Background: IgG4-related disease (IgG4-RD) is a systemic fibroinflammatory disease often associated with elevated serum IgG4 levels. High dose corticosteroids are the cornerstone of treatment, but relapses and side-effects are frequent, requiring synthetic and/or biologic immunosuppressants. Rituximab (RTX) seems to be effective in IgG4-RD. Objectives: To assess the effectiveness of RTX in IgG4-RD patients. Methods: Multicentre retrospective obsevational study of IgG4-RD patients treated with RTX. Outcomes were clinical and serologic response, as well as safety. Results: We included 44 patients (33 men/11 women; mean age±SD 54.6±12.8 years) with IgG4-RD, treated with RTX (Table 1). The most affected organs were lymph nodes (n=24; 54.5%), retroperitoneum (n=15; 34.1%), ear nose and throat (n=13; 29.5%), aorta (n=12; 27.3%), lung/pleura (n=12; 27.3%), kidney (n=12; 27.3%), orbit (n=12; 27.3%), pancreas (n=9; 20.4%), lacrimal glands (n=8; 18.2%), salivary glands (n=8; 18.2%), liver/biliary duct (n=7; 15.9%), pachymeninges (n=3; 6.8%) and mesenterium (n=2; 4.5%). All but 2 patients had received oral corticosteroids, and 12 patients also received corticosteroid boluses. 23 patients received conventional cDMARDs: methotrexate (MTX) (n=15), azathioprine (n=6), and mycophenolate mophetil (n=2). Main RTX schedule was of 1g x 2 (n=35), 500mg x2 (n=5) and 375 mg/m2 (n=3). 30 patients received maintenance treatment with RTX. Median time from diagnosis to RTX initiation was 5 (0-72) months (Table 2). After 12 and 24 moths of follow-up, complete and partial clinical improvement was observed in 15 (50%) and 13 (43.33%) and in 16 (64%) and 7 (28%) patients, respectively. Only 5 relapses were observed. Prednisone could be discontinued in 11 patients. 3 patients died during follow up. One patient needed ICU admission because of Influenza pneumonia, and 2 developed a larynx and a breast cancer, respectively. Conclusion: RTX seems to be an effective and relatively safe therapy in IgG4-RD, with a low rate of relapse. REFERENCES: NIL. Acknowledgements: Cristina Arciniega (Hospital de Mérida), Maria Lourdes Mateo Soria (Hospital German Trias i Pujol), Jorge Juan Fragío Gil (Hospital General Universitario de Valencia), Roxana González Mazarío (Hospital General Universitario de Valencia), Santiago Muñoz (Hospital Universitario Infanta Sofía), Iñigo Jesús Rua Figueroa, (Hospital Universitario de Gran Canaria Dr Negrin), Noelia Cabaleiro Raña (Hospital de Montecelo), as part of the Rituximab in IgG4 Related Disease Spanish Cooperative Group. Disclosure of Interests: Fernando López-Gutiérrez Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Javier Loricera Roche, Galápagos, Novartis, UCB Pharma, MSD, Celgene, Astra Zeneca, and Grünenthal, Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Cristina Hormigos: None declared, Dalifer Freites: None declared, María Rodríguez laguna: None declared, Patricia Moya: None declared, Marta López I Gómez: None declared, Hèctor Corominas: None declared, Ángel García-Aparicio: None declared, Judit Font: None declared, Ivette Casafont-Solé: None declared, Pablo Martinez Calabuig: None declared, Elisabet Castaneda: None declared, Carolina Merino Argumánez: None declared, Raquel Zas: None declared, Rafael Melero: None declared, Eva Galíndez-Agirregoikoa Abbvie, Pfizer, Lilly, Novartis, UCB, Amgen, Janssen, Andrea Hernández: None declared, Lucía Pantoja: None declared, Ignacio Braña Abascal: None declared, Vega Jovani: None declared, Elia Valls-Pascual: None declared, Natalia Mena-Vázquez: None declared, Adela Gallego: None declared, Sabela Fernández: None declared, Raúl Veroz González: None declared, Mariano Andrés: None declared, Ricardo Blanco AbbVie, Pfizer, Roche, Bristol-Myers, Lilly, Galapagos, Novartis, Janssen, GSK, UCB, and MSD, AbbVie, Pfizer, Roche, Lilly, Janssen.Table 1Demographic, clinical and biologic parameters, and treatments at RTX initiation.ParameterValueAge (years, mean ± SD)50.6±12.8Male gender (n, %)33 (75)Number of organs affected, (mean,±SD)3.15 ±1.72Organ site involvement (n,%)Lymph nodes24 (54.5)Retroperitoneum/Aorta/ Kidney15 (34.1)/ 12 (27.3)/ 12 (27.3)ENT/Orbital13 (29.5)/ 12 (27.3)Lung/pleura12 (27.3)Pancreatic/ Hepatobiliary9 (20.4)/ 7 (15.9)Salivary glands/ Lacrimal glands8 (18.2)/ 8 (18.2)Pachymeningitis/ Mesenterium/ Other3 (6.8)/ 2 (4.5)/ 7 (15.9)IgG4-RD classification criteria (n,%)Okazaki/ Umehara (probable or definite)17 (38.6)/ 17 (38.6)ACR/EULAR21 (47.7)Time from diagnosis to RTX initiation (months; median, range)5 (0-72)Laboratory parameters at diagnosis (median, range)CRP (mg/dL)/ ESR (mm/h)/ Serum IgG4 levels (mg/dL)1.14 (0.04-35)/ 22 (4-120)/ 90 (1-537)Previous treatment with cDMARD, n (%)23 (52.3)Prednisone dose (mg/day, mean ±SD)46.09±16.97 Table 2Dosage, clinical and biologic outcomes, glucocorticoid treatment and relapses during treatment with RTX.OutcomesValueRTX regimen intiial dose, n (%)1 g x2 500mg d1-d15 375 mg/m2/w x435 (79.5)5 (11.4)3 (6.8)RTX regimen maintenance dose, n (%)1 g x2 375 mg/m2/w x415 (34.1)1 (2.3)Optimized16 (36.3)Clinical response, n (%)At 12 months Partial  Complete13 (43.3)15 (50)At 24 months Partial Complete7 (28)16 (64)Biological response (mg/dL), median (range)CRP at 12 months of RTX initiation CRP at 24 months of RTX initiation0.6 (0.1-35)0.4 (0.1-7.9)IgG4 at 12 months of RTX initiation IgG4 at 24 months of RTX initiation55.9 (1.3-180)55.4 (3.1-104)Prednisone dose (mg/day), median (range)At 6 months of RTX initiation At 12 months of RTX initiation At 24 months of RTX initiation5 (0-40)3.7 (0-20)2.5 (0 -10)Prednisone withdrawal, n (%)11 (25)Time of follow up (months), median (range)24 (1-70)Time receiving RTX (months), median (range)17 (1-61)Relapses, n (%)5 (11.4)

Background: Primary Sjögren’s Syndrome (pSS) is a systemic autoimmune disease characterized by salivary gland involvement. Some patients may develop systemic extra glandular manifestations that can determine the prognosis of the disease. The influence of serological and immunological biomarkers on the clinical expression of the disease is still not fully known, nor is their role as prognostic factors of the disease. Objectives: The aim of the study was to assess the prevalence of extraglandular involvement in pSS, as well as to determine the relationship between immunological and serological biomarkers, disease activity, and extraglandular manifestations in patients with pSS. Methods: A cohort of patients with pSS who met the ACR/EULAR classification criteria for pSS in 2016 followed up in our Systemic Autoimmune Diseases Unit between 2000 and 2022 was carried out. The sociodemographic, clinical, serological and immunological data and the Disease activity measures calculated with the ESSDAI index (EULAR Sjögren’s Syndrome disease activity index) were collected. For the comparison of qualitative and/or quantitative variables, Fisher’s exact test or the T-test was performed when necessary. Results: 175 patients with pSS were included (85% were women), with a mean age at diagnosis of 58.8±12.2 years and a disease evolution time of 7.6±5.4 years. 62 patients (35%) had extraglandular manifestations. Anti-Ro60 positivity was found in 68%, Anti-Ro52 in 35.3% and anti-Ro60 and anti-La in 47.4% of patients. Associations between serological markers and systemic manifestations in patients with pSS is summarized in Graph 1 and Table 1. A higher risk of renal involvement was found in anti-Ro60, meanwhile a lung involvement, hypocomplementemia and higher levels of rheumatoid factor and hypergammaglobulinemia were associated with anti-Ro52 positivity. Constitutional symptoms, hematological involvement, lymphadenopathy, higher erythrocyte sedimentation rate and ESSDAI score were associated with both anti-Ro and anti-La positivity. Cutaneous involvement was specifically associated with anti-Ro52, C3 levels, IgG and IgM levels. Articular involvement was associated with higher rheumatoid factor levels. Renal involvement was associated with C3 levels, rheumatoid factor, ESR levels, IgG levels and anti-Ro60. Lung involvement was associated with ESR levels and C-reactive protein, IgG, C3 levels and anti-Ro52 positivity. CNS involvement was associated with C3 levels, C-reactive protein and beta2microglobulin and hematological involvement with C3, rheumatoid factor, beta2microglobulin and IgG levels. Conclusion: Our results have demonstrated the role of immunological and serological biomarkers in the clinical expression of pSS and as prognostic factors for disease progression, as well as their applicability in clinical practice. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.Graph 1Systemic manifestations accordingly to autoantibodies Table 1Associations between serological markers and systemic manifestations in patients with pSSC3C4RFESRCRPbeta2microglobulinIgGIgMAnti-Ro60Anti-LaAnti-Ro52Glandularp= 0.40p=0.91p= 0.06p=0.26p=0.69p=0.94p=0.55p= 0.92p=0.002p=0.04p=0.06Cutaneousp=0.003p=0.44p= 0.12p= 0.946p=0.85p=0.59p=0.03p=0.02p=0.23p=0.12p=0.04Articularp 0.23p 0.87p=0.003p=0.12p=0.23p=0.15p=0.06p=0.15p=0.34p=0.87p=0.32Renalp=0.04p=0.32p=0.007p=0.33p=0.53p=0.12p=0.033p=0.65p=0.40p=0.22p=0.45Lungp=0.03p=0.44p=0.45p=0.04p=0.001p=0.13p=0.02p=0.42p=0.26p=0.75p=0.02CNSp=0.04p=0.45p=0.62p=0.24p=0.12p=0.01p=0.39p=36p=0.52p=0.32p=0.14PNSP=0.62P=0.44P=0.64P=0.39P=0.38P=0.77P=0.55P=0.38P=0.42P=0.13P=0.92Hematologicalp=0.03p=0.179p=0.02p=0.01p=0.98p=0.001p=0.03p=0.22p=0.45p=0.45p=0.33Constitutionalp=0.003p=0.54p=0.21p=0.02p=0.94p=0.89p=0.21p=0.92p=0.42p=0.71p=0.23Lymphadenopathyp=0.19p=0.54p=0.02p=0.17p=0.8p=0.001p=0.49p=0.37p=0.78p=0.13p=0.35

Background: Interstitial lung disease (ILD) stands as the primary cause of mortality in patients with Systemic Sclerosis (SSc). Despite the identification of several risk factors to develop ILD in SSc, limited research has been directed towards understanding their impact on the progression of established SSc-ILD. Objectives: This study aims to evaluate the clinical characteristics of SSc patients with ILD and to compare features between those experiencing progressive lung function decline and those without such progression. Methods: We conducted a retrospective study on a cohort of 415 SSc patients. Inclusion criteria required the confirmation of ILD by HRCT. Demographic, clinical, analytical and pulmonary function tests (PFT's) parameters before and after ILD onset were collected. Statistical significance was set at p-values<0.05. Results: 64 patients with SSc-ILD were included, most of them females (93.8%) with a mean age at diagnosis of 60.5 years. Limited SSc was observed in 59.4%, and the predominant specific autoantibody was the anti-topoisomerase (28.1%). Table 1 summarizes the patient's characteristics. Follow-up revealed a significant decline in FVC in all patients since SSc onset (2.80±0.7 vs 2.16±0.76, p=0.000) and after ILD detection (2.37±0.69 vs 2.16±0.76, p=0.000). Male sex was associated with worse %FVC at SSc-ILD onset, persisting throughout follow-up and leading to poor lung function outcomes. However, no significant differences were found in FVC decline based on clinical SSc subset (limited vs. diffuse) or SSc autoantibodies (ATA vs. ACA) after ILD onset. Smoking history, digital ulcers, and pulmonary hypertension were associated with poor lung function outcomes. No significant differences were observed in other clinical features such as myositis, arthritis, gastrointestinal involvement, renal crisis, or cancer. Rheumatoid factor (RF) positivity was associated with poorer pulmonary function after ILD diagnosis (p=0.034). The presence of a UIP pattern did not correlate with worse lung function at the onset of ILD or at follow-up, when compared to non-UIP patterns. Among the twenty-four patients who received ILD treatment, both %FVC and ml-FVC outcomes worsened, with no significant differences noted in DLCO. Conclusion: Worse lung function outcomes after SSc-ILD onset were associated to male sex, smoking history, digital ulcers, pulmonary hypertension, and RF positivity. Notably, in contrast to patients at risk of developing SSc-ILD, no significant differences were observed based on SSc subset or SSc autoantibodies in patients with established ILD. Early volume decline was observed during follow-up, even before ILD onset, in all patients within our cohort. We did not find that treatment prevents pulmonary function decline. It could be explained by the inclusion of patients with unfavorable prognosis factors and the retrospective nature of the analysis. Prospective, multicentric studies to comprehensively assess risk factors for poor prognosis and the progression SSc-ILD patients are needed. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.

Background: The diagnosis of Immunoglobulin IgG4-related disease (IgG4-RD) lacks a definitive gold standard; however, the prevailing diagnostic criteria to date include those proposed by Umehara1 and Okazaki2. Umehara delineates diagnostic categories as definitive, probable, or possible, while Okazaki establishes the presence or absence of the disease. In 2019, ACR and EULAR3 introduced novel classification criteria necessitating a sequential application of exclusion and inclusion criteria, followed by a point count. IgG4-RD is classified if the score surpasses 20 points. Objectives: To assess the sensitivity and specificity of Okazaki, Umehara, and ACR/EULAR 2019 classification criteria for IgG4-RD in a patient cohort, and to compare them with the definitive diagnosis based on medical criteria. Methods: A retrospective study conducted at a national tertiary university center. Eligible patients were those with elevated serum IgG4 in any analytical determination, reviewing a total of 719 medical records between January 2000 and December 2023. Of these, inclusion criteria were patients with a high clinical suspicion of IgG4-RD due to compatible organ involvement or elevated IgG4. Demographic, clinical, serological, histological data, as well as variables related to classification criteria, were collected. The medical criterion, based on the criteria outlined in Figure 1, served as the reference for a definitive diagnosis. Sensitivity, specificity, positive and negative predictive values, as well as the ROC curve, were calculated. Results: A total of 39 patients with a high suspicion of IgG4-RD were included. Clinical characteristics are detailed in Figure 2. Of the 39 suspected patients, 26 (66.6%) met the definitive diagnosis according to medical criteria. Of the 26 IgG4-RD patients, 24 (92.3%) met Umehara’s criteria; 16 (66.66%) possible, 2 (8.33%) probable, 6 (25%) definitive. Seventeen (65.4%) met Okazaki’s criteria, and 18 (69.2%) met the ACR/EULAR 2019 criteria.The sensitivity of Umehara’s criteria was 69.2% if the disease was categorized as probable or definite (NPV 61.9%, PPV 100% and accuracy 79.5%). Sensitivity for Okazaki’s criteria was 65.4% (NPV 59.1%, PPV 100%, and accuracy 76.9%), and 69.2% for the new ACR/EULAR 2019 criteria (NPV 61.9%, PPV 100%, and accuracy 79.5%). For all three criteria, the specificity was 100%.The area under the curve was 0.962, 0.827, and 0.901 for Umehara, Okazaki, and ACR/EULAR 2019 criteria, respectively (p <0.000). Approximately 8% of patients were not classified by any of the three criteria but were accurately classified by the medical criteria. Conclusion: Sensitivity and the area under the curve were superior for Umehara and ACR/EULAR 2019 criteria. Eight percent of patients were not classified by any criteria, underscoring the significance of considering medical criteria. REFERENCES: [1] Umehara, Okazaki, Masaki, Kawano, Yamamoto, Saeki et. al. A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details. Mod Rheumatol. 2012 Feb;22(1):1-14.[2] Okazaki, Umehara. Are Classification Criteria for IgG4-RD Now Possible? The Concept of IgG4-Related Disease and Proposal of Comprehensive Diagnostic Criteria in Japan. Int J Rheumatol. 2012; 2012: 357071.[3] Wallace, Naden, Chari, Choi. The 2019 American College of Rheumatology/European League Against Rheumatism Classification Criteria for IgG4-Related Disease. Arthritis Rheumatol. 2020 Jan;72(1):7-19. Acknowledgements: NIL. Disclosure of Interests: None declared.Figure 1Criteria for Classifying Patients with High Suspicion of IgG4 and Medical Classification Criteria. Figure 2Baseline clinical characteristics

Background: Juvenile Idiopathic Arthritis (JIA) represents the most prevalent inflammatory rheumatic condition in childhood. Its heterogeneous nature presents challenges in identifying feasible biomarkers for effective disease monitoring. Serum calprotectin (sCal) has emerged as a potentially valuable biomarker for precisely assessing inflammatory activity in JIA. Despite various commercially available methods for sCal determination, their usage remains limited and lacks validation. Objectives: To assess the diagnostic accuracy, define an optimal threshold, and evaluate the association between disease activity status in patients with JIA and serum calprotectin measurements obtained through chemiluminescence (CLIA) and solid-phase enzyme immunoassay (EIA) techniques within a real-world clinical setting. Methods: Serum samples from 25 pediatric patients with JIA were analyzed. sCal levels were determined by CLIA and EIA methodologies. Disease activity data was collected through JADAS-27 and the Anink ACR-modified criteria (1). We conducted a comparative analysis of results obtained through CLIA and EIA techniques. Additionally, we assessed the association between distinct biomarkers and disease activity. Results: The tests demonstrated robust performance of sCal. The ideal cut-off value for sCal in identifying disease activity, as determined by ROC analysis related to JADAS-27, was 2.3 µg/mL for both CLIA and EIA techniques. Remarkably, this value aligned with the threshold routinely utilized in our center's daily clinical practice. When evaluating disease activity based on Anink's criteria, the identified optimal thresholds were 2.0 µg/mL for sCal CLIA and 2.9 µg/mL for sCal EIA. Notably, the sCal CLIA identified threshold (2.0 µg/mL) coincided with the one recommended by its commercial kit. In contrast, the thresholds proposed for CRP and ESR (3.1 mg/L and 10 mm/h, respectively), according to both JADAS-27 and Anink, were lower than the values routinely employed in daily clinical practice (5 mg/L for CRP and 20 mm/h for ESR). A good correlation was observed between sCal levels obtained by CLIA and EIA Kendall's tau-b 0.71, p<0.001). The sensitivity of sCal outperformed the conventional inflammatory biomarkers CRP and ESR, exhibiting superior accuracy in distinguishing patients with active disease. In our cohort, a notable case involved an active patient experiencing concurrent arthritis and uveitis during data collection, exhibiting a significant discrepancy in biomarker measurements showing elevated sCal levels (≥2.3µg/ml) but without a corresponding increase in CRP or ESR. However, sCal showed reduced specificity compared to CRP and ESR, resulting in the conventional biomarkers proving more effective in identifying patients in a state of remission. Conclusion: Serum calprotectin, determined through CLIA and EIA, emerges as a valuable biomarker for monitoring disease activity in patients with JIA. It exhibits good sensitivity for identifying active patients at its cutoff point of 2.3 µg/mL, especially through EIA. The results suggest sCal is superior for identifying activity, while CRP and ESR excel in distinguishing remission. The combined use of various serum biomarkers could enhance the precision of disease activity assessment in JIA. REFERENCES: [1] Anink J, Van Suijlekom-Smit LW, Otten MH, Prince FH, van Rossum MA, Dolman KM, et al. MRP8/14 serum levels as a predictor of response to starting and stopping anti-TNF treatment in juvenile idiopathic arthritis. Arthritis research & therapy. 2015;17(1):200 Acknowledgements: NIL. Disclosure of Interests: None declared.

Background: Aortitis related to Giant Cell Arteritis (GCA-aortitis) is a frequent and potential severe complication. Tocilizumab (TCZ) was approved in GCA, but the efficacy in GCA- aortitis has not been specifically studied in randomized clinical trials. Objectives: To assess the effectiveness and safety of TCZ in monotheraphy compared with combined in a wide series of GCA-aortitis. Methods: Multicentre observational study with GCA-aortitis treated with TCZ. GCA was diagnosed by: a) ACR criteria, b) temporal artery biopsy, and/or c) imaging techniques. Aortitis was diagnosed mainly by PET/CT. Main outcomes were EULAR and imaging remission (considered when vascular FDG uptake was less than liver uptake in 18 F-FDG PET/CT). Others were clinical remission, corticosteroid-sparing effect, TCZ optimization and adverse effects. Results: We studied 196 patients with GCA-aortitis treated with TCZ (136 in monotheraphy/60 combined with others DMARDs). Figure 1. After 24 months, there were statistical differences in imaging and complete remission (17.2% vs 42.1%) Figure 2. Nevertheless, there were no differences in clinical and EULAR remission. Conclusion: In GCA-aortitis, TCZ therapy combined with DMARDs could be more effective than in monotherapy in imaging and complete remission. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: Adrián Martín-Gutiérrez: None declared, Javier Loricera Roche, Galápagos, Novartis, UCB Pharma, MSD, Celgene, Astra Zeneca, and Grünenthal, Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Carmen Secada-Gómez: None declared, Javier Narváez: None declared, Olga Maiz: None declared, Iñigo Hernández-Rodríguez AbbVie, Amgen, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, Pfizer, UCB y Galápagos, AbbVie, Amgen, Janssen, Merck Sharp & Dohme, Novartis, Sanofi, Pfizer, UCB y Galápagos, Susana Romero-Yuste Abbvie, Astra-Zeneca, Bristol, Janssen, Lilly, Roche, Sandoz, Sanofi, UCB, Eugenio De Miguel Abbvie, Novartis, Pfizer, Roche, Janssen, Lilly, MSD, BMS, UCB, Grunental and Sanofi, Abbvie, Novartis, Pfizer, Roche, Janssen, Lilly, MSD, BMS, UCB, Grunental and Sanofi, Eva Galíndez-Agirregoikoa: None declared, Iván Ferraz-Amaro Abbvie, Pfizer, Roche, Sanofi, Celgene, and MSD, Abbvie, MSD, Janssen, and Roche, Julio Sanchez-Martin: None declared, Patricia Moya: None declared, Cristina Campos Fernández: None declared, Fernando López-Gutiérrez Janssen, Abbvie, Roche, Novartis, MSD, UCB Pharma, Celgene, Lilly, Pfizer, Galápagos, Santos Castañeda assistant professor of the cátedra EPID-Future, funded by UAM-Roche, Universidad Autónoma de Madrid (UAM), Spain, BMS, Eli-Lilly, Roche, Gedeon-Richter, Grünenthal Pharma and UCB, MSD and Pfizer, Ricardo Blanco AbbVie, Pfizer, Roche, GSK, Lilly, UCB, Bristol-Myers, Novartis, Janssen, UCB and MSD, AbbVie, MSD, and Roche.Figure 1Main general features of 196 patients with aortitis related to GCA at tocilizumab initiation.Abbreviations: ACR: American College of Rheumatology; ACR/LVV: Large vessel vasculitis: criteria of GCA ACR with a positive image suggestive for aortitis; AZA: azathioprine; CQ: cloroquine; CRP: C-reactive protein; DMARDs: disease-modifying antirheumatic drugs; ESR: erythrocyte sedimentation rate; GiACTA: (38) Hb: hemoglobine; HCQ: hydroxychloroquine; IFX: infliximab; IQR: interquartile range; LFN: leflunomide; MMF: mycophenolate mofetil; n: number; PET/CT: positron emission tomography scan; PMR: polymyalgia rheumatica; RTX: rituximab; SD: standard deviation; SSZ: sulfasalazine; TCZ: tocilizumab.The significance of the imaging tests was calculated according to the number of tests performed.Statistical significance is expressed as bold characters. Figure 2Evolution of main outcomes in patients with GCA- aortitis treated with TCZ. A comparison between monotherapy and combined TCZ.(A) Serum C-reactive protein (CRP). (B) Prednisone dose (mg/day). (C), (D) Clinical, EULAR, imaging and complete remission at 12 and 24 month.+: no significant differences.*: p<0.05.**: p<0.0001.

Background: Activity indices in Systemic Lupus Erythematosus (SLE) are tools to assess disease severity, guide treatment decisions, and evaluate treatment response. The commonly used SLEDAI-2K has been recently joined by SLE-DAS. “Treat to target” strategies have gained importance, aiming for remission or low disease activity, defining Lupus Low Disease Activity State (LLDAS) and DORIS2021 remission. Objectives: To assess the relationship between SLEDAI-2K and SLE-DAS and the definition of low disease activity (LLDAS) and remission (DORIS2021) in SLE. Methods: A retrospective descriptive cross-sectional study was conducted in a cohort of patients diagnosed with SLE, visited between September 2022 and November 2023 at a tertiary hospital. Patients had to meet EULAR/ACR 2019 Classification Criteria at some point during their disease course. Demographic, clinical, analytical, and index variables were collected. Analysis of variables was performed using Spearman’s correlation coefficient and Mann-Whitney U test. Statistical significance was set at p<0.05. Results: A total of 57 patients were included (94.7% females, mean age 48.5 years, mean disease duration 13.08 years). Common manifestations included arthralgia (35.1%) and arthritis (12.3%). Less frequent were cutaneous involvement (7%) and oral mucosal ulcerations (3.5%). No cases of serositis, fever, or myositis were observed. Urinary sediment abnormalities were present in 28.1% of patients, and 7% had significant proteinuria. Only 1 patient experienced a renal flare. Serologically, 36.8% had elevated DNA levels, and 36.8% had low C3 and/or C4 levels.Table 1 displays values and relationships between SLEDAI-2K and SLE-DAS by activity. No patients had severe SLEDAI-2K (>10). The correlation between the two indices was good (Spearman’s coefficient 0.786, p<0.001). However, when variables were categorized (remission, mild, moderate, severe), the relationship disappeared (kappa coefficient 0.186, p=0.064). In our cohort, 71.9% of patients were in remission according to SLE-DAS, and 35.1% according to SLEDAI-2K.Additionally, 78.9% and 68.4% of patients met LLDAS and DORIS2021 criteria, respectively. Table 2 shows relationships between each activity index and LLDAS and DORIS2021. Both SLEDAI-2K and SLE-DAS were significantly associated with LLDAS (p=0.006 and p<0.001, respectively) and DORIS2021 (p=0.018 and p<0.001, respectively). Conclusion: A significant correlation exists between SLEDAI-2K and SLE-DAS, but it loses significance when variables are categorized. This is attributed to substantial divergence in remission and low activity categories between the two indices. With the exception of one patient (1.8%) in SLEDAI-2K remission, all others meet remission criteria by SLE-DAS. However, many patients in SLE-DAS remission exhibit mild activity in SLEDAI-2K, mainly due to serological manifestations. Both indices show a significant association with LLDAS and DORIS2021, despite SLE-DAS not being part of their definitions. Notably, the proportion of patients in remission by SLE-DAS aligns more closely with the proportions of LLDAS and DORIS2021 than SLEDAI-2K. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.Table 1SLE-DAS remission (≤2.8)n (%)SLE-DAS mild (2,09-7.64)n (%)SLE-DAS moderate/severe(≥7.65)n (%)Totaln (%)SLEDAI2K remission (=0)n (%)19 (33.3)1 (1.8)020 (35.1)SLEDAI2K mild (1-5)n (%)22 (38.6)7 (12.3)3 (5.3)32 (56.1)SLEDAI2K moderate (6-10)n (%)04 (7)1 (1.8)5 (8.8)Totaln (%)41 (71.9)12 (21.2)4 (7)57 (100) Table 2MedianSLEDAI-2KSLEDAI-2K remission n (%)SLEDAI-2K mild n (%)SLEDAI-2K moderate n (%)LLDAS not met3.831 (1.8)6 (10.5)5 (8.8)LLDAS met1.6919 (33.3)26 (45.6)0DORIS2021 not met3.223 (5.3)10 (17.5)5 (8.8)DORIS2021 met1.6417 (29.8)22 (38.6)0Median SLE-DASSLE-DAS remissionn (%)SLE-DAS mildn (%)SLE-DAS moderate/severen (%)LLDAS not met5.252 (3.5)8 (14)2 (3.5)LLDAS met1.6639 (68.4)4 (7)2 (3.5)DORIS2021 not met4.405 (8.8)11 (19.3)2 (3.5)DORIS2021 met1.536 (63.2)1 (1.8)2 (3.5)

Background: Primary Sjögren's Syndrome (pSS) is a systemic autoimmune disease characterized by salivary gland involvement. Some patients may develop systemic extra glandular manifestations that can determine the prognosis of the disease. The influence of serological and immunological biomarkers on the clinical expression of the disease is still not fully known, nor is their role as prognostic factors of the disease. Objectives: The aim of the study was to assess the prevalence of extraglandular involvement in pSS, as well as to determine the relationship between immunological and serological biomarkers, disease activity, and extraglandular manifestations in patients with pSS. Methods: A cohort of patients with pSS who met the ACR/EULAR classification criteria for pSS in 2016 followed up in our Systemic Autoimmune Diseases Unit between 2000 and 2022 was carried out. The sociodemographic, clinical, serological and immunological data and the Disease activity measures calculated with the ESSDAI index (EULAR Sjögren's Syndrome disease activity index) were collected. For the comparison of qualitative and/or quantitative variables, Fisher's exact test or the T-test was performed when necessary. Results: 175 patients with pSS were included (85% were women), with a mean age at diagnosis of 58.8±12.2 years and a disease evolution time of 7.6±5.4 years. 62 patients (35%) had extraglandular manifestations. Anti-Ro60 positivity was found in 68%, Anti-Ro52 in 35.3% and anti-Ro60 and anti-La in 47.4% of patients. Associations between serological markers and systemic manifestations in patients with pSS is summarized in Graph 1 and Table 1. A higher risk of renal involvement was found in anti-Ro60, meanwhile a lung involvement, hypocomplementemia and higher levels of rheumatoid factor and hypergammaglobulinemia were associated with anti-Ro52 positivity. Constitutional symptoms, hematological involvement, lymphadenopathy, higher erythrocyte sedimentation rate and ESSDAI score were associated with both anti-Ro and anti-La positivity. Cutaneous involvement was specifically associated with anti-Ro52, C3 levels, IgG and IgM levels. Articular involvement was associated with higher rheumatoid factor levels. Renal involvement was associated with C3 levels, rheumatoid factor, ESR levels, IgG levels and anti-Ro60. Lung involvement was associated with ESR levels and C-reactive protein, IgG, C3 levels and anti-Ro52 positivity. CNS involvement was associated with C3 levels, C-reactive protein and beta2microglobulin and hematological involvement with C3, rheumatoid factor, beta2microglobulin and IgG levels. Conclusion: Our results have demonstrated the role of immunological and serological biomarkers in the clinical expression of pSS and as prognostic factors for disease progression, as well as their applicability in clinical practice. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests: None declared.

Background There are no specific biomarkers of disease activity in for Juvenile Idiopathic Arthritis (JIA), and therefore it is important to identify new molecules which help us in daily practice to offer individualized treatment options. Serum Calprotectin (CLP) is an emerging biomarker of inflammation. Recent studies[1] suggest that disease activity correlates better with CLP than with classic acute phase reactants such as C-reactive Protein (CRP). Objectives To determine the clinical characteristics of paediatric patients with Juvenile Idiopathic Arthritis (JIA) who have discrepancy between Serum Calprotectin and C-reactive Protein. Methods An analytical transversal study was performed including patients with JIA from a paediatric rheumatology clinic between 2017 and 2021. A total of 25 patients were included, who had at least one measurement of CLP in daily practice. Demographic, analytical and clinical data were collected. The JADAS score by physical examination and ultrasound was collected in patients with peripheral arthritis. Results A total of 25 patients were included, 48% were female and the mean age was 11.5 (±4.6) years.A total of 11 (44%) patients had discrepancy between CLP and CRP. Among them, 9 (81.8%) had elevated CLP and low CRP, whereas only 2 (18.2%) had low CLP with elevated CRP.At the time of performing the analysis, 44% of the patients had an active disease.The oligoarticular JIA subtype was the one that presented a larger patient's percentage (54.5%) with discrepancy and elevated CLP.The details of clinical and analytical characteristics of the patients are shown in Table 1.In the subgroup of patients with discrepancy and elevated CLP there were 3 (33.3%) with an active disease. Among them, 66.7% were female and all of them had an oligoarticular JIA. One of them was in a flare with both an active arthritis and uveitis at the moment of the analysis. None of them were under treatment with prednisone nor DMARD (disease-modifying antirheumatic drugs). Conclusion There was discrepancy between CLP and CRP in 44% of the sample. Among them, most (81.8%) had high CLP without elevation of CRP. The JIA subtype that presented discrepancy with elevated CLP was the oligoarticular one.A total of 3 (33%) patients were active in the group with discrepancy and elevated CLP, one of them being in a flare with both an active arthritis and uveitis. Reference [1] La C, Lê PQ, Ferster A, Goffin L, Spruyt D, Lauwerys B, et al. Serum calprotectin (S100A8/A9): a promising biomarker in diagnosis and follow-up in different subgroups of juvenile idiopathic arthritis. RMD Open [Internet] 2021 [consultado 10 de abril de 2022]; 7 (2): e001646. Disponible en: https://rmdopen.bmj.com/content/rmdopen/7/2/e001646.full.pdf Acknowledgements: NIL. Disclosure of Interests None Declared.No discrepancy. Low (n=11)Discrepancy. Low CLP (n=2)Discrepancy. High CLP (n=9)No discrepancy. High (n=3)Age (years), mean (SD)12.2 (±4.6)8.0 (±11.1)10.3 (±3.5)14.4 (±3.0)JIA subtypes, n (%)- ERA + juvenile EA + APs5 (45.4)0 (0)2 (22.2)0 (0)- Oligoarticular3 (27.3)1 (50)5 (55.6)2 (66.7)- Polyarticular2 (18.2)1 (50)1 (11.1)1 (33.3)- Systemic1 (9.1)0 (0)1 (11.1)0 (0)Biomarkers, median (IQR)- CRP (mg/L)0.5 (0.6)8.2 (5)1.7 (2.1)6.3 (11.8)- ESR (mm/h)5 (8)28 (32)13 (12)21 (56)- Calprotectin (µg/mL)1.4 (0.8)0.9 (1.6)4.3 (1.7)4 (2.3)JIA activity according to clinical criteria, n (%)- Active4 (36.3)2 (100)3 (33.3)2 (66.7)- Inactive7 (63.6)0 (0)6 (66.7)1 (33.3)JIA activity according to JADAS, n (%)- JADAS: activity0 (0)2 (100)2 (22.2)1 (33.3)- JADAS US: activity0 (0)2 (100)1 (11.1)1 (33.3)Uveitis, n (%)- Acute uveitis0 (0)0 (0)1 (11.1)0 (0)Treatment, n (%)- PDN2 (18.2)1 (50)1 (11.1)1 (33.3)- DMARD6 (54.5)1 (50)3 (33.3)3 (100)- bDMARD3 (27.3)0 (0)2 (22.2)1 (33.3)

Background Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of acquired muscle diseases, which have distinct clinical, pathological and histological features. Autoantibodies are clinically useful biomarkers to help the diagnosis of IIM. Raynaud's phenomenon is very frequent and the presence of microvascular changes in IIM have been described however, the role of nailfold videocapillaroscopy NVC) for diagnosis and prognosis in IIM is not clearly established. Objectives The aim of this study was to study the relationship between clinical and immunological characteristics and nailfold videocapillaroscopy (NVC) abnormalities in patients with idiopathic inflammatory myopathies (IIMs). Methods We performed a retrospective study of IIM patients followed in a University Hospital. Patients underwent a NVC at 200x magnification. Epidemiological, clinical data and antibody status, including myositis and scleroderma antibody panel of all patients was retrieved. NVC findings including loss of capillary density, enlarged and giant capillaries, ramified capillaries, haemorrhages, thrombosis, avascular areas, disorganization of capillary architecture and subpapillary venous plexus presence were recollected, if present. For the comparison of qualitative and/or quantitative variables Fisher's exact Test or T-test was performed when necessary. Results 95 patients with NVC performed during the follow-up were included (66% female) with a median age at inclusion of 55.3±24 years. Median IIM duration was 6.8±7 years. 39% had Raynaud's phenomenon at first clinical evaluation and 58% of them showed NVC pathological findings. Table 1 Summarizes the epidemiological, clinical, and autoantibody status of the patients. We found an association between the presence of dysphagia and avascular areas (p=0.02) or abnormal capillary organization (p<0.01) on NVC. ILD was associated with capillary loss (p=0.04) and avascular areas (p=0.004). Anti-MDA5+ was associated with capillary loss (p=0.03), thrombosis (p=0.02) and ramified capillaries (p=0.04). Anti-Mi2+ and anti-Th/To was associated with abnormal capillary organization (p=0.017 and p=0.001). The presence of haemorrhages was associated with anti-Ku+ (p=0.048) and anti-PL12+ (p=0.046). The presence of enlarged capillaries was associated with anti-RNA-pol III (p=0.04) and anti-NXP2 (p=0.044). A significant association between anti-Ro52 (OR 2.69, CI 95% 1.05-6.8, p 0.03) and anti-Jo1 (OR 7.03 CI 95% 1.46-33.7, p 0.01) with ILD was found. Anti-PML (OR 4.32 CI 95% 1.35-10.42, p 0.038) and anti-Th/To (OR 5.82 CI 95% 1.89-13.24, p 0.04) were associated with dysphagia. Anti-MDA5 (OR 5.85 CI 95% 1.92-14.21, p 0.044) was associated with skin involvement. Conclusion The presence of certain autoantibodies is related to the degree of microangiopathy in IIM and associates with capillaroscopic changes. Studying the association between capillaroscopic changes with diagnostic and pathogenic autoantibodies in IIM can provide useful information regarding the current knowledge about pathogenesis, classification, and prognosis of the disease. REFERENCES: NIL. Acknowledgements: NIL. Disclosure of Interests None Declared.Table 1: Epidemiological, clinical, immunological and NFC features and autoantibody status from patients with IIMClinical featuresMuscle weakness79 (83%)Skin findings30 (32%)ILD47 (49%)Dysphagia18 (19%)Raynaud's phenomenon37 (39%)CK elevation45 (47%)Cardiac disease4 (4%)NFC featuresLoss of capillary density27 (28%)Enlarged and giant capillaries37 (39%)Haemorrhages36 (38%)Thrombosis19 (20%)Avascular areas26 (27%)Disorganization of capillary architecture24 (25%)Subpapillary venous plexus36 (38%)Antibody statusDisease-specific antibodiesAnti-MDA58 (8%)Anti-TIF1G11 (12%)Anti-MI211 (12%)Anti-NXP26 (6%)Anti-synthetase antibodiesAnti-Jo113 (14%)Anti-PL79 (9%)Anti-PL125 (5%)Disease-associated antibodiesAnti-Ro5227 (28%)Anti-KU6 (6%)Antinuclear antibodiesOthers (EJ, SRP, PM-SCL75, PM-SCL100, CN1A)61 (64%)22 (23%)