Aberrant long-chain fatty acid metabolism associated with evolving systemic sclerosis-associated pulmonary arterial hypertension.

We sought to investigate differential metabolism in patients with systemic sclerosis (SSc) who develop pulmonary arterial hypertension (PAH) versus those who do not, as a method of identifying potential disease biomarkers. In a nested case-control design, serum metabolites were assayed in SSc subjects who developed right heart catheterization-confirmed PAH (n = 22) while under surveillance in a longitudinal cohort from Johns Hopkins, then compared with metabolites assayed in matched SSc patients who did not develop PAH (n = 22). Serum samples were collected at "proximate" (within 12 months) and "distant" (within 1-5 yr) time points relative to PAH diagnosis. Metabolites were identified using liquid chromatography-mass spectroscopy (LC-MS). An LC-MS dataset from SSc subjects with either mildly elevated pulmonary pressures or overt PAH from the University of Michigan was compared. Differentially abundant metabolites were tested as predictors of PAH in two additional validation SSc cohorts. Long-chain fatty acid metabolism (LCFA) consistently differed in SSc-PAH versus SSc without PH. LCFA metabolites discriminated SSc-PAH patients with mildly elevated pressures in the Michigan cohort and predicted SSc-PAH up to 2 yr before clinical diagnosis in the Hopkins cohort. Acylcholines containing LCFA residues and linoleic acid metabolites were most important for discriminating SSc-PAH. Combinations of acylcholines and linoleic acid metabolites provided good discrimination of SSc-PAH across cohorts. Aberrant lipid metabolism is observed throughout the evolution of PAH in SSc. Lipidomic signatures of abnormal LCFA metabolism distinguish SSc-PAH patients from those without PH, including before clinical diagnosis and in mild disease.NEW & NOTEWORTHY Abnormal lipid metabolism is evident across time in the development of SSc-PAH, and dysregulated long-chain fatty acid metabolism predicts overt PAH.

Autoantibodies to nuclear valosin-containing protein-like protein: systemic sclerosis-specific antibodies revealed by in vitro human proteome.

OBJECTIVES: To identify and characterize undescribed systemic sclerosis (SSc)-specific autoantibodies targeting nucleolar antigens and to assess their clinical significance. METHODS: We conducted proteome-wide autoantibody screening (PWAS) against serum samples from SSc patients with nucleolar patterned anti-nuclear antibodies (NUC-ANAs) of specific antibodies (Abs) unknown, utilizing wet protein arrays fabricated from in vitro human proteome. Controls included SSc patients with already-known SSc-specific autoantibodies, patients with other connective tissue diseases and healthy subjects. The selection of nucleolar antigens was performed by database search in the Human Protein Atlas. The presence of autoantibodies was certified by immunoblots and immunoprecipitations. Indirect immunofluorescence assays on HEp-2 cells were also conducted. Clinical assessment was conducted by retrospective review of electronic medical records. RESULTS: PWAS identified three candidate autoantibodies, including anti-nuclear valosin-containing protein-like (NVL) Ab. Additional measurements in disease controls revealed that only anti-NVL Abs are exclusively detected in SSc. Detection of anti-NVL Abs was reproduced by conventional assays such as immunoblotting and immunoprecipitation. Indirect immunofluorescence assays demonstrated homogeneous nucleolar patterns. Anti-NVL Ab-positive cases were characterized by significantly low prevalence of diffuse skin sclerosis and interstitial lung disease, compared with SSc cases with NUC-ANAs other than anti-NVL Abs, such as anti-U3-RNP and anti-Th/To Abs. CONCLUSION: Anti-NVL Ab is an SSc-specific autoantibody associated with a unique combination of clinical features, including limited skin sclerosis and lack of lung involvement.

Thymic stromal lymphopoietin and digital microvascular damage in systemic sclerosis patients: A pilot study.

BACKGROUND: Systemic sclerosis (SSc) is a complex autoimmune connective-tissue disease, characterised by vasculopathy and fibrosis of the skin and internal organs. Activation of microvascular endothelial cells (ECs) causes the intimal hyperplasia that characterises the vascular remodelling in SSc. The most frequent complication of SSc is the development of digital ulcers (DUs). Thymic stromal lymphopoietin (TSLP) may trigger fibrosis and sustain vascular damage. Aim of this study was to evaluate the correlation between serum level of TSLP and DUs. METHODS: 75 consecutive SSc patients were enrolled and serum TSLP levels were measured. The presence of history of DUs (HDU) was evaluated. Recurrent new DUs were defined as the presence of at least 3 episodes of DUs in a 12-months follow up period. The risk of developing new DUs was calculated by applying the capillaroscopic skin ulcer risk index (CSURI). RESULTS: The median value of TSLP was higher in patients with HDU than patients without HDU [181.67 pg/ml (IQR 144.67; 265.66) vs 154.67 pg/ml (IQR 110.67; 171.33), p < 0.01]. The median value of TSLP was higher in patients with an increased CSURI index than patients without an increased CSURI [188 pg/ml (IQR 171.33; 246.33) vs 159.33 pg/ml (IQR 128.67; 218), p < 0.01]. Kaplan-Meier curves demonstrated that free survival from new DUs was significantly (p < 0.01) lower in SSc patients with increased TSLP serum levels. CONCLUSION: TSLP might have a key role in digital microvascular damage of SSc patients.

Growth arrest-specific protein 6 as a marker of nephritis in systemic sclerosis and juvenile systemic lupus erythematosus patients.

Background: Renal impairments commonly occur as a complication of autoimmune connective tissue diseases (CTDs). Therefore, early nephritis prediction is vital for patient outcomes. Growth Arrest-Specific Protein 6 (GAS6) was found to be upregulated in many types of inflammatory renal disease, including diabetic nephropathy.Aim: To evaluate GAS6 as a predictor of renal impairment in adults with systemic sclerosis (SSc) and children with systemic lupus Erythematosus (SLE).Methods: The study included 60 patients with SSc and 40 children with SLE. The serum level of GAS6 was measured using the ELISA technique. In adults with SSc, total proteins in 24-h urine concentration of >300 mg/24 h indicated renal inflammation, while in children with SLE, nephritis was diagnosed by abnormal renal pathology.Results: In SSc patients, GAS6 significantly increased in patients with proteinuria. GAS6 is an independent predictor of nephritis with an odds ratio (OR) of 1.06 and a 95% confidence interval (CI) of 1.0-1.1. at cutoff 12.2 ng/mL GAS6 predicted proteinuria with sensitivity 86.7% (95% CI: 59.5% to 98.3%), specificity 57.8% (95% CI: 42.1% to 72.3%), positive predictive value 40.6% (95% CI: 31.5% to 50.4%), negative predictive value 92.9% (95% CI: 77.7% to 97.73%), and accuracy 65.0% (95% CI: 51.6% to 76.9%). In SLE patients, Serum GAS6 did not differ significantly between children with and without lupus nephritis.Conclusion: GAS6 is an independent predictor of nephritis in patients with SSc. However, there is no association between GAS6 and nephritis in juvenile patients with SLE.

Bicaudal D2 autoantibodies are highly specific for systemic sclerosis.

OBJECTIVE: Autoantibodies directed against the intracellular protein bicaudal D2 (BICD2) have been identified as a specific marker of systemic sclerosis (SSc). Since autoantibodies are of value in predicting disease onset and identifying meaningful clinical subsets, as well as having prognostic value, this study aimed to establish the prevalence of BICD2 autoantibodies (anti-BICD2) in a cohort of patients with connective tissue disease and healthy controls. METHOD: In this cross-sectional study, 363 patients with connective tissue disease (121 SSc, 141 systemic lupus erythematosus, 101 myositis, and 100 blood donors) were tested for the presence of anti-BICD2. All SSc patients were tested for specific anti-nuclear antibodies (ANAs), and clinical and laboratory associations were evaluated in the SSc patients, stratified by anti-BICD2 status. RESULTS: In the SSc cohort, 35 patients had autoantibodies directed against BICD2. The specificity of anti-BICD2 in SSc patients was 96.5%; however, the sensitivity was only 28.9%. Anti-BICD2 and centromere autoantibodies were present together in 91% of the anti-BICD2-positive SSc patients, and in none of the cases was anti-BICD2 the only antibody present. Anti-BICD2-positive patients had lower forced expiratory volume in 1 s (FEV1) (p = 0.01) and lower carbon monoxide transfer coefficient (KCO) (p = 0.01) than anti-BICD2-negative SSc patients, but they had higher forced vital capacity (p = 0.03). CONCLUSION: Autoantibodies against BICD2 were highly specific for SSc patients. Reduced FEV1 and KCO in anti-BICD2-positive patients may indicate that the presence of anti-BICD2 is associated with altered lung function in an unknown pathophysiological manner, which awaits further elucidation.

Detection of IgE-autoantibodies to nuclear antigens in patients with systemic sclerosis and analysis of their clinical relevance.

OBJECTIVES: Antinuclear antibodies (ANA) of the IgE-type have been described in several connective tissue disorders (CTD) but not yet in systemic sclerosis (SSc). Aim of the study was, therefore, to establish an ELISA for the demonstration of IgE-autoantibodies to topoisomerase-I (topo-I) and the centromeric proteins A and B (CENP-A/B), to assess their prevalence and reactivity in SSc and to analyse their clinical relevance. METHODS: One hundred fifty-one patients with SSc and 88 with CREST-syndrome, 291 patients with other CTD, and 23 patients with fibromyalgia syndrome (FM) as a control collective were included into the study. Patients' sera were analysed by an in-house-ELISA for IgE autoantibodies against topo-I and CENP-A/B using recombinant antigens. Patients were assessed for median Rodnan skin score(mRSS), different organ and cutaneous manifestations. RESULTS: Of the patients with CREST syndrome, 67% had IgE-anti-CENP-A- and 77% IgE-anti-CENP-B-antibodies. IgE-anti-topo-I antibodies were found in 56% of patients with SSc. Prevalence and reactivity were significantly higher in CREST and SSc, respectively, than in other CTD or FM. IgE-reactivity strongly correlated with IgG-antibody reactivity. In CRESTsyndrome, IgE-anti-CENP-A (but not CENP-B)-antibodies were significantly higher and more prevalent in patients with skin ulcers, high mRSS, and more than four organ manifestations. They did not correlate with blood eosinophil counts. In contrast, for IgE-anti-topo-I antibodies no correlation with clinical manifestations was observed. CONCLUSIONS: IgE-autoantibodies against CENP-A/B and topo-I occur in SSc underlining the concept that SSc may be a T helper cell type 2 mediated disease. IgE-anti-CENP-A-antibodies correlated with disease activity, but this has to be confirmed in larger studies.

Overexpression of BAG3 (Bcl2-associated athanogene 3) in serum and skin of patients with systemic sclerosis.

OBJECTIVES: BAG3 (Bcl2-associated athanogene3) is able to induce the transformation of cancer-associated fibroblasts to alpha smooth muscle actin (a-SMA) positive (+) myofibroblasts. In systemic sclerosis (SSc), a-SMA+ myofibroblasts also play an important role in the progression of fibrosis in the skin and involved internal organs. The aim of the study was to investigate whether BAG3 is overexpressed in SSc and may be a biomarker of fibrogenesis. METHODS: BAG3 serum levels were measured in 106 patients with SSc, 47 with the limited (lc) and 59 the diffuse (dc) SSc, and in age- and sex-matched healthy controls (HC). BAG3 levels were then compared according to their clinical subset, nailfold video-capillaroscopic (NVC) patterns, interstitial lung disease (ILD, and correlated with modified Rodnan skin score (mRSS) and global disease activity. BAG3 expression was also investigated in skin biopsies of 8 dcSSc patients. RESULTS: BAG3 serum levels were significantly higher in dcSSc (143.3 pg/mL, 95%CI 78-208.5) than in HC (0.68 pg/mL, 95%CI 0.13-1.23), and were significantly higher in patients with late NVC pattern and ILD but did not correlate with disease activity and mRSS. Of note, BAG3 was strongly expressed in the skin biopsies of dcSSc patients. CONCLUSIONS: BAG3 is overexpressed in dcSSc patients and may contribute to skin and organ fibrosis by prompting the transition of fibroblasts into myofibroblasts and increasing their survival. Thus, BAG3 may play an important role in SSc fibrotic pathogenesis and be a potential biomarker of fibrosis. Further research on its role as a therapeutic target is warranted.

Associations of Digital Ulcers in Patients with Systemic Sclerosis: An 8-Year Retrospective Study.

INTRODUCTION: This study aimed to investigate the associations of digital ulcers (DUs) in patients with systemic sclerosis (SSc). METHODS: This retrospective study investigated the demographic characteristics, specific autoantibodies, organ involvement, and laboratory tests in patients with SSc from our hospital. RESULTS: This study enrolled 144 patients with SSc. The DU+ group consisted of 15 (10.4%) patients. Patients with SSc having DUs have longer disease duration, higher fibrinogen, higher fibrin degradation product, and lower cholesterol. None of the patients used cholesterol-lowering drugs before onset of DUs. The study also demonstrated a higher prevalence of anti-dsDNA and anti-histone antibodies in patients with SSc with DUs. Anti-dsDNA antibody is a specific antibody for SLE with a specificity of 96-99%. A total of 86.1% (124/144) of patients suffered from diffuse cutaneous SSc, and 28.5% (41/144) of patients suffered from overlap syndrome. CONCLUSION: Our study indicated that patients with SSc with fibrinogen of >2.895 g/L (p = 0.043) and cholesterol of <3.340 mmol/L (p = 0.036), which is equal to 129.258 mg/dL, are at high risk of developing DUs.

Predictive accuracy of the ASIG algorithm in a prospective systemic sclerosis cohort undergoing annual screening for pulmonary arterial hypertension.

The Australian Scleroderma Interest Group (ASIG) algorithm for screening pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) requires only respiratory function tests and serum N-terminal pro-brain natriuretic peptide as first-tier tests, and is recommended in international guidelines. In this communication, we present the findings of the application of the ASIG screening algorithm to a Singaporean cohort undergoing prospective annual screening for PAH, which shows a high negative predictive value. The ASIG algorithm may offer an alternative to more complex and costly SSc-PAH screening algorithms.

The Association Between Serum Ferritin Levels and Main Systemic Sclerosis Features: A Retrospective Study from a Tertiary Center.

BACKGROUND: Serum ferritin is a sensitive inflammatory biomarker reflecting cell damage and oxidative stress in inflammatory rheumatic diseases. The use of ferritin for assessment of systemic sclerosis (SSc) activity, severity, and prognosis has not been fully elucidated. OBJECTIVES: To assess the correlation between serum ferritin levels and SSc disease parameters, complications, and outcome. METHODS: Demographic, clinical, and laboratory data, including blood levels of ferritin, were collected from files of patients with SSc who were treated at the Rheumatology Institute at Rambam Health Care Campus from January 2004 to July 2021. The study compared SSc patients with elevated levels of ferritin to those with normal levels. RESULTS: We extracted data of 241 SSc patients (80% female, 60% with diffuse SSc, mean age 54 ± 15.4 years, mean disease duration 6.8 ± 4.5 years). During follow-up, 39% died. Elevated ferritin levels positively correlated with male sex; short disease duration; lung, heart, and kidney involvement; higher modified Rodnan skin score; anemia; elevated levels of creatinine kinase, C-reactive protein, creatinine, and troponin; reduced pulmonary function tests (forced vital capacity and diffusion capacity of the lung for carbon monoxide); and left ventricular ejection fraction. There were no correlations between ferritin levels and pulmonary hypertension or gastrointestinal involvement. Levels of ferritin negatively correlated with anti-centromere antibodies. CONCLUSIONS: In SSc, ferritin can serve as a marker for ongoing systemic inflammation and prognosis, particularly in patients with lung and heart involvement. Further studies on serial ferritin measurement in the management of SSc patients are warranted.

Progranulin, sICAM-1, and sVCAM-1 May Predict an Increased Risk for Ventricular Arrhythmias in Patients with Systemic Sclerosis.

In systemic sclerosis (SSc), fibrosis of the myocardium along with ongoing autoimmune inflammation can alter the electric function of the cardiac myocytes, which may increase the risk for ventricular arrhythmias and sudden cardiac death. We analyzed the electrocardiographic (ECG) variables describing ventricular repolarization such as QT interval, QT dispersion (QTd), T wave peak-to-end interval (Tpe), and arrhythmogeneity index (AIX) of 26 patients with SSc and 36 healthy controls. Furthermore, echocardiographic and laboratory parameters were examined, with a focus on inflammatory proteins like C-reactive ptotein (CRP), soluble intracellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), and progranulin (PGRN). The CRP, sICAM-1, and sVCAM-1 levels were positively correlated with the length of the QT interval. Although the serum PGRN levels were not increased in the SSc group compared to the controls, in SSc patients, the PGRN levels were positively correlated with the QT interval and the AIX. According to our results, we conclude that there may be a potential association between autoimmune inflammation and the risk for ventricular arrhythmias in patients with SSc. We emphasize that the measurement of laboratory parameters of inflammatory activity including CRP, PGRN, sVCAM-1, and sICAM-1 could be helpful in the prediction of sudden cardiac death in patients with SSc.

Inorganic pyrophosphate is reduced in patients with systemic sclerosis.

OBJECTIVE: The pathogenesis of calcinosis cutis, a disabling complication of SSc, is poorly understood and effective treatments are lacking. Inorganic pyrophosphate (PPi) is a key regulator of ectopic mineralization, and its deficiency has been implicated in ectopic mineralization disorders. We therefore sought to test the hypothesis that SSc may be associated with reduced circulating PPi, which might play a pathogenic role in calcinosis cutis. METHODS: Subjects with SSc and age-matched controls without SSc were recruited from the outpatient rheumatology clinics at Rutgers and Northwestern Universities (US cohort), and from the Universities of Szeged and Debrecen (Hungarian cohort). Calcinosis cutis was confirmed by direct palpation, by imaging or both. Plasma PPi levels were determined in platelet-free plasma using ATP sulfurylase to convert PPi into ATP in the presence of excess adenosine 5' phosphosulfate. RESULTS: Eighty-one patients with SSc (40 diffuse cutaneous, and 41 limited cutaneous SSc) in the US cohort and 45 patients with SSc (19 diffuse cutaneous and 26 limited cutaneous SSc) in the Hungarian cohort were enrolled. Calcinosis was frequently detected (40% of US and 46% of the Hungarian cohort). Plasma PPi levels were significantly reduced in both SSc cohorts with and without calcinosis (US: P = 0.003; Hungarian: P < 0.001). CONCLUSIONS: Circulating PPi are significantly reduced in SSc patients with or without calcinosis. Reduced PPi may be important in the pathophysiology of calcinosis and contribute to tissue damage with chronic SSc. Administering PPi may be a therapeutic strategy and larger clinical studies are planned to confirm our findings.

Serum and urine free light chains measurements in patients with systemic sclerosis: novel biomarkers for disease activity.

Circulating free light chains (FLCs), considered biomarkers of B cell activity, are frequently elevated in patients affected by systemic inflammatory autoimmune diseases. As the systemic sclerosis (SSc) clinical course can be variable, this study is aimed at evaluating FLCs levels in affected individuals as biomarkers of disease activity. We assessed FLC levels in serum and urine of 72 SSc patients and 30 healthy controls (HC). Results were analyzed in comparison with overall clinical and laboratory findings, disease activity index (DAI) and disease severity scale (DSS). SSc patients displayed increased levels of κ and λ FLC in serum significantly higher than HC (p = 0.0001) alongside the mean values of free κ/λ ratio and κ + λ sum (p = 0.0001). SSc patients showed increased free κ in urine with a κ/λ higher than HC (p = 0.0001). SSc patients with increased κ + λ in serum showed that erythro-sedimentation rate (p = 0.034), C-reactive protein (p = 0.003), DAI (p = 0.024) and DSS (p = 0.015) were higher if compared to SSc patients with normal levels of FLC. A positive linear correlation was found between serum levels of free κ and DAI (r = 0.29, p = 0.014). In addition, SSc patients with increased free κ in urine had higher DAI (p = 0.048) than SSc patients with normal κ levels. Our results strengthen the role of serum FLC as useful biomarker in clinical practice to early diagnosis and monitor disease activity, showing for the first time that also urine FLC levels correlated with disease activity in SSc patients.

Variety of endosomal TLRs and Interferons (IFN-α, IFN-ß, IFN-γ) expression profiles in patients with SLE, SSc and MCTD.

We investigated Toll-like receptor (TLR)-3/-7/-8/-9 and interferon (IFN)-α/ß/γ mRNA expression in whole blood and serum IFN-α/ß/γ levels in patients with mixed connective tissue disease (MCTD), systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) and in healthy subjects to assess the association between the TLR-IFN expression and severity of and susceptibility to diseases, and identify potential biomarkers. Expression of the IFN-γ, TLR-3 and TLR-8 was detected only in SLE patients. TLR-7, IFN-α and IFN-ß expression was highest in SLE, while TLR-9 expression was highest in SSc patients. In SLE and MCTD patients a strong correlation was observed between TLR-7 and IFN-α expression and IFN-ß and IFN-α expression. In MCTD patients, negative correlation between IFN-α and TLR-9 and TLR-7 and TLR-9 was revealed. TLR-9 expression in anti-U1-70k-negative, anti-C negative and anti-SmB-negative MCTD patients was higher than in MCTD-positive patients. We observed negative correlations between serum IFN-α levels and TLR-7 expression and C3 and C4 levels in SLE patients. In SLE patients we observed that with increased IFN-γ, TLR-3 and TLR-8 expression increased the value of C3 and C4. Our results confirmed that the endosomal TLR-IFN pathway seems to be more important in SLE than in MCTD or SSc, and that IFN-α and IFN-ß may be possible biomarkers for SLE.

Autoantibodies targeting telomere-associated proteins in systemic sclerosis.

OBJECTIVES: Systemic sclerosis (SSc) is an autoimmune fibrotic disease affecting multiple tissues including the lung. A subset of patients with SSc with lung disease exhibit short telomeres in circulating lymphocytes, but the mechanisms underlying this observation are unclear. METHODS: Sera from the Johns Hopkins and University of California, San Francisco (UCSF) Scleroderma Centers were screened for autoantibodies targeting telomerase and the shelterin proteins using immunoprecipitation and ELISA. We determined the relationship between autoantibodies targeting the shelterin protein TERF1 and telomere length in peripheral leucocytes measured by qPCR and flow cytometry and fluorescent in situ hybridisation (Flow-FISH). We also explored clinical associations of these autoantibodies. RESULTS: In a subset of patients with SSc, we identified autoantibodies targeting telomerase and the shelterin proteins that were rarely present in rheumatoid arthritis, myositis and healthy controls. TERF1 autoantibodies were present in 40/442 (9.0%) patients with SSc and were associated with severe lung disease (OR 2.4, p=0.04, Fisher's exact test) and short lymphocyte telomere length. 6/6 (100%) patients with TERF1 autoantibodies in the Hopkins cohort and 14/18 (78%) patients in the UCSF cohort had a shorter telomere length in lymphocytes or leukocytes, respectively, relative to the expected age-adjusted telomere length. TERF1 autoantibodies were present in 11/152 (7.2%) patients with idiopathic pulmonary fibrosis (IPF), a fibrotic lung disease believed to be mediated by telomere dysfunction. CONCLUSIONS: Autoantibodies targeting telomere-associated proteins in a subset of patients with SSc are associated with short lymphocyte telomere length and lung disease. The specificity of these autoantibodies for SSc and IPF suggests that telomere dysfunction may have a distinct role in the pathogenesis of SSc and pulmonary fibrosis.

Anti-centromere antibodies target centromere-kinetochore macrocomplex: a comprehensive autoantigen profiling.

OBJECTIVES: Anti-centromere antibodies (ACAs) are detected in patients with various autoimmune diseases such as Sjögren's syndrome (SS), systemic sclerosis (SSc) and primary biliary cholangitis (PBC). However, the targeted antigens of ACAs are not fully elucidated despite the accumulating understanding of the molecular structure of the centromere. The aim of this study was to comprehensively reveal the autoantigenicity of centromere proteins. METHODS: A centromere antigen library including 16 principal subcomplexes composed of 41 centromere proteins was constructed. Centromere protein/complex binding beads were used to detect serum ACAs in patients with SS, SSc and PBC. ACA-secreting cells in salivary glands obtained from patients with SS were detected with green fluorescent protein-fusion centromere antigens and semiquantified with confocal microscopy. RESULTS: A total of 241 individuals with SS, SSc or PBC and healthy controls were recruited for serum ACA profiling. A broad spectrum of serum autoantibodies was observed, and some of them had comparative frequency as anti-CENP-B antibody, which is the known major ACA. The prevalence of each antibody was shared across the three diseases. Immunostaining of SS salivary glands showed the accumulation of antibody-secreting cells (ASCs) specific for kinetochore, which is a part of the centromere, whereas little reactivity against CENP-B was seen. CONCLUSIONS: We demonstrated that serum autoantibodies target the centromere-kinetochore macrocomplex in patients with SS, SSc and PBC. The specificity of ASCs in SS salivary glands suggests kinetochore complex-driven autoantibody selection, providing insight into the underlying mechanism of ACA acquisition.

Decreased serum ACE2 levels in patients with connective tissue diseases.

OBJECTIVE: To evaluate serum concentration and activity of angiotensin-converting enzyme 2 (ACE2) in patients with connective tissue diseases (CTDs). METHODS: Serum samples from healthy subjects and patients with SLE, systemic sclerosis (SSc), primary Sjögren's syndrome (SS) and RA were collected. The concentration and activity of ACE2 were measured by ELISA and fluorometric method, respectively, and analysed for associations with clinical features and concurrent medications. RESULTS: In total, 66 SLE, 55 SSc, 31 SS and 31 RA patients were involved. ACE2 concentration was significantly decreased in patients with either of the four CTDs compared with healthy subjects. The concentration was not linked to special clinical features expect that it was slightly lower in patients with lupus nephritis than those without. In SLE patients, ACE2 concentration elevated with the increase of glucocorticoids, and was not associated with other treatments. Different from the concentration, ACE2 activity was increased in CTD patients. A weak correlation of ACE2 activity with SLE disease activity index score was also observed. CONCLUSION: The clinical significance of ACE2 concentration and activity looks quite different among CTD patients. Preliminary data suggest ACE2 levels are not affected by most of the treatments.

IL11 is elevated in systemic sclerosis and IL11-dependent ERK signalling underlies TGFß-mediated activation of dermal fibroblasts.

OBJECTIVES: Interleukin 11 (IL11) is highly upregulated in skin and lung fibroblasts from patients with systemic sclerosis (SSc). Here we tested whether IL11 is mechanistically linked with activation of human dermal fibroblasts (HDFs) from patients with SSc or controls. METHODS: We measured serum IL11 levels in volunteers and patients with early diffuse SSc and manipulated IL11 signalling in HDFs using gain- and loss-of-function approaches that we combined with molecular and cellular phenotyping. RESULTS: In patients with SSc, serum IL11 levels are elevated as compared with healthy controls. All transforming growth factor beta (TGFß) isoforms induced IL11 secretion from HDFs, which highly express IL11 receptor α-subunit and the glycoprotein 130 (gp130) co-receptor, suggestive of an autocrine loop of IL11 activity in HDFs. IL11 stimulated ERK activation in HDFs and resulted in HDF-to-myofibroblast transformation and extracellular matrix secretion. The pro-fibrotic action of IL11 in HDFs appeared unrelated to STAT3 activity, independent of TGFß upregulation and was not associated with phosphorylation of SMAD2/3. Inhibition of IL11 signalling using either a neutralizing antibody against IL11 or siRNA against IL11RA reduced TGFß-induced HDF proliferation, matrix production and cell migration, which was phenocopied by pharmacological inhibition of ERK. CONCLUSIONS: These data reveal that autocrine IL11-dependent ERK activity alone or downstream of TGFß stimulation promotes fibrosis phenotypes in dermal fibroblasts and suggest IL11 as a potential therapeutic target in SSc.

Laser speckle contrast analysis predicts major vascular complications and mortality of patients with systemic sclerosis.

OBJECTIVES: The aim of study was to evaluate peripheral blood perfusion and the proximal-distal gradient (PDG) of the hands as biomarkers of SSc major vascular complications (digital ulcers, pulmonary arterial hypertension, scleroderma renal crisis) and mortality by laser speckle contrast analysis. METHODS: In this retrospective observational study, 176 SSc patients [158 female, median age 53 (51-57) years] and 142 healthy controls [115 female, median age 53 (48-55) years] were enrolled. Clinical data were collected at baseline and annually through 5 years of follow-up. Hand dorsum perfusion images were divided into three regions of interest (ROI): ROI1 included the second, third, and fourth fingers distal to the proximal interphalangeal finger joint; ROI2 included the area between the proximal interphalangeal finger joint and the metacarpophalangeal joint; ROI3 included the hand dorsum. PDG was identified when the perfusion mean difference between ROI1 and ROI2 was >30 perfusion units. RESULTS: Median peripheral blood perfusion was significantly lower for SSc patients than healthy controls. PDG was present in 51.5% of SSc patients and in 98.6% of healthy controls. Using the final multivariate model, nailfold videocapillaroscopy (NVC) pattern [hazard ratio (HR) 0.065 (0.015-0.283), P <0.0001] and PDG [HR 0.376 (0.194-0.727), P <0.01] were found to be risk factors for major vascular complications. By multivariate analysis, age [HR 1.051 (1.014-1.088), P <0.01), NVC pattern [HR 0.001 (0.000-3.111), P >0.05], and PDG [HR 0.207 (0.073-0.589), P <0.01] were found to be risk factors for 5-year SSc mortality. CONCLUSION: PDG predicts major vascular complication and 5-year mortality of SSc patients.

Serum S100A12 levels: Possible association with skin sclerosis and interstitial lung disease in systemic sclerosis.

Damage-associated molecular patterns (DAMPs) have drawn much attention as a member of disease-associated molecules in systemic sclerosis (SSc). In this study, we investigated the potential contribution of S100A12, a member of DAMPs, to the development of SSc by evaluating S100A12 expression in the lesional skin and the clinical correlation of serum S100A12 levels. S100A12 expression was markedly elevated in the epidermis of SSc-involved skin at protein levels and in the bulk skin at mRNA levels. The deficiency of transcription factor Fli1, a predisposing factor of SSc, enhanced S100A12 expression and Fli1 occupied the S100A12 promoter in normal human keratinocytes. Serum S100A12 levels were higher in SSc patients, especially in those with diffuse cutaneous involvement, than in healthy controls and positively correlated with skin score. Furthermore, the presence of interstitial lung disease significantly augmented serum levels of S100A12. Importantly, serum S100A12 levels correlated inversely with both per cent forced vital capacity and per cent diffusing capacity for carbon monoxide and positively with serum levels of KL-6 and surfactant protein-D. Collectively, these results indicate a possible contribution of S100A12 to skin sclerosis and interstitial lung disease associated with SSc, further supporting the critical roles of DAMPs in the pathogenesis of this disease.