OBJECTIVES IgA vasculitis (IgAV, formerly known as Henoch-Schönlein purpura) is the most common cause of systemic vasculitis in childhood. To date, there are no internationally agreed, evidence-based guidelines concerning the appropriate diagnosis and treatment of IgAV in children. Accordingly, treatment regimens differ widely. The European initiative SHARE (Single Hub and Access point for paediatric Rheumatology in Europe) aims to optimize care for children with rheumatic diseases. The aim therefore was to provide internationally agreed consensus recommendations for diagnosis and treatment for children with IgAV. METHODS Recommendations were developed by a consensus process in accordance with the EULAR standard operating procedures. An extensive systematic literature review was performed, and evidence-based recommendations were extrapolated from the included papers. These were evaluated by a panel of 16 international experts via online surveys and subsequent consensus meeting, using nominal group technique. Recommendations were accepted when ⩾80% of experts agreed. RESULTS In total, 7 recommendations for diagnosis and 19 for treatment of paediatric IgAV were accepted. Diagnostic recommendations included: appropriate use of skin and renal biopsy, renal work-up and imaging. Treatment recommendations included: the importance of appropriate analgesia and angiotensin-converting enzyme inhibitor use and non-renal indications for CS use, as well as a structured approach to treating IgAV nephritis, including appropriate use of CS and second-line agents in mild, moderate and severe disease along with use of angiotensin-converting enzyme inhibitors and maintenance therapy. CONCLUSION The SHARE initiative provides international, evidence-based recommendations for the diagnosis and treatment of IgAV that will facilitate improvement and uniformity of care.

Actin nucleators initiate formation of actin filaments. Among them, the Arp2/3 complex has the ability to form branched actin networks. This complex is regulated by members of the Wiscott-Aldrich syndrome protein (WASp) family. Polymerization of actin filaments can be evaluated through flow cytometry by fluorescent phalloidin staining before and after stimulation with N-formyl-methionyl-leucyl-phenylalanine (fMLP). We identified a missense mutation in the gene ARPC1B (Arp2/3 activator subunit) resulting in defective actin polymerization in four patients (three of them were related). All patients (1 male, 3 female) developed microthrombocytopenia, cellular immune deficiency, eczema, various autoimmune manifestations, recurrent skin abscesses and elevated IgE antibodies. Besides four patients with homozygous mutation in ARPC1B, we also identified six heterozygous carriers without clinical disease (3 males, 3 females) within the same family. We developed a functional test to evaluate Arp2/3 complex function, which consists of flow cytometric detection of intracellular polymerized actin after in vitro fMLP stimulation of leukocytes. Median fluorescence intensities of FITC-phalloidin stained actin were measured in monocytes, neutrophils and lymphocytes of patients, carriers, and healthy control subjects. We detected non-efficient actin polymerization in monocytes and neutrophils of homozygous patients compared to carriers or the healthy subjects. In monocytes, the increase in median fluorescence intensities was significantly lower in patients compared to carriers (104 vs. 213%; p < 0.01) and healthy controls (104 vs. 289%; p < 0.01). Similarly, the increase in median fluorescence intensities in neutrophils was significantly increased in the group with carriers (208%; p < 0.01) and healthy controls (238%; p < 0.01) and significantly decreased in the patient's group (94%). Our functional fMLP/phalloidin test can therefore be used as a practical tool to separate symptomatic patients from asymptomatic mutation associated to actin polymerization.

Objective. Childhood-onset systemic lupus erythematosus (cSLE) is usually a more severe and aggressive disease than adult-onset SLE (aSLE), but cellular and subcellular reasons for these differences are not well understood. The present study analyzed Th subsets, STAT1/STAT5 signaling response, and cytokine profiles of cSLE. Methods. FOXP3+ regulatory (Treg) and effector Th subsets, expression and phosphorylation of STAT1/STAT5 in Th, and cytokine profiles were measured in the peripheral blood of patients with cSLE and healthy controls (HC), using flow cytometry and immunoassay on a biochip. Results. Significant correlation between expression of the activation marker HLA-DR and decreased Th counts, an increase in the percentage of FOXP3+ Th, and a decrease in the activated Treg (aTreg) subset among them were found in cSLE. In contrast to our previous findings in aSLE, no significant differences in percentages and a significant decrease in the numbers of the naive-resting Treg (rTreg) subset compared to HC were found. The percentages of CD25− cells, possibly reflecting interleukin 2 depletion, were significantly increased in cSLE aTreg, but not in the rTreg subset. Consistent with the results of our previous studies in aSLE, increased expression of STAT1, along with significant correlation between decreased Th counts and their increased basal phosphorylation of STAT5, were also found in cSLE. Conclusion. Our results suggest that the key difference in Treg homeostasis between cSLE and aSLE is in the rTreg subset. However, perturbed aTreg homeostasis, increased levels of STAT1 protein, and homeostatic STAT5 signaling appear to be intrinsic characteristics of the disease, present in cSLE and aSLE alike.

OBJECTIVES To provide an overview of the paediatric rheumatology (PR) services in Europe, describe current delivery of care and training, set standards for care, identify unmet needs and inform future specialist service provision. METHODS An online survey was developed and presented to national coordinating centres of the Paediatric Rheumatology International Trials Organisation (PRINTO) (country survey) and to individual PR centres (centre and disease surveys) as a part of the European Union (EU) Single Hub and Access point for paediatric Rheumatology in Europe project. The survey contained components covering the organization of PR care, composition of teams, education, health care and research facilities and assessment of needs. RESULTS Response rates were 29/35 (83%) for country surveys and 164/288 (57%) for centre surveys. Across the EU, approximately one paediatric rheumatologist is available per million population. In all EU member states there is good access to specialist care and medications, although biologic drug availability is worse in Eastern European countries. PR education is widely available for physicians but is insufficient for allied health professionals. The ability to participate in clinical trials is generally high. Important gaps were identified, including lack of standardized clinical guidelines/recommendations and insufficient adolescent transition management planning. CONCLUSION This study provides a comprehensive description of current specialist PR service provision across Europe and did not reveal any major differences between EU member states. Rarity, chronicity and complexity of diseases are major challenges to PR care. Future work should facilitate the development, dissemination and implementation of standards of care, treatment and service recommendations to further improve patient-centred health care across Europe.

Background: Infections are a major concern for patients affected by juvenile idiopathic arthritis (JIA) treated with immunosuppressive therapy. Evidence is inconsistent as to whether the start of synthetic or biological disease modifying anti-rheumatic drugs (DMARDs) is associated with an increased risk of serious and at least moderate infection. Objectives: To determine whether the addition of a TNF inhibitor (TNFi) to methotrexate (MTX) may increase the risk of serious and at least moderate infections in JIA patients included in the Pharmachild registry.(1) Methods: Serious and at least moderate infections were analysed in JIA patients, enrolled in the Pharmachild registry at September 30th, 2018, who started as first drug with MTX. We divided patients in 3 treatment groups: “MTX alone”, in which patients had received MTX as the only drug all over their history; “MTX Start”, in which patients had received MTX as first drug; “MTX+TNFi” for those patients who received a TNFi in addition to MTX after a period of “MTX Start”. All the 3 groups were pure, since they received only these drugs. We considered initial infections as related to the treatment if the infection occurred in the drug period or within 90 days after treatment stop.(2) For the group “MTX Start”, infection was related to treatment if occurring in the drug period stopped as soon as the second drug was introduced. For the group “MTX+TNFi”, we considered all the possible correlations between start and end dates of the two drugs, including the time lag of 90 days after any treatment stop. If the interval between two drugs was shorter than 90 days, treatment was considered continuous. Crude rates (number of infections divided by drug exposure, excluding off-drug periods) and true incidence rates (number of first infections divided by the time lag between first drug administration and the date of the infection if the patient experienced the infection, the last Pharmachild visit if the patient didn’t experience the event) were calculated. Results: We enrolled in Pharmachild a total of 8061 patients who experienced 1686 infections. We excluded 41 patients who had infections before any treatment start. Of the final number of 8020 patients, we considered: 1226 patients in the group “MTX alone”, 3128 in the group “MTX start” and 1026 in the group “MTX+TNFi”. 7.7% of the patients in the “MTX alone” group, 2.7% of the patients in the “MTX Start” group and 7.0% of the patients in the “MTX+TNFi” group experienced at least one infection. Crude rates of infections per 1000 person-years resulted: 48.0 for the group “MTX alone”, 22.0 for “MTX Start”, 74.0 for “MTX+TNFi”. Incidence rates per 1000 person-years were: 32.0 for the group “MTX alone”, 17.0 for “MTX Start”, 59.5 for “MTX+TNFi”. The percentage of drug exposure on the patient follow-up was variable among the 3 treatment groups (from 15.6% for the “MTX+TNFi” group to 51.5% for the “MTX alone” group). Conclusion: Pharmachild showed, through the analysis of pure treatment groups, that the addition of the anti-TNF biologic to MTX even triples the incidence rate of infections. References: [1] Swart, et al. Arthritis Res Ther. 2018;20:285; (2) Dixon WG, et al. Arthritis&Rheumatism 56:2896–2904. Disclosure of Interests: Gabriella Giancane: None declared, Joost F. Swart: None declared, Nikolay Tzaribachev: None declared, Nadina Rubio: None declared, Ruben Cuttica Grant/research support from: Roche, Pfizer, Lilly, Bristol Myers Squibb, Novartis, Sanofi Aventis, UCB, Janssen., Consultant for: Roche, Pfizer, Lilly, Bristol Myers Squibb, Novartis, Sanofi Aventis, UCB, Janssen., Speakers bureau: Roche, Pfizer, Lilly, Bristol Myers Squibb, Novartis, Sanofi Aventis, UCB, Janssen., Ingrida Rumba-Rozenfelde: None declared, Wafaa Mohammed Saad Suwairi: None declared, Calin Lazar: None declared, Yosef Uziel: None declared, Albena Telcharova: None declared, Tadej Avcin: None declared, Angela Minaici: None declared, Claudio Len: None declared, Stella Maris Garay: None declared, Alina Boteanu: None declared, Angela Pistorio: None declared, Nico Wulffraat: None declared, Nicolino Ruperto Grant/research support from: The Gaslini Hospital, where NR works as full-time public employee, has received contributions (> 10.000 USD each) from the following industries in the last 3 years: BMS, Eli-Lilly, GlaxoSmithKline, F Hoffmann-La Roche, Janssen, Novartis, Pfizer, Sobi. This funding has been reinvested for the research activities of the hospital in a fully independent manner, without any commitment with third parties., Consultant for: Received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, AbbVie, Astrazeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, SanofiServier, Sinergie, Sobi and Takeda., Speakers bureau: Received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, AbbVie, Astrazeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, SanofiServier, Sinergie, Sobi and Takeda.

Background Juvenile systemic scleroderma (jSSc) is an orphan disease with a prevalence of 3 in 1 000 000 children (1). There are limited data published regarding the differences in clinical presentation of male and female patients with jSSc. The Juvenile Systemic Scleroderma Inception Cohort (JSSIC) is a multinational cohort with a prospective standardized assessment of the patients. The data regarding the difference in clinical characteristics at time of inclusion in the cohort are presented. Objectives Evaluation of the differences in clinical presentation of male and female jSSc patients at the time of inclusion in the JSSIC. Methods The JSSIC is a prospective multicentre registry of patients with jSSc, who fulfil the adult classification criteria (2), and presented the first non-Raynaud symptoms before 16 years old and were younger than 18 years old at the time of inclusion in the cohort. Patients characteristics at time of inclusion in the cohort were evaluated. Results As of 15th of December 2018 120 patients are included in JSSIC. The great majority are female (80%). There were more female patients with CK elevation (29% vs 22%) and more female patients with Gottron papulae (25% vs 12%). The mean modified skin score was higher in males (18.6 vs 13.9). Sclerodactyly was more frequent in males (90% vs 76%). Active ulceration was present in 33% of males compared to 14% of females (p=0.026). FVC<80% occurred more often in males with 47% compared with 24% in females (p=0.018). Pulmonary hypertension was more common in females with 7% compared to 4% in males. Urine sediment changes were more common in males (8% vs 4%). Gastrointestinal involvement was more common in females (37% vs 29%). Contractures occurred more often in males with 62% compared with 46% in females. Tendon friction rub was observed in 21% of males and 3% of females (p=0.001). Physician global scores of disease activity and damage were higher in males with 48 for both assessments compared to 36 and 30 in females. Conclusion Male patients with jSSc have a higher severity of disease, as it has been reported in adults. References [1] Beukelman T, Xie F, Foeldvari I. Assessing the prevalence of juvenile systemic sclerosis in childhood using administrative claims data from the United States. Journal of Scleroderma and Related Disorders. 2018;3(2):189-90. [2] van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013classification criteria for systemic sclerosis: an American College of Rheumatology/European Disclosure of Interests Ivan Foeldvari Consultant for: Chugai, Novartis, Jens Klotsche: None declared, Ozgur Kasapcopur: None declared, Amra Adrovic: None declared, Kathryn Torok: None declared, Valda Stanevicha: None declared, Flávio R. Sztajnbok: None declared, Ana Paula Sakamoto: None declared, Ekaterina Alexeeva: None declared, Jordi Anton Grant/research support from: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Consultant for: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Speakers bureau: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Maria Katsikas: None declared, Vanessa Smith: None declared, Tadej Avcin: None declared, Rolando Cimaz: None declared, Mikhail Kostik: None declared, Thomas Lehman: None declared, Walter Alberto Sifuentes-Giraldo: None declared, Simone Appenzeller: None declared, Mahesh Janarthanan: None declared, Monika Moll: None declared, Dana Nemcova: None declared, Maria Jose Santos: None declared, Amara Nassar: None declared, Cristina Battagliotti: None declared, Lillemor Berntson: None declared, Blanca Bica: None declared, Juergen Brunner: None declared, Patricia Costa Reis: None declared, Despina Eleftheriou: None declared, Liora Harel: None declared, Gerd Horneff: None declared, Tilmann Kallinich Grant/research support from: Novartis, Speakers bureau: Sobi, Roche, Novartis, CLB, Dragana Lazarevic: None declared, Kirsten Minden Consultant for: AbbVie, Susan Nielsen: None declared, Farzana Nuruzzaman: None declared, Anjali Patwardhan: None declared, Yosef Uziel: None declared, Nicola Helmus: None declared

Background Juvenile systemic scleroderma (jSSc) is an orphan disease with a prevalence of 3 in 1 000 000 children. There are limited data regarding the clinical presentation of jSSc. The Juvenile Systemic Scleroderma Inception Cohort (JSSIC) is a multinational registry that prospectively collects information regarding patients with this disease in a standardized manner. Objectives Evaluation of the jSSc patients at the time of inclusion in the JSSIC. Methods Patients were included in the JSSIC if they fulfilled the adult classification criteria, if they presented the first non Raynaud symptom before 16 years old and if they were younger than 18 years of age at the time of inclusion. Patients’ characteristics at time of inclusion were evaluated. Results Currently, the cohort includes 120 patients, being 89% Caucasian and 80% female. The majority had diffuse subtype (74%) and 18% had overlap features. The mean age of onset of Raynaud phenomenon was 9.7 years in the diffuse subtype (djSSc) and 10.7 years in the limited subtype (ljSSc). The mean age of non-Raynaud’s symptoms was 10.0 years in the djSSc and 11.4 years in the ljSSc (p=0.041). Mean disease duration at time of inclusion was 3.4 years in the djSSc and 2.4 years in the ljSSc group. Mean Modified Rodnan skin score was 17.5 in the djSSc and 7.3 in the ljSSc (p=0.002). Gottron papulae were significantly more common in the djSSc compared to ljSSc group (29% vs 6%, respectively) (p=0.011). History of ulceration was significantly more common in the djSSc than in the ljSSc group (57% vs 30%, respectively) (p=0.004). FVC<80% occurred in 31% in the djSSc and 24% in the ljSSc group (p=0.55). Pulmonary hypertension assessed by echocardiogram occurred around 7% in both groups. No systemic hypertension or renal crisis was reported. Gastrointestinal involvement occurred in 39% in the djSSc and in 26% in the ljSSc (p=0.176). Number of joints with decreased range of motion was observed in approximately half of patients in both groups. Muscle weakness with joint contractures was present in 18% in the djSSc and 38% in the ljSSc group (p=0.271). Tendon friction rub was present in 11% in djSSc and 4% in the ljSSc group. djSSc patients had significantly worse scores for physician global disease activity (VAS 0-100) (41vs 30) (p=0.020) and for physician global disease damage (VAS 0-100) (37 vs 18) (p=0.001). Patient judgment of disease activity and damage was similar in both subtypes. ANA positivity was 88% in both groups. Anti-Scl70 was positive in 33% in djSSc and 37% in the ljSSc group. Anticentromere positivity occurred in 3% in the djSSc and 10% in the ljSSc group. ESR was elevated in 30% in djSSc compared to 18% in the ljSSc group. DMARDs were used in 86% of the patients. Conclusion In this large cohort of jSSc patients there were surprisingly not many significant differences between djSSc and ljSSc. According to the physician global scores the djSSc patients have a significantly more severe disease. Disclosure of Interests Ivan Foeldvari Consultant for: Chugai, Novartis, Jens Klotsche: None declared, Ozgur Kasapcopur: None declared, Amra Adrovic: None declared, Kathryn Torok: None declared, Valda Stanevicha: None declared, Flávio R. Sztajnbok: None declared, Maria T. Tererri: None declared, Ekaterina Alexeeva: None declared, Jordi Anton Grant/research support from: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Consultant for: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Speakers bureau: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Maria Katsikas: None declared, Vanessa Smith: None declared, Tadej Avcin: None declared, Rolando Cimaz: None declared, Mikhail Kostik: None declared, Thomas Lehman: None declared, Walter Alberto Sifuentes-Giraldo: None declared, Simone Appenzeller: None declared, Mahesh Janarthanan: None declared, Monika Moll: None declared, Dana Nemcova: None declared, Maria Jose Santos: None declared, Dieneke Schonenberg: None declared, Cristina Battagliotti: None declared, Lillemor Berntson: None declared, Blanca Bica: None declared, Juergen Brunner: None declared, Patricia Costa Reis: None declared, Despina Eleftheriou: None declared, Liora Harel: None declared, Gerd Horneff: None declared, Tilmann Kallinich Grant/research support from: Novartis, Speakers bureau: Sobi, Roche, Novartis, CLB, Dragana Lazarevic: None declared, Kirsten Minden Consultant for: AbbVie, Susan Nielsen: None declared, Farzana Nuruzzaman: None declared, Anjali Patwardhan: None declared, Yosef Uziel: None declared, Nicola Helmus: None declared

Background Juvenile systemic sclerosis (jSSc) is an orphan disease with a prevalence of 3 in a 1 000 000 children(1). Currently there is nearly no data published about the course of jSSc patients with standardized assessment. We report our date from Juvenile Scleroderma Inception cohort (JSSIC) with a follow up of 24 months. Objectives: to evaluate the organ involvement and patient reported outcomes (PRO) during the first 24 months in the JSIC Methods The JSSIC is a prospective multicenter registry of patients with jSSc, who fulfill the adult classification criteria(2), and presented the first non-Raynaud symptom before 16 years of age and were younger then 18 years at the time of inclusion in the JSSIC. Patients who were followed at least 24 months in the JSSIC, were evaluated. Results 52 patients were followed at least 24 months in the registry. 77% were female and 77% had diffuse subtype. 19% had overlap features. Mean disease duration at time of inclusion was 3.2 years. Mean age of at Raynaud’s onset was 8.8 years and the first non-Raynaud’s symptom 9.4 years. 85% received DMARDs at the time of inclusion and 96% after 24 months. 88% of the patients were ANA positive, 35% anti-Scl70 positive and 3% anticentromere positive. The mean modified skin score decreased from 14.3 to 12.6. The frequency of Raynaud’s stayed around 87%. The frequency of the nailfold capillary changes increased from 56% to 63%, but the frequency of active ulcerations stayed stable around 21%. The number of patients with FVC <80% decreased from 39% to 34% (p=0.734). The number of patients with pulmonary hypertension assessed by ultrasound increased from 4% to 8% (p=0.652). No patient developed systemic hypertension or renal crisis. Urinary sedimentary changes decreased from 8% to 4%. Gastrointestinal involvement decreased from 33% to 29% (p=0.829). Number of joints with decreased range increased from 46% to 63% (p=0.076). Total muscle weakness decreased from 8% to 3% (p=0.237) and elevated CK from 22% to 9% (p=0.033) too. Several PROs improved significantly. Patient global disease activity (VAS 0-100) changed from 46 to 29 (p=0.002), patient global disease damage (VAS 0-100) from 46 to 28 (p=0.02) and patient Raynaud activity VAS 0-100) from 27 to 14 (p=0.009) as physician global disease activity (VAS 0-100) from 43 to 29 (p=0.021) and physician global disease damage from 46 to 28 (P=0.01). Conclusion Over the 24 months observation period patient and physician related outcomes improved significantly. Regarding organ involvement there was an increase in patients of pulmonary hypertension and joint contractures. References [1] Beukelman T, Xie F, Foeldvari I. Assessing the prevalence of juvenile systemic sclerosis in childhood using administrative claims data from the United States. Journal of Scleroderma and Related Disorders. 2018;3(2):189-90. [2] van den Hoogen F, Khanna D, Fransen J, Johnson SR, Baron M, Tyndall A, et al. 2013classification criteria for systemic sclerosis: an American College of Rheumatology/European League against Rheumatism collaborative initiative. Arthritis Rheum. 2013;65(11):2737-47. Disclosure of Interests Ivan Foeldvari Consultant for: Chugai, Novartis, Jens Klotsche: None declared, Ozgur Kasapcopur: None declared, Amra Adrovic: None declared, Maria T. Tererri: None declared, Jordi Anton Grant/research support from: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Consultant for: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Speakers bureau: Grant/research support, consultant or speakers bureau from AbbVie, Alexion, Bristol-Myers Squibb, ChemoCentryx, Gebro, GlaxoSmithKline, Novartis, Novimmune, Pfizer, Roche, Sanofi and Sobi, Tadej Avcin: None declared, Rolando Cimaz: None declared, Mikhail Kostik: None declared, Maria Katsikas: None declared, Dana Nemcova: None declared, Maria Jose Santos: None declared, Cristina Battagliotti: None declared, Lillemor Berntson: None declared, Juergen Brunner: None declared, Liora Harel: None declared, Tilmann Kallinich Grant/research support from: Novartis, Speakers bureau: Sobi, Roche, Novartis, CLB, Kirsten Minden Consultant for: AbbVie, Monika Moll: None declared, Anjali Patwardhan: None declared, Kathryn Torok: None declared, Nicola Helmus: None declared

Background: Despite being considered as a distinct diagnostic category in the current ILAR classification criteria, Juvenile Psoriasic Arthritis (JPsA) is known to be a heterogeneous clinical entity, with growing evidence suggesting at least two age-based distinct subgroups(1) Objectives: To identify and characterize subgroups of patients classified as JPsA according to the ILAR criteria and their possible differences in outcomes. Methods: Cross-sectional data from patients enrolled in The EPidemiology, treatment and Outcome of Childhood Arthritis (EPOCA) study and classified as JPsA according to ILAR criteria (n=308) were analyzed. Latent class analysis (LCA) was used to identify subgroups of subjects with similar profiles ILAR criteria for JPsA (presence at onset of psoriasis, dactylitis, nail changes, first-degree relative with psoriasis) and age of arthritis onset. Multinomial logistic regression (three-step method) was performed to explore differences across the obtained classes in clinical-laboratoristic features at onset and outcomes measures collected at visit, namely JADAS scores, VAS-measured Pain, Overall Well-Being (PGA) Pediatric Rheumatology Quality of Life Scale (PRQL). In patients with disease duration more than 2 years (n=233), the relation with Articular and Extraarticular Juvenile Arthritis Damage Index (JADI) was also assessed. Results: LCA revealed 5 classes: 1) late-onset patients with psoriasis, characterized by higher frequency of axial involvement at visit (n = 121); 2) early-onset patients with psoriasis, more likely to be ANA-positive (n = 66); 3) young females with dactylitis at onset and family history of psoriasis, more likely to present with symmetric joint involvement (n = 62); 4) subjects with nail changes and family history of psoriasis(n=34); 5) patients exhibiting dactylitis and nail changes at onset, mostly males, with higher rates of HLA-B27 positivity, small joint involvement and enthesitis at visit (n = 25). Class 1 is associated with higher scores of JADAS10, pain, PGA and JQ; these group also shows higher JADI-A than Class 3. Extraarticular damage is worst for Class 2 subjects. Conclusion: The data driven clustering approach revealed several subgroups, confirming the heterogeneity of JPSA in a multinational cohort. Later-onset subjects with psoriasis have more aggressive disease, being clearly distinct from early-onset ANA-positive patients with psoriasis. The results suggest the need to revise the current classification in order to identify groups that may benefit from different therapeutic choices. References [1] Stoll ML, Nigrovic PA. Clin Dev Immunol. 2006;13(2–4):377–80. Disclosure of Interests: Hala Etayari: None declared, Arūnė Ramanauskiene: None declared, Alessandra Alongi: None declared, Yaryna Boyko: None declared, Yosef Uziel: None declared, Tadej Avcin: None declared, Pierre Quartier Consultant for: AbbVie, Chugai-Roche, lilly, Novartis, Novimmune, Sanofi, and SOBI, Consultant for: AbbVie, Chugai-Roche, Lilly, Novartis, Novimmune, Sanofi, and SOBI, Speakers bureau: AbbVie, BMS, Chugai-Roche, Novartis, Pfizer, and SOBI, Speakers bureau: AbbVie, BMS, Chugai-Roche, Novartis, Pfizer, and SOBI, Nicolino Ruperto Grant/research support from: The Gaslini Hospital, where NR works as full-time public employee, has received contributions (> 10.000 USD each) from the following industries in the last 3 years: BMS, Eli-Lilly, GlaxoSmithKline, F Hoffmann-La Roche, Janssen, Novartis, Pfizer, Sobi. This funding has been reinvested for the research activities of the hospital in a fully independent manner, without any commitment with third parties., Consultant for: Received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, AbbVie, Astrazeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, SanofiServier, Sinergie, Sobi and Takeda., Speakers bureau: Received honoraria for consultancies or speaker bureaus (< 10.000 USD each) from the following pharmaceutical companies in the past 3 years: Ablynx, AbbVie, Astrazeneca-Medimmune, Biogen, Boehringer, Bristol-Myers Squibb, Eli-Lilly, EMD Serono, GlaxoSmithKline, Hoffmann-La Roche, Janssen, Merck, Novartis, Pfizer, R-Pharma, SanofiServier, Sinergie, Sobi and Takeda., Angelo Ravelli Grant/research support from: Angelini, AbbVie, Bristol-Myers Squibb, Johnson & Johnson, Novartis, Pfizer, Reckitt Benkiser, and Roche, Consultant for: Angelini, AbbVie, Bristol-Myers Squibb, Johnson & Johnson, Novartis, Pfizer, Reckitt Benkiser, and Roche, Speakers bureau: Angelini, AbbVie, Bristol-Myers Squibb, Johnson & Johnson, Novartis, Pfizer, Reckitt Benkiser, and Roche, Alessandro Consolaro Grant/research support from: AbbVie, Pfizer,