Neurological, cardiac, musculoskeletal, and renal manifestations of scleroderma along with insights into its genetics, pathophysiology, diagnostic, and therapeutic updates.

Background: Scleroderma, also referred to as systemic sclerosis, is a multifaceted autoimmune condition characterized by abnormal fibrosis and impaired vascular function. Pathologically, it encompasses the persistent presence of inflammation, abnormal collagen buildup, and restructuring of blood vessels in various organs, resulting in a wide range of clinical symptoms. This review incorporates the most recent scientific literature on scleroderma, with a particular emphasis on its pathophysiology, clinical manifestations, diagnostic approaches, and treatment options. Methodology: A comprehensive investigation was carried out on numerous databases, such as PubMed, MEDLINE, Scopus, Web of Science, and Google Scholar, to collect pertinent studies covering diverse facets of scleroderma research. Results: Scleroderma presents with a range of systemic manifestations, such as interstitial lung disease, gastrointestinal dysmotility, Raynaud's phenomenon, pulmonary arterial hypertension, renal complications, neurological symptoms, and cardiac abnormalities. Serological markers, such as antinuclear antibodies, anti-centromere antibodies, and anti-topoisomerase antibodies, are important for classifying diseases and predicting their outcomes. Discussion: The precise identification of scleroderma is crucial for promptly and correctly implementing effective treatment plans. Treatment approaches aim to improve symptoms, reduce complications, and slow down the progression of the disease. An integrated approach that combines pharmacological agents, including immunosuppressants, endothelin receptor antagonists, and prostanoids, with nonpharmacological interventions such as physical and occupational therapy is essential for maximizing patient care. Conclusion: Through the clarification of existing gaps in knowledge and identification of emerging trends, our goal is to improve the accuracy of diagnosis, enhance the effectiveness of therapeutic interventions, and ultimately enhance the overall quality of life for individuals suffering from scleroderma. Ongoing cooperation and creative research are necessary to advance the field and achieve improved patient outcomes and new therapeutic discoveries.

Speckle-tracking global longitudinal strain predicts death and cardiovascular events in patients with systemic sclerosis.

Aims: Albeit often asymptomatic, heart involvement in systemic sclerosis (SSc) represents a negative prognostic factor, accounting for nearly one-fourth of all deaths. Global longitudinal strain (GLS) is accurate in detecting heart involvement in patients with SSc and no overt cardiac disease and allows early detection and longitudinal monitoring, but its association with clinical endpoints has not been tested so far. The primary outcome was the association between left and right GLS and mortality for all causes. The secondary outcome was the association between left and right GLS and hospitalizations. Methods and results: A prospective longitudinal study enrolling all consecutive patients with SSc without structural heart disease or previous cardiovascular event.A total of 164 patients were enrolled, of whom 19 (11.5%) died during follow-up and 48 (29.3%) were hospitalized. Both left (LV) and right ventricle (RV) GLS at enrolment were independently associated with an increased risk of death for all causes and hospitalizations. Patients with biventricular GLS impairment, respectively, had a 4.2-, 4.9-, and 13.9-fold increased risk of death when compared with patients with only LV, only RV, or no impairment (P < 0.001). The incidence of hospitalization in patients with biventricular GLS impairment was nearly four times higher when compared with patients with only LV or only RV impairment, and nine times higher when compared with normal biventricular GLS (P < 0.001). Conclusion: Biventricular GLS is associated with an increased risk of death and hospitalization in patients with SSc during a median of 3-year follow-up, acting as a reliable and accurate prognostic tool in everyday practice.

Ginkgo biloba extract ameliorates skin fibrosis in a bleomycin-induced mouse model of systemic sclerosis.

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by skin and internal organ fibrosis and obliterative vasculopathy. Few effective treatments are currently available for fibrosis in SSc, therefore, demand persists for novel therapies. Although use of Ginkgo biloba extract (GBE) has been reported to improve blood circulation and alleviate liver and lung fibrosis, its effect on skin fibrosis in SSc remains unclear. In this study, the effects and underlying mechanisms of GBE on skin fibrosis in bleomycin (BLM)-induced mouse model of SSc was investigated. GBE significantly reduced dermal thickness and protein levels of profibrotic factors in the BLM-induced SSc mouse model. Moreover, GBE inhibited the gene expression of profibrotic factors, such as COL1A1, α-SMA, and connective tissue growth factor (CTGF), in fibroblasts by suppressing transforming growth factor (TGF)-ß signaling. Furthermore, GBE inhibited the transdifferentiation of adipocytes into myofibroblasts. Thus, our findings suggest that GBE is a promising therapeutic candidate for the treatment of SSc.

The Value of Ultrasound for Detecting and Following Subclinical Interstitial Lung Disease in Systemic Sclerosis.

BACKGROUND: Interstitial lung disease (ILD) is a complication in patients with systemic sclerosis (SSc). Accurate strategies to identify its presence in early phases are essential. We conducted the study aiming to determine the validity of ultrasound (US) in detecting subclinical ILD in SSc, and to ascertain its potential in determining the disease progression. METHODS: 133 patients without respiratory symptoms and 133 healthy controls were included. Borg scale, Rodnan skin score (RSS), auscultation, chest radiographs, and respiratory function tests (RFT) were performed. A rheumatologist performed the lung US. High-resolution CT (HRCT) was also performed. The patients were followed every 12 weeks for 48 weeks. RESULTS: A total of 79 of 133 patients (59.4%) showed US signs of ILD in contrast to healthy controls (4.8%) (p = 0.0001). Anti-centromere antibodies (p = 0.005) and RSS (p = 0.004) showed an association with ILD. A positive correlation was demonstrated between the US and HRCT findings (p = 0.001). The sensitivity and specificity of US in detecting ILD were 91.2% and 88.6%, respectively. In the follow-up, a total of 30 patients out of 79 (37.9%) who demonstrated US signs of ILD at baseline, showed changes in the ILD score by US. CONCLUSIONS: US showed a high prevalence of subclinical ILD in SSc patients. It proved to be a valid, reliable, and feasible tool to detect ILD in SSc and to monitor disease progression.

Testing a candidate composite serum protein marker of skin severity in systemic sclerosis.

Objectives: Using an integrated multi-omic analysis, we previously derived a candidate marker that estimates the modified Rodnan Skin Score (mRSS) and thus the severity of skin involvement in SSc. In the present study we explore technical and biological validation of this composite marker in a well-characterized cohort of SSc patients. Methods: Cartilage oligomeric matrix protein (COMP), collagen type IV (COL4A1), tenascin-C (TNC) and spondin-1 (SPON1) were examined in serum samples from two independent cohorts of patients with dcSSc. The BIOlogical Phenotyping of diffuse SYstemic sclerosis cohort had previously been used to derive the composite marker and Molecular Determinants to Improve Scleroderma (SSc) treatment (MODERNISE) was a novel validation cohort. Multiple regression analysis derived a formula to predict the mRSS based on serum ELISA protein concentration. Results: The serum concentration of two of the proteins-COMP and TNC-positively correlated with the mRSS, particularly in early dcSSc patients. Interpretable data could not be obtained for SPON1 due to technical limitations of the ELISA. COL4A1 showed a correlation with disease duration but not overall mRSS. Patients receiving MMF showed lower serum concentrations of COMP, COL4A1 and TNC and a lower composite biomarker score not established on treatment. A revised ELISA-based three-protein composite formula was derived for future validation studies. Conclusions: Although more validation is required, our findings represent a further step towards a composite serum protein assay to assess skin severity in SSc. Future work will establish its utility as a predictive or prognostic biomarker.

What have we learned on pre, very early, and early systemic sclerosis microcirculatory pathophysiology? A scoping review.

OBJECTIVE: Microvascular dysfunction is an early event in the pathogenesis of systemic sclerosis (SSc). The objective of this scoping review is to update the current information and the level of knowledge about the mechanisms of microvascular dysfunction in pre-SSc, very early diagnosis of SSc (VEDOSS) and early SSc. METHODS: A PubMed® database search allowed us to include original data from full-length articles in English in which the main topic was microvascular dysfunction in pre-SSC, VEDOSS or early SSc. Data was extracted using a customized form. RESULTS: In the present review 437 articles were identified, and 42 studies included, reporting data from a total of 1069 patients with pre-SSc, VEDOSS or early-SSc. Distinct mechanisms of microvascular injury were identified comprising, angiogenesis and vasculogenesis, cell surface proteins and adhesion, molecules expression, cytokines profile, inflammatory and oxidation pathways, and skin perfusion determinants. Most of the studies were conducted in early SSc, with a reduced number in pre-disease stages, in which the prompt recognition of specific mechanisms and biomarkers may allow targeted treatment to prevent disease progression. CONCLUSIONS: Although different molecular expression patterns and signaling pathways related to microvascular dysfunction in pre-SSc, VEDOSS, and early SSc were identified, additional prospective longitudinal studies and combined work with functional evaluation of peripheral skin perfusion are needed.

Safety of prolonged use of metoclopramide and domperidone as treatment for chronic gastrointestinal dysmotility disorders in patients with systemic sclerosis.

Background: Metoclopramide and domperidone are prokinetic agents commonly used to treat gastrointestinal dysmotility disorders. This study aimed to evaluate the safety and associated side effects of prolonged-use metoclopramide and domperidone as treatment for chronic gastrointestinal dysmotility disorders in patients with systemic sclerosis (SSc). Methods: A quantitative observational survey was conducted by interview questionnaire in rheumatology outpatients at a tertiary teaching hospital in Riyadh, Saudi Arabia. The study included all patients aged 25-80 years diagnosed with SSc. All patients were on metoclopramide or domperidone for the treatment of chronic gastrointestinal dysmotility symptoms over at least 12 weeks. Results: Eighteen eligible patients were included. Most study participants were diagnosed with SSc complicated by interstitial lung disease (n = 13; 72.2 %). The most frequently reported side effect that occurred while taking prokinetic drugs was shortness of breath (n = 12; 66.7 %). None of the participants reported experiencing depression, galactorrhea, or syncope. CNS side effects were reported in 5.6 %. There were no differences in side effects based on the type and dosage of prokinetic drug used. Conclusions: Use of metoclopramide and domperidone for the treatment of chronic gastrointestinal dysmotility in SSc patients for 12 weeks or longer was not associated with any troublesome side effects. Further studies with more participants are needed to confirm our findings.

Hearing impairment in systemic sclerosis patients-what do we really know?

Background: Systemic sclerosis (SSc) is a disease of a very heterogeneous clinical picture and immunological profile with progression rate that varies between individuals. Although hearing deterioration is not a complaint that comes to the fore in SSc patients, as it is not life-threatening compared to many other more severe symptoms of this disease, it can significantly impair the quality of life. Medical literature concerning this problem is rather scarce. Materials and methods: In this article we systematically reviewed the medical publications concerning hearing impairment in patients with systemic sclerosis to evaluate current understanding of this complex problem. Following PRISMA guidelines a total of 19 papers were found and analysed including 11 original studies and 8 case reports. Results: Although it seems that hearing impairment in SSc patients is relatively more common than in the general population, based on the analysis of available literature, no firm conclusions regarding its frequency and pathomechanism can be drawn yet. Microangiopathy leading to damage to the sensory cells of the inner ear is suspected to be the main mechanism of hearing loss, although damage to the higher levels of the auditory pathway appears to be underestimated due to incomplete audiological diagnosis. Conclusion: Undoubtedly, the reason for the difficulty in such an evaluation are the complex and still not fully elucidated pathomechanism of SSc, the individually variable dynamics of the disease and the unique heterogeneity of symptoms. Nevertheless, further studies in larger and appropriately selected groups of patients, focused more on the dynamics of microangiopathy and not solely on clinical symptoms could provide answers to many key questions in this regard.

Gastric dysrhythmias in patients with early systemic sclerosis: a cross-sectional study.

Objectives: Gastric involvement in patients with early systemic sclerosis (SSc) has not been previously investigated. We aim to evaluate the association of gastric dysrhythmias with gastrointestinal (GI) symptoms and nailfold video capillaroscopy (NVC). Methods: Cross-sectional study. Patients with early SSc, completed the UCLA GIT 2.0 questionnaire, performed an NVC, and a surface Electrogastrography (EGG). Descriptive statistics was used for demographic and clinical characteristics and Fisher and Kendall Tau tests were used for association analysis. Results: 75 patients were screened, 30 patients were consecutively enrolled, 29 performed the EGG and 1 patient had a non-interpretable NVC. 29/30 were female with a mean age of 48.7 years (25-72). The mean disease duration from the first non-RP symptom was 22.6 +/-10.8 months and most of the patients had limited disease (76.6%). Total GIT 2.0 score symptoms were moderate-severe in 63% of the participants and 28/29 had an abnormal EGG. Bradygastria was the most common pattern present in 70% of the participants. NVC patterns: 17% early, 34% active, 28% scleroderma-like, 14% non-specific, and 2 patients had a normal NVC. There was no association between severe GI symptoms or NVC patterns and severely abnormal EGG, but the presence of bradygastria was associated with severe impairment in the social functioning area (p 0.018). Conclusions: Gastric dysmotility is common in early SSc and there is a lack of correlation between GI symptoms and NVC scleroderma patterns. EGG is a sensitive, cheap, and non-invasive exam, that may be an alternative to early diagnosis of GI involvement.

Systemic Sclerosis in Males-Deciphering the Enigma of Erasmus Syndrome.

Background: Systemic sclerosis is an autoimmune connective tissue disease characterized by fibrosis in skin and internal organs. Chronic exposure to silica may not only lead to silicosis of lungs but also systemic sclerosis. Systemic sclerosis is relatively commoner in females; however, occupational exposure to silica in males makes them vulnerable to silica--associated systemic sclerosis (Erasmus syndrome). Objective: To describe the clinico-epidemiological aspects of systemic sclerosis in males in a retrospective cohort study. Materials and Methods: The data were analysed retrospectively for demographic profile and clinical characteristics including examination findings, laboratory investigations, and treatments of all male patients diagnosed with systemic sclerosis with or without silica exposure, managed from January 2018 to December 2021. Results: Eight out of twelve patients were having silica exposure in the form of stone cutting, cement exposure, and working with concrete. The average age was 55 ± 10.72 years with average smoking exposure of around 24.4 ± 12.8 pack years. Skin thickening was reported by all patients with an average modified Rodnan score of 18.33/51 in diffuse and 7/51 in limited cutaneous systemic sclerosis. Raynaud's phenomenon and sclerodactyly were universal findings, while 9 (75%) patients had digital pitted scars. Antinuclear antibodies were present in all patients and specific antibodies substantiated the clinical assessment in almost all patients. Interstitial lung disease was the most common systemic finding present in 11 (91%) patients and tuberculosis was diagnosed in 2 (25%) cases with silica exposure. Gastrointestinal and cardiac system involvement was seen in 5 (41.6%) and 4 (33.3%) patients, respectively. Conclusion: Systemic sclerosis in males against the gender predilection indicates the role of occupational exposure. Silicosis and systemic sclerosis synergistically add to lung damage, and at the same time, these patients are more prone to infections like tuberculosis.

The deficiency of DNASE1L3 does not affect systemic sclerosis pathogenesis in two inducible murine models of the disease.

We induced systemic sclerosis (SSc)-like disease in both wild-type and Dnase1l3-deficient mice using two distinct approaches involving bleomycin and hypochlorous acid injections. Our observations revealed that the deficiency in DNASE1L3 did not affect tissue fibrosis or inflammation caused by these treatments. Despite the association of single nucleotide polymorphisms in humans with SSc pathogenesis, our study demonstrates that DNASE1L3 is dispensable in two inducible murine models of SSc-like pathogenesis.

Interferons Dominate Damage and Activity in Juvenile Scleroderma.

Juvenile scleroderma is a heterogeneous group of diseases associated with sclerotic skin lesions, grouped as juvenile systemic sclerosis systemic sclerosis) and juvenile localized scleroderma. This study aims to measure the cytokine and chemokine levels involved in interferon signaling in patients with juvenile scleroderma and determine their correlation with disease severity. METHOD: Twenty-nine juvenile localized scleroderma five juvenile systemic sclerosis, and nine healthy controls were included in the study. Patients with juvenile localized scleroderma were scored according to the LoSAI (LoSCAT activity index), LoSDI (LoSCAT damage index), and PGA-A (physician global assessment-activity) indices. Cytokines and chemokines involved in interferon gene signaling (IL-1, IL-6, IL-8, IP-10, MCP1, TNF-α, CXCL-11, IFN-α, IFN-ß, IFN-γ) and interferon-stimulated genes (ISGs) including IFI27, IFI44, ISIG15, IFIT1, OAS1, RSAD2 were measured by ELISA and RT-PCR method respectively. RESULTS: A significant increase in IFN-α, IFN-ß, IFN-γ, TNF-α, IL -1, IL -6 IL -8, IP-10, and MCP1 levels was observed in patients with juvenile systemic sclerosis compared with the healthy control group. Furthermore, IFN- α and IP-10 were elevated in both juvenile localized scleroderma and juvenile systemic sclerosis compared to the healthy control group. IFN-γ and IFN-α positively correlated with LoSAI and LoSDI levels, respectively. According to PGA-A analysis, IFN-ß, IFN-γ, TNF-α, IL -8, IP10, MCP1, and CXCL11 were significantly higher in active disease than in the inactive state in both groups. CONCLUSION: The results suggest that interferon signaling may be impaired in patients with juvenile scleroderma. Significant changes were observed in cytokines and genes related to IFN signaling, which may have a crucial role in monitoring disease activity. In addition, we have gained important insights into the possibility of using IFN-α and IFN-γ as biomarkers for monitoring juvenile scleroderma activity and damage.

Patient characteristics, diagnostic testing, and initial treatment profiles of patients with connective tissue disease-associated pulmonary arterial hypertension (CTD-PAH) using a Japanese claims database.

OBJECTIVES: To investigate the diagnostic and therapeutic landscape for patients with connective tissue disease (CTD) and CTD-associated pulmonary arterial hypertension (CTD-PAH) in acute-care general hospitals in Japan. METHODS: We conducted a retrospective cohort study by analysing the Medical Data Vision (MDV) database from April 2008 and September 2020. CTD patients who prescribed immunosuppressants were included in cohort 1, and CTD-PAH patients extracted from cohort 1 were included in cohort 2. Patient characteristics, diagnostic screening frequencies for PAH, and initial PAH-specific treatment patterns were assessed. RESULTS: Overall, 16648 patients with CTD and 81 patients with CTD-PAH were included in cohorts 1 and 2, respectively. The frequencies of screening tests for PAH, including brain natriuretic peptide (BNP), transthoracic echocardiogram (TTE), and diffusing capacity of the lungs for carbon monoxide (DLCO), among CTD patients were 0.7, 0.3, and 0.1 tests/person-year, respectively. The most common initial PAH-specific treatment therapy was monotherapy (87.7%), followed by dual therapy (7.4%), and triple therapy (2.5%). CONCLUSION: This is the first study to describe the patient flow from PAH diagnosis to initial PAH-specific treatment for real-world patients who were followed regularly due to CTD in Japanese clinical practice.

Reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles scleroderma clinical trial consortium gastrointestinal tract instrument: Application to efficacy assessment of intravenous immunoglobulin administration.

This study aimed to develop and assess the reliability, validity, and sensitivity of the Japanese version of the University of California Los Angeles Scleroderma Clinical Trial Consortium gastrointestinal tract (GIT) Instrument 2.0 (the GIT score), as an evaluation tool for GIT symptoms in systemic sclerosis (SSc). The Japanese version of the GIT score was constructed using the forward-backward method. The reliability and validity of this instrument were evaluated in a cohort of 38 SSc patients. Correlation analysis was conducted to assess the relationship between the GIT score and existing patient-reported outcome measures. Additionally, the sensitivity of the GIT score was examined by comparing GIT scores before and after intravenous immunoglobulin (IVIG) administration in 10 SSc-myositis overlap patients, as IVIG has recently demonstrated effectiveness in alleviating GIT symptoms of SSc. As a result, the Japanese version of the GIT score exhibited internal consistency and a significant association with the Frequency Scale for the Symptoms of Gastroesophageal Reflux Disease. Furthermore, the total GIT score, as well as the reflux and distention/bloating subscales, displayed moderate correlations with the EuroQol 5 dimensions (EQ-5D) pain/discomfort subscale and the Short Form-36 body pain subscale. Notably, following IVIG treatment, there was a statistically significant reduction in the total GIT score and multiple subscales. We first validated the Japanese version of the GIT score in Japanese SSc patients in real-world clinical settings. This instrument holds promise for application in future clinical trials involving this patient population.

Alterations in peripheral T- and B-cell subsets in patients with systemic sclerosis.

OBJECTIVES: To determine the alteration of peripheral T and B cell subsets in patients with systemic sclerosis (SSc) and to evaluate their correlation with the progression of SSc. METHODS: We recruited 47 SSc patients and 45 healthy controls (HCs) in this study. Demographic and clinical data were then collected. Flow cytometry was used to detect the proportions of 44 different T and B cell subsets in circulating blood. RESULTS: The proportion of total B cells (p = .043) decreased in SSc patients, together with similar frequencies of total T cells, CD4+ T cells, and CD8+ T cells in both groups. Several subsets of T and B cells differed significantly between these two groups. Follicular helper T cells-1 (Tfh1) (p < .001), helper T cells-1 (Th1) (p = .001), regulatory T cells (Treg) (p = .004), effector memory CD8+ T cells (p = .041), and cytotoxic T cells-17 (Tc17) (p = .01) were decreased in SSc patients. Follicular helper T cells-2 (Tfh2) (p = .001) and, helper T cells-2 (Th2) (p = .001) levels increased in the SSc group. Regulatory B cells (Breg) (p = .015) were lower in the SSc group, together with marginal zone (MZ) B cells (p < .001), memory B cells (p = .001), and non-switched B cells (p = .005). The modified Rodnan skin score (mRSS) correlated with helper T cells-17 (Th17) (r = -.410, p = .004), Tfh1 (r = -.321, p = .028), peripheral helper T cells (Tph) (r = -.364, p = .012) and plasma cells (r = -.312, p = .033). CONCLUSIONS: The alterations in T and B cells implied immune dysfunction, which may play an essential role in systemic sclerosis.

A Phase 1a Study to Evaluate Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of RO7303509, an Anti-TGFß3 Antibody, in Healthy Volunteers.

INTRODUCTION: Transforming growth factor beta (TGFß) cytokines (TGFß1, TGFß2, and TGFß3) play critical roles in tissue fibrosis. However, treatment with systemic pan-TGFß inhibitors have demonstrated unacceptable toxicities. In this study, we evaluated the safety, tolerability, pharmacokinetics, and pharmacodynamics of RO7303509, a high-affinity, TGFß3-specific, humanized immunoglobulin G1 monoclonal antibody, in healthy adult volunteers (HVs). METHODS: This phase 1a, randomized, double-blind trial included six cohorts for evaluation, with each cohort receiving single doses of placebo or RO7303509, administered intravenously (IV; 50 mg, 150 mg, 240 mg) or subcutaneously (SC; 240 mg, 675 mg, 1200 mg). The frequency and severity of adverse events (AEs) and RO7303509 serum concentrations were monitored throughout the study. We also measured serum periostin and cartilage oligomeric matrix protein (COMP) by immunoassay and developed a population pharmacokinetics model to characterize RO7303509 serum concentrations. RESULTS: The study enrolled 49 HVs, with a median age of 39 (range 18-73) years. Ten (27.8%) RO7303509-treated subjects reported 24 AEs, and six (30.8%) placebo-treated subjects reported six AEs. The most frequent AEs related to the study drug were injection site reactions and infusion-related reactions. Maximum serum concentrations (Cmax) and area under the concentration-time curve from time 0 to infinity (AUC0-inf) values for RO7303509 appeared to increase dose-proportionally across all doses tested. Serum concentrations across cohorts were best characterized by a two-compartment model plus a depot compartment with first-order SC absorption kinetics. No subjects tested positive for anti-drug antibodies (ADAs) at baseline; one subject (2.8%; 50 mg IV) tested positive for ADAs at a single time point (day 15). No clear pharmacodynamic effects were observed for periostin or COMP upon TGFß3 inhibition. CONCLUSION: RO7303509 was well tolerated at single SC doses up to 1200 mg in HVs with favorable pharmacokinetic data that appeared to increase dose-proportionally. TGFß3-specific inhibition may be suitable for development as a chronic antifibrotic therapy. TRIAL REGISTRATION: ISRCTN13175485.

A mouse model of progressive lung fibrosis with cutaneous involvement induced by a combination of oropharyngeal and osmotic minipump bleomycin delivery.

Systemic sclerosis (SSc) with interstitial lung disease (SSc-ILD) lacks curative pharmacological treatments, thus necessitating effective animal models for candidate drug discovery. Existing Bleomycin (BLM)-induced SSc-ILD mouse models feature spatially limited pulmonary fibrosis, spontaneously resolving after 28 days. Here, we present an alternative BLM administration approach in female C57BL/6 mice, combining oropharyngeal aspiration (OA) and subcutaneous mini-pump delivery (pump) of BLM to induce a sustained and more persistent fibrosis, while retaining stable skin fibrosis. A dose-finding study was performed with BLM administered as 10 µg (OA) +80 mg/kg (pump) (10+80), 10+100 and 15+100. Forty-two days after OA, micro-CT imaging and histo-morphometric analyses showed that the 10+100 and 15+100 treatments induced significant alterations in lung micro-CT-derived readouts, Ashcroft Score, and more severe fibrosis grades compared to saline controls. Additionally, a marked reduction in hypodermal thickness was observed in the 15+100 group. A time-course characterization of the BLM 15+100 treatment at days 28, 35, and 42, including longitudinal micro-CT imaging, revealed progressing alterations in lung parameters. Lung histology highlighted a sustained fibrosis accompanied by a reduction in hypodermis thickness throughout the explored time-window, with a time-dependent increase in fibrotic biomarkers detected by immunofluorescence analysis. BLM-induced alterations were partly mitigated by Nintedanib treatment. Our optimized BLM delivery approach leads to extensive and persistent lung fibrotic lesions coupled with cutaneous fibrotic alterations: it thus represents a significant advance compared to current preclinical models of BLM-induced SSc-ILD.

Brentuximab vedotin for skin involvement in refractory diffuse cutaneous systemic sclerosis, an open-label trial.

OBJECTIVE: We explored the efficacy and safety of brentuximab vedotin, a chimeric anti-CD30 antibody drug conjugate, in patients with severe active diffuse cutaneous systemic sclerosis (dcSSc). METHODS: This phase II proof-of-concept, single center, open-label, single arm, investigator-initiated trial included patients ≥18 years, with dcSSc, modified Rodnan skin score (mRSS) ≥15 with <5 years since the first non-Raynaud's symptom and/or skin worsening despite immunosuppression who were treated with intravenous brentuximab vedotin 0.6 mg/Kg q3 weeks for 45 weeks. The primary end point was a decrease in mRSS of ≥ 8 points at 48 weeks. RESULTS: Eleven patients were treated with brentuximab vedotin, with 9 completing the study. The mean mRSS reduction at week 48 was 11.3 (95% CI 6.9, 15.8; p= 0.001), meeting the primary end point in the intention to treat analysis (7/11 had a decrease in mRSS ≥8). The % forced vital capacity increased by 7.8% (12.5). The Composite Response Index in dcSSc (CRISS) suggested a beneficial treatment effect (86% ≥0.6). Most adverse events were mild. No SAEs were attributed to brentuximab vedotin. CONCLUSION: In dcSSc, brentuximab vedotin improved skin and FVC; without safety concerns. A placebo-controlled trial is warranted to corroborate these initial findings.