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Background: The updates to the European recommendations and the German guidelines for the treatment of systemic sclerosis are expected shortly, which are very good evidence-based guidelines for all those treating the disease; however, there are still disease manifestations with insufficient studies and current study results that were published after the review of the literature for the guidelines and might be of interest to the reader., Objective and Methods: The aim of this work is to provide an overview of the publications in the last year that are interesting from the authors' point of view. The aim is to provide practically relevant information on the current state of knowledge that can supplement the guidelines., Results: The pathogenesis of systemic sclerosis (SSc) is becoming better understood in its interplay between environmental factors and the development of autoantibodies. There have also been overviews of the manifestation and prognosis of cardiac involvement in the last year. The American Thoracic Society issued the first guidelines for the treatment of interstitial lung disease in SSc. There are an increasing number of studies that suggest that disease-modulating combination therapies, such as rituximab and mycophenolate mofetil (MMF) are beneficial. Work addressing the involvement of joints suggests that inflammatory changes are common. Current options for the treatment of gastrointestinal involvement are presented., Conclusion: The diagnosis and treatment of systemic sclerosis is making progress and many symptoms and complications are treatable. Nevertheless, much remains to be done to improve the quality of life of the patients., (© 2024. The Author(s), under exclusive licence to Springer Medizin Verlag GmbH, ein Teil von Springer Nature.)

Background: Interdisciplinary medical treatment is required to care for patients with complex autoimmune diseases. Although there are an increasing number of interdisciplinary centers for autoimmune diseases in Germany, they are not yet available throughout the country and the focuses and interdisciplinary structures are not organized according to a generally agreed standard. Furthermore, they are not regularly reflected in the general care structure., The Aim of the Work: To analyze the care structure using as an example an established center and a clinical case to demonstrate the usefulness of in-house standardized procedures., Material and Methods: In order to determine the status quo regarding interdisciplinary centers for autoimmune diseases in Germany, a university hospital is exemplarily presented for a structural analysis and a case presentation from another center to demonstrate the importance of an interdisciplinary patient care., Results: At the selected center for autoimmune diseases of the university hospital, patients with autoimmune diseases receive interdisciplinary care from experts from various disciplines. The structures are anchored in an organizational chart. The case report demonstrates a standardized diagnostic and therapeutic pathway (standardized operating procedures, SOP) in a patient with systemic sclerosis and lung involvement., Discussion: The article discusses which measures are necessary across disciplines for comprehensive diagnostics and treatment of certain autoimmune diseases, which challenges arise during implementation and which advantages can arise compared to guidelines because, among other things, they can be immediately adapted. The establishment of a national consensus for the structure, necessary settings and implementation into patient care within an interdisciplinary center for autoimmune diseases is desirable., (© 2024. The Author(s).)

Background: The 2022 European Society of Cardiology/European Respiratory Society guidelines define pulmonary hypertension (PH) as a resting mean pulmonary artery pressure (mPAP) > 20 mm Hg at right heart catheterization (RHC). Previously, patients with an mPAP between 21 and 24 mm Hg were classified in a "gray zone" of unclear clinical significance., Research Question: What is the diagnostic performance of the main parameters used for PH screening in detecting patients with systemic sclerosis (SSc) with an mPAP of 21 to 24 mm Hg at RHC?, Study Design and Methods: Patients with SSc from the European Scleroderma Trials and Research (EUSTAR) database with available tricuspid annular plane systolic excursion (TAPSE), systolic PAP (sPAP), and mPAP data were included. Patients with mPAP 21 to 24 mm Hg and patients with mPAP ≤ 20 mm Hg were considered for the analysis. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy were calculated., Results: TAPSE/sPAP was lower in the group of patients with SSc with mPAP 21 to 24 mm Hg than in the non-PH group (0.58 [0.46-0.72] vs 0.69 [0.57-0.81] mm/mm Hg, respectively; P < .01). No difference was found in other parameters between the two groups. Diffusing capacity of the lungs for carbon monoxide < 80% of the predicted value had the highest sensitivity (88.9%) and NPV (80%), but the lowest specificity (18.2%) and PPV (30.8%) in detecting patients with SSc with mPAP 21 to 24 mm Hg. TAPSE/sPAP < 0.55 mm/mm Hg had the highest specificity (78.9%), PPV (50%), and accuracy (68.1%); its NPV was 75.4%, and its sensitivity was 45.1%., Interpretation: In this study, diffusing capacity of the lungs for carbon monoxide < 80% of the predicted value was the parameter with the highest sensitivity and NPV in detecting patients with SSc with mPAP 21 to 24 mm Hg. TAPSE/sPAP < 0.55 mm/mm Hg had the highest specificity, PPV, and accuracy and, therefore, can be a useful additional parameter to decrease the number of unnecessary RHCs., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: V. S. is senior clinical investigator of the Research Foundation—Flanders (Belgium): (FWO) (1.8.029.20N). This funding source had no role in the literature review and the synthesis and interpretation of the data; in the writing of the report; or in the decision to submit the paper for publication. C. B. received grants from Boehringer-Ingelheim, consulting fees from Janssen, honoraria for lectures from Novartis, and travel grants from Kyverna, which were not related to this project. E. Z. received speaking and lecture fees from Janssen and consulting fees from Janssen and GSK. F. I. received honoraria and speaking fees from AbbVie, Eli Lilly, Galapagos, Janssen, Novartis, Pfizer, and UCB outside this work. C. P. S. A. received consulting fees and support for attending meetings from Janssen-Cilag SAS, Boehringer Ingelheim Ltd and MSD. None declared (A. C., E. H., C. P., G. R., J. H., D. L., A. M., A. M. G., M.-E. T., S. O., M. V., F. D. G., E. R.)., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Background: High-density lipoproteins (HDL) affect endothelial functions such as the expression of endothelial cell adhesion molecules and exert anti-apoptotic/-thrombotic functionalities. Therefore, profound analysis of lipoproteins may unveil biomarkers for (micro-)vasculopathy in systemic sclerosis (SSc) and mortality determining disease manifestations like interstitial lung disease (SSc-ILD). Because nuclear magnetic resonance (NMR) spectroscopy provides a wide range of lipoprotein parameters beyond the capabilities of classical analyses it has been used herein to examine lipoprotein profiles in SSc., Methods: To detect the metabolic and lipidomic profile serum samples from clinically well-characterized SSc patients (n = 100) and age-and sex-matched healthy controls (n = 40) were analyzed by 1H NMR spectroscopy using Bruker's in-vitro diagnostic research (IVDr) protocol. Statistical analyses were performed to validate significant findings and to search for associations between lipoproteins and clinical phenotypes., Results: Patients with SSc-ILD and lung fibrosis displayed reduced HDL levels. Furthermore, a reduction in apolipoprotein A1 + A2 and its HDL fractions reflected a distinct lipoprotein profile for SSc-ILD patients. This association was independent of potential clinical confounders for dyslipidemia. Notably, in SSc-ILD HDL levels correlate with FVC (forced vital capacity), DLCO (diffusion capacity of the lungs for carbon monoxide), and the modified Rodnan-Skin-Score., Conclusion: These results suggest HDL and its lipoproteins may be considered as potential new biomarkers for SSc-ILD. Immune-mediated HDL effects on the endothelium facilitate microvasculopathy - one of the pathophysiological hallmarks in SSc. Therefore, a closer prospective evaluation of the capability of HDL-determination and its lipoproteins regarding a more individualized evaluation of SSc-ILD is warranted., Competing Interests: Declaration of competing interest STJ reports consulting fees for GlaxoSmithKline Group of Companies (GSK) and received honoraria for presentations from Pfizer, GlaxoSmithKline (GSK), Novartis, UCB Pharma, Center for Travel Medicine and Janssen-Cilag - all outside the submitted work. JYH reports consulting fees for MSD Sharp & Dohme, AstraZeneca, GlaxoSmithKline, Selecta Biosciences, Janssen Cilag, Ono Pharma And received honoraria for presentations from AstraZeneca, MSD Sharp & Dohme, Sanofi Pharma, Chugai Pharma, Pfizer Pharma - all outside the submitted work. JYH received support for attending meetings and/or travel by AstraZeneca, Galapagos Pharma, Pfizer Pharma - outside the submitted work. HG received honoraria for presentations from Abbvie outside the submitted work. The other authors report no competing interests outside or related to this work., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Due to optimised treatment strategies and the availability of new therapies during the last decades, formerly devastating chronic inflammatory diseases such as rheumatoid arthritis or systemic sclerosis (SSc) have become less menacing. However, in many patients, even state-of-the-art treatment cannot induce remission. Moreover, the risk for flares strongly increases once anti-inflammatory therapy is tapered or withdrawn, suggesting that underlying pathological processes remain active even in the absence of overt inflammation. It has become evident that tissues have the ability to remember past encounters with pathogens, wounds and other irritants, and to react more strongly and/or persistently to the next occurrence. This priming of the tissue bears a paramount role in defence from microbes, but on the other hand drives inflammatory pathologies (the Dr Jekyll and Mr Hyde aspect of tissue adaptation). Emerging evidence suggests that long-lived tissue-resident cells, such as fibroblasts, macrophages, long-lived plasma cells and tissue-resident memory T cells, determine inflammatory tissue priming in an interplay with infiltrating immune cells of lymphoid and myeloid origin, and with systemically acting factors such as cytokines, extracellular vesicles and antibodies. Here, we review the current state of science on inflammatory tissue priming, focusing on tissue-resident and tissue-occupying cells in arthritis and SSc, and reflect on the most promising treatment options targeting the maladapted tissue response during these diseases., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ on behalf of EULAR.)

Advanced bioinformatics analysis, such as systems biology (SysBio) and artificial intelligence (AI) approaches, including machine learning (ML) and deep learning (DL), is increasingly present in stem cell (SC) research. An approximate timeline on these developments and their global impact is still lacking. We conducted a scoping review on the contribution of SysBio and AI analysis to SC research and therapy development based on literature published in PubMed between 2000 and 2024. We identified an 8-10-fold increase in research output related to all three search terms between 2000 and 2021, with a 10-fold increase in AI-related production since 2010. Use of SysBio and AI still predominates in preclinical basic research with increasing use in clinically oriented translational medicine since 2010. SysBio- and AI-related research was found all over the globe, with SysBio output led by the United States (US, n=1487), United Kingdom (UK, n=1094), Germany (n=355), The Netherlands (n=339), Russia (n=215), and France (n=149), while for AI-related research the US (n=853) and UK (n=258) take a strong lead, followed by Switzerland (n=69), The Netherlands (n=37), and Germany (n=19). The US and UK are most active in SCs publications related to AI/ML and AI/DL. The prominent use of SysBio in ESC research was recently overtaken by prominent use of AI in iPSC and MSC research. This study reveals the global evolution and growing intersection between AI, SysBio, and SC research over the past two decades, with substantial growth in all three fields and exponential increases in AI-related research in the past decade., (© The Author(s) 2024. Published by Oxford University Press. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Background: Chronic inflammatory diseases (immune-mediated inflammatory diseases, IMID) can overlap or occur simultaneously due to clinical similarities. The resulting utilization of heathcare structures has not yet been investigated across disciplines but is of potential importance for optimizing the treatment of patients with IMID., Aim of the Work: Analysis of epidemiological data including utilization of care services in patients with selected IMIDs: psoriasis, psoriatic arthritis (PsA), rheumatoid arthritis (RA), ankylosing spondylitis, ulcerative colitis, Crohn's disease and connective tissue disease., Material and Methods: In a retrospective cross-sectional analysis based on health insurances accounting data with a sample of approximately 4 million insured persons, the prevalence of the abovementioned IMID and the frequency of IMID combinations were analyzed based on documented diagnoses (ICD-10 GM). The frequency of hospitalizations and utilization of outpatient physician contacts was recorded in predefined specialist disciplines (general medicine, dermatology, gastroenterology, rheumatology) and compared with an age-adjusted and gender-adjusted reference population., Results: A total of 188,440 patients had at least 1 of the IMID diagnoses analyzed (4.7%), with an age peak of 61-70 years. The highest prevalence was observed for psoriasis (1.85%), followed by rheumatoid arthritis (1.38%). Combinations with at least one other IMID were relatively common (29%), with this being most common in patients with psoriatic arthritis (82.9%, of which 68.2% had psoriasis), followed by ankylosing spondylitis (27.5%) and Crohn's disease (21.6%). Compared to the reference population, patients with IMID were hospitalized more often and more frequently utilized the outpatient disciplines., Discussion: The study results describe that IMIDs occur in combination and that the patients make comparatively more use of care structures of different disciplines. A multidisciplinary approach could increase the efficiency of care; an evaluation is still pending., (© 2023. The Author(s).)

Aiping Ma,1,* Lifang Wen,2,* Junping Yin,3 Yi Hu,4 Xiaoyang Yue,3 Jiurong Li,1 Xiaoru Dong,2 Yask Gupta,5 Ralf J Ludwig,5 Susanne Krauss-Etschmann,3,6 Gabriela Riemekasten,7 Frank Petersen,3 Xinhua Yu2,3 1Department of Respiratory Medicine, The First Affiliated Hospital, School of Medicine, Xiamen University, Xiamen, People’s Republic of China; 2Xiamen-Borstel Joint Laboratory of Autoimmunity, The Medical College of Xiamen University; 3Priority Area Asthma and Allergy, Research Center Borstel, Airway Research Center North (ARCN), Members of the German Center for Lung Research (DZL), Borstel, Germany; 4Department of Clinical Laboratory, The First Affiliated Hospital, School of Medicine, Xiamen University, Xiamen, People’s Republic of China; 5Lübeck Institute of Experimental Dermatology, University of Lübeck, Lübeck, Germany; 6Institute for Experimental Medicine, Christian-Albrechts-Universitaetzu Kiel, Kiel, Germany; 7Department of Rheumatology, University of Lübeck, Lübeck 23538, Germany*These authors contributed equally to this workCorrespondence: Xinhua YuPriority Area Asthma and Allergy, Research Center Borstel, Borstel 23845, GermanyTel +49 453 7188 2520Email xinhuayu@fz-borstel.deBackground: Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease leading to irreversible airflow limitation and is characterized by chronic pulmonary inflammation, obstructive bronchiolitis and emphysema. Etiologically, COPD is mediated by toxic gases and particles, eg, cigarette smoke, while the pathogenesis of the disease is largely unknown. Several lines of evidence indicate a link between COPD and autoimmunity but comprehensive studies are lacking.Methods: By using a protein microarray assaying more than 19,000 human proteins we determined in this study the autoantibody profiles of COPD and non-COPD smokers. The discovery cohort included 5 COPD patients under acute exacerbation (AECOPD) and 5 age- and gender-matched non-COPD smokers. One putative candidate autoantibody, anti-lactoferrin IgG, was further investigated by using immunoblotting with a large validation cohort containing 124 healthy controls, 92 patients with AECOPD and 52 patients with stable COPD.Results: We show that i) autoantigens targeted by autoantibodies with higher titers in COPD patients were enriched in extracellular regions, while those with lower titers in COPD patients were enriched in intracellular compartments. ii) levels of IgG autoantibodies against many neutrophil granule proteins were significantly higher in COPD patients than in non-COPD smokers. Furthermore, increased levels of anti-lactoferrin antibodies in COPD patients were confirmed in a cohort with a large number of samples.Conclusion: The comprehensive autoantibody profiles from COPD patients established in this study demonstrated for the first time a shift in the cellular localization of antigens targeted by autoantibodies in COPD.Keywords: chronic obstructive pulmonary disease, autoimmunity, autoantibody profile, neutrophil granule proteins, lactoferrin

A German expert committee recommends defining fast-track clinics (FTC) for the acute diagnosis of giant cell arteritis (GCA) as follows: easy and prompt reachability at least on weekdays, scheduling appointments ideally within 24 h, examination by a specialist with GCA expertise, ≥ 2 experts per FTC, ≥ 50 patients with suspected GCA per year, sonologists with ≥ 300 (≥ 50) temporal and axillary artery examinations, adherence to standard operating procedures, availability of an ≥ 18 (≥ 15) MHz and a lower frequency linear ultrasound probe, and collaboration with partners for neurology and ophthalmology consultations, magnetic resonance imaging (MRI), positron emission tomography-computed tomography (PET-CT, possibly CT), and for temporal artery biopsy., (© 2024. The Author(s).)

Purpose of Review: Low-dose interleukin-2 (IL-2) therapy is increasingly recognized as a promising novel therapeutic concept in inflammatory and autoimmune diseases, in particular in systemic lupus erythematosus (SLE). As IL-2 is indispensable for the growth and survival of regulatory T cells (Treg), deficiency of this regulatory cytokine plays a significant role in immune dysregulation and breach of tolerance in SLE. Recovery of Treg activity by low-dose IL-2 therapy directly interferes with the immune pathology in SLE and thus can be considered a targeted treatment approach with a unique and physiological mode of action., Recent Findings: In this review, the pathophysiological rationales behind the concept of low-dose IL-2 therapy in SLE will be explained and major advances in translational research and the clinical development of low-dose IL-2 therapy focusing on the results from two recent, randomized and placebo-controlled phase 2 trials will be highlighted., Summary: Several clinical studies including two recent randomized trials have proven the very good safety profile of low-dose IL-2 therapy and its capability to selectively recover and expand the Treg population in patients with active SLE. Given the emerging evidence for the clinical potential of low-dose IL-2 therapy in SLE, these studies strongly confirm the pathophysiological concept behind this targeted therapeutic approach in SLE and provide a robust basis for establishing further in-depth and confirmatory clinical trials testing the application of low-dose IL-2 in SLE and other autoimmune diseases., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Immune-mediated inflammatory diseases (IMID) can lead to a substantial disease burden for those affected, in particular by the concomitant occurrence of other IMIDs or in the presence of comorbidities. The care of patients with IMIDs is complex and involves various medical disciplines., Objective: To describe the burden of disease and the current routine drug treatment of patients with IMID., Material and Methods: The retrospective cross-sectional analysis was based on statutory health insurance claims data from the InGef database. Prevalent patients with psoriasis (Pso), psoriatic arthritis (PsA), spondylarthritis (SpA), rheumatoid arthritis (RA), Crohn's disease (MC), ulcerative colitis (CU), or connective tissue disease were identified among 3,988,695 insured patients in 2018. The concomitant occurrence of different IMIDs and the extent to which patients with IMID are affected by other comorbidities compared to a reference population were investigated. The current routine drug treatment was described based on the use of predefined forms of treatment., Results: In the database 188,440 patients with IMID (4.7%) were identified. Compared to the reference population the prevalence of comorbidities, such as depressive episodes and cardiovascular risk factors was higher in patients with IMID. For MC, CU, RA, and PsA disease-modifying antirheumatic drugs (DMARD) and classical systemic forms of treatment were used most commonly. In Pso, SpA, and connective tissue disease nonsteroidal anti-inflammatory drugs (NSAID) were the most frequently used treatment often in combination with other drugs., Conclusion: A considerable number of patients with IMIDs (16.9-27.5%) suffer from different diseases of the IMID group. They are frequently affected by accompanying illnesses and require interdisciplinary medical treatment., (© 2022. The Author(s).)

Background: Pulmonary involvement is the leading cause of death in systemic sclerosis (SSc) and may manifest as interstitial lung disease (ILD), pulmonary arterial hypertension (PAH), or in combination of both (ILD with pulmonary hypertension [ILD-PH]). The aim of this analysis was to determine prevalence, clinical characteristics, and survival of these different forms within the registry of the German Network for Systemic Sclerosis., Research Question: Does SSc-associated ILD-PH or ILD without PH affect survival differently, and are there any risk factors that have an additional impact?, Study Design and Methods: Clinical data of 5,831 patients with SSc were collected in the German Network for Systemic Sclerosis registry. Kaplan-Meier estimates were used to compare overall survival in patients with SSc-associated ILD-PH and ILD without PH with patients without pulmonary involvement and those with PAH. The Cox proportional hazard model was used to analyze the influence of pulmonary involvement and other potential predictors on patient survival., Results: Clinical data of 3,257 patients with a mean follow-up time of 3.45 ± 1.63 years have been included in our analysis. At baseline, ILD was present in 34.5%, whereas PH without ILD had a lower prevalence with 4.5%. At the end of follow-up, 47.6% of patients with SSc had ILD, 15.2% had ILD-PH, and 6.5% had PAH. ILD was more frequent in the diffuse cutaneous form (57.3%), whereas PAH did not differ significantly between SSc subtypes. Significant differences in baseline characteristics between PAH vs ILD-PH vs ILD without PH were found for age at diagnosis, sex, SSc subsets, antibody status, FVC, diffusing capacity of the lung for carbon monoxide, and therapy. Overall survival at 5 years was 96.4% for patients without pulmonary involvement and differed significantly between patients with ILD without PH, PAH, and being worst in patients with ILD-PH. Female sex (hazard ratio [HR], 0.3), higher BMI (HR, 0.9), and higher diffusing capacity of the lung for carbon monoxide values (HR, 0.98) were associated with a lower mortality risk., Interpretation: ILD is the most prevalent pulmonary involvement in SSc, whereas the combination of ILD and PH is associated with the most detrimental survival., Competing Interests: Financial/Nonfinancial Disclosures The authors have reported to CHEST the following: M. K. reports grants and personal fees from Boehringer Ingelheim and Roche, and personal fees from Galapagos. P. M. reports lecture fees from Boehringer Ingelheim. F. B. reports grants and personal fees from Boehringer Ingelheim, Roche, Galapagos, and Savara Pharma. N. B. reports personal fees from Actelion, Boehringer Ingelheim, Roche, Pfizer, MSD, and AbbVie; and grants and personal fees from Novartis and SOBI. C. P. reports personal fees from Boehringer Ingelheim, Pfizer, and Takeda; grants and personal fees from Actelion and Novartis; and grants from Corbus and Amgen. M. S. reports grants and personal fees from Roche/Chugai, Hexal/Sandoz, Janssen, and BMS; and personal fees from AbbVie, Novartis, UCB, Boehringer Ingelheim, and Gilead. P. K. reports personal fees and nonfinancial support from AbbVie, Chugai, Novartis, and Pfizer, unrelated to the present manuscript; and personal fees from Bristol-Myers Squibb, Gilead, and GlaxoSmithKline, unrelated to the present manuscript. N. H. reports lecture fees from Boehringer Ingelheim and Janssen. Nothing declared (M. O., J. W., G. R., U. M.-L., J. H., E. S., C. G., I. K., G. Z., L. S., A. J., M. W., I. J., J. E., C. S., G. K., A. R., T. S., A. K., H. M.-L.)., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

Objective: The outcome of patients with COVID-19 improved over the pandemic, including patients with systemic rheumatic diseases. However, data on patients with systemic sclerosis (SSc) are lacking. This study aimed to assess the outcome of patients with both SSc and COVID-19 over several waves., Methods: Patients with both SSc and COVID-19 who were registered in the European Scleroderma Trials and Research group (EUSTAR) were collected between April 2020 and April 2021. Patients were assigned to waves 1, 2, or 3 depending on the date of their COVID-19 diagnosis. Primary endpoints were death, intensive care unit stay, or ventilatory support (severe outcome). Subgroup analyses of patients who were hospitalized or died were conducted. General and SSc-specific characteristics and treatment were compared over the waves. Descriptive statistics and multivariate logistic regression were applied., Results: A total of 333 patients were included; 57 patients (17%) had a severe outcome, and 30 patients (9%) died. Compared to wave 1, significantly fewer patients with SSc suffered from severe COVID-19 in waves 2 and 3 (28.2% vs 9.8% and 12.7%; P < 0.001), fewer patients required hospitalization (46.7% vs 19.6% and 25.5%; P < 0.001) or ventilatory support (24.0% vs 8.7% and 10.9%; P = 0.001), and fewer patients died (15.7% vs 5.0% and 7.5%; P = 0.011). Patients were significantly younger, more often men, had less frequent arterial hypertension, and less SSc cardiac involvement over waves 1 to 3. Patients received significantly less medium to high doses of corticosteroids as they did SSc treatment., Conclusion: The outcome of patients with both SSc and COVID-19 improved significantly over time because of intrinsic and extrinsic factors., (© 2023 The Authors. Arthritis Care & Research published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)

Background and Aims: Chronic inflammation and autoimmunity contribute to cardiovascular (CV) disease. Recently, autoantibodies (aAbs) against the CXC-motif-chemokine receptor 3 (CXCR3), a G protein-coupled receptor with a key role in atherosclerosis, have been identified. The role of anti-CXCR3 aAbs for CV risk and disease is unclear., Methods: Anti-CXCR3 aAbs were quantified by a commercially available enzyme-linked immunosorbent assay in 5000 participants (availability: 97.1%) of the population-based Gutenberg Health Study with extensive clinical phenotyping. Regression analyses were carried out to identify determinants of anti-CXCR3 aAbs and relevance for clinical outcome (i.e. all-cause mortality, cardiac death, heart failure, and major adverse cardiac events comprising incident coronary artery disease, myocardial infarction, and cardiac death). Last, immunization with CXCR3 and passive transfer of aAbs were performed in ApoE(-/-) mice for preclinical validation., Results: The analysis sample included 4195 individuals (48% female, mean age 55.5 ± 11 years) after exclusion of individuals with autoimmune disease, immunomodulatory medication, acute infection, and history of cancer. Independent of age, sex, renal function, and traditional CV risk factors, increasing concentrations of anti-CXCR3 aAbs translated into higher intima-media thickness, left ventricular mass, and N-terminal pro-B-type natriuretic peptide. Adjusted for age and sex, anti-CXCR3 aAbs above the 75th percentile predicted all-cause death [hazard ratio (HR) (95% confidence interval) 1.25 (1.02, 1.52), P = .029], driven by excess cardiac mortality [HR 2.51 (1.21, 5.22), P = .014]. A trend towards a higher risk for major adverse cardiac events [HR 1.42 (1.0, 2.0), P = .05] along with increased risk of incident heart failure [HR per standard deviation increase of anti-CXCR3 aAbs: 1.26 (1.02, 1.56), P = .03] may contribute to this observation. Targeted proteomics revealed a molecular signature of anti-CXCR3 aAbs reflecting immune cell activation and cytokine-cytokine receptor interactions associated with an ongoing T helper cell 1 response. Finally, ApoE(-/-) mice immunized against CXCR3 displayed increased anti-CXCR3 aAbs and exhibited a higher burden of atherosclerosis compared to non-immunized controls, correlating with concentrations of anti-CXCR3 aAbs in the passive transfer model., Conclusions: In individuals free of autoimmune disease, anti-CXCR3 aAbs were abundant, related to CV end-organ damage, and predicted all-cause death as well as cardiac morbidity and mortality in conjunction with the acceleration of experimental atherosclerosis., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Vasoregulatory autoantibodies including autoantibodies targeting G-protein-coupled receptors might play a functional role in vascular diseases. We investigated the impact of vasoregulatory autoantibodies on clinical outcome after ischemic stroke., Methods and Results: Data were used from the PROSCIS-B (Prospective Cohort With Incident Stroke-Berlin). Autoantibody-targeting receptors such as angiotensin II type 1 receptor (AT1R), endothelin-1 type A receptor, complement factor-3 and -5 receptors, vascular endothelial growth factor receptor-1 and -2, vascular endothelial growth factor A and factor B were measured. We explored associations of high antibody levels with (1) poor functional outcome defined as modified Rankin Scale >2 or Barthel Index <60 at 1 year after stroke, (2) Barthel Index scores over time using general estimating equations, and (3) secondary vascular events (recurrent stroke, myocardial infarction) or death up to 3 years using Cox proportional hazard models. We included 491 patients with ischemic stroke with data on autoantibody levels and outcome. In models adjusted for demographics and vascular risk factors, high autoantibody concentrations (quartile 4) targeting complement factor C3a receptor, vascular endothelial growth factor receptor-2, and vascular endothelial growth factor B were associated with poor functional outcome at 1 year: (odds ratio, 2.0 [95% CI, 1.1-3.6]; odds ratio, 1.8 [95% CI, 1.1-3.2]; and odds ratio, 2.1 [95% CI, 1.2-3.6], respectively) and with lower Barthel Index scores over 3 years (complement factor C3a receptor: adjusted β=-3.3 [95% CI, -5.7 to -0.5]; VEGF-B: adjusted β=-2.4 [95% CI, -4.8 to -0.06]). Patients with high autoantibody levels were not at higher risk for secondary vascular events or death., Conclusions: High levels of autoantibodies against vascular endothelial growth factor receptor-2, vascular endothelial growth factor B, and complement factor C3a receptor measured are associated with poor functional outcome after stroke but not with recurrent vascular events or death., Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01363856.

Introduction: Progressive loss of regulatory T cell (Treg)-mediated control over autoreactive effector T cells contributes to the development of systemic lupus erythematosus (SLE). Accordingly, we hypothesized that Treg may also have the capacity to suppress the activation of autoreactive CD4 + T cells that are considered to drive autoimmunity., Methods: To investigate whether Treg are involved in the control of autoreactive CD4 + T cells, we depleted CD25 + Treg cells either in vivo or in vitro , or combined both approaches before antigen-specific stimulation with the SLE-associated autoantigen SmD1(83-119) in the NZB/W F1 mouse model either after immunization against SmD1(83-119) or during spontaneous disease development. Frequencies of autoantigen-specific CD4 + T cells were determined by flow cytometry using the activation marker CD154., Results: Both in vitro and in vivo depletion of CD25 + Treg, respectively, increased the frequencies of detectable autoantigen-specific CD4 + T cells by approximately 50%. Notably, the combined in vivo and in vitro depletion of CD25 + Treg led almost to a doubling in their frequencies. Frequencies of autoantigen-specific CD4 + T cells were found to be lower in immunized haploidentical non-autoimmune strains and increased frequencies were detectable in unmanipulated NZB/W F1 mice with active disease. In vitro re-addition of CD25 + Treg after Treg depletion restored suppression of autoantigen-specific CD4 + T cell activation., Discussion: These results suggest that the activation and expansion of autoantigen-specific CD4 + T cells are partly controlled by Treg in murine lupus. Depletion of Treg therefore can be a useful approach to increase the detectability of autoantigen-specific CD4 + T cells allowing their detailed characterization including lineage determination and epitope mapping and their sufficient ex vivo isolation for cell culture., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Rosenberger, Undeutsch, Akbarzadeh, Ohmes, Enghard, Riemekasten and Humrich.)

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) is a devastating disease affecting millions of people worldwide. Due to the 2019 pandemic of coronavirus disease (COVID-19), we are facing a significant increase of ME/CFS prevalence. On May 11th to 12th, 2023, the second international ME/CFS conference of the Charité Fatigue Center was held in Berlin, Germany, focusing on pathomechanisms, diagnosis, and treatment. During the two-day conference, more than 100 researchers from various research fields met on-site and over 700 attendees participated online to discuss the state of the art and novel findings in this field. Key topics from the conference included: the role of the immune system, dysfunction of endothelial and autonomic nervous system, and viral reactivation. Furthermore, there were presentations on innovative diagnostic measures and assessments for this complex disease, cutting-edge treatment approaches, and clinical studies. Despite the increased public attention due to the COVID-19 pandemic, the subsequent rise of Long COVID-19 cases, and the rise of funding opportunities to unravel the pathomechanisms underlying ME/CFS, this severe disease remains highly underresearched. Future adequately funded research efforts are needed to further explore the disease etiology and to identify diagnostic markers and targeted therapies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with increased levels of autoantibodies targeting immunological proteins such as cytokines and chemokines. Reports further indicate that COVID-19 patients may develop a broad spectrum of autoimmune diseases due to reasons not fully understood. Even so, the landscape of autoantibodies induced by SARS-CoV-2 infection remains uncharted territory. To gain more insight, we carried out a comprehensive assessment of autoantibodies known to be linked to diverse autoimmune diseases observed in COVID-19 patients in a cohort of 231 individuals, of which 161 were COVID-19 patients (72 with mild, 61 moderate, and 28 with severe disease) and 70 were healthy controls. Dysregulated IgG and IgA autoantibody signatures, characterized mainly by elevated concentrations, occurred predominantly in patients with moderate or severe COVID-19 infection. Autoantibody levels often accompanied anti-SARS-CoV-2 antibody concentrations while stratifying COVID-19 severity as indicated by random forest and principal component analyses. Furthermore, while young versus elderly COVID-19 patients showed only slight differences in autoantibody levels, elderly patients with severe disease presented higher IgG autoantibody concentrations than young individuals with severe COVID-19. This work maps the intersection of COVID-19 and autoimmunity by demonstrating the dysregulation of multiple autoantibodies triggered during SARS-CoV-2 infection. Thus, this cross-sectional study suggests that SARS-CoV-2 infection induces autoantibody signatures associated with COVID-19 severity and several autoantibodies that can be used as biomarkers of COVID-19 severity, indicating autoantibodies as potential therapeutical targets for these patients., (© 2023 The Authors. Journal of Medical Virology published by Wiley Periodicals LLC.)

Although medication adherence (MA) contributes to therapeutic outcome in systemic sclerosis (SSc), research data are scarce. Factors influencing MA in SSc are hardly known. We conducted a monocentric, cross-sectional study on 85 patients with SSc at the University of Lübeck, Germany, using the Compliance Questionnaire of Rheumatology as the main measurement tool of MA. We also used the Scleroderma Health Assessment Questionnaire, Illness Perception Questionnaire – Revised, Health Literacy Questionnaire, Lübeck Medication Satisfaction Questionnaire (a novel instrument created for this study), and patients' demographic and clinical data, to find factors contributing to MA. Good MA was seen in 51.8% of patients. MA was positively associated with therapy satisfaction (p < 0.001), modified Rodnan Skin Score (p = 0.032), age (p = 0.025), intake of micronutrients (p = 0.033), number of prescribed drugs (p = 0.014), and some dimensions of health literacy. Negative associations were found for patients with weight loss attributed to SSc (p = 0.009) and the perception that the disease is caused by the patient's personality (p = 0.011) or emotional state (p = 0.037). Although most SSc patients display good MA, non-adherence remains a major problem. Patients should be assessed for non-adherence. The factors affecting MA identified herein could help to improve therapeutic outcomes. [ABSTRACT FROM AUTHOR]

Non-HLA-directed regulatory autoantibodies (RABs) are known to target G-protein coupled receptors (GPCRs) and thereby contribute to kidney transplant vasculopathy and failure. However, the detailed underlying signaling mechanisms in human microvascular endothelial cells (HMECs) and immune cells need to be clarified in more detail. In this study, we compared the immune stimulatory effects and concomitant intracellular and extracellular signaling mechanisms of immunoglobulin G (IgG)-fractions from kidney transplant patients with allograft vasculopathy (KTx-IgG), to that from patients without vasculopathy, or matched healthy controls (Con-IgG). We found that KTx-IgG from patients with vasculopathy, but not KTx-IgG from patients without vasculopathy or Con-IgG, elicits HMEC activation and subsequent upregulation and secretion of tumor necrosis factor alpha (TNF-α) from HMECs, which was amplified in the presence of the protease-activated thrombin receptor 1 (PAR1) activator thrombin, but could be omitted by selectively blocking the PAR1 receptor. The amount and activity of the TNF-α secreted by HMECs stimulated with KTx-IgG from patients with vasculopathy was sufficient to induce subsequent THP-1 monocytic cell activation. Furthermore, AP-1/c-FOS, was identified as crucial transcription factor complex controlling the KTx-IgG-induced endothelial TNF-α synthesis, and mircoRNA-let-7f-5p as a regulatory element in modulating the underlying signaling cascade. In conclusion, exposure of HMECs to KTx-IgG from patients with allograft vasculopathy, but not KTx-IgG from patients without vasculopathy or healthy Con-IgG, triggers signaling through the PAR1-AP-1/c-FOS-miRNA-let7-axis, to control TNF-α gene transcription and TNF-α-induced monocyte activation. These observations offer a greater mechanistic understanding of endothelial cells and subsequent immune cell activation in the clinical setting of transplant vasculopathy that can eventually lead to transplant failure, irrespective of alloantigen-directed responses., Competing Interests: Author HH was employed by CellTrend GmbH. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Moll, Luecht, Gyamfi, da Fonseca, Wang, Zhao, Gong, Chen, Ashraf, Heidecke, Hackel, Dragun, Budde, Penack, Riemekasten, Cabral-Marques, Witowski and Catar.)

Objectives: Gastroesophageal reflux disease (GERD) occurs frequently in patients with SSc. We investigated whether the presence of GERD and/or the use of anti-acid therapy, specifically proton-pump inhibitors (PPIs), are associated with long-term outcomes, especially in SSc-associated interstitial lung disease (SSc-ILD)., Methods: We retrospectively analysed patients with SSc and SSc-ILD from the German Network for Systemic Sclerosis (DNSS) database (2003 onwards). Kaplan-Meier analysis compared overall survival (OS) and progression-free survival (PFS) in patients with GERD vs without GERD (SSc and SSc-ILD), and PPI vs no PPI use (SSc-ILD only). Progression was defined as a decrease in either percentage predicted forced vital capacity of ≥10% or single-breath diffusing capacity for carbon monoxide of ≥15%, or death., Results: It was found that 2693/4306 (63%) registered patients with SSc and 1204/1931 (62%) with SSc-ILD had GERD. GERD was not associated with decreased OS or decreased PFS in patients in either cohort. In SSc-ILD, PPI use was associated with improved OS vs no PPI use after 1 year [98.4% (95% CI: 97.6, 99.3); n = 760 vs 90.8% (87.9-93.8); n = 290] and after 5 years [91.4% (89.2-93.8); n = 357 vs 70.9% (65.2-77.1); n = 106; P < 0.0001]. PPI use was also associated with improved PFS vs no PPI use after 1 year [95.9% (94.6-97.3); n = 745 vs 86.4% (82.9-90.1); n = 278] and after 5 years [66.8% (63.0-70.8); n = 286 vs 45.9% (39.6-53.2); n = 69; P < 0.0001]., Conclusion: GERD had no effect on survival in SSc or SSc-ILD. PPIs improved survival in patients with SSc-ILD. Controlled, prospective trials are needed to confirm this finding., (© The Author(s) 2023. Published by Oxford University Press on behalf of the British Society for Rheumatology.)

Introduction: Natural products have been shown to an important source of therapeutics for human disease. In this study, we aimed to identify natural compounds as potential therapeutics for epidermolysis bullosa acquisita (EBA), an autoimmune disease caused by autoantibodies to type VII collagen (COL7)., Methods: Utilizing an in vitro experimental system, we screened a natural product library composed of 800 pure compounds for their inhibitory effect on COL7-anti-COL7 IgG immune complex (IC)-mediated neutrophil activation and on neutrophil-mediated tissue damage., Results: Three natural compounds, namely luteolin peracetate, gossypol, and gossypolone were capable in inhibiting the IC-induced neutrophil adhesion and oxygen burst in vitro . Furthermore, luteolin peracetate and gossypolone were able to inhibit the anti-COL7 IgG induced dermal-epidermal separation in an ex vivo model for EBA., Discussion: In summary, this study demonstrates that luteolin peracetate and gossypolone are potential therapeutics for experimental EBA, which deserves further investigation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yang, Yin, Yue, Bieber, Riemekasten, Ludwig, Petersen and Yu.)

A growing body of evidence underscores the relevance of functional autoantibodies in the development of various pathogenic conditions but also in the regulation of homeostasis. However, the definition of functional autoantibodies varies among studies and a comprehensive overview on this emerging topic is missing. Here, we do not only explain functional autoantibodies but also summarize the mechanisms underlying the effect of such autoantibodies including receptor activation or blockade, induction of receptor internalization, neutralization of ligands or other soluble extracellular antigens, and disruption of protein-protein interactions. In addition, in this review article we discuss potential triggers of production of functional autoantibodies, including infections, immune deficiency and tumor development. Finally, we describe the contribution of functional autoantibodies to autoimmune diseases including autoimmune thyroid diseases, myasthenia gravis, autoimmune pulmonary alveolar proteinosis, autoimmune autonomic ganglionopathy, pure red cell aplasia, autoimmune encephalitis, pemphigus, acquired thrombotic thrombocytopenic purpura, idiopathic dilated cardiomyopathy and systemic sclerosis, as well as non-autoimmune disorders such as allograft rejection, infectious diseases and asthma., Competing Interests: Declaration of Competing Interest The authors declare that there is no competing interests exist., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Age is a significant risk factor for the coronavirus disease 2019 (COVID-19) severity due to immunosenescence and certain age-dependent medical conditions (e.g., obesity, cardiovascular disorder, and chronic respiratory disease). However, despite the well-known influence of age on autoantibody biology in health and disease, its impact on the risk of developing severe COVID-19 remains poorly explored. Here, we performed a cross-sectional study of autoantibodies directed against 58 targets associated with autoimmune diseases in 159 individuals with different COVID-19 severity (71 mild, 61 moderate, and 27 with severe symptoms) and 73 healthy controls. We found that the natural production of autoantibodies increases with age and is exacerbated by SARS-CoV-2 infection, mostly in severe COVID-19 patients. Multiple linear regression analysis showed that severe COVID-19 patients have a significant age-associated increase of autoantibody levels against 16 targets (e.g., amyloid β peptide, β catenin, cardiolipin, claudin, enteric nerve, fibulin, insulin receptor a, and platelet glycoprotein). Principal component analysis with spectrum decomposition and hierarchical clustering analysis based on these autoantibodies indicated an age-dependent stratification of severe COVID-19 patients. Random forest analysis ranked autoantibodies targeting cardiolipin, claudin, and platelet glycoprotein as the three most crucial autoantibodies for the stratification of severe COVID-19 patients ≥50 years of age. Follow-up analysis using binomial logistic regression found that anti-cardiolipin and anti-platelet glycoprotein autoantibodies significantly increased the likelihood of developing a severe COVID-19 phenotype with aging. These findings provide key insights to explain why aging increases the chance of developing more severe COVID-19 phenotypes., (© 2023. Springer Nature Limited.)

The sequela of COVID-19 include a broad spectrum of symptoms that fall under the umbrella term post-COVID-19 condition or syndrome (PCS). Immune dysregulation, autoimmunity, endothelial dysfunction, viral persistence, and viral reactivation have been identified as potential mechanisms. However, there is heterogeneity in expression of biomarkers, and it is unknown yet whether these distinguish different clinical subgroups of PCS. There is an overlap of symptoms and pathomechanisms of PCS with postinfectious myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS). No curative therapies are available for ME/CFS or PCS. The mechanisms identified so far provide targets for therapeutic interventions. To accelerate the development of therapies, we propose evaluating drugs targeting different mechanisms in clinical trial networks using harmonized diagnostic and outcome criteria and subgrouping patients based on a thorough clinical profiling including a comprehensive diagnostic and biomarker phenotyping., Competing Interests: The Charité Universitaetsmedizin Berlin holds a patent for the use of vericiguat in Post-COVID Syndrome. CS, JB-S, CH, KW, ES, CaF, HPru, HPre, M-LM, HA, ChF, HZ, BS, CM, MT, AK, MR, MM, LS, FKo, FP, LB, and SB are employed at Charité Universitaetsmedizin Berlin. CM was employed by Labor Berlin - Charité Vivantes GmbH. The remaining authors declare that the research was conducted in the absence of any comercial or financial relationships that could be construed as a potential conflict of interest. The Handling Editor NS declared a past collaboration with the Author CS., (Copyright © 2023 Scheibenbogen, Bellmann-Strobl, Heindrich, Wittke, Stein, Franke, Prüss, Preßler, Machule, Audebert, Finke, Zimmermann, Sawitzki, Meisel, Toelle, Krueger, Aschenbrenner, Schultze, Beyer, Ralser, Mülleder, Sander, Konietschke, Paul, Stojanov, Bruckert, Hedderich, Knolle, Riemekasten, Vehreschild, Cornely, Behrends and Burock.)

Systemic sclerosis (SSc) is a chronic, multisystem connective tissue, and autoimmune disease with the highest case-specific mortality and complications among rheumatic diseases. It is characterized by complex and variable features such as autoimmunity and inflammation, vasculopathy, and fibrosis, which pose challenges in understanding the pathogenesis of the disease. Among the large variety of autoantibodies (Abs) present in the sera of patients suffering from SSc, functionally active Abs against G protein-coupled receptors (GPCRs), the most abundant integral membrane proteins, have drawn much attention over the last decades. These Abs play an essential role in regulating the immune system, and their functions are dysregulated in diverse pathological conditions. Emerging evidence indicates that functional Abs targeting GPCRs, such as angiotensin II type 1 receptor (AT1R) and the endothelin-1 type A receptor (ETAR), are altered in SSc. These Abs are part of a network with several GPCR Abs, such as those directed to the chemokine receptors or coagulative thrombin receptors. In this review, we summarize the effects of Abs against GPCRs in SSc pathologies. Extending the knowledge on pathophysiological roles of Abs against GPCRs could provide insights into a better understanding of GPCR contribution to SSc pathogenesis and therefore help in developing potential therapeutic strategies that intervene with pathological functions of these receptors., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Akbarzadeh, Müller, Humrich and Riemekasten.)

Objectives: Scleroderma renal crisis (SRC) is a rare vascular complication of systemic sclerosis with substantial risks for end-stage renal disease and premature death. Activating autoantibodies (Abs) targeting the angiotensin II type 1 (AT1R) and the endothelin-1 type A receptor (ETAR) have been identified as predictors for SRC. Here, we sought to determine their pathogenic significance for acute renal vascular injury potentially triggering kidney failure and malignant hypertension., Methods: IgG from patients with SRC was studied for AT1R and ETAR dependent biologic effects on isolated rat renal interlobar arteries and vascular cells including contraction, signalling and mechanisms of receptor activation., Results: In myography experiments, patient IgG exerted vasoconstriction sensitive to inhibition of AT1R and ETAR. This relied on MEK-ERK signalling indicating functional relevance of anti-AT1R and anti-ETAR Abs. The contractile response to angiotensin II and endothelin-1 was amplified by patient IgG containing anti-AT1R and anti-ETAR Abs with substantial crosstalk between both receptors implicating autoimmune receptor hypersensitization. Co-immunoprecipitation experiments indicated heterodimerization between both receptor types which may enable the observed functional interrelation by direct structural interactions., Conclusion: We provide experimental evidence that agonistic Abs may contribute to SRC. This effect is presumably related to direct receptor stimulation and additional allosteric effects, at least in heterodimeric receptor constellations. Novel therapies targeted at autoimmune hyperactivation of AT1R and ETAR might improve outcomes in severe cases of SRC., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Objectives: The prevalence and characteristics of SSc-associated interstitial lung disease (SSc-ILD) vary between geographical regions worldwide. The objectives of this study were to explore the differences in terms of prevalence, phenotype, treatment and prognosis in patients with SSc-ILD from predetermined geographical regions in the EUSTAR database., Material and Methods: Patients were clustered into seven geographical regions. Clinical characteristics and survival of patients with SSc-ILD were compared among these pre-determined regions., Results: For baseline analyses, 9260 SSc patients were included, with 6732 for survival analyses. The prevalence of SSc-ILD in the overall population was 50.2%, ranging from 44.0% in 'Western Europe and Nordic countries' to 67.5% in 'Eastern European, Russia and Baltic countries'. In all regions, anti-topoisomerase antibodies were associated with SSc-ILD. Management also significantly differed; mycophenolate mofetil was prescribed at baseline in 31.6% of patients with SSc-ILD in 'America (North and South)' and 31.7% in 'Middle East' but only 4.3% in 'Asia and Oceania' (P <0.0001). Patients from 'America (North and South)' and 'Middle East' had the highest survival rate at the end of follow-up (85.8% and 85.2%, respectively)., Conclusions: Our study highlights key differences among regions in terms of clinical presentation and prognosis of SSc-ILD. This work also demonstrates that the management of SSc-ILD is highly variable among the different regions considered, suggesting that efforts are still needed for the standardization of medical practice in the treatment of this disease., (© The Author(s) 2022. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

G protein-coupled receptors (GPCR) are involved in various physiological and pathophysiological processes. Functional autoantibodies targeting GPCRs have been associated with multiple disease manifestations in this context. Here we summarize and discuss the relevant findings and concepts presented in the biennial International Meeting on autoantibodies targeting GPCRs (the 4th Symposium), held in Lübeck, Germany, 15-16 September 2022. The symposium focused on the current knowledge of these autoantibodies' role in various diseases, such as cardiovascular, renal, infectious (COVID-19), and autoimmune diseases (e.g., systemic sclerosis and systemic lupus erythematosus). Beyond their association with disease phenotypes, intense research related to the mechanistic action of these autoantibodies on immune regulation and pathogenesis has been developed, underscoring the role of autoantibodies targeting GPCRs on disease outcomes and etiopathogenesis. The observation repeatedly highlighted that autoantibodies targeting GPCRs could also be present in healthy individuals, suggesting that anti-GPCR autoantibodies play a physiologic role in modeling the course of diseases. Since numerous therapies targeting GPCRs have been developed, including small molecules and monoclonal antibodies designed for treating cancer, infections, metabolic disorders, or inflammatory conditions, anti-GPCR autoantibodies themselves can serve as therapeutic targets to reduce patients' morbidity and mortality, representing a new area for the development of novel therapeutic interventions., (Copyright © 2023. Published by Elsevier B.V.)

Objective: To examine concentrations of circulating antibodies targeting C3a and C5a complement receptors in antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) and analyze their association with disease activity., Methods: Concentrations of antibodies against C3a and C5a complement receptors (anti-C3aR and anti-C5aR) and plasma complement fragments C3a and C5a were determined in patients with AAV (n = 110; granulomatosis with polyangiitis [GPA; n = 82] or microscopic polyangiitis [MPA; n = 28]), systemic lupus erythematosus (SLE) patients as disease controls (n = 36), and healthy donors (n = 220). C3aR and C5aR expression by circulating neutrophils, monocytes, and T cells was analyzed using flow cytometry. Clinical data were assessed at time of serum sampling and during follow-up for 60 months., Results: In AAV, anti-C3aR and anti-C5aR antibodies were decreased (P = 0.0026 and P ≤ 0.0001, respectively). In remission, anti-C3aR antibody concentrations rose to values comparable to healthy donors, whereas anti-C5aR antibody concentrations did not. In GPA, anti-C5a and anti-C5aR antibody concentrations inversely correlated with each other (r = -0.6831, P = 0.0127). In newly diagnosed GPA, decreased concentrations of anti-C5aR antibodies but not anti-C3aR antibodies were associated with disease activity (P = 0.0009). Moreover, low anti-C5aR antibodies were associated with relapse in GPA (hazard ratio 3.54, P = 0.0009) and MPA (hazard ratio 4.41, P = 0.0041). The frequency of C5aR-expressing cells within T cell populations was increased in GPA (P = 0.0021 for CD4+ T cells; P = 0.0118 for CD8+ T cells), but not in MPA., Conclusion: Low concentrations of anti-C5aR antibodies reflect disease activity and are associated with an increased risk for relapse in AAV., (© 2022 The Authors. Arthritis & Rheumatology published by Wiley Periodicals LLC on behalf of American College of Rheumatology.)