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.

Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of 3 in 1 000 000 children. In adult patients there are significant differences between the clinical presentation of diffuse and limited subtypes. We reviewed clinical differences in presentation of subtypes in patients in the juvenile systemic scleroderma inception cohort (jSScC).To study the clinical presentation of jSSc patients with diffuse (djSSc) and limited (ljSSc) subtypes.We reviewed the baseline clinical characteristics of the patients, who were recruited to the jSScC till December 2022. jSScC is a prospective cohort of jSSc patients, who developed the first non-Raynaud´s symptom before the age of 16 years and are under the age of 18 years at the time of inclusion.The JSScC included 232 patients, 68% (n=159) had diffuse subtype. The median age at onset of Raynaud phenomenon was 10.4 years (7.3-12.9), at the first non-Raynaud symptom 10.9 years (7.3-13.0) and median disease duration 2.5 years (1.0-4.6). The female/male ratio was significantly lower in the djSSc subtype (3:1 versus 5:1, p<0.001). Antibody profile was similar, with the exception of a significantly higher number of anticentromere positive patients in the ljSSc. Decreased FVC<80% was found in approximately 30% and decreased DLCO<80% was found in around 40% in both subtypes. Abnormal HRCT findings were found in 44% of patients. Pulmonary hypertension assessed by ultrasound occurred in approximately 5% in both groups and gastrointestinal involvement in 43% of djSSc and 36% in ljSSc (p=0.303). Patients with djSSc had significantly higher modified Rodnan Skin Score, more frequently sclerodactyly, a history of digital ulceration active ulceration, telangiectasia, a decreased Body Mass Index z score ≤ -2 and decreased joint range of motion. Patients with ljSSc had significantly higher rate of cardiac involvement. Regarding patient related outcomes assessed by VAS 0-100 djSSc patients had more severe disease also physician related outcome assessed by VAS 0-100 were significantly higher in djSSc (see Table 1).Table 1.Comparison of subtypes at time of inclusion in the cohortWhole Group N=232Diffuse Subtype N=159Limited Subtype N=73P value Anticentromere5% (7/156)2% (2/106)10% (5/50)0.022 MRSS, median (IQR)10 (4 – 20)16 (8 - 27)4 (0 – 8)0.001 Gottron Papules26% (59/228)31% (48/155)15% (11/73)0.011 Sclerodactyly75% (165/219)85% (127/150)55% (38/69)<0.001 Telangiectasia37% (77/209)44%(62/141)22% (15/68)0.002 History of ulceration52% (119/229)62% (98/158)30% (21/71)<0.001 Active ulceration17% (39/229)21% (33/158)8% (6/71)0.021 Only Cardiac involvement5% (12/232)3% (4/159)11% (8/73)0.007 BMI<- 2 z score15% (33/217)20% (29/148)6% (4/69)0.008 Joints with decreased range59% (136/231)64% (101/158)48% (35/73)0.022Physician Reported (Median, IQR) Physician global disease activity30 (20 – 45)n=19735 (20– 50)n=13820 (10 – 30)n=590.001 Physician global disease damage30 (15 – 40)n=19530 (20 – 45)n=13820 (5 – 30)n=570.004 Physician ulceration activity0 (0 – 16)n=2165 (0 – 20)n=1540 (0 – 0)n=620.018Patient Reported (Median, IQR) Patient global disease activity40 (20 – 50)n=17840 (20 – 50)n=12930 (15 – 55)n=490.024 Patient global disease damage30 (15 – 60)n=17740 (20 – 60)n=12825 (5 – 55)n=490.001 Patient Raynaud activity30 (10 – 60)n=20230 (10 – 60)n=14515 (0 – 55)n=570.001 Patient ulceration activity0 (0 – 30)n=20310 (0 – 30)n=1450 (0 – 20)n=580.001In the largest jSSc cohort in the world, djSSc patients have a significantly more severe disease. Patients and physician related outcomes were significantly more severe in djSSc group. Interestingly, we found no differences regarding interstitial lung disease, pulmonary hypertension or gastrointestinal involvement, although the number of patients with decreased BMI ≤ -2 z score was significantly higher in the djSSc patients.NIL.NIL.None Declared.

Children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) usually present minimal symptoms or are asymptomatic. Nevertheless, a subset of children 2-6 weeks after the initial SARS-CoV-2 infection develops a postinfectious SARS-CoV-2-related multisystem inflammatory syndrome in (MIS-C). Recently, transient expansion of TRBV11-2 T cell clonotypes in MIS-C was associated with signatures of inflammation and T cell activation, however, the underlying pathophysiology of MIS-C is not fully understood [1].The purpose of our project is to characterize the complexity of cell populations and capture cellular heterogeneity to uncover the regulatory networks and interactions that are disrupted during MIS-C flare with simultaneous profiling of gene expression and open chromatin regions from the same nuclei.Samples of peripheral blood mononuclear cells from patients with MIS-C diagnosed at the University Children’s Hospital, University Medical Center Ljubljana, were collected during the initial presentation before any treatment and at 6-12 months in remission. The primary aim is to identify which regulatory networks are driving inflammation in MIS-C flare, for which we are performing single cell Multiome ATAC + Gene Expression Sequencing. To enable simultaneous profiling of epigenomic landscape and gene expression from the same nuclei, we are using Chromium Next GEM Single Cell Multiome ATAC + Gene Expression kit from 10X Genomics.We included 32 patients with MIS-C from whom we collected paired blood samples during the initial presentation before treatment and at 6-12 months in remission. In single cell multiomic experiment we included 10 patients with paired samples, with the most viable cell count prior cryopreservation. All samples that are included into multiomic single cell analysis have 75% - 99% viability prior cryopreservation. In the protocol the key is to remove remaining granulocytes causing high mitochondrial RNA burden and extensively optimize the dilution factor of lysis buffer and the length of cell lysis step in order to get intact nuclei with no significant blebbing. Afterward, the single cell ATAC libraries as well as single-cell gene expression libraries are constructed and sequenced. Data are undergoing pairwise analysis to compare the cell population heterogeneity, expression profile and open chromatin landscape in the time of the initial presentation of MIS-C and in the remission, with Cell ranger software as well as with R package scREG [2], and custom scripting. In the second step we will inspect if the resulting altered transcriptomic signature from single-cell experiment is present on larger cohort. In that regard, we will perform bulk transcriptomic profiling on all paired collected samples during the initial presentation of MIS-C before treatment and at 6-12 months in remission.The results of this project are expected to enlighten the underlying pathophysiology of MIS-C flare and thus support clinical decision on more targeted treatment. The identified disrupted networks during MIS-C flare could lead the way to establish an early diagnosis and improve long-term outcome, including prevention of myocardial and neuropsychological impairment. Moreover, a better understanding of the disrupted regulatory networks that are driving inflammation in MIS-C, could lead to new insights into diseases with similar clinical presentations as is Kawasaki Disease.[1]Sacco, K., Castagnoli, R., Vakkilainen, S.et al.Immunopathological signatures in multisystem inflammatory syndrome in children and pediatric COVID-19.Nat Med28, 1050–1062 (2022).[2]Duren, Z., Chang, F., Naqing, F.et al.Regulatory analysis of single cell multiome gene expression and chromatin accessibility data with scREG.Genome Biol23, 114 (2022).This research was supported by Slovenian research agency grant J3-3061 and Interreg ITA-SLO project Cattedra.None Declared.

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.

OBJECTIVES CLIPPER2 was an 8-year, open-label extension of the phase 3 b, 2-year CLIPPER study on the safety and efficacy of etanercept in patients with juvenile idiopathic arthritis (JIA), categorized as extended oligoarticular arthritis (eoJIA), enthesitis-related arthritis (ERA), or psoriatic arthritis (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 American College of Rheumatology (ACR) 30/50/70/90/100 criteriaand ACR inactive disease criteria, and clinical remission (ACR criteria) or Juvenile Arthritis Disease Activity Score (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 1-9 [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 17 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 favorable. CLINICALTRIALS.GOV IDS CLIPPER (NCT00962741); CLIPPER2 (NCT01421069).

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.

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.

International interest in development of treat-to-target (T2T) in both childhood-onset systemic lupus erythematosus (cSLE) and adult-onset SLE (aSLE) is increasing. T2T could facilitate more effective and structured use of treatments, aggressively controlling disease activity, preventing organ damage, and improving health-related quality of life. The first step is the selection of an appropriate target. Remission is deemed the ultimate target, but may not be attainable by all. Low disease activity (LDA), based on the principle of “tolerable” disease activity on stable treatment, with low corticosteroid dosage, may be more appropriate for some patients. The aim of this study was to derive a consensus-based cSLE appropriate definition of LDA, building upon existing aSLE definitions to improve applicability to cSLE, whilst maintaining sufficient unity to ensure that future T2T studies including adolescents and adults together are possible. The International cSLE T2T Task Force, including 18 specialists from paediatric rheumatology/nephrology, and adult rheumatology undertook a series of Delphi surveys, exploring views on aSLE LDA targets. Two virtual consensus meetings were held, utilising a modified nominal group technique to debate, modify, and vote upon topics underpinning the cSLE LDA target and its criteria. Agreement of > 80% was considered consensus. The task force agreed that the LDA target should encompass cSLE as a whole and be based upon the aSLE Lupus Low Disease Activity State definition (LLDAS), with modifications to make it more applicable to cSLE (cLLDAS, all 100% agreement). A conceptual definition of cLLDAS was defined: ‘A state, which if sustained, is associated with a low likelihood of adverse outcome (considering disease activity, damage, and medication toxicity)’ (100% agreement). Five cLLDAS criteria were agreed, as detailed within Table 1. The final cLLDAS definition was endorsed by the Paediatric Rheumatology European Society (PReS) Executive Council and PReS cSLE Working Party Chair, on behalf of the Society. A cSLE, age-appropriate definition of cLLDAS has been generated, preserving sufficient unity with the aSLE LLDAS definition to encourage life-course research. The development and validation of targets has been a key enabler for T2T trials, therefore this initiative represents a significant step forward for cSLE. Disclosure E.M.D. Smith: None. A. Aggarwal: None. J. Ainsworth: None. E. Al-Abadi: None. T. Avcin: None. L. Bortey: None. J. Burnham: None. C. Ciurtin: None. C.M. Hedrich: None. S. Kamphuis: None. D. Levy: None. L. Lewandowski: None. N. Maxwell: None. E. Morand: None. S. Ozen: None. C. Pain: None. A. Ravelli: None. C. Saad Magalhaes: None. C. Pilkington: None. D. Schonenberg: None. C. Scott: None. K. Tullus: None. M.W. Beresford: None.

Recent studies have shown that people who are immunocompromised may inadvertently play a role in spurring the mutations of the virus that create new variants. This is because some immunocompromised individuals remain at risk of getting COVID-19 despite vaccination, experience more severe disease, are susceptible to being chronically infected and remain contagious for longer if they become infected and considering that immunocompromised individuals represent approximately 2% of the overall population, this aspect should be carefully considered. So far, some autoimmune rheumatic disease (ARD) patients with COVID-19 have been treated with antiviral therapies or anti-SARS-CoV-2 antibody products. However, there is no homogeneous approach to these treatment strategies. This issue was addressed within the European Reference Network (ERN) on Rare and Complex Connective Tissue and Musculoskeletal Diseases (ReCONNET) in a discussion among experts and patient's representatives in the context of the rare and complex connective tissue diseases (rCTDs) covered by the Network. ERN ReCONNET is one of the 24 ERNs launched by the European Commission in 2017 with the aim of tackling low prevalence and rare diseases that require highly specialised treatment and promoting concentration of knowledge and resources through virtual networks involving healthcare providers (HCPs) across the European Union (EU). Considering the urgent need to provide guidance not only to the rCTDs community, but also to the whole ARDs community, a multidisciplinary Task Force, including expert clinicians and European Patient Advocacy Group (ePAG) Advocates, was created in the framework of ERN ReCONNET with the aim of developing overarching principles (OP) and points-to-consider (PtC) on a homogenous approach to treat immunocompromised patients with ARDs (with a particular focus on CTDs) affected by COVID-19 using antiviral therapies and anti-SARS-CoV-2 antibody products. The present work reports the final OP and PtC agreed by the Task Force.

Objectives Application of ‘treat-to-target’ (T2T) in childhood-onset systemic lupus erythematosus (cSLE) may improve care and health outcomes. This initiative aimed to harmonise existing evidence and expert opinion regarding T2T for cSLE. Methods An international T2T Task Force was formed of specialists in paediatric rheumatology, paediatric nephrology, adult rheumatology, patient and parent representatives. A steering committee formulated a set of draft overarching principles and points-to-consider, based on evidence from systematic literature review. Two on-line preconsensus meeting Delphi surveys explored healthcare professionals’ views on these provisional overarching principles and points-to-consider. A virtual consensus meeting employed a modified nominal group technique to discuss, modify and vote on each overarching principle/point-to-consider. Agreement of >80% of Task Force members was considered consensus. Results The Task Force agreed on four overarching principles and fourteen points-to-consider. It was agreed that both treatment targets and therapeutic strategies should be subject to shared decision making with the patient/caregivers, with full remission the preferred target, and low disease activity acceptable where remission cannot be achieved. Important elements of the points-to-consider included: aiming for prevention of flare and organ damage; glucocorticoid sparing; proactively addressing factors that impact health-related quality of life (fatigue, pain, mental health, educational challenges, medication side effects); and aiming for maintenance of the target over the long-term. An extensive research agenda was also formulated. Conclusions These international, consensus agreed overarching principles and points-to-consider for T2T in cSLE lay the foundation for future T2T approaches in cSLE, endorsed by the Paediatric Rheumatology European Society.