Rituximab retention rate in systemic sclerosis: a long term real-life multicenter study.

OBJECTIVES: to report real-life data on rituximab retention-rate as indicator of safety and efficacy in a multicentric national cohort of systemic sclerosis patients. METHODS: SSc patients treated with rituximab and followed for at least 36 months were included, clinically characterized, and longitudinally monitored. A competing risk analysis with sub-Hazard Ratio(sHR) definition was performed to explore the clinical variables linked to specific cause of rituximab discontinuation. RESULTS: One-hundred-fifty-two SSc-patients (mean age 47.3 ± 12.3 years; females 79.6%; diffuse disease 77.6%; anti-topoisomerase-I positivity 63.2%) were evaluated over a median(IQR) time of 3.3(1.7-5.0) years. The primary indication for rituximab were interstitial lung disease (ILD)(38.8%), worsening skin fibrosis(36.8%), and arthritis(13.8%); 138 patients(90.8%) received more than one rituximab course. The 5-years rituximab retention rate was 59.9%(44.6-64.7%). Clinical response was the most common reason for rituximab discontinuation[5.7(3.7-8.4) per 100 patient-year] and was associated with a shorter disease duration[sHR 0.8(0.7-0.9)], anti-topoisomerase-I negativity[sHR 0.4(0.2-0.9)], previous digital ulcers[sHR 2.6(1.1-6.2] and no history of arthritis[sHR 0.3 (0.1-0.8)]. Treatment failure was the second cause of rituximab discontinuation[3.7(2.2-6.0) per 100 patient-year] and was associated with anti-centromere antibody positivity[sHR 2.8(1.1-7.4)] and anti-topoisomerase-I negativity[sHR 0.2(0.1-0.6)]. Adverse events(AEs) were the less common cause of discontinuation[3.1(1.7-5.2) per 100 patient-year], associated with limited cutaneous subset[sHR 3.4(1.2-9.7)] and previous mycophenolate mofetil treatment[sHR 4.5(1.2-16.3)]. CONCLUSION: rituximab is a safe and effective treatment in SSc: clinical response emerged as the primary reason for rituximab discontinuation, and AEs had a limited impact on treatment persistence. The identification of specific disease features associated with a response to rituximab will be useful in the management of SSc-patients.

Survival and prognostic factors from a multicentre large cohort of unselected Italian systemic sclerosis patients.

OBJECTIVES: Survival and death prognostic factors of SSc patients varied during the past decades. We aimed to update the 5- and 10-year survival rates and identify prognostic factors in a multicentre cohort of Italian SSc patients diagnosed after 2009. MATERIAL AND METHODS: Patients who received a diagnosis of SSc after 1 January 2009 and were longitudinally followed up in four Italian rheumatologic centres were retrospectively assessed up to 31 December 2020. Overall survival of SSc patients was described using the Kaplan-Meier method. Predictors of mortality at 10-year follow-up were assessed by the Cox regression model. A comparison of our cohort with the Italian general population was performed by determining the standardized mortality ratio (SMR). RESULTS: A total of 912 patients (91.6% females, 20% dcSSc) were included. Overall survival rates at 5 and 10 years were 94.4% and 89.4%, respectively. The SMR was 0.96 (95% CI 0.81, 1.13), like that expected in the Italian general population. Pulmonary arterial hypertension (PAH) and interstitial lung disease (ILD) associated with pulmonary hypertension (PH) significantly reduced survival (P < 0.0001). Main death predictors were male gender (HR = 2.76), diffuse cutaneous involvement (HR = 3.14), older age at diagnosis (HR = 1.08), PAH (HR = 3.21), ILD-associated PH (HR = 4.11), comorbidities (HR = 3.53) and glucocorticoid treatment (HR= 2.02). CONCLUSIONS: In the past decade, SSc patients have reached similar mortality of that expected in the Italian general population. Male gender, diffuse cutaneous involvement, comorbidities and PAH with or without ILD represent the main poor prognostic factors.

Ultrasound in anti-CCP+ at-risk individuals without clinical synovitis: development of a novel 6-joint protocol for feasible risk prediction.

OBJECTIVES: To investigate, in anti-cyclic citrullinated peptide antibody positive individuals with musculoskeletal symptoms but no clinical synovitis (CCP+ at-risk), the additional value of ultrasound (US) for the prediction of inflammatory arthritis (IA). Furthermore, to define a concise US protocol for feasible risk prediction. METHODS: Demographic and clinical data were collected in 417 CCP+ at-risk (Leeds CCP cohort) with a baseline US scan assessing synovitis and bone erosions in 36 joints, and a follow-up duration ≥24 months. Multivariable binary regression models for IA development at 24 months evaluated routine clinical variables associated with IA alone ("clinical" model) and combined with a 36-joint US scanning protocol ("clinical-US extended" model). A "clinical-US short" model was developed. RESULTS: At 24 months, 92/417 (22.1%) CCP+ at-risk developed IA (median time: 7 months, IQR : 3-12). The "clinical-US extended" model performed better than the "clinical" model (AUC 0.788 vs AUC 0.731 respectively, p< 0.001) with an odds ratio for IA development of 3.18 (95% IC 1.80-5.63) for US synovitis and 2.54 (95% IC 1.21-5.37) for bone erosions. The "clinical-US short" model, which retained the wrists, knees and MTP5 joints, performed better (AUC 0.782) than the "clinical" model (p< 0.001) and similarly (difference in Akaike information criteria <2) to the "clinical-US extended" model. CONCLUSIONS: US provides valuable information for predicting progression to IA in CCP+ individuals both alone and in addition to clinical variables. US synovitis was associated with a threefold increase risk of IA development. A concise US protocol of 6 joints provides clinically feasible risk prediction in CCP+ at-risk.

Lung vascular changes as biomarkers of severity in systemic sclerosis-associated interstitial lung disease.

OBJECTIVES: It has recently become possible to assess lung vascular and parenchymal changes quantitatively in thoracic CT images using automated software tools. We investigated the vessel parameters of patients with SSc, quantified by CT imaging, and correlated them with interstitial lung disease (ILD) features. METHODS: SSc patients undergoing standard of care pulmonary function testing and CT evaluation were retrospectively evaluated. CT images were analysed for ILD patterns and total pulmonary vascular volume (PVV) extents with Imbio lung texture analysis. Vascular analysis (volumes, numbers and densities of vessels, separating arteries and veins) was performed with an in-house developed software. A threshold of 5% ILD extent was chosen to define the presence of ILD, and commonly used cut-offs of lung function were adopted. RESULTS: A total of 79 patients [52 women, 40 ILD, mean age 56.2 (s.d. 14.2) years, total ILD extent 9.5 (10.7)%, PVV/lung volume % 2.8%] were enrolled. Vascular parameters for total and separated PVV significantly correlated with functional parameters and ILD pattern extents. SSc-associated ILD (SSc-ILD) patients presented with an increased number and volume of arterial vessels, in particular those between 2 and 4 mm of diameter, and with a higher density of arteries and veins of <6 mm in diameter. Considering radiological and functional criteria concomitantly, as well as the descriptive trends from the longitudinal evaluations, the normalized PVVs, vessel numbers and densities increased progressively with the increase/worsening of ILD extent and functional impairment. CONCLUSION: In SSc patients CT vessel parameters increase in parallel with ILD extent and functional impairment, and may represent a biomarker of SSc-ILD severity.

Sudden winter iloprost withdrawal in scleroderma patients during COVID-19 pandemic.

INTRODUCTION: Intravenous iloprost is currently recommended in the treatment of Raynaud's phenomenon (RP) refractory to oral therapy and of digital ulcers (DUs) related to systemic sclerosis (SSc). In real-life practice there is a huge heterogeneity about the Iloprost regimens used. METHODS: A survey was carried out on SSc patients that interrupted Iloprost infusion to compare acral vascular symptoms just before Iloprost withdrawal and just after the missed infusion. Severity, and frequency of RP, new DUs onset or aggravation of those pre-existing were reported. Last available capillaroscopic images were also evaluated. RESULTS: The analysis includes 50 patients. After iloprost withdrawal, 11 patients reported a RP worsening because of enhanced intensity (p = 0.007). Only 8 patients of them also complained of an increased frequency (p = 0.07). None of the patients experienced digital ulcers for the first-time during quarantine. Among the 27 patients with a history of digital ulcers, 9 reported worsening and 7 recurrence of DUs. Overall, 17 patients (34.0 %) complained of a worsening of SSc vascular acral manifestations, namely RP or DUs. Reduced capillary density was associated with RP worsening, in particular, each unit increase of capillary density corresponds to an average 44 % decrease in the odds of RP worsening (OR 0.56, CI 95 % 0.36-0.97, p = 0.037). As for RP worsening, the aggravation of DU was associated with a lower capillary density. CONCLUSIONS: Low capillary density can predict a worsening of both RP and DUs in controlled quarantine conditions within a month after iloprost discontinuation in SSc patients.

Nailfold capillaroscopy findings in patients with coronavirus disease 2019: Broadening the spectrum of COVID-19 microvascular involvement.

OBJECTIVE: Increasing evidence points to endothelial dysfunction as a key pathophysiological factor in coronavirus disease-2019 (COVID-19). No specific methods have been identified to predict, detect and quantify the microvascular alterations during COVID-19. Our aim was to assess microvasculature through nailfold videocapillaroscopy (NVC) in COVID-19 patients. METHODS: We performed NVC in patients with a confirmed diagnosis of COVID-19 pneumonia. Elementary alterations were reported for each finger according to a semi-quantitative score. Capillary density, number of enlarged and giant capillaries, number of micro-hemorrhages and micro-thrombosis (NEMO score) were registered. RESULTS: We enrolled 82 patients (mean age 58.8 ± 13.2 years, male 68.3%) of whom 28 during the hospitalization and 54 after recovery and hospital discharge. At NVC examination we found abnormalities classifiable as non-specific pattern in 53 patients (64.6%). Common abnormalities were pericapillary edema (80.5%), enlarged capillaries (61.0%), sludge flow (53.7%), meandering capillaries and reduced capillary density (50.0%). No pictures suggestive of scleroderma pattern have been observed. Acute COVID-19 patients, compared to recovered patients, showed a higher prevalence of hemosiderin deposits as a result of micro-hemorrhages (P = .027) and micro-thrombosis (P < .016), sludge flow (P = .001), and pericapillary edema (P < .001), while recovered patients showed a higher prevalence of enlarged capillaries (P < .001), loss of capillaries (P = .002), meandering capillaries (P < .001), and empty dermal papillae (P = .006). CONCLUSION: COVID-19 patients present microvascular abnormalities at NVC. Currently ill and recovered subjects are characterized by a different distribution of elementary capillaroscopic alterations, resembling acute and post-acute microvascular damage. Further studies are needed to assess the clinical relevance of NVC in COVID-19.

Postural control and disability in patients with early rheumatoid arthritis.

OBJECTIVES: Rheumatoid arthritis (RA) may affect the postural control through abnormal sensory inputs and impaired motor responses. Sensory Organization Test (SOT) objectively evaluates contribution of different sensorial afferences in postural control. The aim of the study is to assess mechanisms of postural instability and their relations with disability and disease characteristics in an early RA(ERA) cohort. METHODS: The equilibrium scores were assessed in 30 ERA patients and 30 age- and sex-matched controls. The somatosensory (SOM), visual (VIS) and vestibular (VEST) ratios were computed to assess the use of different sensory and the composite equilibrium score (CES) as a measure of global balance performance. RESULTS: ERA patients had lower CES (78.4±6.0% vs. 83.4±5.0%, p=0.002), SOM ratio (98.5±1.8% vs. 99.6±2.1%, p=0.035), VIS ratio (85.2±7.6% vs. 91.5±6.0%, p=0.001) and VEST ratio (70.8±10.0% vs. 80.3±7.8%, p<0.001) compared to controls. The presence of ankle arthritis correlated negatively to both SOM (r=-0.369, p=0.045) and VIS ratio (r=0.470, p=0.009), pain severity to CES (r=-0.389, p=0.045) and VIS ratio (r=-0.385, p=0.048) and HAQ-DI to CES (r=-0.591, p=0.001), SOM (r=-0.510, p=0.004) and VIS ratio (r=-0.390, p=0.033.). Patients-reported postural instability was associated with lower CES (75.4±5.4% vs. 80.7±5.5%, p=0.016) and VEST ratios (66.5±10.1% vs. 74.1±8.8%, p=0.036). SOT outcomes did not differ according to acute phase reactants, disease activity or autoantibody positivity. CONCLUSIONS: RA patients showed an early impairment of postural control related to the degree of disability and subjective postural instability. Our data suggest that the lack of balance could result from both impaired motor response and abnormal sensory organisation.

Systemic sclerosis myocarditis has unique clinical, histological and prognostic features: a comparative histological analysis.

OBJECTIVE: To outline the clinical, histological and prognostic features of systemic sclerosis (SSc) endomyocardial biopsy-proven myocarditis with respect to those of diverse endomyocardial biopsy-proven virus-negative myocarditis (VNM). METHODS: We retrospectively analysed data from three cohorts of endomyocardial biopsy-proven myocarditis: SSc-related VNM (SSc-VNM); isolated VNM (i-VNM); and VNM related to other systemic autoimmune diseases (a-VNM). The degree of myocardial fibrosis was expressed as relative percentage and fibrotic score (0-3). Clinical data, cardiac enzymes, echocardiogram, 24 h ECG Holter and cardiac magnetic resonance were obtained at baseline and during follow-up. Non-parametric tests were used. RESULTS: We enrolled 12 SSc-VNM [11 females, mean age 49.3 (14.2) years; seven diffuse-SSc, five early-SSc], 12 i-VNM [12 females, mean age 47.7 (10.8) years] and 10 a-VNM [four females, mean age 48.4 (16.3) years] patients. SSc patients had higher degrees of myocardial fibrosis as assessed by both percentage [SSc-VNM: 44.8 (18.8)%; a-VNM: 28.6 (16.5)%; i-VNM: 24.9 (10.3)%; P = 0.019] and score [SSc-VNM: 2.3 (0.8); a-VNM: 1.4 (1.1); i-VNM: 1.2 (0.7); P = 0.002]. Myocardial fibrosis directly correlated with skin score (r = 0.625, P = 0.03) and number of ventricular ectopic beats on 24 h ECG Holter in SSc patients (r = 0.756, P = 0.01). Dyspnoea class was higher at presentation in SSc-VNM patients (P = 0.041) and we found heart failure only in SSc patients (25%) (P = 0.05). At cardiac magnetic resonance, myocardial oedema was nearly undetectable in SSc-VNM patients compared with others (P = 0.02). All patients received immunosuppressive treatment. The number of patients who died during follow-up due to cardiac complications was significantly higher in SSc-VNM patients (50%), as compared with a-VNM (0%) and i-VNM (8.3%) patients (P = 0.006). Patients who died during follow-up had higher degrees of myocardial fibrosis [52.2 (11.6)% vs 27.5 (12.9)%, P = 0.024; fibrotic score: 2.83 (0.41) vs 1.4 (0.9), P < 0.001]. CONCLUSION: SSc has unique clinical and histological features, as it tends to present more frequently with heart failure and a higher dyspnoea class and to show higher degrees of myocardial fibrosis. These specific features are paralleled by a worse cardiac prognosis.

Gut microbiota analysis in systemic sclerosis according to disease characteristics and nutritional status.

OBJECTIVES: Systemic sclerosis (SSc) is a rare multi-organ disorder with a prominent gastrointestinal (GI) involvement. Altered gut microbiota is now considered a pivotal factor associated with the development of immune-mediated and inflammatory diseases. We performed a 16S ribosomal RNA (rRNA) gene-sequencing analysis of fecal microbiota in a cohort of SSc patients and matched healthy controls (HCs), with the aim to obtain some hints about a possible role of dysbiosis in the onset, progression, and severity of the disease. METHODS: We analysed stool samples from 63 SSc patients with different disease duration, phenotype, and nutritional status and from 17 HCs through 16S ribosomal RNA (rRNA) gene-sequencing. RESULTS: Microbial richness was lower for patients with long-standing disease. A similar observation was made for patients with diffuse cutaneous SSc (dsSSc) compared to those with limited variant (lcSSc) and for patients who reported a recent weight loss. Consistent with previous reports, we noted a deviation of the intestinal microbial composition in patients with SSc compared to HCs, with a greater expression of Lactobacillus and Streptococcus and a depletion of Sutterella. Nutritional status, assessed using BMI as a surrogate, appeared to have a marked impact on the gut microbiota, with overweight patients showing lower richness compared both to underweight and normal-BMI patients. CONCLUSIONS: Our findings expand the current knowledge of gut microbiota in SSc and could be useful to identify patients who would most benefit from treatments aimed at restoring the eu-biosis.

Protein Chips for Detection of Salmonella spp. from Enrichment Culture.

Food pathogens are the cause of foodborne epidemics, therefore there is a need to detect the pathogens in food productions rapidly. A pre-enrichment culture followed by selective agar plating are standard detection methods. Molecular methods such as qPCR have provided a first rapid protocol for detection of pathogens within 24 h of enrichment culture. Biosensors also may provide a rapid tool to individuate a source of Salmonella contamination at early times of pre-enrichment culture. Forty mL of Salmonella spp. enrichment culture were processed by immunoseparation using the Pathatrix, as in AFNOR validated qPCR protocols. The Salmonella biosensor combined with immunoseparation showed a limit of detection of 100 bacteria/40 mL, with a 400 fold increase to previous results. qPCR analysis requires processing of bead-bound bacteria with lysis buffer and DNA clean up, with a limit of detection of 2 cfu/50 µL. Finally, a protein chip was developed and tested in screening and identification of 5 common pathogen species, Salmonella spp., E. coli, S. aureus, Campylobacter spp. and Listeria spp. The protein chip, with high specificity in species identification, is proposed to be integrated into a Lab-on-Chip system, for rapid and reproducible screening of Salmonella spp. and other pathogen species contaminating food productions.

Detection of mycobacterial DNA by a specific and simple lateral flow assay incorporating cadmium selenide quantum dots.

Cadmium selenide quantum dots have been incorporated to a lateral flow assay for the specific and very simple detection of different mycobacterial DNA targets within only a few minutes, bypassing the complexity of conventional DNA hybridization assays. The method extends our previous work on protein detection using an identical procedure.

Alveolar epithelial-to-mesenchymal transition in scleroderma interstitial lung disease: Technical challenges, available evidence and therapeutic perspectives.

The alveolar epithelial-to-mesenchymal transition is the process of transformation of differentiated epithelial cells into mesenchymal-like cells through functional and morphological changes. A partial epithelial-to-mesenchymal transition process can indirectly contribute to lung fibrosis through a paracrine stimulation of the surrounding cells, while a finalized process could also directly enhance the pool of pulmonary fibroblasts and the extracellular matrix deposition. The direct demonstration of alveolar epithelial-to-mesenchymal transition in scleroderma-related interstitial lung disease is challenging due to technical pitfalls and the limited availability of lung tissue samples. Similarly, any inference on epithelial-to-mesenchymal transition occurrence driven from preclinical models should consider the limitations of cell cultures and animal models. Notwithstanding, while the occurrence or the relevance of this phenomenon in scleroderma-related interstitial lung disease have not been directly and conclusively demonstrated until now, pre-clinical and clinical evidence supports the potential role of epithelial-to-mesenchymal transition in the development and progression of lung fibrosis. Evidence consolidation on scleroderma-related interstitial lung disease epithelial-to-mesenchymal transition would pave the way for new therapeutic opportunities to prevent, slow or even reverse lung fibrosis, drawing lessons from current research lines in neoplastic epithelial-to-mesenchymal transition.

Serum CCL24 as a Biomarker of Fibrotic and Vascular Disease Severity in Systemic Sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a heterogeneous disease, characterized by variable tissue and vascular fibrosis in the context of autoimmune activation. CCL24 (or Eotaxin2) has been shown to promote microangiopathic, proinflammatory, and profibrotic processes in preclinical models of SSc. Here, we study serum CCL24 levels in a real-life cohort of patients with SSc, to determine its distribution across disease features and its value in predicting disease progression and related mortality. METHODS: Serum CCL24 was assessed in an observational cohort of consecutively enrolled patients with SSc. A high CCL24 cutoff was defined based on its distribution in a matched cohort of healthy controls. Disease progression and mortality were analyzed from the date of serum assessment. RESULTS: Two-hundred thirteen consecutively enrolled patients with SSc were included in this analysis. Median disease duration was six years (interquartile range 3-14), 28.6% of patients presented with interstitial lung disease (ILD), 46.9% had digital ulcers, and 25.3% showed high CCL24 serum concentration. High-CCL24 patients were more frequently male and positive for anti-scl-70, with a diagnosis of ILD and synovitis (P < 0.05 for all). Notably, high-CCL24 patients had lower diffusion of carbon monoxide and higher prevalence of digital ulcers, telangiectasias, and calcinosis (P < 0.05 for all). In a longitudinal setting, high CCL24 was associated with greater lung function decline and with higher disease-related mortality. CONCLUSION: Serum CCL24 is a biomarker of disease severity across fibrotic and vascular disease manifestations. These data support the development of therapies targeting CCL24 as a novel comprehensive therapeutic target in SSc.

Clinical trajectories of hand function impairment in systemic sclerosis: an unmet clinical need across disease subsets.

BACKGROUND: Hand involvement is an early manifestation of systemic sclerosis (SSc), culprit of diagnosis and classification, and recognised major driver of disability. Impairment of hand function burdens both limited and diffuse cutaneous subsets and therefore could be targeted as 'basket' endpoint in SSc. Nevertheless, its natural history in current standard of care is not well characterised, limiting the design of targeted trials. The aim of this study is to describe prevalence, natural history and clinical factors associated with hand function deterioration in a longitudinal, multicentre, observational SSc cohort. METHODS: Hand function was captured through the validated Cochin Hand Function Scale in patients consecutively enrolled in a multicentre observational study and observed over 24 months. Minimal clinically important differences and patient acceptable symptom state were analysed as previously described. RESULTS: Three hundred and ninety-six consecutive patients were enrolled from 10 centres; 201 with complete follow-up data were included in the analysis. Median (IQR) disease duration was 5 (2-11) years. One hundred and five (52.2%) patients reported clinically significant worsening. Accordingly, the proportion of patients reporting unacceptable hand function increased over 2 years from 27.8% to 35.8% (p<0.001). Least absolute shrinkage and selection operator analysis identified male gender, disease subset, Raynaud's Condition Score, tenosynovitis and pain, as some of the key factors associated with worsening hand involvement. CONCLUSIONS: Hand function deteriorates over time in more than 50% of SSc patients despite available therapies. The analysis of factors associated with hand function worsening supports the involvement of both inflammation, vascular and fibrotic processes in hand involvement, making it a hallmark clinical manifestation of SSc. Our data are poised to inform the design of intervention studies to target this major driver of disability in SSc.

The ß-Secretase BACE1 Drives Fibroblast Activation in Systemic Sclerosis through the APP/ß-Catenin/Notch Signaling Axis.

BACE1 is well-known for its role in the development of Alzheimer's disease. Recent publications, including our own, have demonstrated a role for this enzyme in other chronic diseases. The aim of this study was to investigate the role of BACE1 in the autoimmune disease systemic sclerosis (SSc). BACE1 protein levels were elevated in the skin of patients with SSc. Inhibition of BACE1 with small-molecule inhibitors or small interfering RNA blocked SSc and fibrotic stimuli-mediated fibroblast activation. Furthermore, we show that BACE1 regulation of dermal fibroblast activation is dependent on ß-catenin and Notch signaling. The neurotropic factor brain-derived neurotrophic factor negatively regulates BACE1 expression and activity in dermal fibroblasts. Finally, sera from patients with SSc show higher ß-amyloid and lower brain-derived neurotrophic factor levels than healthy controls. The ability of BACE1 to regulate SSc fibroblast activation reveals a therapeutic target in SSc. Several BACE1 inhibitors have been shown to be safe in clinical trials for Alzheimer's disease and could be repurposed to ameliorate fibrosis progression.

Circulating extracellular vesicles in the context of interstitial lung disease related to systemic sclerosis: A scoping literature review.

BACKGROUND: Interstitial lung disease (ILD) is a significant cause of disability and mortality in systemic sclerosis (SSc), where lung fibrosis stems from the interaction of cells within the epithelial, endothelial, interstitial, and immune cell compartments. Extracellular vesicles (EVs) are particles released by cells capable of transferring functionally active molecules, playing a crucial role in intercellular communication. This scoping review aims to identify and map existing evidence about the role of EVs as biomarkers or pathophysiological actors in SSc-ILD. It also retrospectively assesses the compliance of published articles with the current reporting guidelines established by the International Society of Extracellular Vesicles (ISEV). METHODS: This scoping review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) checklist. The searches were conducted up until 31 May 2023, with no restrictions on the starting year. RESULTS: Out of 778 publications identified and screened, 9 references were selected. The eligible studies collectively involved a total of 539 SSc patients, with 220 patients presenting with ILD, as demonstrated by high-resolution computed tomography. The studies largely focused on the quantitative assessment of EVs through flow cytometry, primarily concerning larger EVs. The studies primarily focused on the association of EV features with vascular complications, with fibrotic pulmonary involvement typically explored as a secondary finding. The evaluated patients' clinical characteristics were significantly heterogeneous across the studies as well as the association of EV features with the evidence of ILD but none of them longitudinally investigated the relationships with SSc-ILD prognosis. Adherence of these exploratory studies to ISEV reporting guidelines in terms of EV nomenclature, reporting of pre-analytic variables, and qualitative verification of EV separation products was incomplete. CONCLUSIONS: The evidence concerning the clinical association of EV features is limited and conflicting. The interpretation of available data is substantially biased due to patient selection tailored for vascular complications, heterogeneity of separation methodology, and a lack of validation procedures.