Untangling the relationship between smoking and systemic sclerosis: an analysis of the EUSTAR cohort.

OBJECTIVES: To untangle the association between smoking and systemic sclerosis (SSc). METHODS: In the European Scleroderma Trials and Research cohort, the autoantibody status was compared between ever-smokers and never-smokers. Time until disease progression was assessed using Kaplan-Meier curves. Cox models were built to investigate the influence of smoking over 15 years of follow-up. All analyses were performed for the total cohort and stratified for sex and for positivity of anti-centromere (ACA) and anti-topoisomerase antibodies (ATA). RESULTS: Overall, 12 314 patients were included in the study. Of these, 10 393 were women (84%), 4637 were ACA-positive (38%), 3919 were ATA-positive (32%) and 4271 (35%) were ever-smokers. In men, but not in women, smoking was associated with mortality (HR 1.63, 95% CI 1.23 to 2.16, p=0.001). Ever-smoking women were at higher risk for skin progression (HR 1.10, 95% CI 1.00 to 1.22, p=0.046) and for 'any organ progression' (HR 1.07, 95% CI 1.00 to 1.13, p=0.036). In women, 34% of never-smokers were ATA-positive compared with 21% of ever-smokers (p<0.001). In the group of ever-smokers, higher exposure rates, reflected by the number of pack-years (OR 0.98, 95% CI 0.97 to 0.99, p<0.001) and by smoking duration (OR 0.96, 95% CI 0.95 to 0.97, p<0.001), were associated with lower frequency of ATA. In ACA-positive patients, the risk of mortality (HR 1.29, 95% CI 1.02 to 1.63, p=0.033), cardiac involvement (HR 1.25, 95% CI 1.03 to 1.43, p=0.001), skin progression (HR 1.21, 95% CI 1.03 to 1.42, p=0.018) and 'any organ progression' (HR 1.14, 95% CI 1.05 to 1.24, p=0.002) was increased among smokers. In ATA-positive smoking patients, mortality (HR 1.40, 95% CI 1.10 to 1.78, p=0.006), skin progression (HR 1.19, 95% CI 1.03 to 1.37, p=0.020) digital ulcers (HR 1.17, 95% CI 1.02 to 1.34, p=0.029) and 'any organ progression' (HR 1.11, 95% CI 1.00 to 1.22, p=0.048) occurred more frequently. CONCLUSIONS: Our stratified analysis demonstrates that smoking is associated with an increased risk for mortality in male SSc patients but not in women. Strikingly, smoking is associated with lower prevalence of ATA positivity, in particular in women. In both ATA-positive and ACA-positive patients, smoking is a risk factor for mortality, skin progression and 'any organ progression'.

The Performance of Pulmonary Function Tests in Predicting Systemic Sclerosis-Interstitial Lung Disease in the European Scleroderma Trial and Research Database.

BACKGROUND AND OBJECTIVES: In SSc, ILD is a major cause of morbidity and mortality. We aimed to investigate the performance of DLCO (diffusing capacity of lung carbon monoxide) and FVC (forced vital capacity) delta change (Δ) and baseline values in predicting the development of SSc-ILD. METHODS: Longitudinal data of DLCO, FVC, and ILD on the HRCT of SSc patients from the EUSTAR database were evaluated at baseline (t0) and after 12 (±4) (t1) and 24 (±4) (t2) months. RESULTS: 474/17805 patients were eligible for the study (403 females); 46 (9.7%) developed ILD at t2. Positivity for anti-topoisomerase antibodies (117 patients) showed an association with ILD development at t2 (p = 0.0031). Neither the mean t0 to t1 change (Δ) of DLCO nor the mean t0 to t1 FVCΔ predicted the appearance of ILD at t2. Investigating the possible role of baseline DLCO and FVC values in predicting ILD appearance after 24 (±4) months, we observed a moderate predictive capability of t0 DLCO < 80%, stronger than that of FVC < 80%. CONCLUSIONS: We suggest that an impaired baseline DLCO may be predictive of the appearance of ILD after 2 years of follow-up. This result advances the hypothesis that a reduction in gas exchange may be considered an early sign of lung involvement. However, further rigorous studies are warranted to understand the predictive role of DLCO evaluation in the course of SSc.

Does the Impact of COVID-19 on Patients With Systemic Sclerosis Change Over Time?

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.

Sex-specific difference in cardiac function in patients with systemic sclerosis: association with cardiovascular outcomes.

BACKGROUND: Cardiovascular involvement is one of the leading causes of mortality in systemic sclerosis (SSc) and is reported to be higher in men as compared with women. However, the cause of this difference is largely unknown. The objective of this study was to assess sex differences in echocardiographic characteristics, including left ventricular global longitudinal strain (LV GLS), as a potential explanation of sex differences in outcomes. METHODS: A total of 746 patients with SSc from four centres, including 628 (84%, 54±13 years) women and 118 (16%, 55±15 years) men, were evaluated with standard and advanced echocardiographic examinations. The independent association of the echocardiographic parameters with the combined endpoint of cardiovascular events-hospitalisation/death was evaluated. RESULTS: Men and women with SSc showed significant differences in disease characteristics and cardiac function. After adjusting for the most important clinical characteristics, while LV ejection fraction and diastolic function were not significantly different anymore, men still presented with more impaired LV GLS as compared with women (-19% (IQR -20% to -17%) vs -21% (IQR: -22% to -19%), p<0.001). After a median follow-up of 48 months (IQR: 26-80), the combined endpoint occurred in 182 patients. Men with SSc experienced higher cumulative rates of cardiovascular events-hospitalisation/mortality (χ2=8.648; Log-rank=0.003), and sex differences were maintained after adjusting for clinical confounders, but neutralised when matching the groups for LV GLS. CONCLUSION: In patients with SSc, male sex is associated with worse cardiovascular outcomes even after adjusting for important clinical characteristics. LV GLS was more impaired in men as compared with women and potentially explains the sex difference in cardiovascular outcomes.

The long-term course of the Health Assessment Questionnaire in patients with systemic sclerosis.

Objective: The Health Assessment Questionnaire-Disability Index is an important outcome measure reflecting functional disability, but knowledge on its course over time in patients with systemic sclerosis is scarce. Therefore, we investigated the long-term course of the Health Assessment Questionnaire-Disability Index and its association with baseline characteristics in systemic sclerosis patients. Methods: Systemic sclerosis patients, fulfilling the European League Against Rheumatism and the American College of Rheumatology 2013 criteria, were included from the Leiden Combined Care in Systemic Sclerosis cohort with annual assessments including the Scleroderma Health Assessment Questionnaire-Disability Index (range = 0-3). The course of the Health Assessment Questionnaire-Disability Index was evaluated over the total follow-up (baseline to last available Health Assessment Questionnaire-Disability Index) and between yearly visits. Based on a minimal clinical important difference of 0.22, courses were categorized into worsening, stable or improvement. The course of the Health Assessment Questionnaire-Disability Index over time was evaluated with linear mixed models. Baseline characteristics were compared between patients with a worsening or improvement of the Health Assessment Questionnaire-Disability Index over the total follow-up period with logistic regression analyses. Results: A total of 517 systemic sclerosis patients were included, with a median follow-up of 7 years (interquartile range = 4-9; 2649 visits) and a baseline Health Assessment Questionnaire-Disability Index of 0.625 (interquartile range = 0.125-1.25). On group level, the Health Assessment Questionnaire-Disability Index is stable with an annual increase of 0.019 (95% confidence interval = 0.011 to 0.027). Looking at subgroups, patients >65 years or who died/were physically unable to come during follow-up had a worse mean Health Assessment Questionnaire-Disability Index. In individual courses from baseline to the last follow-up, the proportions of patients with a clinically meaningful worsening, stable or improved Health Assessment Questionnaire-Disability Index were 35%, 42% and 23%, respectively. Patients with immunosuppressants (odds ratio = 0.5, 95% confidence interval = 0.3 to 0.9) or gastrointestinal involvement (odds ratio = 0.6, 95% confidence interval = 0.4 to 0.9) at baseline showed a reduced chance of worsening of the Health Assessment Questionnaire-Disability Index over the total follow-up period. Conclusion: Over time, the average course of the Health Assessment Questionnaire-Disability Index was stable in systemic sclerosis patients. However, individual courses vary, with worsening occurring in one-third. Worsening occurred less often in individuals using immunosuppressants or with gastrointestinal involvement at baseline.

Anti-topoisomerase, but not anti-centromere B cell responses in systemic sclerosis display active, Ig-secreting cells associated with lung fibrosis.

OBJECTIVES: Almost all patients with systemic sclerosis (SSc) harbour autoantibodies. Anti-topoisomerase antibodies (ATA) and anti-centromere antibodies (ACA) are most prevalent and associate with distinct clinical phenotypes. B cell responses underlying these phenotypes are ill-defined. To understand how B cell autoreactivity and disease pathology connect, we determined phenotypic and functional characteristics of autoreactive B cells in ATA-positive and ACA-positive patients. METHODS: Levels and isotypes of autoantibodies secreted by ex vivo cultured peripheral blood mononuclear cells from patients with ATA-positive (n=22) and ACA-positive (n=20) SSc were determined. Antibody secreting cells (ASCs) were isolated by cell sorting and cultured separately. Correlations were studied between the degree of spontaneous autoantibody production and the presence and degree of interstitial lung disease (ILD). RESULTS: Circulating B cells secreting either ATA-immunoglobulin G (IgG) or ACA-IgG on stimulation was readily detectable in patients. The ATA response, but not the ACA response, showed additional secretion of autoreactive IgA. ATA-IgG and ATA-IgA were also secreted spontaneously. Additional cell sorting confirmed the presence of ATA-secreting plasmablasts. The degree of spontaneous ATA-secretion was higher in patients with ILD than in those without (p<0.001) and correlated with the degree of pulmonary fibrosis (p<0.001). CONCLUSION: In contrast to ACA-positive patients, ATA-positive patients show signs of recent activation of the B cell response that hallmarks this disease. The degree of activation correlates with the presence and severity of ILD, the most deleterious disease manifestation. This could explain differential responsiveness to B cell depleting therapy. The abundant and spontaneous secretion of ATA-IgG and ATA-IgA may point toward a continuously activating trigger.

Anti-carbamylated protein antibodies in systemic sclerosis.

BACKGROUND: To investigate the presence of different isotypes of anti-carbamylated protein (CarP) antibodies in systemic sclerosis (SSc) patients and its association with skin involvement. METHODS: Sera of 194 SSc patients from the Leiden CCISS cohort, fulfilling ACR/EULAR 2013 criteria and a clinical diagnosis of SSc, 83 patients with other connective tissue diseases/Raynaud's Phenomenon, 24 rheumatoid arthritis patients and 98 age and sex-matched healthy controls were tested for the presence of anti-CarP IgG, IgA and IgM, determined by ELISA. Clinical characteristics, that were evaluated in SSc patients, included age, anti-topoisomerase antibodies (ATA), anti-centromere antibodies (ACA) and modified Rodnan Skin Score (mRSS). RESULTS: The SSc patients were 55 (SD:13) years and 155 (80%) were female. Forty-four (23%) patients tested positive for ATA, and 80 (42%) ACA. The median mRSS was 2 (range: 0; 47). Prevalence of anti-CarP IgG was higher in SSc patients than in healthy controls (8% vs 3%, p = 0.007. Prevalence of anti-CarP IgA and IgM and levels of anti-CarP isotypes were comparable between SSc patients and healthy controls. Fifteen (8%) SSc patients tested positive for anti-CarP IgG, 16 (8%) for anti-CarP IgA, and 36 (19%) for anti-CarP IgM. There were no significant correlations between age and levels of anti-CarP isotypes. No correlation between anti-CarP IgG levels and mRSS was found (r = 0.141, p = 0.049), nor for anti-CarP IgM and IgA levels. Anti-CarP IgA levels were higher in ATA compared to ACA positive SSc patients (ATA: 616 aU/ml [359; 1103]; ACA: 424 aU/ml [300; 673], p = 0.015). CONCLUSION: SSc patients can test positive for Anti-CarP IgG, IgA and IgM. We do not observe a relevant clinical association between anti-CarP antibody response and skin involvement in SSc.

Tricuspid Annular Plane Systolic Excursion/Systolic Pulmonary Artery Pressure Ratio and Cardiorenal Syndrome Type 2 in the Systemic Sclerosis EUSTAR Cohort.

OBJECTIVE: The aim of the study was to evaluate the association between the tricuspid annular plane systolic excursion (TAPSE)/systolic pulmonary artery pressure (sPAP) ratio and estimated glomerular filtration rate (eGFR) and their association with mortality in the European Scleroderma Trials and Research (EUSTAR) cohort. METHODS: Patients with systemic sclerosis (SSc) from the EUSTAR database with TAPSE, sPAP, and parameters required to calculate eGFR were included. Logistic regression and Cox regression analysis were performed to evaluate TAPSE/sPAP as a risk factor for chronic kidney disease (CKD) and overall survival. RESULTS: A total of 2,370 patients with SSc were included; 284 (12%) patients had CKD stage 3a-5. TAPSE/sPAP (odds ratio [OR] 0.479; 95% CI 0.310-0.743; P < 0.001), arterial hypertension (OR 3.118; 95% CI 2.173-4.475; P < 0.001), diastolic dysfunction (OR 1.670; 95% CI 1.148-2.428; P < 0.01), and N-terminal pro-B-type natriuretic peptide (OR 1.165; 95% CI 1.041-1.304; P < 0.01) were associated with CKD stage 3a-5. TAPSE/sPAP ≤0.32 mm/mm Hg (hazard ratio [HR] 3.589; 95% CI 2.236-5.761; P < 0.001), eGFR <60 mL/min per 1.73 m2 (HR 2.818; 95% CI 1.777-4.468; P < 0.001), and age (HR 1.782; 95% CI 1.348-2.356; P < 0.001) were the most significant predictive factors for all-cause mortality. A total of 276 patients with SSc had pulmonary hypertension (PH) confirmed by right heart catheterization, with 69 (25%) having CKD stage 3a-5. No difference was found in eGFR between patients with PH with reduced or normal cardiac index. CONCLUSION: Reduced TAPSE/sPAP ratio is independently associated with CKD. TAPSE/sPAP ratio ≤0.32 mm/mm Hg and eGFR <60 mL/min per 1.73 m2 are prognostic factors for all-cause mortality. In patients with SSc with PH, eGFR is independent by reduced cardiac output.

Cutaneous Manifestations, Clinical Characteristics, and Prognosis of Patients With Systemic Sclerosis Sine Scleroderma: Data From the International EUSTAR Database.

Importance: Systemic sclerosis (SSc) sine scleroderma (ssSSc) is a subset of SSc defined by the absence of skin fibrosis. Little is known about the natural history and skin manifestations among patients with ssSSc. Objective: To characterize the clinical phenotype of patients with ssSSc compared with patients with limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) within the EUSTAR database. Design, Setting, and Participants: This longitudinal observational cohort study based on the international EUSTAR database included all patients fulfilling the classification criteria for SSc assessed by the modified Rodnan Skin score (mRSS) at inclusion and with at least 1 follow-up visit; ssSSc was defined by the absence of skin fibrosis (mRSS = 0 and no sclerodactyly) at all available visits. Data extraction was performed in November 2020, and data analysis was performed from April 2021 to April 2023. Main Outcomes and Measures: Main outcomes were survival and skin manifestations (onset of skin fibrosis, digital ulcers, telangiectasias, puffy fingers). Results: Among the 4263 patients fulfilling the inclusion criteria, 376 (8.8%) were classified as having ssSSc (mean [SD] age, 55.3 [13.9] years; 345 [91.8%] were female). At last available visit, in comparison with 708 patients with lcSSc and 708 patients with dcSSc with the same disease duration, patients with ssSSc had a lower prevalence of previous or current digital ulcers (28.2% vs 53.1% in lcSSc; P < .001; and 68.3% in dcSSc; P < .001) and puffy fingers (63.8% vs 82.4% in lcSSc; P < .001; and 87.6% in dcSSc; P < .001). By contrast, the prevalence of interstitial lung disease was similar in ssSSc and lcSSc (49.8% and 57.1%; P = .03) but significantly higher in dcSSc (75.0%; P < .001). Skin telangiectasias were associated with diastolic dysfunction in patients with ssSSc (odds ratio, 4.778; 95% CI, 2.060-11.081; P < .001). The only independent factor for the onset of skin fibrosis in ssSSc was the positivity for anti-Scl-70 antibodies (odds ratio, 3.078; 95% CI, 1.227-7.725; P = .02). Survival rate was higher in patients with ssSSc (92.4%) compared with lcSSc (69.4%; P = .06) and dcSSc (55.5%; P < .001) after up to 15 years of follow-up. Conclusions and Relevance: Systemic sclerosis sine scleroderma should not be neglected considering the high prevalence of interstitial lung disease (>40%) and SSc renal crisis (almost 3%). Patients with ssSSc had a higher survival than other subsets. Dermatologists should be aware that cutaneous findings in this subgroup may be associated with internal organ dysfunction. In particular, skin telangiectasias in ssSSc were associated with diastolic heart dysfunction.

Association of endothelial to mesenchymal transition and cellular senescence with fibrosis in skin biopsies of systemic sclerosis patients: a cross-sectional study.

OBJECTIVES: Fibrosis is the dominant hallmark of systemic sclerosis (SSc). Several mechanisms have been proposed to drive the disease process, but how these relate to skin fibrosis is poorly understood. METHODS: We performed a cross-sectional study on archival skin biopsies from 18 SSc patients and four controls. Dermal fibrosis and inflammatory cell infiltration were scored in HE and Masson's Trichrome-stained sections. The presence of senescence was defined by P21 and/or P16 positivity in Ki-67 negative cells. Endothelial to mesenchymal transition (EndMT) was identified by co-localisation of CD31 and α-SMA in immunofluorescent double-stained sections, and by an enclosure of ERG positive endothelial cell nuclei by α-SMA stained cytoplasm in immunohistochemical double staining. RESULTS: The histological dermal fibrosis score of SSc skin biopsies was correlated with the modified Rodnan skin score (rho 0.55, p=0.042). Staining for markers of cellular senescence on fibroblasts was correlated with fibrosis score, inflammatory score, and CCN2 staining on fibroblasts. Moreover, EndMT was more abundant in skin from patients with SSc (p<0.01) but did not differ between groups with different fibrosis severity. The frequency of these EndMT features increased with the abundance of senescence markers and CCN2 on fibroblasts and dermal inflammation. CONCLUSIONS: EndMT and fibroblast senescence were more abundant in skin biopsies from SSc patients. This finding indicates that both senescence and EndMT are involved in the pathway leading to skin fibrosis and might be valuable biomarkers and/or possible targets for novel therapeutic interventions.

Efficacy and Safety of Lenabasum, a Cannabinoid Type 2 Receptor Agonist, in a Phase 3 Randomized Trial in Diffuse Cutaneous Systemic Sclerosis.

OBJECTIVE: This phase 3 study was undertaken to investigate the efficacy and safety of lenabasum, a cannabinoid type 2 receptor agonist, in patients with diffuse cutaneous systemic sclerosis (dcSSc). METHODS: A multinational double-blind study was conducted in 365 dcSSc patients who were randomized and dosed 1:1:1 with lenabasum 20 mg, lenabasum 5 mg, or placebo, each twice daily and added to background treatments, including immunosuppressive therapies (IST). RESULTS: The primary end point, the American College of Rheumatology combined response index in dcSSc (CRISS) at week 52 for lenabasum 20 mg twice a day versus placebo, was not met, with CRISS score of 0.888 versus 0.887 (P = 0.4972, using mixed models repeated measures [MMRM]). The change in the modified Rodnan skin thickness score (MRSS) at week 52 for lenabasum 20 mg twice a day versus placebo was -6.7 versus -8.1 (P = 0.1183, using MMRM). Prespecified analyses showed higher CRISS scores, greater improvement in MRSS, and lower decline in forced vital capacity in patients on background mycophenolate and those who were taking IST for ≤1 year. No deaths or excess in serious or severe adverse events related to lenabasum were observed. CONCLUSION: A benefit of lenabasum in dcSSc was not demonstrated. Most patients were treated with background IST, and treatment with mycophenolate mofetil in particular was associated with better outcomes. These findings support the use of IST in the treatment of dcSSc and highlight the challenge of demonstrating a treatment effect when investigational treatment is added to standard of care IST. These findings have relevance to trial design in SSc, as well as to clinical care.

Step forward in early recognition of systemic sclerosis: data from the Leiden CCISS cohort.

BACKGROUND: Since 2009, Dutch patients with a confirmed diagnosis/suspicion of systemic sclerosis (SSc) can be referred to the Leiden Combined Care in Systemic Sclerosis (CCISS) cohort. This study evaluated whether early recognition of SSc has improved over time and whether disease characteristics and survival has changed over time. METHODS: 643 SSc patients fulfilling American College of Rheumatology/European Alliance of Associations for Rheumatology 2013 SSc criteria were included and categorised into three groups based on cohort-entry year: (1) 2010-2013 (n=229 (36%)), (2) 2014-2017 (n=207 (32%)) and (3) 2018-2021 (n=207 (32%)). Variables including disease duration, interstitial lung disease (ILD), digital ulcers (DU), diffuse cutaneous SSc (dcSSc), antitopoisomerase (ATA) and anticentromere (ACA) antibodies, and survival from disease onset were compared between cohort-entry groups, including analyses stratified for sex and autoantibodies. RESULTS: Over time, duration between onset of disease symptoms and cohort entry decreased in males and females, but was always longer in females than in males.The proportion of patients presenting with DU decreased, especially in ACA+SSc patients. Almost no ACA+ patients presented with ILD, while in ATA+ patients this proportion was 25% in 2010-2013 and decreased to 19% in 2018-2021. A reduction in patients presenting with clinically meaningful ILD and dcSSc was observed.Overall 8-year survival for males was 59% (95% CI 40% to 73%) and for females 89% (95% CI 82% to 93%). Eight-year survival showed a trend for improvement over time, and was always worse in males. CONCLUSION: We observed a decrease in disease duration in Leiden CCISS cohort at cohort entry, possibly indicating more timely diagnosis of SSc. This could provide opportunities for early interventions. While symptom duration at presentation is longer in females, mortality is consistently higher in males, underlining the urge for sex-specific treatment and follow-up.

Interstitial Lung Disease: How Should Therapeutics Be Implemented?

Systemic sclerosis-interstitial lung disease (SSc-ILD) is a major complication of SSc resulting in important morbidity and mortality. Next to cyclophosphamide and mycophenolate mofetil, tocilizumab and nintedanib have proven efficacy in the treatment of SSc-ILD. The highly variable course of SSc-ILD, the complexity in determining and predicting the progression of SSc-ILD, and the diversity of treatment options for SSc-ILD, pose many challenges for everyday clinical practice. In this review, currently available evidence for monitoring and treatment of SSc-ILD is summarized and areas where additional evidence is highly desirable are discussed.

Whole body insulin sensitivity is increased in systemic sclerosis.

OBJECTIVES: In the present study, we aimed to evaluate whole-body insulin sensitivity in systemic sclerosis (SSc) patients and to compare the results with controls with no autoimmune rheumatic disease (non-ARD) and with patients affected by rheumatoid arthritis (RA). METHODS: In all patients and controls, oral glucose tolerance test (OGTT) was performed according to the World Health Organization (WHO) recommendations. Plasma glucose and insulin concentrations were measured at time 0 and then after 30, 60, 90, and 120 minutes. Whole-body insulin sensitivity (ISI), insulinogenic index (IGI), oral disposition index (ODI), and insulin resistance (HOMA-IR) were estimated accordingly. RESULTS: A total of 41 SSc patients were evaluated and, for comparison, 41 individuals with RA and 82 non-ARD control patients were recruited. OGTT yielded a proportion of normotolerant individuals among SSc patients higher than in RA controls (p = 0.040) but lower than in the non-ARD group (p = 0.028). The ISI was significantly higher in SSc patients compared with RA controls (p <0.001) and with non-ARD patients (p <0.001). Significant differences emerged also when analysing the HOMA-IR, which was lower in SSc patients than in RA (p <0.001) and non-ARD (p <0.001) groups. Additionally, IGI was lower in SSc patients compared with RA (p = 0.011) and with non-ARD controls (p <0.001), whereas ODI was not significantly different between groups. CONCLUSIONS: Interestingly, we found that SSc patients are more insulin sensitive than those with RA and even than individuals without inflammatory diseases. In contrast, no significant difference was found in terms of ß-cell function.

Autoantibodies targeting G protein-coupled receptors: An evolving history in autoimmunity. Report of the 4th international symposium.

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.

Mouth opening in systemic sclerosis: Its course over time, determinants and impact on mouth handicap.

Objective: Decreased maximal mouth opening is a common and disabling manifestation in systemic sclerosis patients. We aimed to study the course of maximal mouth opening, determinants of smaller maximal mouth opening over time and the burden of smaller maximal mouth opening on mouth handicap. Methods: Consecutive systemic sclerosis patients participating in the prospective Leiden Combined Care in systemic sclerosis cohort were included. Annual clinical assessment included maximal mouth opening measurement and mouth handicap evaluation (Mouth Handicap in Systemic Sclerosis scale). Presence of microstomia (maximal mouth opening < 30 mm) was studied. Maximal mouth opening over time was assessed on group level and for all patients individually. Baseline characteristics were analysed for their association with smaller maximal mouth opening over time (linear mixed-effects models). Furthermore, cross-sectional association between maximal mouth opening with Mouth Handicap in Systemic Sclerosis scale was assessed (linear regression analysis). Results: A total of 382 systemic sclerosis patients were studied with median follow-up time of 2.0 years (interquartile range = 0.0-3.0). At baseline, mean maximal mouth opening was 42.2 ± 8.0 mm and 7% suffered from microstomia. Annual decrease of > 5.0 mm in maximal mouth opening during follow-up occurred in 63 patients and was accompanied by increase in disease severity. Disease characteristics at baseline independently predictive for smaller maximal mouth opening over time were: more extended skin subtype; peripheral vasculopathy; pulmonary, renal and gastrointestinal involvement. Smaller maximal mouth opening was significantly associated with more reported mouth handicap. Conclusion: The course of maximal mouth opening is stable in a majority of systemic sclerosis patients. Still, maximal mouth opening over time was smaller in patients with more severe organ involvement. Although microstomia was infrequent, a smaller maximal mouth opening was significantly associated with more mouth handicap, indicating the importance to address maximal mouth opening in routine care of systemic sclerosis patients.

Progression from suspected to definite systemic sclerosis and the role of anti-topoisomerase I antibodies.

INTRODUCTION: Early diagnosis of systemic sclerosis (SSc) is important to start therapeutic interventions timely. Important risk factors for progression to SSc are the SSc-specific autoantibodies, of whom anti-centromere antibodies (ACA) and anti-topoisomerase I antibodies (ATA) are the most frequent. ATA is associated with a severe disease course. A more detailed characterisation of the ATA-response in SSc might increase insights in preclinical disease stages and improve prognostication. To address this we identified all patients with suspected very early ATA-positive SSc, defined as all patients who are ATA-positive not fulfilling American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2013 criteria, in the Leiden Combined Care in Systemic Sclerosis (CCISS)-cohort and found very low numbers. METHODS: This triggered us to search the literature on the ATA prevalence in patients with suspected very early SSc and contribution of the SSc-specific autoantibodies to progression from suspected very early to definite SSc. To increase insights on the ATA-response in suspected very early SSc, we then evaluated the association between the ATA-response and time between onset of Raynaud's phenomenon (RP) and first non-RP symptom, as a proxy for progressing to definite SSc, in all patients with ATA-positive SSc from the Leiden CCISS-cohort. RESULTS: In short, included studies show that prevalence of ATA is much lower in suspected very early SSc than in populations fulfilling ACR/EULAR 2013 criteria. After 1-15 years of follow-up, only 52% of the patients with suspected very early SSc progress to definite SSc. ATA-IgG levels tend to be higher in patients with ATA-positive SSc with more rapid disease progression. CONCLUSION: Although a role of ATA in disease progression is suggested, more studies on the ATA response in suspected very early SSc are warranted.

Autoreactive B cell responses targeting nuclear antigens in systemic sclerosis: Implications for disease pathogenesis.

A hallmark of disease pathogenesis of systemic sclerosis (SSc) is the presence of autoreactive B cell responses targeting nuclear proteins. Almost all SSc-patients harbour circulating antinuclear autoantibodies of which anti-topoisomerase 1, anti-centromere protein, anti-RNA polymerase III and anti-fibrillarin autoantibodies (ATA, ACA, ARA and AFA, respectively) are the most common and specific for SSc. In clinical practice, autoantibodies serve as diagnostic biomarkers and can aid in the identification of clinical phenotypes of the disease. However, factors driving disease progression in SSc are still poorly understood, and it is difficult to predict disease trajectories in individual patients. Moreover, treatment decisions remain rather empirical, with variable response rates in clinical trials due to patient heterogeneity. Current evidence has indicated that certain patients may benefit from B cell targeting therapies. Hence, it is important to understand the contribution of the antinuclear autoantibodies and their underlying B cell response to the disease pathogenesis of SSc.