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Patients with diffuse cutaneous systemic sclerosis (dcSSc) display a complex clinical phenotype. Transcriptional profiling of whole blood or tissue from patients are affected by changes in cellular composition that drive gene expression and an inability to detect minority cell populations. Here, we focused on the two main subtypes of circulating monocytes, classical (CM) and non-classical (NCM).SSc patients were recruited from the Prospective Registry for Early SSc registry. Clinical data were collected as well as peripheral blood for isolation of CM and NCM. Age-, sex-, and race-matched healthy volunteers were recruited as controls. Bulk macrophages were isolated from skin in a separate cohort. All samples were assayed by RNA-seq.We used an unbiased approach to cluster patients into three groups (A-C) based on their transcriptional signatures of CM relative to controls. Further, each group maintained their characteristic transcriptional signature in NCM. Genes upregulated in Group C demonstrated the highest signature compared to the other groups in skin macrophages. Patients from Group B and C exhibited worse lung function than Group A, although there was no difference in skin disease at baseline. We validated our approach by applying our group classifications to published bulk monocyte RNA-seq data on SSc patients: we found that patients with no skin disease were most likely to be classified as Group A.We are the first to show that transcriptional signature of CM and NCM can be used to unbiasedly stratify SSc patients and correlate with disease activity outcome measures.

Objectives Prior work demonstrates that co-cultured macrophages and fibroblasts from patients with SSc engage in reciprocal activation. However, the mechanism by which these cell types communicate and contribute to fibrosis and inflammation in SSc is unknown. Methods Fibroblasts were isolated from skin biopsies obtained from 7 SSc patients or 6 healthy age and gender-matched control subjects following written informed consent. Human donor-derived macrophages were cultured with exosomes isolated from control or SSc fibroblasts for an additional 48 h. Macrophages were immunophenotyped using flow cytometry, qRT-PCR and multiplex. For mutual activation studies, exosome-activated macrophages were co-cultured with SSc or healthy fibroblasts using Transwells. Results Macrophages activated with dermal fibroblast-derived exosomes from SSc patients upregulated surface expression of CD163, CD206, MHC Class II and CD16 and secreted increased levels of IL-6, IL-10, IL-12p40 and TNF compared with macrophages incubated with healthy control fibroblasts (n = 7, P Conclusion In this work, we demonstrate for the first time that human SSc dermal fibroblasts mediate macrophage activation through exosomes. Our findings suggest that macrophages and fibroblasts engage in cross-talk in SSc skin, resulting in mutual activation, inflammation, and extracellular matrix (ECM) deposition. Collectively, these studies implicate macrophages and fibroblasts as cooperative mediators of fibrosis in SSc and suggest therapeutic targeting of both cell types may provide maximal benefit in ameliorating disease in SSc patients.

Objectives Symptoms of people who have SSc are heterogeneous and difficult to address clinically. Because diverse symptoms often co-occur and may share common underlying mechanisms, identifying symptoms that cluster together may better target treatment approaches. We sought to identify and characterize patient subgroups based on symptom experience. Methods An exploratory hierarchical agglomerative cluster analysis was conducted to identify subgroups from a large SSc cohort from a single US academic medical centre. Patient-reported symptoms of pain interference, fatigue, sleep disturbance, dyspnoea, depression and anxiety were used for clustering. A multivariate analysis of variance (MANOVA) was used to examine the relative contribution of each variable across subgroups. Analyses of variance were performed to determine participant characteristics based on subgroup assignment. Presence of symptom clusters were tallied within subgroup. Results Participants (n = 587; 84% female, 41% diffuse cutaneous subtype, 59% early disease) divided into three subgroups via cluster analysis based on symptom severity: (i) no/minimal, (ii) mild, and (iii) moderate. Participants in mild and moderate symptoms subgroups had similar disease severity, but different symptom presentation. In the mild symptoms subgroup, pain, fatigue and sleep disturbance was the main symptom cluster. Participants in the moderate symptoms subgroup were characterized by co-occurring pain, fatigue, sleep disturbance, depression and anxiety. Conclusion Identification of distinct symptom clusters, particularly among SSc patients who experience mild and moderate symptoms, suggests potential differences in treatment approach and in mechanisms underlying symptom experience that require further study.

BACKGROUND/OBJECTIVES: The subset of ANA-positive patients with systemic sclerosis (SSc) who lack prototypic SSc-specific autoantibodies (centromere, topoisomerase, RNA polymerase III, “triple negative SSc”) is poorly characterized. We assessed clinical features and prevalence of additional autoantibodies in these patients. METHODS: In this case series patients with ANA+ and triple negative SSc antibodies were identified from two independent SSc cohorts (n=280) and demographic and clinical data were obtained over two years. Sera were screened for ANA and autoantibodies were examined by immunoblots. Significance was assessed through Fisher’s exact test and Student’s T-test. RESULTS: Forty ANA+ triple negative SSc patients (14% of the two SSc cohorts) were identified. Mean age was 53 ± 14.5 years, 53% had limited disease, average disease duration was 9 ± 9.7 years, and MRSS was 7.6 ± 6.8. 47.5% of the patients had digital ulcers, 60% had interstitial lung disease and 15% had pulmonary hypertension. The most common immunofluorescence patterns were speckled and mixed speckled/nucleolar. Of 29 autoantibodies tested, the most prevalent were Ro-52 (50%), Th/To (40%), MDA5 (35%), SAE1 (28%). Ro-52 was associated with ILD (RR 2.67, p

Objectives Four intrinsic molecular subsets (inflammatory, fibroproliferative, limited, normal-like) have previously been identified in SSc and are characterized by unique gene expression signatures and pathways. The intrinsic subsets have been linked to improvement with specific therapies. Here, we investigated associations between baseline demographics and intrinsic molecular subsets in a meta-analysis of published datasets. Methods Publicly available gene expression data from skin biopsies of 311 SSc patients measured by DNA microarray were classified into the intrinsic molecular subsets. RNA-sequencing data from 84 participants from the ASSET trial were used as a validation cohort. Baseline clinical demographics and intrinsic molecular subsets were tested for statistically significant associations. Results Males were more likely to be classified in the fibroproliferative subset (P = 0.0046). SSc patients who identified as African American/Black were 2.5 times more likely to be classified as fibroproliferative compared with White/Caucasian patients (P = 0.0378). ASSET participants sera positive for anti-RNA pol I and RNA pol III autoantibodies were enriched in the inflammatory subset (P = 5.8 × 10−5, P = 9.3 × 10−5, respectively), while anti-Scl-70 was enriched in the fibroproliferative subset. Mean modified Rodnan Skin Score (mRSS) was statistically higher in the inflammatory and fibroproliferative subsets compared with normal-like (P = 0.0027). The average disease duration for inflammatory subset was less than fibroproliferative and normal-like intrinsic subsets (P = 8.8 × 10−4). Conclusions We identified multiple statistically significant differences in baseline demographics between the intrinsic subsets that may represent underlying features of disease pathogenesis (e.g. chronological stages of fibrosis) and have implications for treatments that are more likely to work in certain SSc populations.

Epithelial polyploidization post-injury is a conserved phenomenon, recently shown to improve barrier restoration during wound healing. Whether lung injury can induce alveolar epithelial polyploidy is not known. We show that bleomycin injury induces AT2 cell hypertrophy and polyploidy. AT2 polyploidization is also seen in short term ex vivo cultures, where AT2-to-AT1 trans-differentiation is associated with substantial binucleation due to failed cytokinesis. Both hypertrophic and polyploid features of AT2 cells can be attenuated by inhibiting the integrated stress response (ISR) using the small molecule ISRIB. These data suggest that AT2 hypertrophic growth and polyploidization may be a feature of alveolar epithelial injury. As AT2 cells serve as facultative progenitors for the distal lung epithelium, a propensity for injury-induced binucleation has implications for AT2 self-renewal and regenerative potential upon reinjury, which may benefit from targeting the ISR.

Explore trial participants’ and research team members’ perceptions of the impact of the videoconference-based, supportive care program (SPIN-CHAT Program) during early COVID-19 for individuals with systemic sclerosis (SSc). Data were collected cross-sectionally. A social constructivist paradigm was adopted, and one-on-one videoconference-based, semi-structured interviews were conducted with SPIN-CHAT Trial participants and research team members. A hybrid inductive-deductive approach and reflexive thematic analysis were used. Of the 40 SPIN-CHAT Trial participants and 28 research team members approached, 30 trial participants (Mean age = 54.9; SD = 13.0 years) and 22 research team members agreed to participate. Those who took part in interviews had similar characteristics to those who declined. Five themes were identified: (1) The SPIN-CHAT Program conferred a range of positive psychological health outcomes, (2) People who don’t have SSc don’t get it: The importance of SSc-specific programming, (3) The group-based format of the SPIN-CHAT Program created a safe space to connect and meet similar others, (4) The structure and schedule of the SPIN-CHAT Program reduced feelings of boredom and contributed to enhanced psychological health, (5) The necessity of knowledge, skills, and tools to self-manage SSc and navigate COVID-19. Participants’ and research team members’ perspectives elucidated SPIN-CHAT Program benefits and how these benefits may have been realized. Results underscore the importance of social support from similar others, structure, and self-management to enhance psychological health during COVID-19. clinicaltrials.gov (NCT04335279)IMPLICATIONS FOR REHABILITATIONThe videoconference-based, supportive care SPIN-CHAT Program enhanced psychological health amongst individuals affected by systemic sclerosis.SPIN-CHAT Program participants and research team members shared that being around similar others, program structure, and self-management support were important and may have contributed to enhanced psychological health.Further efforts are required to explore experiences within supportive care programs to better understand if and how psychological health is impacted. The videoconference-based, supportive care SPIN-CHAT Program enhanced psychological health amongst individuals affected by systemic sclerosis. SPIN-CHAT Program participants and research team members shared that being around similar others, program structure, and self-management support were important and may have contributed to enhanced psychological health. Further efforts are required to explore experiences within supportive care programs to better understand if and how psychological health is impacted.

Immune cells are fundamental regulators of extracellular matrix (ECM) production by fibroblasts and have important roles in determining extent of fibrosis in response to inflammation. Although much is known about fibroblast signaling in fibrosis, the molecular signals between immune cells and fibroblasts that drive its persistence are poorly understood. We therefore analyzed skin and lung samples of patients with diffuse cutaneous systemic sclerosis, an autoimmune disease that causes debilitating fibrosis of the skin and internal organs. Here, we define a critical role of epiregulin-EGFR signaling between dendritic cells and fibroblasts to maintain elevated ECM production and accumulation in fibrotic tissue. We found that epiregulin expression marks an inducible state of DC3 dendritic cells triggered by type I interferon and that DC3-derived epiregulin activates EGFR on fibroblasts, driving a positive feedback loop through NOTCH signaling. In mouse models of skin and lung fibrosis, epiregulin was essential for persistence of fibrosis in both tissues, which could be abrogated by epiregulin genetic deficiency or a neutralizing antibody. Therapeutic administration of epiregulin antibody reversed fibrosis in patient skin and lung explants, identifying it as a previously unexplored biologic drug target. Our findings reveal epiregulin as a crucial immune signal that maintains skin and lung fibrosis in multiple diseases and represents a promising antifibrotic target.

Background Systemic sclerosis (scleroderma; SSc) is a rare autoimmune connective tissue disease. We completed an initial feasibility trial of an online self-administered version of the Scleroderma Patient-centered Intervention Network Self-Management (SPIN-SELF) Program using the cohort multiple randomized controlled trial (RCT) design. Due to low intervention offer uptake, we will conduct a new feasibility trial with progression to full-scale trial, using a two-arm parallel, partially nested RCT design. The SPIN-SELF Program has also been revised to include facilitator-led videoconference group sessions in addition to online material. We will test the group-based intervention delivery format, then evaluate the effect of the SPIN-SELF Program on disease management self-efficacy (primary) and patient activation, social appearance anxiety, and functional health outcomes (secondary). Methods This study is a feasibility trial with progression to full-scale RCT, pending meeting pre-defined criteria, of the SPIN-SELF Program. Participants will be recruited from the ongoing SPIN Cohort (http://www.spinsclero.com/en/cohort) and via social media and partner patient organizations. Eligible participants must have SSc and low to moderate disease management self-efficacy (Self-Efficacy for Managing Chronic Disease (SEMCD) Scale score ≤ 7.0). Participants will be randomized (1:1 allocation) to the group-based SPIN-SELF Program or usual care for 3 months. The primary outcome in the full-scale trial will be disease management self-efficacy based on SEMCD Scale scores at 3 months post-randomization. Secondary outcomes include SEMCD scores 6 months post-randomization plus patient activation, social appearance anxiety, and functional health outcomes at 3 and 6 months post-randomization. We will include 40 participants to assess feasibility. At the end of the feasibility portion, stoppage criteria will be used to determine if the trial procedures or SPIN-SELF Program need important modifications, thereby requiring a re-set for the full-scale trial. Otherwise, the full-scale RCT will proceed, and outcome data from the feasibility portion will be utilized in the full-scale trial. In the full-scale RCT, 524 participants will be recruited. Discussion The SPIN-SELF Program may improve disease management self-efficacy, patient activation, social appearance anxiety, and functional health outcomes in people with SSc. SPIN works with partner patient organizations around the world to disseminate its programs free-of-charge. Trial registration ClinicalTrials.govNCT04246528. Registered on 27 January 2020

Tissue availability remains an important limitation of single-cell genomic technologies for investigating cellular heterogeneity in human health and disease. Bronchoalveolar lavage (BAL) represents a minimally invasive approach to assess an individual's lung cellular environment for diagnosis and research. However, the lack of high-quality healthy lung reference data is a major obstacle to using single-cell approaches to study a plethora of lung diseases. Here, we performed single-cell RNA-sequencing (scRNA-seq) on over 40,000 cells isolated from BAL of four healthy volunteers. Of the six cell types or lineages that we identified, macrophages were consistently the most numerous across individuals. Our analysis confirmed the expression of marker genes defining cell types despite background signal due to the ambient RNA found in many single-cell studies. We assessed variability of gene expression across macrophages and defined a distinct subpopulation of cells expressing a set of genes associated with the Macrophage Inflammatory Protein (MIP-1). RNA in situ hybridization and re-analysis of published lung single-cell data validated the presence of this macrophage subpopulation. Thus, our study characterizes lung macrophage heterogeneity in healthy individuals and provides a valuable resource for future studies to understand the lung environment in health and disease.

Objective.To investigate the association between Raynaud phenomenon (RP) and coronary microvascular dysfunction, we measured myocardial flow reserve (MFR) using positron emission tomography/computed tomography (PET/CT) in patients with primary and secondary RP and controls.Methods.Patients with RP, patient controls, and healthy participants who underwent dynamic rest-stress 82-rubidium PET/CT were studied. Differences in heart rate–blood pressure product-corrected MFR and clinical predictors of reduced MFR (< 2.0) were determined.Results.Forty-nine patients with RP (80% female; aged 65 ± 11 yrs; 11 with primary RP, 18 with systemic sclerosis [SSc], and 20 with other autoimmune rheumatic diseases [AIRDs] including 6 with systemic lupus erythematosus, 6 with rheumatoid arthritis, 4 with overlap syndrome, 2 with Sjögren syndrome, and 2 with inflammatory arthritis), 49 matched patients without RP or AIRD (78% female; 64 ± 13 yrs), and 14 healthy participants (50% female; 35 ± 5 yrs) were studied. Patients with primary RP, matched patient controls, and healthy participants had comparable MFR. Patients with SSc-RP had significantly reduced MFR (1.62 ± 0.32) compared to matched patient controls (P = 0.03, 2.06 ± 0.61) and to healthy participants (P = 0.01, 2.22 ± 0.44). In multivariable logistic regression, SSc was an independent predictor of reduced MFR. We identified a correlation between time since AIRD diagnosis and MFR (r = –0.30, 95% CI –0.63 to –0.02, P = 0.04).Conclusion.Our findings suggest that only secondary, not primary, RP is associated with reduced MFR, and that patients with SSc-RP have reduced MFR compared to those with primary RP and patients with other AIRDs. Larger prospective studies are warranted to fully elucidate the prognostic value of MFR in patients with secondary RP.

While interstitial lung disease (ILD) is the leading cause of morbidity and mortality in systemic sclerosis (SSc), there remains a paucity of predictive markers to assess disease progression. We previously demonstrated that adipose tissue metabolism and adipokine homeostasis is dysregulated in SSc. The present study was undertaken to determine the association and predictive ability of the novel adipokine C1q/tumor necrosis factor-related protein 9 (CTRP9) for SSc-associated ILD.We performed a retrospective longitudinal study utilizing the Northwestern Scleroderma Program Patient Registry and Biorepository. Serum levels of CTRP9 were measured in 110 SSc patients at baseline, and demographic, clinical, and pulmonary function test data were collected in 12-month intervals to 48 months. Longitudinal trajectory of forced vital capacity percent predicted (FVC%) was used as a primary outcome measure. We utilized a mixed model to compare trajectories of lung function by CTRP9 groups and performed latent trajectory analysis to accommodate for heterogeneity.In cross-sectional analysis, elevated circulating CTRP9 was associated with significantly lower FVC% at baseline (72% ± 17 versus 80% ± 18; P = 0.02) and 48 months (68 ± 19 versus 84 ± 18; P = 0.001). In mixed model analysis, high CTRP9 was associated with worse lung function but not with a different trajectory (P = 0.23). In contrast, low CTRP9 identified patients with stability of lung disease with reasonable accuracy (sensitivity 73%). Latent trajectory analysis confirmed the association of lower CTRP9 with higher FVC%.Higher circulating CTRP9 associated with worse pulmonary function, while low CTRP9 identified patients with lung disease stability over time. These findings suggest that CTRP9 may be a potential biomarker in SSc-associated ILD.

Systemic sclerosis (SSc) patients are classified according to degree of skin fibrosis (limited and diffuse cutaneous) and serum autoantibodies. We undertook the present multicenter study to determine if intrinsic subset (IS) classification based upon skin gene expression yields additional valuable clinical information.SSc patients and healthy participants (HP) were classified as Normal-like, Limited, Fibroproliferative and Inflammatory IS using a previously trained classifier. Clinical data were obtained (serum autoantibodies, pulmonary function testing, modified Rodnan Skin scores [mRSS], and high-resolution chest computed tomography [HRCT]). Statistical analyses were performed to compare patients classified by IS, traditional cutaneous classification, and serum autoantibodies.223 participants (165 SSc [115 dcSSc and 50 lcSSc] and 58 HP) were classified. Inflammatory IS patients had higher mRSS (22.1±9.9, p0.001) than other IS and dcSSc (19.4±9.4, p= 0.05) despite similar disease duration (median [IQR] months 14.9[19.9] vs 18.4[31.6], p=0.48). In multivariable modeling, no significant association between mRSS and RNA Pol III (p=0.07) or Scl-70 (p=0.09) was found. Radiographic ILD was more prevalent in Fibroproliferative IS compared to other IS (91%, p=0.04) with similar prevalence between lcSSc and dcSSc (67% vs. 76%, p=0.73). Positive Scl-70 antibody was the strongest ILD predictor (p0.001). Interestingly, all lcSSc/Fibroproliferative patients were demonstrated radiographic ILD.Classification by IS identifies patients with distinct clinical phenotypes versus traditional cutaneous or autoantibody classification. IS classification identifies subgroups of SSc patients with more radiographic ILD (Fibroproliferative), higher mRSS (Inflammatory) and milder phenotype (Normal-like), and may provide additional clinically useful information to current SSc classification systems. This article is protected by copyright. All rights reserved.

Disease severity biomarkers in patients with systemic sclerosis (SSc) provide an early and noninvasive screening tool to identify patients at increased risk for internal organ involvement that may impact diagnostic testing and treatment decisions. This review will focus on soluble SSc vascular and gastrointestinal disease biomarkers. Due to high morbidity and mortality associated with SSc pulmonary hypertension, multiple biomarkers are currently under investigation including serum autoantibodies, chemistries (such as N-terminal pro-brain natriuretic peptide (NT-proBNP)), proteins (midkine (MDK) and follistatin-like 3 (FSTL3)), chemokines (C-X-C motif ligand 4 (CXCL4) and C-C motif ligand 21 (CCL21)), plasma growth factors (vascular endothelial growth factor (VEGF) and placental growth factor (PlGF)), cell adhesion molecules (vascular cell adhesion molecule 1 (VCAM-1)), and endothelial microparticles (CD144+ endothelial microparticle (CD144+ EMP)). A subset of these has also been proposed as SSc digital ulcer biomarkers (anti-endothelin-1 type A receptor (anti-ETAR), PlGF, and NT-proBNP). A combination of NT-proBNP and high sensitivity cardiac troponins T (hs-cTnT) and I (hs-cTnI) may be useful for assessing primary SSc cardiac involvement. Putative SSc renal disease biomarkers include VEGF and endostatin levels, while anti-U1 and U3 ribonucleoprotein (anti-U1- and anti-U3-RNP) antibodies and fecal-calprotectin (F-calprotectin) are associated with GI involvement. Serum autoantibodies are the mainstay SSc severity biomarkers, but new biomarkers are under investigation.

Autoantibodies that recognize extracellular proteins (the exoproteome) exert potent biological effects but are challenging to detect. Here, we developed rapid extracellular antigen profiling (REAP), a high-throughput technique for the comprehensive discovery of exoproteome-targeting autoantibodies. Patient samples are applied to a genetically barcoded yeast surface display library containing 2,688 human extracellular proteins. Antibody-coated yeast are isolated, and sequencing of barcodes is used to identify displayed antigens. To benchmark REAP's performance, we screened 77 patients with autoimmune polyglandular syndrome type 1 (APS-1). REAP sensitively and specifically detected both known and previously unidentified autoantibodies in APS-1. We further screened 106 patients with systemic lupus erythematosus (SLE) and identified numerous autoantibodies, several of which were associated with disease severity or specific clinical manifestations and exerted functional effects on cell signaling

Objective Calcinosis is a debilitating complication of systemic sclerosis (SSc) with no effective treatments. We sought to identify clinical correlations and to characterize complications and disability associated with calcinosis in a multi-center, international cohort of SSc patients. Methods We established a cohort of 568 consecutive SSc patients who fulfill 2013 revised ACR/EULAR criteria at 10 centers within North America, Australia, and Mexico. Calcinosis was defined as subcutaneous calcium deposition by imaging and/or physical examination, or a clear history of extruded calcium. All patients completed the Scleroderma Health Assessment Questionnaire Disability Index and Cochin Hand Functional Scale. Results 215 (38%) patients had calcinosis. In multivariable analysis, disease duration (OR=1.24, p = 0.029), digital ischemia (OR=1.8, p = 0.002) and Acro-osteolysis (OR=2.97, p = 0.008) were significantly associated with calcinosis. In the subset of patients with bone densitometry (n = 68), patients with calcinosis had significantly lower median T-scores than patients without (-2.2 vs. -1.7, p = 0.004). The most common location of calcinosis lesions was the hands (70%), particularly the thumbs (19%) with decreasing frequency moving to the fifth fingers (8%). The most common complications were tenderness (29% of patients) and spontaneous extrusion of calcinosis through the skin (20%), while infection was rare (2%). Disability and hand function were worse in patients with calcinosis, particularly if locations in addition to the fingers/thumbs were involved. Conclusions We confirmed a strong association between calcinosis and digital ischemia. Calcinosis in SSc patients most commonly affects the hands and is associated with a high burden of disability and hand dysfunction.

Introduction: Previously, we discovered similar esophageal gene expression patterns in patients with systemic sclerosis and eosinophilic esophagitis where eosinophil/mast cell–targeted therapies are beneficial. Because systemic sclerosis and eosinophilic esophagitis patients experience similar esophageal symptoms, we hypothesized that eosinophil/mast cell–directed therapy may potentially benefit systemic sclerosis patients. Herein, we determine the association between esophageal mast cell quantities, gene expression, and clinical parameters in order to identify systemic sclerosis patients who may benefit from eosinophil/mast cell–directed therapy. Methods: Esophageal biopsies from systemic sclerosis patients and healthy participants were stained for tryptase, a mast cell marker, and associations with relevant clinical parameters including 24-h esophageal pH testing were assessed. Intra-epithelial mast cell density was quantified by semi-automated microscopy. Microarray data were utilized for functional and gene set enrichment analyses and to identify intrinsic subset assignment, a systemic sclerosis molecular classification system that includes inflammatory, proliferative, limited, and normal-like subsets. Results: Esophageal biopsies from 40 systemic sclerosis patients (39 receiving proton pump inhibition) and eleven healthy participants were studied. Mast cell numbers in both the upper esophagus ( rs = 0.638, p = 0.004) and the entire (upper + lower) esophagus ( rs = 0.562, p = 0.019) significantly correlated with acid exposure time percentage. The inflammatory, fibroproliferative, and normal-like intrinsic subset originally defined in skin biopsies were identified in esophageal biopsies. Although esophageal mast cell numbers in systemic sclerosis patients and healthy participants were similar, gene expression for mast cell–related pathways showed significant upregulation in the inflammatory intrinsic subset of systemic sclerosis patients compared to patients classified as proliferative or normal-like. Discussion: Esophageal mast cell numbers are heterogeneous in systemic sclerosis patients and may correlate with acid exposure. Patients with inflammatory intrinsic subset profiles in the esophagus demonstrate more tryptase staining. Mast cell–targeted therapy may be a useful therapeutic approach in systemic sclerosis patients belonging to the inflammatory intrinsic subset, but additional studies are warranted.

OBJECTIVE Genome-wide gene expression studies implicate macrophages as mediators of fibrosis in systemic sclerosis (SSc), but little is known about how these cells contribute to fibrotic activation in SSc. We undertook this study to characterize the activation profile of SSc monocyte-derived macrophages and assessed their interaction with SSc fibroblasts. METHODS Plasma and peripheral blood mononuclear cells (PBMCs) were obtained from whole blood from SSc patients (n = 24) and age- and sex-matched healthy controls (n = 12). Monocytes were cultured with autologous or allogeneic plasma to differentiate cells into macrophages. For reciprocal activation studies, macrophages were cocultured with fibroblasts using Transwell plates. RESULTS The gene expression signature associated with blood-derived human SSc macrophages was enriched in SSc skin in an independent cohort and correlated with skin fibrosis. SSc macrophages expressed surface markers associated with activation and released CCL2, interleukin-6, and transforming growth factor β under basal conditions (n = 8) (P < 0.05). Differentiation of healthy donor monocytes in plasma from SSc patients conferred the immunophenotype of SSc macrophages (n = 13) (P < 0.05). Transwell experiments demonstrated that coculture of SSc macrophages with SSc fibroblasts induced fibroblast activation (n = 3) (P < 0.05). CONCLUSION These data demonstrate that the activation profile of SSc macrophages is profibrotic. SSc macrophages are activated under basal conditions and release mediators and express surface markers associated with both alternative and inflammatory macrophage activation. These findings also suggest that activation of SSc macrophages arises from soluble factors in local microenvironments. These studies implicate macrophages as likely drivers of fibrosis in SSc and suggest that therapeutic targeting of these cells may be beneficial in ameliorating disease in SSc patients.

Background Skin fibrosis is the clinical hallmark of systemic sclerosis (SSc), where collagen deposition and remodeling of the dermis occur over time. The most widely used outcome measure in SSc clinical trials is the modified Rodnan skin score (mRSS), which is a semi-quantitative assessment of skin stiffness at seventeen body sites. However, the mRSS is confounded by obesity, edema, and high inter-rater variability. In order to develop a new histopathological outcome measure for SSc, we applied a computer vision technology called a deep neural network (DNN) to stained sections of SSc skin. We tested the hypotheses that DNN analysis could reliably assess mRSS and discriminate SSc from normal skin. Methods We analyzed biopsies from two independent (primary and secondary) cohorts. One investigator performed mRSS assessments and forearm biopsies, and trichrome-stained biopsy sections were photomicrographed. We used the AlexNet DNN to generate a numerical signature of 4096 quantitative image features (QIFs) for 100 randomly selected dermal image patches/biopsy. In the primary cohort, we used principal components analysis (PCA) to summarize the QIFs into a Biopsy Score for comparison with mRSS. In the secondary cohort, using QIF signatures as the input, we fit a logistic regression model to discriminate between SSc vs. control biopsy, and a linear regression model to estimate mRSS, yielding Diagnostic Scores and Fibrosis Scores, respectively. We determined the correlation between Fibrosis Scores and the published Scleroderma Skin Severity Score (4S) and between Fibrosis Scores and longitudinal changes in mRSS on a per patient basis. Results In the primary cohort (n = 6, 26 SSc biopsies), Biopsy Scores significantly correlated with mRSS (R = 0.55, p = 0.01). In the secondary cohort (n = 60 SSc and 16 controls, 164 biopsies; divided into 70% training and 30% test sets), the Diagnostic Score was significantly associated with SSc-status (misclassification rate = 1.9% [training], 6.6% [test]), and the Fibrosis Score significantly correlated with mRSS (R = 0.70 [training], 0.55 [test]). The DNN-derived Fibrosis Score significantly correlated with 4S (R = 0.69, p = 3 × 10− 17). Conclusions DNN analysis of SSc biopsies is an unbiased, quantitative, and reproducible outcome that is associated with validated SSc outcomes.

Background/PurposePatients with systemic sclerosis (SSc) display a complex clinical phenotype. There are numerous studies that relate transcriptional signatures from PBMC or whole skin of SSc patients to disease activity. However, analyses of whole tissue RNA-sequencing studies are subjected to changes in cellular composition that can drive gene expression signatures and a loss of the ability to detect biologically important transcriptional changes within minority cell populations. Here, we focused on circulating monocytes, which have been shown to exist as two central populations classical (CM) and non-classical (NCM).MethodsSSc patients were recruited from four different sites that form PRESS: Northwestern University, University of Texas, University of Michigan and University of Utah. Comprehensive clinical data was collected for all patients. We isolated CM and NCM from these patients and age, sex, and race-matched healthy volunteers were used as controls. RNA-seq was performed on CM and NCM populations as well as on isolated bulk macrophages from skin.ResultsWe first performed RNA-seq on CM, which are the predominant population in circulation. In order to capture the variability across the SSc cohort, we defined 1790 differentially expressed genes in each patient. We then used these genes to cluster patients into 3 subgroups: Groups A-C. Group A exhibited the strongest interferon signature and innate immune pathways. Group B patients expressed genes in the same pathways but was also enriched for response to cAMP and corticosteroids. Both Group B and Group C exhibited upregulation of genes associated with vasculature development and blood vessel formation. Group C uniquely upregulated TGFB pathways. Next, we performed RNA-seq on NCM isolated from the same patients. When NCM were clustered based on the same 1790 genes as CM, we found that Groups A and C were recapitulated, while Group B was less cohesive. Our analysis stratified SSc patients based on their transcriptional profiles in monocytes but was agnostic to their clinical presentation. We found that Group B and C patients exhibited significantly worsened lung function at the time of monocyte isolation than Group A patients. However, there were no significant differences in skin disease. We then isolated macrophages from skin biopsies of SSc patients and showed that the transcriptional profile of Group A and C in SSc patients was conserved. We also used gene expression data from another study on monocytes which stratified patients based on disease presentation. We found that Group A accurately distinguished dcSSc and ncSSc patients from controls, but not lcSSc.ConclusionWe are the first to show that transcriptomic analysis of classical and non-classical circulating monocytes can unbiasedly stratify SSc patients and correlate with disease activity outcome measures.

Background Although esophageal dysmotility is common in systemic sclerosis (SSc)/scleroderma, little is known regarding the pathophysiology of motor abnormalities driving reflux severity and dysphagia. This study aimed to assess primary and secondary peristalsis in SSc using a comprehensive esophageal motility assessment applying high-resolution manometry (HRM) and functional luminal imaging probe (FLIP) Panometry. Methods A total of 32 patients with scleroderma (28 female; ages 38-77; 20 limited SSc, 12 diffuse SSc) completed FLIP Panometry and HRM. Secondary peristalsis, i.e., contractile responses (CR), was classified on FLIP Panometry by pattern of contractility as normal (NCR), borderline (BCR), impaired/disordered (IDCR), or absent (ACR). Primary peristalsis on HRM was assessed according to the Chicago classification. Results The manometric diagnoses were 56% (n = 18) absent contractility, 22% (n = 7) ineffective esophageal motility (IEM), and 22% (n = 7) normal motility. Secondary peristalsis (CRs) included 38% (n = 12) ACR, 38% (n = 12) IDCR, 19% (n = 6) BCR, and 15% (n = 5) NCR. The median (IQR) esophagogastric junction (EGJ) distensibility index (DI) was 5.8 mm2 /mmHg (4.8-10.1) mm2 /mmHg; EGJ-DI was >8.0 mm2 /mmHg in 31%, and >2.0 mm2 /mmHg in 100% of patients. Among 18 patients with absent contractility on HRM, 11 had ACR, 5 had IDCR, and 2 had BCR. Among 7 patients with IEM, 1 had ACR, 5 had IDCR, and 1 NCR. All of the patients with normal peristalsis had NCR or BCR. Conclusions This was the first study assessing combined HRM and FLIP Panometry in a cohort of SSc patients, which demonstrated heterogeneity in primary and secondary peristalsis. This complementary approach facilitates characterizing esophageal function in SSc, although future study to examine clinical outcomes remains necessary.

Background: Coronary microvascular dysfunction has been described in patients with autoimmune rheumatic disease (ARD). However, it is unknown whether positron emission tomography (PET)-derived myocardial flow reserve (MFR) can predict adverse events in this population. Methods: Patients with ARD without coronary artery disease who underwent dynamic rest-stress 82 Rubidium PET were retrospectively studied and compared with patients without ARD matched for age, sex, and comorbidities. The association between MFR and a composite end point of mortality or myocardial infarction or heart failure admission was evaluated with time to event and Cox-regression analyses. Results: In 101 patients with ARD (88% female, age: 62±10 years), when compared with matched patients without ARD (n=101), global MFR was significantly reduced (median: 1.68 [interquartile range: 1.34–2.05] versus 1.86 [interquartile range: 1.58–2.28]) and reduced MFR (1.5) and when compared with patients without ARD and low MFR, after adjustment for the nonlaboratory-based Framingham risk score, rest left ventricular ejection fraction, severe coronary calcification, and the presence of medium/large perfusion defects. In Cox-regression analysis, ARD diagnosis and reduced MFR were both independent predictors of adverse events along with congestive heart failure diagnosis and presence of medium/large stress perfusion defects on PET. Further analysis with inclusion of an interaction term between ARD and impaired MFR revealed no significant interaction effects between ARD and impaired MFR. Conclusions: In our retrospective cohort analysis, patients with ARD had significantly reduced PET MFR compared with age-, sex-, and comorbidity-matched patients without ARD. Reduced PET MFR and ARD diagnosis were both independent predictors of adverse outcomes.

ObjectiveTo identify clinical factors, including esophageal dilation on chest high-resolution computed tomography (HRCT), that are associated with pulmonary function decline in patients with systemic sclerosis (SSc).MethodsPatients fulfilled 2013 SSc criteria and had ≥ 1 HRCT and ≥ 2 pulmonary function tests (PFTs). According to published methods, widest esophageal diameter (WED) and radiographic interstitial lung disease (ILD) were assessed, and WED was dichotomized as dilated (≥ 19 mm) vs not dilated (< 19 mm). Clinically meaningful PFT decline was defined as % predicted change in forced vital capacity (FVC) ≥ 5 and/or diffusion capacity for carbon monoxide (DLCO) ≥ 15. Linear mixed effects models were used to model PFT change over time.ResultsOne hundred thirty-eight patients with SSc met the study criteria: 100 (72%) had radiographic ILD; 49 (35%) demonstrated FVC decline (median follow-up 2.9 yrs). Patients with antitopoisomerase I (Scl-70) autoantibodies had 5-year FVC% predicted decline (–6.33, 95% CI –9.87 to –2.79), whereas patients without Scl-70 demonstrated 5-year FVC stability (+1.78, 95% CI –0.59 to 4.15). Esophageal diameter did not distinguish between those with vs without FVC decline. Patients with esophageal dilation had statistically significant 5-year DLCO% predicted decline (–5.58, 95% CI –10.00 to –1.15), but this decline was unlikely clinically significant. Similar results were observed in the subanalysis of patients with radiographic ILD.ConclusionIn patients with SSc, Scl-70 positivity is a risk factor for FVC% predicted decline at 5 years. Esophageal dilation on HRCT was associated with a minimal, nonclinically significant decline in DLCO and no change in FVC during the 5-year follow-up. These results have prognostic implications for SSc-ILD patients with esophageal dilation.

OBJECTIVE: To investigate the association between Raynaud phenomenon (RP) and coronary microvascular dysfunction, we measured myocardial flow reserve (MFR) using positron emission tomography/computed tomography (PET/CT) in primary and secondary RP patients and controls. METHODS: RP patients, patient controls and healthy participants who underwent dynamic rest-stress 82-Rubidium PET/CT were studied. Differences in heart rate-blood pressure product corrected MFR and clinical predictors of reduced MFR (< 2.0) were determined. RESULTS: 49 RP patients (80% female, 65 ± 11 years): 11 primary RP, 18 systemic sclerosis (SSc) and 20 other autoimmune diseases (AID) (n=6 systemic lupus erythematosus, n=6 rheumatoid arthritis, n=4 overlap syndrome, n=2 Sjogren’s syndrome, n=2 inflammatory arthritis), 49 matched patients without RP or AID (78% female, 64 ± 13 years) and 14 healthy participants (50% female, 35 ± 5 years) were studied. Primary RP patients, matched patient controls and healthy participants had comparable MFR. SSc-RP patients had significantly reduced MFR (1.62 ± 0.32) compared to matched patient controls (p=0.03, 2.06 ± 0.61) and to healthy participants (p=0.01, 2.22 ± 0.44). In multivariable logistic regression, SSc was an independent predictor of reduced MFR. We identified a correlation between time since AID diagnosis and MFR (r= −0.37; 95% CI: −0.61 to −0.09; p=0.01). CONCLUSION: Our findings suggest that only secondary, not primary, RP is associated with reduced MFR, and that SSc-RP patients have reduced MFR compared to primary RP and other autoimmune disease patients. Larger prospective studies are warranted to fully elucidate the prognostic value of MFR in patients with secondary RP.

Interstitial lung disease is common among patients with connective tissue disease and is an important contributor to morbidity and mortality. Infection and drug toxicity must always be excluded as the cause of radiographic findings. Immunosuppression remains a mainstay of therapy despite few controlled trials supporting its use. When a decision regarding therapy initiation is made, considerations include an assessment of disease severity as well as a determination of the rate of progression. Because patients may have extrathoracic disease activity, a multidisciplinary approach is crucial and should include supportive and nonpharmacologic management strategies.

Rationale: The contributions of diverse cell populations in the human lung to pulmonary fibrosis pathogenesis are poorly understood. Single-cell RNA sequencing can reveal changes within individual cell populations during pulmonary fibrosis that are important for disease pathogenesis. Objectives: To determine whether single-cell RNA sequencing can reveal disease-related heterogeneity within alveolar macrophages, epithelial cells, or other cell types in lung tissue from subjects with pulmonary fibrosis compared with control subjects. Methods: We performed single-cell RNA sequencing on lung tissue obtained from eight transplant donors and eight recipients with pulmonary fibrosis and on one bronchoscopic cryobiospy sample from a patient with idiopathic pulmonary fibrosis. We validated these data using in situ RNA hybridization, immunohistochemistry, and bulk RNA-sequencing on flow-sorted cells from 22 additional subjects. Measurements and Main Results: We identified a distinct, novel population of profibrotic alveolar macrophages exclusively in patients with fibrosis. Within epithelial cells, the expression of genes involved in Wnt secretion and response was restricted to nonoverlapping cells. We identified rare cell populations including airway stem cells and senescent cells emerging during pulmonary fibrosis. We developed a web-based tool to explore these data. Conclusions: We generated a single-cell atlas of pulmonary fibrosis. Using this atlas, we demonstrated heterogeneity within alveolar macrophages and epithelial cells from subjects with pulmonary fibrosis. These results support the feasibility of discovery-based approaches using next-generation sequencing technologies to identify signaling pathways for targeting in the development of personalized therapies for patients with pulmonary fibrosis.

Summary Background There is an urgent need for biomarkers to better stratify patients with idiopathic pulmonary fibrosis by risk for lung transplantation allocation who have the same clinical presentation. We aimed to investigate whether a specific immune cell type from patients with idiopathic pulmonary fibrosis could identify those at higher risk of poor outcomes. We then sought to validate our findings using cytometry and electronic health records. Methods We first did a discovery analysis with transcriptome data from the Gene Expression Omnibus at the National Center for Biotechnology Information for 120 peripheral blood mononuclear cell (PBMC) samples of patients with idiopathic pulmonary fibrosis. We estimated percentages of 13 immune cell types using statistical deconvolution, and investigated the association of these cell types with transplant-free survival. We validated these results using PBMC samples from patients with idiopathic pulmonary fibrosis in two independent cohorts (COMET and Yale). COMET profiled monocyte counts in 45 patients with idiopathic pulmonary fibrosis from March 12, 2010, to March 10, 2011, using flow cytometry; we tested if increased monocyte count was associated with the primary outcome of disease progression. In the Yale cohort, 15 patients with idiopathic pulmonary fibrosis (with five healthy controls) were classed as high risk or low risk from April 28, 2014, to Aug 20, 2015, using a 52-gene signature, and we assessed whether monocyte percentage (measured by cytometry by time of flight) was higher in high-risk patients. We then examined complete blood count values in the electronic health records (EHR) of 45 068 patients with idiopathic pulmonary fibrosis, systemic sclerosis, hypertrophic cardiomyopathy, or myelofibrosis from Stanford (Jan 01, 2008, to Dec 31, 2015), Northwestern (Feb 15, 2001 to July 31, 2017), Vanderbilt (Jan 01, 2008, to Dec 31, 2016), and Optum Clinformatics DataMart (Jan 01, 2004, to Dec 31, 2016) cohorts, and examined whether absolute monocyte counts of 0·95 K/μL or greater were associated with all-cause mortality in these patients. Findings In the discovery analysis, estimated CD14+ classical monocyte percentages above the mean were associated with shorter transplant-free survival times (hazard ratio [HR] 1·82, 95% CI 1·05–3·14), whereas higher percentages of T cells and B cells were not (0·97, 0·59–1·66; and 0·78, 0·45–1·34 respectively). In two validation cohorts (COMET trial and the Yale cohort), patients with higher monocyte counts were at higher risk for poor outcomes (COMET Wilcoxon p=0·025; Yale Wilcoxon p=0·049). Monocyte counts of 0·95 K/μL or greater were associated with mortality after adjusting for forced vital capacity (HR 2·47, 95% CI 1·48–4·15; p=0·0063), and the gender, age, and physiology index (HR 2·06, 95% CI 1·22–3·47; p=0·0068) across the COMET, Stanford, and Northwestern datasets). Analysis of medical records of 7459 patients with idiopathic pulmonary fibrosis showed that patients with monocyte counts of 0·95 K/μL or greater were at increased risk of mortality with lung transplantation as a censoring event, after adjusting for age at diagnosis and sex (Stanford HR=2·30, 95% CI 0·94–5·63; Vanderbilt 1·52, 1·21–1·89; Optum 1·74, 1·33–2·27). Likewise, higher absolute monocyte count was associated with shortened survival in patients with hypertrophic cardiomyopathy across all three cohorts, and in patients with systemic sclerosis or myelofibrosis in two of the three cohorts. Interpretation Monocyte count could be incorporated into the clinical assessment of patients with idiopathic pulmonary fibrosis and other fibrotic disorders. Further investigation into the mechanistic role of monocytes in fibrosis might lead to insights that assist the development of new therapies. Funding Bill & Melinda Gates Foundation, US National Institute of Allergy and Infectious Diseases, and US National Library of Medicine.

Rationale and objective While COVID-19 infection has been associated with acute kidney injury (AKI), it is unclear whether this association is independent of traditional risk factors such as hypotension, nephrotoxin exposure, and inflammation. We tested the independent association of COVID-19 with AKI. Study Design Multicenter, observational, cohort study. Setting and participants Patients admitted to one of six hospitals within the Yale-New Haven Health System between 3/10/2020 and 8/31/2020 and tested for SARS-CoV-2 via nasopharyngeal PCR test. Exposure Positive test for SARS-CoV-2. Outcome AKI by Kidney Disease: Improving Global Outcomes criteria. Analytic approach Evaluated the association of COVID-19 with AKI after controlling for time-invariant factors at admission (e.g., demographics, comorbidities) and time-varying factors updated continuously during hospitalization (e.g., vital signs, medications, laboratory results, respiratory failure) using time-updated Cox proportional hazard models. Results Of the 22,122 patients hospitalized between, 2,600 tested positive and 19,522 tested negative for SARS-CoV-2. Compared to patients who tested negative, patients with COVID-19 had more AKI [30.6% vs. 18.2%, absolute risk difference 12.5 (95% CI, 10.6, 14.3)%] and dialysis-requiring AKI (8.5% vs. 3.6%) and lower recovery from AKI (58% vs. 69.8%]. Compared to patients who tested negative, patients with COVID-19 had higher inflammatory markers (C-reactive protein, ferritin), and greater use of vasopressors and diuretics. Compared to patients who tested negative, patients with COVID-19 had higher rate of AKI in univariable analysis (HR, 1.84 [1.73, 1.95]). In fully adjusted model controlling for demographics, comorbidities, vital signs, medications, and laboratory results, COVID-19 remained associated with a high rate of AKI (adjusted HR, 1.40 [1.29-1.53]). Limitations Possibility of residual confounding. Conclusions COVID-19 is associated with high rates of AKI not fully explained by adjustment for known risk factors. This suggests the presence of mechanisms of AKI not accounted for in this analysis, which may include a direct effect of COVID-19 on the kidney or other unmeasured mediators. Future studies should evaluate the possible unique pathways by which COVID-19 may cause AKI., One-third of patients hospitalized with COVID-19 experience acute kidney injury (AKI), which is higher than in other hospitalized patients. Patients with COVID-19 carry many well-known risk factors for AKI including severe lung disease requiring mechanical ventilation, shock and significant inflammation. Whether higher rates of AKI in COVID-19 are above what could be expected in patients with similar risk factors is unknown. We compared AKI rates between those with and without COVID-19 after controlling for risk factors for AKI both before and during hospitalization. We found that COVID-19 was independently associated with high rates of AKI. This indicates that some of the AKI risk in patients with COVID-19 is unexplained by traditional AKI risk factors and is unique to this disease.

Systemic sclerosis (SSc; scleroderma) is a poorly understood autoimmune rheumatic disease that primarily affects women. The clinical hallmark is hardening of the skin, but internal organ dysfunction is the leading cause of death. Diagnosis and treatment are complicated by heterogeneity within the disease including variable lethality, fibrosis severity, serum autoantibody production, and internal organ involvement. Important gaps remain in our knowledge of the exact molecular and cellular pathways underlying distinct SSc subtypes. Herein, we identify genome-wide chromatin accessibility profiles of peripheral CD4+ T cells to distinguish and better understand the observed heterogeneity in SSc patients. We identify a link between serum anticentromere autoantibody (ACA) subtype and elevated levels of T helper 2 (Th2) cells and increased chromatin access at gene loci encoding fibrosis-driving Th2 cytokines IL4, IL13, and IL4 receptor. Biological sex followed by autoantibody subtype are the predominant variables associated with differences in CD4+ T cell epigenomic profiles, while mycophenolate mofetil treatment appeared to have no effect. These results suggest new mechanistic basis and therapeutic strategies to address SSc, especially the ACA+ subtype that is associated with pulmonary arterial hypertension.

BackgroundAlthough treatments have been proposed for calcinosis cutis (CC) in patients with systemic sclerosis (SSc), a standardized and validated method for CC burden quantification is necessary to enable valid clinical trials. We tested the hypothesis that computer vision applied to dual-energy computed tomography (DECT) finger images is a useful approach for precise and accurate CC quantification in SSc patients.MethodsDe-identified 2-dimensional (2D) DECT images from SSc patients with clinically evident lesser finger CC lesions were obtained. An expert musculoskeletal radiologist confirmed accurate manual segmentation (subtraction) of the phalanges for each image as a gold standard, and a U-Net Convolutional Neural Network (CNN) computer vision model for segmentation of healthy phalanges was developed and tested. A validation study was performed in an independent dataset whereby two independent radiologists manually measured the longest length and perpendicular short axis of each lesion and then calculated an estimated area by assuming the lesion was elliptical using the formula long axis/2 × short axis/2 ×π, and a computer scientist used a region growing technique to calculate the area of CC lesions. Spearman’s correlation coefficient, Lin’s concordance correlation coefficient with 95% confidence intervals (CI), and a Bland-Altman plot (Stata V 15.1, College Station, TX) were used to test for equivalence between the radiologists’ and the CNN algorithm-generated area estimates.ResultsForty de-identified 2D DECT images from SSc patients with clinically evident finger CC lesions were obtained and divided into training (N = 30 with image rotation × 3 to expand the set toN = 120) and test sets (N = 10). In the training set, five hundred epochs (iterations) were required to train the CNN algorithm to segment phalanges from adjacent CC, and accurate segmentation was evaluated using the ten held-out images. To test model performance, CC lesional area estimates calculated by two independent radiologists and a computer scientist were compared (radiologist 1 vs. radiologist 2 and radiologist 1 vs. computer vision approach) using an independent test dataset comprised of 31 images (8 index finger and 23 other fingers). For the two radiologists’, and the radiologist vs. computer vision measurements, Spearman’s rho was 0.91 and 0.94, respectively, bothp p p 2(95% limits of agreement − 10.0–9.0 mm2) and 1.7 mm2(95% limits of agreement − 6.0–9.5 mm2, respectively.ConclusionsWe demonstrate that CNN quantification has a high degree of correlation with expert radiologist measurement of finger CC area measurements. Future work will include segmentation of 3-dimensional (3D) images for volumetric and density quantification, as well as validation in larger, independent cohorts.

Background Early diffuse cutaneous systemic sclerosis (dcSSc) has the highest case fatality among rheumatic diseases. We report baseline characteristics, current immunosuppressive therapies, progression of skin and internal organ involvement, and mortality in a multicenter prospective cohort from the United States (US) of America. Methods We performed a longitudinal analysis of participants from 12 US centers, from April 2012 to July 2020. All participants had early dcSSc or were at-risk for dcSSc, with ≤2 years since the first non-Raynaud’s phenomenon (RP) symptom. Results Three hundred one patients were included with a baseline median disease duration of 1.2 years since RP and a mean modified skin score of 21.1 units. At baseline, 263 (87.3%) had definite dcSSc and 38 (12.7%) were classified as at-risk; 112 (49.6%) patients were positive for anti-RNA polymerase III antibodies. The median follow-up duration was 24.5 months (IQR = 10.3–40.7 months). One hundred ninety (63.1%) participants were treated with an immunosuppressive therapy, of which mycophenolate mofetil was most used at baseline and follow-up. Of 38 who were classified as at-risk at baseline, 27 (71%) went on to develop dcSSc; these patients were characterized by higher baseline mean HAQ-DI (0.8 versus 0.4, p = 0.05) and higher baseline mRSS (8.8 versus 4.4, p < 0.01) in comparison with those who remained as limited cutaneous SSc. In the overall cohort, 48 participants (21.1%) had clinically significant worsening of skin fibrosis, mainly occurring in the first year of follow-up; 41 (23.3%) had an absolute forced vital capacity decline of ≥10%. Twenty participants (6.6%) died, of which 18 died in the first 3 years of follow-up. Cardiac involvement (33.3%), gastrointestinal dysmotility (22.2%), and progressive interstitial lung disease (ILD) (16.7%) were the main causes of death. Conclusion This US cohort highlights the management of early SSc in the current era, demonstrating progression of skin and lung involvement despite immunosuppressive therapy and high mortality due to cardiac involvement.