Inflammatory tissue priming: novel insights and therapeutic opportunities for inflammatory rheumatic diseases.

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 Moreover, the risk for flares strongly increases once anti-inflammatory therapy is tapered or withdrawn, suggesting that underlying pathological processes remain active even in the absence of overt inflammation.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.

Autoantibodies against the chemokine receptor 3 predict cardiovascular risk.

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.

Recommendations for defining giant cell arteritis fast-track clinics. English version.

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.

[Recommendations for defining giant cell arteritis fast-track clinics]. / Empfehlungen zur Definition von Riesenzellarteriitis-Fast-Track-Kliniken.

An expert committee recommends defining fast-track clinics (FTC) for the acute diagnostics of giant cell arteritis (GCA) as follows: low-threshold, 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 fast performance of neurological and ophthalmological examinations, magnetic resonance imaging (MRI), positron emission tomography-computed tomography (PET-CT, possibly CT) and for temporal artery biopsy.

[Immune-mediated inflammatory diseases in Germany : A cross-sectional analysis of comorbidities and pharmacotherapy]. / Chronische Entzündungserkrankungen in Deutschland : Eine Querschnittanalyse über Begleiterkrankungen und Arzneimitteleinsatz.

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.

Low-dose interleukin-2 therapy: a promising targeted therapeutic approach for systemic lupus erythematosus.

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.

Cross-sectional analysis reveals autoantibody signatures associated with COVID-19 severity.

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.

Autoimmune activation and hypersensitization of the AT1 and ETA receptors contributes to vascular injury in scleroderma renal crisis.

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.

Late skin fibrosis in systemic sclerosis: a study from the EUSTAR cohort.

OBJECTIVES: The early trajectory of skin fibrosis provides insights into the disease course of systemic sclerosis (SSc) including mortality; however, little is known about late skin fibrosis. The aims of our study were to ascertain the prevalence and characteristics of late skin fibrosis in SSc. METHODS: We developed and tested three conceptual scenarios of late (>5 years after first non-RP feature) skin fibrosis including new worsening of skin disease, and failure to improve after worsening within 5-year window. We defined skin worsening as change in modified Rodnan skin score (mRSS) ≥5 units or ≥25%. Using strict inclusion criteria including complete mRSS, we identified 1,043 (out of 19 115) patients within the EUSTAR database for our analysis. We further restricted analysis within 887 (out of 1043) patients who had lcSSc or dcSSc at baseline. RESULTS: One-fifth of patients among the whole cohort (n = 208/1043, 19.9%) experienced mRSS worsening, including in patients with lcSSc or dcSSc at baseline (n = 193/887, 21.8%). This was largely due to new skin worsening after the 5-year window or failure to improve with worsening within the 5-year window. Patients with lower baseline mRSS and lcSSc were more likely to develop late skin fibrosis. Anti-Scl-70 was associated with progression from baseline lcSSc to dcSSc, and anticentromere was protective. CONCLUSIONS: Late skin fibrosis is not uncommon in SSc. We have identified different patterns relevant to clinical practice and trial design. Late skin fibrosis is a neglected manifestation of SSc and warrants further investigation including to determine clinical outcomes and optimal therapeutic strategy.

Systemic sclerosis-associated interstitial lung disease in the EUSTAR database: analysis by region.

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.

Anti-acid therapy in SSc-associated interstitial lung disease: long-term outcomes from the German Network for Systemic Sclerosis.

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.

Spectrum of ANCA-specificities in eosinophilic granulomatosis with polyangiitis. A retrospective multicentre study.

OBJECTIVES: To determine the spectrum of anti-neutrophil cytoplasmic antibody (ANCA) antigen-specificities in eosinophilic granulomatosis with polyangiitis (EGPA), an ANCA-associated vasculitis (AAV) entity. METHODS: We conducted a retrospective analysis of 73 EGPA patients from three German tertiary referral centres for vasculitis. In addition to in-house ANCA testing, pentraxin 3 (PTX3)- and olfactomedin 4 (OLM4)-ANCA were determined using a prototype cell-based assay for research (EUROIMMUN, Lübeck, Germany). Patient characteristics and clinical manifestations were evaluated and compared based on ANCA status. RESULTS: Myeloperoxidase (MPO)-ANCA positive patients (n=8; 11%) significantly more frequently displayed peripheral nervous system (PNS) and pulmonary involvement and less frequently heart involvement compared to MPO-ANCA negative patients. PTX3-ANCA positive patients (n=5; 6.8%) had a significantly higher prevalence of ear, nose and throat, pulmonary, gastrointestinal and PNS involvement, and a lower prevalence of renal and central nervous system involvement compared to PTX3-ANCA negative patients. Proteinase 3 (PR3)-ANCA and OLM4-ANCA were detected in 2 patients (2.7%) each with multiorgan involvement. One PR3-ANCA positive patient was also positive for bactericidal permeability increasing protein (BPI)-ANCA. CONCLUSIONS: In addition to MPO, the spectrum of ANCA antigen specificities includes various other target antigens such as PR3, BPI, PTX3, and OLM4, potentially segregating further EGPA subgroups. A lower prevalence of MPO-ANCA was detected in this study compared with other studies. OLM4 is reported as novel ANCA antigen-specificity in EGPA, and thus AAV.

[Epidemiological data and medical care situation of patients with chronic inflammatory diseases in Germany : Real-world evidence on prevalence, disease combinations, care]. / Epidemiologische Daten und medizinische Versorgungssituation von Patienten mit chronischen Entzündungserkrankungen in Deutschland : Real-World-Evidenz zu Prävalenz, Erkrankungskombinationen, Versorgung.

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.

Low-dose interleukin-2 therapy in active systemic lupus erythematosus (LUPIL-2): a multicentre, double-blind, randomised and placebo-controlled phase II trial.

OBJECTIVES: A regulatory T cell (Treg) insufficiency due to shortage of interleukin-2 (IL-2) is central to the pathophysiology of systemic lupus erythematosus (SLE). We performed a multicentre, double-blinded, randomised, placebo-controlled phase II proof-of-concept trial to evaluate the efficacy of low-dose IL-2 therapy in patients with SLE having moderate-to-severe disease activity while receiving standard treatment. METHODS: We randomly assigned 100 patients in a 1:1 ratio to receive either 1.5 million IU/day of subcutaneous IL-2 (ILT-101) or placebo for 5 days followed by weekly injections for 12 weeks. Clinical efficacy was assessed at week 12 in a predefined hierarchical analysis of (1) the SLE responder index-4 (SRI-4) response as a primary end point, and of (2) relative and (3) absolute changes in the Safety of Estrogens in Lupus Erythematosus National Assessment-Systemic Lupus Erythematosus Disease Activity Index scores as key secondary end points. RESULTS: The primary end point was not met in the intention-to-treat population (ILT-101: 68%, placebo: 58%; p=0.3439), due to a 100% SRI-4 response rate in the placebo group from the two sites from Bulgaria. A post hoc per-protocol analysis on a prespecified population that excluded patients from these two sites (n=53) showed a statistically significant difference for the SRI-4 response rate (ILT-101: 83.3%; placebo: 51.7%; p=0.0168), and for the two key secondary end points, accompanied by differences in several secondary exploratory end points. ILT-101 was well tolerated and there was no generation of antidrug antibodies. CONCLUSIONS: The post hoc hierarchical analysis of the primary and key secondary end points in a per-protocol population, complemented by the exploratory analyses of multiple other secondary end points, support that low-dose IL-2 is beneficial in active SLE. TRIAL REGISTRATION NUMBER: NCT02955615.

Induced antibodies directed to the angiotensin receptor type 1 provoke skin and lung inflammation, dermal fibrosis and act species overarching.

OBJECTIVE: To determine contributions and functions of autoantibodies (Abs) directed to the angiotensin receptor type 1 (AT1R), which are suggested to be involved in the pathogenesis of AT1R Abs-related diseases such as systemic sclerosis (SSc). METHODS: C57BL/6J mice were immunised with membrane-embedded human AT1R or empty membrane as control. Mice deficient for CD4+ or CD8+ T cells and B cells were immunised with membrane-embedded AT1R or an AT1R peptide proposed to be a dominant T cell epitope. A monoclonal (m)AT1R Ab was generated by hybridoma technique and transferred into C57BL/6J and AT1Ra/b knockout mice. The induced phenotype was examined by histology, immunohistochemistry, immunofluorescence, apoptosis assay and ELISA. In vitro, Abs responses towards AT1R were measured in cells of different origins and species. RESULTS: AT1R-immunised mice developed perivascular skin and lung inflammation, lymphocytic alveolitis, weak lung endothelial apoptosis and skin fibrosis accompanied by Smad2/3 signalling, not present in controls or mice deficient for CD4+ T and B cells. The AT1R peptide 149-172 provoked lung inflammation. Application of the mAT1R Ab induced skin and lung inflammation, not observed in AT1Ra/b knockout mice. In vitro, AT1R Abs activated rat cardiomyocytes and human monocytes, enhanced angiotensin II-mediated AT1R activation in AT1R-transfected HEK293 cells via AT1R binding and mAT1R Ab-activated monocytes mediated the induction of profibrotic markers in dermal fibroblasts. CONCLUSION: Our immunisation strategy successfully induced AT1R Abs, contributing to inflammation and, possibly, to fibrosis via activation of AT1R. Therefore, AT1R Abs are valuable targets for future therapies of SSc and other AT1R Ab-related diseases.

Phenotype of limited cutaneous systemic sclerosis patients with positive anti-topoisomerase I antibodies: data from the EUSTAR cohort.

OBJECTIVES: To characterize patients with positive anti-topoisomerase I (ATA) in lcSSc. METHODS: SSc patients enrolled in the EUSTAR cohort with a disease duration of ≤3 years at database entry were considered. We assessed the risk of major organ involvement in the following groups: ATA-lcSSc vs ACA-lcSSc and vs ANA without specificity (ANA)-lcSSc, and ATA-lcSSc vs ATA-dcSSc. Cox regression models with time-dependent covariates were performed with the following outcomes: new-onset interstitial lung disease (ILD), ILD progression [forced vital capacity (FVC) decline ≥10% and ≥5% vs values at ILD diagnosis), primary myocardial involvement (PMI), pulmonary hypertension (PH), any organ involvement and all-cause mortality. RESULTS: We included 1252 patients [194 ATA-lcSSc (15.5%)], with 7.7 years (s.d. 3.5) of follow-up. ILD risk was higher in ATA-lcSSc vs ACA- and ANA-lcSSc and similar to ATA-dcSSc, although with less frequent restrictive lung disease. The risk of FVC decline ≥10% (35% of ATA-lcSSc) was lower in ATA-lcSSc than in ATA-dcSSc, whereas FVC decline ≥5% occurs similarly between ATA-lcSSc (58% of patients) and other SSc subsets, including ATA-dcSSc. The risk of PMI was similar in ATA-lcSSc and ANA-lcSSc but lower than in ACA-lcSSc; no difference in PH and mortality risk was observed among lcSSc subsets. The risk of any organ involvement, PMI and PH was lower and the mortality tended to be lower in ATA-lcSSc vs ATA-dcSSc. CONCLUSION: ATA-lcSSc patients have a high risk of ILD, albeit with a lower risk of progression compared with ATA-dcSSc, supporting careful screening for ILD in this subgroup.

Molecular Effects of Auto-Antibodies on Angiotensin II Type 1 Receptor Signaling and Cell Proliferation.

The angiotensin II (Ang II) type 1 receptor (AT1R) is involved in the regulation of blood pressure (through vasoconstriction) and water and ion homeostasis (mediated by interaction with the endogenous agonist). AT1R can also be activated by auto-antibodies (AT1R-Abs), which are associated with manifold diseases, such as obliterative vasculopathy, preeclampsia and systemic sclerosis. Knowledge of the molecular mechanisms related to AT1R-Abs binding and associated signaling cascade (dys-)regulation remains fragmentary. The goal of this study was, therefore, to investigate details of the effects of AT1R-Abs on G-protein signaling and subsequent cell proliferation, as well as the putative contribution of the three extracellular receptor loops (ELs) to Abs-AT1R signaling. AT1R-Abs induced nuclear factor of activated T-cells (NFAT) signaling, which reflects Gq/11 and Gi activation. The impact on cell proliferation was tested in different cell systems, as well as activation-triggered receptor internalization. Blockwise alanine substitutions were designed to potentially investigate the role of ELs in AT1R-Abs-mediated effects. First, we demonstrate that Ang II-mediated internalization of AT1R is impeded by binding of AT1R-Abs. Secondly, exclusive AT1R-Abs-induced Gq/11 activation is most significant for NFAT stimulation and mediates cell proliferation. Interestingly, our studies also reveal that ligand-independent, baseline AT1R activation of Gi signaling has, in turn, a negative effect on cell proliferation. Indeed, inhibition of Gi basal activity potentiates proliferation triggered by AT1R-Abs. Finally, although AT1R containing EL1 and EL3 blockwise alanine mutations were not expressed on the human embryonic kidney293T (HEK293T) cell surface, we at least confirmed that parts of EL2 are involved in interactions between AT1R and Abs. This current study thus provides extended insights into the molecular action of AT1R-Abs and associated mechanisms of interrelated pathogenesis.

Nuclear antigen-reactive CD4+ T cells expand in active systemic lupus erythematosus, produce effector cytokines, and invade the kidneys.

Systemic lupus erythematosus is a systemic and chronic autoimmune disease characterized by loss of tolerance towards nuclear antigens with autoreactive CD4+ T cells implicated in disease pathogenesis. However, very little is known about their receptor specificity since the detection of human autoantigen specific CD4+ T cells has been extremely challenging. Here we present an analysis of CD4+ T cells reactive to nuclear antigens using two complementary methods: T cell libraries and antigen-reactive T cell enrichment. The frequencies of nuclear antigen specific CD4+ T cells correlated with disease severity. These autoreactive T cells produce effector cytokines such as interferon-γ, interleukin-17, and interleukin-10. Compared to blood, these cells were enriched in the urine of patients with active lupus nephritis, suggesting an infiltration of the inflamed kidneys. Thus, these previously unrecognized characteristics support a role for nuclear antigen-specific CD4+ T cells in systemic lupus erythematosus.

Progressive interstitial lung disease in patients with systemic sclerosis-associated interstitial lung disease in the EUSTAR database.

OBJECTIVES: To identify overall disease course, progression patterns and risk factors predictive for progressive interstitial lung disease (ILD) in patients with systemic sclerosis-associated ILD (SSc-ILD), using data from the European Scleroderma Trials And Research (EUSTAR) database over long-term follow-up. METHODS: Eligible patients with SSc-ILD were registered in the EUSTAR database and had measurements of forced vital capacity (FVC) at baseline and after 12±3 months. Long-term progressive ILD and progression patterns were assessed in patients with multiple FVC measurements. Potential predictors of ILD progression were analysed using multivariable mixed-effect models. RESULTS: 826 patients with SSc-ILD were included. Over 12±3 months, 219 (27%) showed progressive ILD: either moderate (FVC decline 5% to 10%) or significant (FVC decline >10%). A total of 535 (65%) patients had multiple FVC measurements available over mean 5-year follow-up. In each 12-month period, 23% to 27% of SSc-ILD patients showed progressive ILD, but only a minority of patients showed progression in consecutive periods. Most patients with progressive ILD (58%) had a pattern of slow lung function decline, with more periods of stability/improvement than decline, whereas only 8% showed rapid, continuously declining FVC; 178 (33%) experienced no episode of FVC decline. The strongest predictive factors for FVC decline over 5 years were male sex, higher modified Rodnan skin score and reflux/dysphagia symptoms. CONCLUSION: SSc-ILD shows a heterogeneous and variable disease course, and thus monitoring all patients closely is important. Novel treatment concepts, with treatment initiation before FVC decline occurs, should aim for prevention of progression to avoid irreversible organ damage.

Immunoglobulin G of systemic sclerosis patients programs a pro-inflammatory and profibrotic phenotype in monocyte-like THP-1 cells.

OBJECTIVES: Functional IgG autoantibodies against diverse G protein-coupled receptors, i.e. antibodies with agonistic or antagonistic activity at these receptors, are abundant in human serum. Their levels are altered in patients with SSc, and autoantibodies against angiotensin II receptor 1 (ATR1) and endothelin receptor A (ETA) have been suggested to drive SSc by inducing the chemokines CXCL8 and CCL18 in the blood. The objective of our study is to profile the effect of IgG in SSc (SSc-IgG) on the production of soluble mediators in monocytic cells. METHODS: Monocyte-like THP-1 cells were stimulated with SSc-IgG and their secretome was analysed. Furthermore, the significance of major pro-inflammatory pathways for the induction of CXCL8 and CCL18 in response to SSc-IgG was assessed by a pharmacological approach. RESULTS: Stimulation with SSc-IgG significantly alters the secretome of THP-1 cells towards a general pro-inflammatory and profibrotic phenotype, which includes an increase of CCL18 and CXCL8. The consequent expression profiles vary depending on the individual donor of the SSc-IgG. CCL18 and CXCL8 expression is thus regulated differentially, with AP-1 driving the induction of both CCL18 and CXCL8 and the TAK/IKK-ß/NF-κB pathway and ERK1/2 driving that of CXCL8. CONCLUSIONS: Our results suggest that SSc-IgG contributes to the generation of the pro-inflammatory/profibrotic tissue milieu characteristic of SSc by its induction of a respective phenotype in monocytes. Furthermore, our results highlight AP-1 as a critical regulator of gene transcription of CCL18 in monocytic cells and as a promising pharmacological therapeutic target for the treatment of SSc.