Systemic sclerosis (SSc) is a life-threatening autoimmune disease characterized by widespread fibrosis in the skin and several internal organs. Nudix Hydrolase 21 (NUDT2 or CFIm25) downregulation in fibroblasts is known to play detrimental roles in both skin and lung fibrosis. This study aims to investigate the upstream mechanisms that lead to NUDT21 repression in skin fibrosis. We identified transforming growth factor β (TGFβ1) as the primary cytokine that downregulated NUDT21 in normal skin fibroblasts. In the bleomycin-induced dermal fibrosis model, consistent with the peak activation of TGFβ1 at the late fibrotic stage, NUDT21 was downregulated at this stage, and delayed NUDT21 knockdown during this fibrotic phase led to enhanced fibrotic response to bleomycin. Further investigation suggested TGFβ downregulated NUDT21 through microRNA (miRNA) 181a and 181b induction. Both miR-181a and miR-181b were elevated in bleomycin-induced skin fibrosis in mice and primary fibroblasts isolated from SSc patients, and they directly targeted NUDT21 and led to its downregulation in skin fibroblasts. Functional studies demonstrated that miR-181a and miR-181b inhibitors attenuated bleomycin-induced skin fibrosis in mice in association with decreased NUDT21 expression, while miR-181a and miR-181b mimics promoted bleomycin-induced fibrosis. Overall, these findings suggest a novel role for miR-181a/b in SSc pathogenesis by repressing NUDT21 expression.

Systemic sclerosis (SSc) is a severe autoimmune disease characterized by vasculopathy, fibrosis, and dysregulated immunity, with hallmark autoantibodies targeting nuclear antigens such as centromere protein (ACA) and topoisomerase I (ATA). These autoantibodies are highly prevalent and disease-specific, rarely coexisting, thus serving as crucial biomarkers for SSc diagnosis. Despite their diagnostic value, their roles in SSc pathogenesis remain unclear. This review summarizes current literature on ACA and ATA in SSc, comparing them to autoantibodies in other rheumatic diseases to elucidate their potential pathogenic roles. Similarities are drawn with anti-citrullinated protein antibodies (ACPA) in rheumatoid arthritis, particularly regarding disease specificity and minimal pathogenic impact of antigen binding. In addition, differences between ANA and ACPA in therapeutic responses and Fab glycosylation patterns are reviewed. While ACA and ATA are valuable for disease stratification and monitoring activity, understanding their origins and the associated B cell responses is critical for advancing therapeutic strategies for SSc.

Interstitial lung disease (ILD) is a common and serious manifestation of autoimmune rheumatic diseases. While the prevalence of ILD differs among the individual autoimmune rheumatic diseases, ILD remains an important cause of morbidity and mortality in systemic sclerosis, systemic lupus erythematosus, mixed connective tissue disease, primary Sjögren\'s disease, rheumatoid arthritis, and idiopathic inflammatory myositis. The present review summarizes recent literature on autoimmune-associated ILD with a focus on screening and monitoring for ILD progression. Reflecting on the currently available evidence, the authors propose a guideline for monitoring for progression in patients with newly diagnosed autoimmune-associated ILD. This review also highlights clinical and biological predictors of progressive pulmonary fibrosis and describes opportunity for further study in the rapidly evolving area of rheumatology and pulmonology.
La enfermedad pulmonar intersticial (EPI) es una manifestación común y seria de las enfermedades autoinmunes. Aunque la prevalencia de EPI difıere de acuerdo a cada enfermedad, continúa siendo una causa importante de morbilidad y mortalidad en la esclerosis sistémica, la artritis reumatoide, el síndrome de Sjögren, la enfermedad mixta del tejido conjuntivo y las miopatías inflamatorias. Este artículo de revisión resume la literatura reciente sobre la EPI asociada con autoinmunidad, con enfoque en la búsqueda y el monitoreo de la progresión de la EPI. Con base en la evidencia disponible, los autores proponen una guía para el monitoreo de la progresión en pacientes con la EPI asociada con autoinmunidad de reciente diagnóstico. Esta revisión también aborda los predictores clínicos y biológicos de la fibrosis pulmonar progresiva y resalta la oportunidad para estudios adicionales en áreas de rápida evolución como la reumatología y la neumología.

As the clinical course of systemic sclerosis (SSc) varies widely, prognostic indicators have been sought to predict the outcomes of individual patients. Racial differences in SSc render it necessary to validate prognostic indicators in different patient cohorts. In this study, we aimed to assess clinical and laboratory parameters in Japanese patients with early-stage SSc with diffuse cutaneous involvement and/or interstitial lung disease, and identify predictive factors for disease progression. We performed multivariate analyses of baseline clinical information to estimate symptoms 4 years later in Japanese patients with diffuse cutaneous SSc and/or SSc with interstitial lung disease. Patients were enrolled in the study within 5 years of disease onset at 10 Japanese SSc centers. Over 12 years, 115 patients followed up for 4 years were included in this study. The modified Rodnan skin score (mRSS) at 4 years correlated with the baseline mRSS and finger-to-palm distance, defined as the average length from the distal tip of the fourth finger to the distal palmar crease. The percentage predicted vital capacity (%VC) in year 4 positively and negatively correlated with initial %VC and the presence of anti-topoisomerase I antibodies, respectively. The Health Assessment Questionnaire Disability Index (HAQ-DI) at 4 years was positively and negatively associated with baseline HAQ-DI and %VC, respectively. The occurrence of digital ulcers within 4 years was associated with the initial presence of digital ulcers, finger-to-palm distance, and the presence of digital pitting scars and anti-topoisomerase I antibodies. This study identified several factors that may predict the progression of early-stage SSc in Japanese patients. Finger-to-palm distance may be a useful tool for predicting the progression of skin thickening and the development of digital ulcers in the early stages of severe SSc, but larger, long-term prospective studies are needed to confirm our findings.

UNASSIGNED: Patients with systemic sclerosis (SSc) have an increased risk of endothelial dysfunction, atherosclerosis, and cardiovascular events compared to the general population. Therefore, the availability of robust circulating biomarkers of endothelial dysfunction and atherogenesis may facilitate early recognition and management of cardiovascular risk in SSc. We sought to address this issue by conducting a systematic review and meta-analysis of studies investigating various types of circulating cell adhesion molecules involved in endothelial dysfunction and atherogenesis (i.e., immunoglobulin-like vascular cell, VCAM-1, intercellular, ICAM-1, platelet endothelial cell, PECAM-1, neural cell, NCAM, Down syndrome cell, DSCAM, and endothelial cell-selective, ESAM, adhesion molecules, E-, L-, and P-selectin, integrins, and cadherins) in SSc patients and healthy controls.
UNASSIGNED: We searched PubMed, Scopus, and Web of Science from inception to 1 May 2024. Risk of bias and certainty of evidence were assessed using validated tools.
UNASSIGNED: In 43 eligible studies, compared to controls, patients with SSc had significantly higher plasma or serum concentrations of ICAM-1 (standard mean difference, SMD=1.16, 95% CI 0.88 to 1.44, p<0.001; moderate certainty), VCAM-1 (SMD=1.09, 95% CI 0.72 to 1.46, p<0.001; moderate certainty), PECAM-1 (SMD=1.65, 95% CI 0.33 to 2.98, p=0.014; very low certainty), E-selectin (SMD=1.17, 95% CI 0.72 to 1.62, p<0.001; moderate certainty), and P-selectin (SMD=1.10, 95% CI 0.31 to 1.90, p=0.007; low certainty). There were no significant between-group differences in L-selectin concentrations (SMD=-0.35, 95% CI -1.03 to 0.32, p=0.31; very low certainty), whereas minimal/no evidence was available for cadherins, NCAM, DSCAM, ESAM, or integrins. Overall, no significant associations were observed between the effect size and various patient and study characteristics in meta-regression and subgroup analyses.
UNASSIGNED: The results of this systematic review and meta-analysis suggest that specific circulating cell adhesion molecules, i.e., ICAM-1, VCAM-1, PECAM-1, E-selectin, and P-selectin, can be helpful as biomarkers of endothelial dysfunction and atherogenesis in the assessment of cardiovascular risk in SSc patients.
UNASSIGNED: https://www.crd.york.ac.uk/prospero/, identifier CRD42024549710.

OBJECTIVE: Systemic sclerosis (SSc) is heterogeneous in its clinical presentation. Common manifestations cluster together, defining unique subgroups. This investigation aims to characterize gastrointestinal (GI) phenotypes and determine whether they can be distinguished by temporal progression.
METHODS: We examine a well-established SSc patient cohort with a modified Medsger GI severity score measured over time to determine heterogeneity in disease progression. Growth mixture models estimate each patient\'s phenotype and disease severity trajectory over time. We compare the characteristics of estimated phenotypes using non-parametric statistics and linear and logistic regression to compare patient characteristics between phenotypes while adjusting for disease duration.
RESULTS: We examined 2696 SSc patients with at least two Medsger GI scores, identifying four unique phenotypes. The most common phenotype (n = 2325) (\"Stable\") had an average score of 1 that was consistent over time. Two phenotypes were progressive [\"Early Progressive\" (n = 142) and \"Late Progressive\" (n = 115)] with an initial average score of 1. The Early Progressive group increased initially and stabilized, and the Late Progressive group worsened slowly over time. A fourth phenotype [\"Early Severe GI\"; (n = 114)] had an initial average Medsger GI score just below 3 with high mortality and improving GI severity over time.
CONCLUSIONS: Clinically distinct GI phenotypes exist among patients with SSc. These phenotypes are not only distinguished by GI and extra-intestinal SSc clinical complications, but they are also temporally distinct. Distinct autoantibody profiles are associated strongly with more severe GI disease.

UNASSIGNED: To differentiate the nailfold capillaroscopy (NFC) findings in patients with MCTD-ILD and SSc-ILD and correlate the NFC changes and lung functions among them.
UNASSIGNED: In this observational study from Oct 2020 to Oct 2022, 27 patients with MCTD-ILD and 27 patients with SSc-ILD were included. NFC was performed using Jiangsu Jiahua, JH 1004, China. Statistical analysis was conducted using IBM SPSS software, version 26, and tests including Mann-Whitney U-test, student t-test, chi-square test, or Fisher\'s exact test were used to compare between groups.
UNASSIGNED: In this study, major capillaroscopic changes were more frequent in SSc-ILD group (92%) than in MCTD-ILD group (72.3%), with normal capillaries seen in 7.4% of MCTD-ILD cases. The mean FVC was higher in SSc-ILD group compared to MCTD-ILD group, and patients with capillary loss had a lower mean FVC. Loss of capillaries was more frequent in SSc-ILD group, while dilated capillaries were predominantly observed in MCTD-ILD group. A significant association was found between the severity of restriction in spirometry and NFC.
UNASSIGNED: There is an important role for NFC in detecting the severity of lung involvement, as the grading of restrictive severity in spirometry is strongly associated with capillaroscopic abnormalities.

Systemic sclerosis (SSc) is a progressive autoimmune disorder that mainly affects the skin. There are other clinical manifestations as renal, pulmonary, cardiovascular, and gastrointestinal tract involvements. Based on the skin involvement there are two subtypes of SSc, as limited cutaneous SSc (lSSc) which involves the acral part of the body and diffuse cutaneous SSc (dSSc) resulting in significant skin thickening of the body. Despite of the extensive research the pathomechanism is not fully clarified, how Ssc develops, moreover identifying biomarkers to predict the clinical outcome and prognosis still remains challenging. Circulating biomarkers can be crucial to define the diagnosis, to predict the prognosis and monitor the clinical course. However, only some patients are responsive to the therapy in SSc, and there is a need to reach the ideal therapy for any individual to prevent or slow down the progression in early stages of the disease. In this narrative review, our purpose was to summarize the potential biomarkers in Ssc, describe their role in the diagnosis, pathomechanism, clinical course, organ manifestations, as well as the response to the therapy. Biomarkers assessment aids in the evaluation of disease progression, and disease outcome.

BACKGROUND: Systemic sclerosis (SSc) is an autoimmune disease (AD), that receives less attention compared to rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and primary Sjögren\'s syndrome (pSS). This study aims to analyze transcriptional profiles and immune cell composition in peripheral blood mononuclear cells (PBMC) from SSc patients compared to other ADs.
METHODS: RNA-seq data from 119 untreated patients (eight with SSc, 42 with RA, 41 with pSS, 28 with SLE) and 20 healthy controls were analyzed. Bioinformatics tools were employed to identify differentially expressed genes (DEGs), biological functions and immune cell profiles unique to SSc and shared with other ADs.
RESULTS: 1,148 DEGs were found in SSc, with upregulated genes associated with megakaryocyte processes and downregulated genes associated with neutrophil function and immune response. DEGs, including ALDH1A1 and MEGF9, were associated with neutropenia. Upregulated transcription factors (TFs) were linked to embryonic hematopoiesis and downregulated TFs were involved in leukocyte differentiation and immune regulation. Comparative analysis with other ADs revealed common pathogenic pathways, emphasizing megakaryocyte proliferation. Neutrophils count was significantly decreased in ADs (p < 0.001) compared to healthy controls. Comparative analysis highlighted common pathways, particularly in megakaryocyte proliferation, and unique genes (MEGF9, MMP8, and KRT family members) in SSc, suggesting roles in neutrophil function, skin integrity, and fibrosis.
CONCLUSIONS: This study identifies dysregulated gene expression (KRT and MMP8) associated with neutrophil function and increased megakaryocytes in SSc, highlighting common patterns across autoimmune diseases. These findings offer new insights into the potential pathogenesis of SSc, and help to explore new targets for the treatment.

The use of artificial intelligence (AI) in high-resolution computed tomography (HRCT) for diagnosing systemic sclerosis-associated interstitial lung disease (SSc-ILD) is relatively limited. This study aimed to analyse lung HRCT images of patients with systemic sclerosis with interstitial lung disease (SSc-ILD) using artificial intelligence (AI), conduct correlation analysis with clinical manifestations and prognosis, and explore the features and prognosis of SSc-ILD. Overall, 72 lung HRCT images and clinical data of 58 patients with SSC-ILD were collected. ILD lesion type, location, and volume on HRCT images were identified and evaluated using AI. The imaging characteristics of diffuse SSC (dSSc)-ILD and limited SSc-ILD (lSSc-ILD) were statistically analysed. Furthermore, the correlations between lesion type, clinical indicators, and prognosis were investigated. dSSc and lSSc were more prevalent in patients with a disease duration of < 1 and ≥ 5 years, respectively. SSc-ILD mainly comprises non-specific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), and unclassifiable idiopathic interstitial pneumonia. HRCT reveals various lesion types in the early stages of the disease, with an increase in the number of lesion types as the disease progresses. Lesions appearing as grid, ground-glass, and nodular shadows were dispersed throughout both lungs, while those appearing as consolidation shadows and honeycomb were distributed across the lungs. Ground-glass opacity lesion type was absent on HRCT images of patients with SSc-ILD and pulmonary hypertension. This study showed that AI can efficiently analyse imaging characteristics of SSc-ILD, demonstrating its potential to learn from complex images with high generalisation ability.