (MIS-C), in order to highlight a relationship between clinical presentation, age of onset and geographical distribution on the clinical outcome. STUDY DESIGN: Multicenter retrospective study involving different international societies for rare immunological disorders.1009 patients diagnosed with MIS-C between March and September 2022, from 48 centers and 22 countries were collected. Five age groups (<1, 1-4, 5-11, 12-16, >16 years) and four geographic macro-areas, Western Europe, Central-Eastern Europe, Latin America, Asian-African resource-limited countries (LRC), were identified. RESULTS: Time to referral was significantly higher in LRC. Intensive anti-inflammatory treatment, including biologics, respiratory support and mechanic ventilation were more frequently used in older children and in European countries. The mortality rate was higher in very young children (<1 year), in older patients (>16 years of age) and in LRC. Multivariate analysis identified the residence in LRC, presence of severe cardiac involvement, renal hypertension, lymphopenia and non-use of heparin prophylaxis, as the factors most strongly associated with unfavorable outcomes. CONCLUSIONS: The stratification of patients by age and geographic macro-area provided insights into the clinical presentation, treatment and outcome of MIS-C. The mortality and sequelae rates exhibited a correlation with the age and geographical areas. Patients admitted and treated in LRC displayed more severe outcomes, possibly due to delays in hospital admission and limited access to biologic drugs and to intensive care facilities.

The outcomes of children born to mothers with autoimmune rheumatic diseases.

Maternal autoimmune rheumatic diseases can influence the outcomes of children through several life stages. During pregnancy, maternal inflammation and autoantibodies can hinder fetal development and lead to growth restriction, preterm birth, and low birth weight; prematurity, especially at extreme gestational ages, can in turn impair future child health. Treatment with compatible immunomodulatory drugs and preventive medications aims to keep maternal disease under control and minimise the risk of adverse pregnancy outcomes. However, concerns have been raised about the effects of immunomodulatory drugs on neonatal conditions (ie, the risk of serious infections, inadequate responses to vaccinations, and organ toxicity) and long-term outcomes (metabolic and cardiovascular problems and neurodevelopmental disorders). Among the unmet needs of parents with autoimmune rheumatic diseases, there is the estimation of risk for the children to develop autoimmune disorders and the need for reassurance about parenting capacity while living with a chronic condition. This Series paper provides a comprehensive overview of the literature and guidance on discussing these topics with patients.

Multisystem inflammatory syndrome in children: A review.

AIM: To comprehensively review the literature on multisystem inflammatory syndrome in children (MIS-C). METHODS: Narrative review of relevant studies published between April 2020 and January 2024. RESULTS: MIS-C is a SARS-CoV-2-related hyperinflammatory syndrome developing 2-6 weeks after COVID-19 in genetically susceptible individuals. Persisting fever, mucocutaneous manifestations, GI and cardiac involvement, together with lymphopenia and elevated inflammatory and cardiac markers are the main clinical features. It is believed to recognise some pathogenetic and clinical overlap with Kawasaki disease. New case definitions have been proposed after an assessment of the diagnostic performance of existing criteria; epidemiological criterion is however progressively losing its usefulness as the pandemic turns into an endemic and in the areas with the highest rates of COVID-19 vaccination. Current guidelines recommend both intravenous immunoglobulin and glucocorticoids in the first-line immunomodulatory treatment, mainly based on comparative retrospective cohorts; the actual role of biologics remains to be adequately established. Strict follow-up is mandatory, especially for those with severe cardiac involvement, as longitudinal studies evaluate the long-term evolution of cardiac damage. CONCLUSION: In this paper, we review the epidemiological, pathogenetic, clinical and prognostic features of MIS-C, and outline the main questions which still remain unanswered after more than 3 years of research.

Ocular Manifestations in Juvenile Behçet's Disease: A Registry-Based Analysis from the AIDA Network.

INTRODUCTION: This study aims to characterize ocular manifestations of juvenile Behçet's disease (jBD). METHODS: This was a registry-based observational prospective study. All subjects with jBD from the Autoinflammatory Diseases Alliance (AIDA) Network BD Registry showing ocular manifestations before 18 years were enrolled. RESULTS: We included 27 of 1000 subjects enrolled in the registry (66.7% male patients, 45 affected eyes). The median (interquartile range [IQR]) age at ocular involvement was 14.2 (4.7) years. Uveitis affected 91.1% of eyes (anterior 11.1%, posterior 40.0%, panuveitis 40.0%), retinal vasculitis 37.8% and other manifestations 19.8%. Later onset (p = 0.01) and male predominance (p = 0.04) characterized posterior involvement. Ocular complications occurred in 51.1% of eyes. Patients with complications had earlier onset (p < 0.01), more relapses (p = 0.02) and more prolonged steroidal treatment (p = 0.02). The mean (standard deviation [SD]) central macular thickness (CMT) at the enrolment and last visit was 302.2 (58.4) and 293.3 (78.2) µm, respectively. Fluorescein angiography was pathological in 63.2% of procedures, with a mean (SD) Angiography Scoring for Uveitis Working Group (ASUWOG) of 17.9 (15.5). At the last visit, ocular damage according to the BD Overall Damage Index (BODI) was documented in 73.3% of eyes. The final mean (SD) best corrected visual acuity (BCVA) logMAR was 0.17 (0.47) and blindness (BCVA logMAR < 1.00 or central visual field ≤ 10°) occurred in 15.6% of eyes. At multivariate regression analysis, human leukocyte antigen (HLA)-B51 + independently predicted a + 0.35 change in the final BCVA logMAR (p = 0.01), while a higher BCVA logMAR at the first assessment (odds ratio [OR] 5.80; p = 0.02) independently predicted blindness. CONCLUSIONS: The results of this study may be leveraged to guide clinical practice and future research on this rare sight-threatening condition.

Long-term follow-up of 109 children with juvenile idiopathic oligoarthritis after first intra-articular corticosteroid injection.

BACKGROUND: To evaluate long-term outcomes and prognostic factors in patients with juvenile idiopathic arthritis (JIA), presenting as oligoarthritis, who received IAC as the first treatment for their disease. METHODS: We conducted retrospective study at the University Children's Hospital Ljubljana, Slovenia, from January 2015 to May 2023 in children with JIA, clinically presenting as oligoarthritis receiving intra-articular corticosteroid injection (IAC) as the initial treatment. Patient and treatment data were collected, and the outcomes were categorized into three groups based on the later need for therapy: no therapy needed, only additional IAC needed and systemic therapy needed. The last group was further divided based on the requirement of bDMARD. Log-rank (Mantel-Cox) survival analyses compared different outcome groups. RESULTS: We included 109 patients with JIA, presenting as oligoarthritis (63% female), who were first treated with IAC. The mean age at IAC was 8.0 years, with a 4.3-year follow-up. Notably, 38.5% of patients did not require additional therapy post-IAC, whereas 15.5% required only additional IAC. Systemic therapy, mainly methotrexate (MTX), was necessary for 45.9% of patients, initiated in average 7.8 months post-IAC. Biologic therapy was initiated in 22% in average 2.2 years post-IAC. Number of injected joints correlated with the need for biologics. At the last follow-up, 88.9% had inactive disease. ANA positivity (P = 0.049, chi square 3.89) and HLA B27 antigen presence (P = 0.050, chi square 3.85) were associated with the need for systemic therapy. A subgroup of children older than 8 years, ANA and HLA B27 negative required significantly less systemic (25.8%) and biologic therapy (9.6%) compared to other patients (p = 0.050, chi square 3.77). CONCLUSION: Almost 40% of children with oligoarticular JIA requiring IAC did not progress to chronic disease. Younger age, ANA positivity, and HLA B27 presence were predictive factors for systemic therapy, while the number of injected joints predicted the future need for biologic therapy.

A clinical perspective on imaging in juvenile idiopathic arthritis.

In recent years, imaging has become increasingly important to confirm diagnosis, monitor disease activity, and predict disease course and outcome in children with juvenile idiopathic arthritis (JIA). Over the past few decades, great efforts have been made to improve the quality of diagnostic imaging and to reach a consensus on which methods and scoring systems to use. However, there are still some critical issues, and the diagnosis, course, and management of JIA are closely related to clinical assessment. This review discusses the main indications for conventional radiography (XR), musculoskeletal ultrasound (US), and magnetic resonance imaging (MRI), while trying to maintain a clinical perspective. The diagnostic-therapeutic timing at which one or the other method should be used, depending on the disease/patient phenotype, will be assessed, considering the main advantages and disadvantages of each imaging modality according to the currently available literature. Some brief clinical case scenarios on the most frequently and severely involved joints in JIA are also presented.

Ten-year safety and clinical benefit from open-label etanercept treatment in children and young adults with juvenile idiopathic arthritis.

OBJECTIVES: CLIPPER2 was an 8-year, open-label extension of the phase 3b, 2-year CLIPPER study on the safety and efficacy of etanercept in patients with JIA, categorized as extended oligoarticular arthritis (eoJIA), enthesitis-related arthritis (ERA) or PsA. METHODS: Participants with eoJIA (2-17 years old), ERA or PsA (each 12-17 years old) who received ≥1 etanercept dose (0.8 mg/kg weekly; maximum 50 mg) in CLIPPER could enter CLIPPER2. Primary end point was occurrence of malignancy. Efficacy assessments included proportions achieving JIA ACR 30/50/70/90/100 criteria and ACR inactive disease criteria, and clinical remission (ACR criteria) or Juvenile Arthritis DAS (JADAS) ≤1. RESULTS: Overall, 109/127 (86%) CLIPPER participants entered CLIPPER2 [n = 55 eoJIA, n = 31 ERA, n = 23 PsA; 99 (78%) on active treatment]; 84 (66%) completed 120 months' follow-up [32 (25%) on active treatment]. One malignancy (Hodgkin's disease in 18-year-old patient with eoJIA treated with methotrexate for 8 years) was reported; there were no cases of active tuberculosis or deaths. Numbers and incidence rates (events per 100 patient-years) of TEAEs (excluding infections/ISRs) decreased from 193 (173.81) in Year 1 to 9 (27.15) in Year 10; TE infections and serious infections also decreased. Over 45% of participants (n = 127) achieved JIA ACR50 responses from Month 2 onwards; 42 (33%) and 34 (27%) participants achieved JADAS and ACR clinical remission, respectively. CONCLUSIONS: Etanercept treatment up to 10 years was well tolerated, consistent with the known safety profile, with durable response in the participants still on active treatment. The benefit-risk assessment of etanercept in these JIA categories remains favourable. TRIAL REGISTRATION: ClinicalTrials.gov IDs: CLIPPER (NCT00962741); CLIPPER2 (NCT01421069).

Towards telehealth delivery in pediatric rheumatology practice.

INTRODUCTION: Much has been written and spoken about telemedicine since about two decades including an article in this journal at the start of the pandemic. It took a global catastrophe to enforce its usage across the world in various medical specialties. Telemedicine however remains unstructured, unregulated and lacks uniformity. DISCUSSION: This article highlights the practical learnings and opinions of the authors who provided over two thousand video consults and asynchronous telemedicine services through the entire pandemic. It includes lessons learnt from emerging economies where pediatric rheumatologists are scarce. Pediatric rheumatology, which relies heavily on history, musculoskeletal and skin examination is aptly suited to exploit telemedicine in its synchronous and asynchronous forms. Pediatric tele rheumatology could temporarily address the shortage and uneven distribution of specialists in vast parts of the globe, besides serving as a method of triage and shared care with the primary physician. Reduction of direct and indirect costs and family/primary physician education are additional benefits. There also exist challenges for all stakeholders and it is important to address the latter. CONCLUSION: The learnings of the pandemic suggest a vital role for telemedicine in the practice of pediatric rheumatology. This is a fertile area for research and consensus building by international and national pediatric societies and issue position statements like some adult bodies already have. The authors speculate a hybrid system of care in the not-so-distant future.

Application and performance of disease activity indices proposed for patients with systemic sclerosis in an international cohort of patients with juvenile systemic sclerosis.

Objectives: Juvenile systemic sclerosis is a rare childhood disease. Three disease activity indices have been published for adult patients with systemic sclerosis: the European Scleroderma Study Group Index, a modified version of the European Scleroderma Study Group Index and the revised European Scleroderma Trials and Research index. The objective of this study was to determine the feasibility and performance of the three disease activity indices in a prospectively followed cohort of patients with juvenile systemic sclerosis. Methods: The analysis cohort was selected from the prospective international inception cohort enrolling juvenile systemic sclerosis patients. The correlation of the disease activity indices with the physicians' and the patients' global assessment of disease activity was determined. The disease activity indices were compared between patients with active and inactive disease. Sensitivity to change between 6- and 12-month follow-up was investigated by mixed models. Results: Eighty percent of the 70 patients had a diffuse cutaneous subtype. The revised European Scleroderma Trials and Research index was highly correlated with the physician-reported global disease activity/parents-reported global disease activity (r = 0.74/0.64), followed by the European Scleroderma Study Group activity index (r = 0.61/0.55) and the modified version of the European Scleroderma Study Group activity index (r = 0.51/0.43). The disease activity indices significantly differed between active and inactive patients. The disease activity indices showed sensitivity to change between 6- and 12-month follow-up among patients who improved or worsened according to the physician-reported global disease activity and the parents-reported global disease activity. Conclusion: Overall, no disease activity score is superior to the other, and all three scores have limitations in the application in juvenile systemic sclerosis patients. Furthermore, research on the concept of disease activity and suitable scores to measure disease activity in patients with juvenile systemic sclerosis is necessary in future.

The 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria.

OBJECTIVE: To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR. METHODS: This international multidisciplinary initiative included 4 phases: 1) Phase I, criteria generation by surveys and literature review; 2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; 3) Phase III, criteria definition, further reduction with the guidance of real-world patient scenarios, and weighting via consensus-based multicriteria decision analysis, and threshold identification; and 4) Phase IV, validation using independent adjudicators' consensus as the gold standard. RESULTS: The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL-associated clinical criterion, followed by additive weighted criteria (score range 1-7 points each) clustered into 6 clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and 2 laboratory domains (lupus anticoagulant functional coagulation assays, and solid-phase enzyme-linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti-ß2 -glycoprotein I antibodies). Patients accumulating at least 3 points each from the clinical and laboratory domains are classified as having APS. In the validation cohort, the new APS criteria versus the 2006 revised Sapporo classification criteria had a specificity of 99% versus 86%, and a sensitivity of 84% versus 99%. CONCLUSION: These new ACR/EULAR APS classification criteria were developed using rigorous methodology with multidisciplinary international input. Hierarchically clustered, weighted, and risk-stratified criteria reflect the current thinking about APS, providing high specificity and a strong foundation for future APS research.

2023 ACR/EULAR antiphospholipid syndrome classification criteria.

OBJECTIVE: To develop new antiphospholipid syndrome (APS) classification criteria with high specificity for use in observational studies and trials, jointly supported by the American College of Rheumatology (ACR) and EULAR. METHODS: This international multidisciplinary initiative included four phases: (1) Phase I, criteria generation by surveys and literature review; (2) Phase II, criteria reduction by modified Delphi and nominal group technique exercises; (3) Phase III, criteria definition, further reduction with the guidance of real-world patient scenarios, and weighting via consensus-based multicriteria decision analysis, and threshold identification; and (4) Phase IV, validation using independent adjudicators' consensus as the gold standard. RESULTS: The 2023 ACR/EULAR APS classification criteria include an entry criterion of at least one positive antiphospholipid antibody (aPL) test within 3 years of identification of an aPL-associated clinical criterion, followed by additive weighted criteria (score range 1-7 points each) clustered into six clinical domains (macrovascular venous thromboembolism, macrovascular arterial thrombosis, microvascular, obstetric, cardiac valve, and hematologic) and two laboratory domains (lupus anticoagulant functional coagulation assays, and solid-phase enzyme-linked immunosorbent assays for IgG/IgM anticardiolipin and/or IgG/IgM anti-ß2-glycoprotein I antibodies). Patients accumulating at least three points each from the clinical and laboratory domains are classified as having APS. In the validation cohort, the new APS criteria vs the 2006 revised Sapporo classification criteria had a specificity of 99% vs 86%, and a sensitivity of 84% vs 99%. CONCLUSION: These new ACR/EULAR APS classification criteria were developed using rigorous methodology with multidisciplinary international input. Hierarchically clustered, weighted, and risk-stratified criteria reflect the current thinking about APS, providing high specificity and a strong foundation for future APS research.

Gender differences in juvenile systemic sclerosis patients: Results from the international juvenile scleroderma inception cohort.

Objective: To compare organ involvement and disease severity between male and female patients with juvenile onset systemic sclerosis. Methods: Demographics, organ involvement, laboratory evaluation, patient-reported outcomes and physician assessment variables were compared between male and female juvenile onset systemic sclerosis patients enrolled in the prospective international juvenile systemic sclerosis cohort at their baseline visit and after 12 months. Results: One hundred and seventy-five juvenile onset systemic sclerosis patients were evaluated, 142 females and 33 males. Race, age of onset, disease duration, and disease subtypes (70% diffuse cutaneous) were similar between males and females. Active digital ulceration, very low body mass index, and tendon friction rubs were significantly more frequent in males. Physician global assessment of disease severity and digital ulcer activity was significantly higher in males. Composite pulmonary involvement was also more frequent in males, though not statistically significantly. After 12 months, they are the pattern of differences changed female patients had significantly more frequent pulmonary involvement. Conclusion: In this cohort, juvenile onset systemic sclerosis had a more severe course in males at baseline and but the pattern changed after 12 months. Some differences from adult findings persisted, there is no increased signal of pulmonary arterial hypertension or heart failure in male pediatric patients. While monitoring protocols of organ involvement in juvenile onset systemic sclerosis need to be identical for males and females.

Disease relapse rate in children with autoimmune rheumatic diseases after COVID-19 infection and vaccination.

BACKGROUND: Paediatric patients with autoimmune rheumatic diseases (pARD) are often immunocompromised because of the disease and/or the therapy they receive. At the beginning of COVID-19 pandemic there was a great concern about the possibility of severe SARS-CoV-2 infection in these patients. The best method of protection is vaccination, so as soon as vaccine was licenced, we aimed to vaccinate them. Data on disease relapse rate after COVID-19 infection and vaccination are scarce, but they play important role in everyday clinical decisions. METHODS: The aim of this study was to determine the relapse rate of autoimmune rheumatic disease (ARD) after COVID-19 infection and vaccination. Data on demographic, diagnosis, disease activity, therapy, clinical presentation of the infection and serology were collected from pARD who had COVID-19 and from pARD who were vaccinated against COVID-19, from March 2020 to April 2022. All vaccinated patients received two doses of the BNT162b2 BioNTech vaccine, on average, 3.7 (S.D.=1.4) weeks apart. Activity of the ARD was followed prospectively. Relapse was defined as a worsening of the ARD in a time frame of 8 weeks after infection or vaccination. For statistical analysis, Fisher's exact test and Mann-Whitney U test were used. RESULTS: We collected data from 115 pARD, which we divided into two groups. We included 92 pARD after infection and 47 after vaccination, with 24 in both groups (they were infected before/after vaccination). In 92 pARD we registered 103 SARS-CoV-2 infections. Infection was asymptomatic in 14%, mild in 67% and moderate in 18%, 1% required hospitalization; 10% had a relapse of ARD after infection and 6% after vaccination. There was a trend towards higher disease relapse rate after infection compared to vaccination, but the difference was not statistically significant (p = 0.76). No statistically significant difference was detected in the relapse rate depending on the clinical presentation of the infection (p = 0.25) or the severity of the clinical presentation of COVID-19 between vaccinated and unvaccinated pARD (p = 0.31). CONCLUSIONS: There is a trend towards a higher relapse rate in pARD after infection compared to vaccination and connection between the severity of COVID-19 and vaccination status is plausible. Our results were, however, not statistically significant.

Points to consider: EULAR-UEMS standards for the training of European rheumatologists.

BACKGROUND: Postgraduate rheumatology training programmes are already established at a national level in most European countries. However, previous work has highlighted a substantial level of heterogeneity in the organisation and, in part, content of programmes. OBJECTIVE: To define competences and standards of knowledge, skills and professional behaviours required for the training of rheumatologists. METHODS: A European Alliance of Associations for Rheumatology (EULAR) task force (TF) of 23 experts, including two members of the European Union of Medical Specialists (UEMS) section of rheumatology, was convened. The mapping phase consisted of the retrieval of key documents on specialty training in rheumatology and other related specialties across a broad set of international sources. The content of these documents was extracted and represented the foundation for the document draft that underwent several rounds of online discussion within the TF, and afterwards was also distributed to a broad group of stakeholders for collecting feedback. The list of generated competences was voted on during the TF meetings, while the level of agreement (LoA) with each statement was established by anonymous online voting. RESULTS: A total of 132 international training curricula were retrieved and extracted. In addition to the TF members, 253 stakeholders commented and voted on the competences through an online anonymous survey. The TF developed (1) an overarching framework indicating the areas that should be addressed during training, (2) 7 domains defining broad areas that rheumatology trainees should master by the end of the training programme, (3) 8 core themes defining the nuances of each domain and (4) 28 competences that trainees should acquire to cover each of the areas outlined in the overarching framework. A high LoA was achieved for all competences. CONCLUSION: These points to consider for EULAR-UEMS standards for the training of European rheumatologists are now defined. Their dissemination and use can hopefully contribute to harmonising training across European countries.

Alterations in immunophenotype and metabolic profile of mononuclear cells during follow up in children with multisystem inflammatory syndrome (MIS-C).

Introduction: Although children seem to be less susceptible to COVID-19, some of them develop a rare but serious hyperinflammatory condition called multisystem inflammatory syndrome in children (MIS-C). While several studies describe the clinical conditions of acute MIS-C, the status of convalescent patients in the months after acute MIS-C is still unclear, especially the question of persistence of changes in the specific subpopulations of immune cells in the convalescent phase of the disease. Methods: We therefore analyzed peripheral blood of 14 children with MIS-C at the onset of the disease (acute phase) and 2 to 6 months after disease onset (post-acute convalescent phase) for lymphocyte subsets and antigen-presenting cell (APC) phenotype. The results were compared with six healthy age-matched controls. Results: All major lymphocyte populations (B cells, CD4 + and CD8+ T cells, and NK cells) were decreased in the acute phase and normalized in the convalescent phase. T cell activation was increased in the acute phase, followed by an increased proportion of γ/δ-double-negative T cells (γ/δ DN Ts) in the convalescent phase. B cell differentiation was impaired in the acute phase with a decreased proportion of CD21 expressing, activated/memory, and class-switched memory B cells, which normalized in the convalescent phase. The proportion of plasmacytoid dendritic cells, conventional type 2 dendritic cells, and classical monocytes were decreased, while the proportion of conventional type 1 dendritic cells was increased in the acute phase. Importantly the population of plasmacytoid dendritic cells remained decreased in the convalescent phase, while other APC populations normalized. Immunometabolic analysis of peripheral blood mononuclear cells (PBMCs) in the convalescent MIS-C showed comparable mitochondrial respiration and glycolysis rates to healthy controls. Conclusions: While both immunophenotyping and immunometabolic analyzes showed that immune cells in the convalescent MIS-C phase normalized in many parameters, we found lower percentage of plasmablasts, lower expression of T cell co-receptors (CD3, CD4, and CD8), an increased percentage of γ/δ DN Ts and increased metabolic activity of CD3/CD28-stimulated T cells. Overall, the results suggest that inflammation persists for months after the onset of MIS-C, with significant alterations in some immune system parameters, which may also impair immune defense against viral infections.