Wong G, Chizzolini C, Frasca L. CXCL4 assembles DNA into liquid crystalline complexes to amplify TLR9-mediated interferon-α production in systemic sclerosis

Systemic sclerosis (SSc) is a chronic autoimmune disease characterized by fibrosis and vasculopathy. CXCL4 represents an early serum biomarker of severe SSc and likely contributes to inflammation via chemokine signaling pathways, but the exact role of CXCL4 in SSc pathogenesis is unclear. Here, we elucidate an unanticipated mechanism for CXCL4-mediated immune amplification in SSc, in which CXCL4 organizes "self" and microbial DNA into liquid crystalline immune complexes that amplify TLR9-mediated plasmacytoid dendritic cell (pDC)-hyperactivation and interferon-α production. Surprisingly, this activity does not require CXCR3, the CXCL4 receptor. Importantly, we find that CXCL4-DNA complexes are present in vivo and correlate with type I interferon (IFN-I) in SSc blood, and that CXCL4-positive skin pDCs coexpress IFN-I-related genes. Thus, we establish a direct link between CXCL4 overexpression and the IFN-I-gene signature in SSc and outline a paradigm in which chemokines can drastically modulate innate immune receptors without being direct agonists.

Systemic sclerosis patients with and without pulmonary arterial hypertension: a nailfold capillaroscopy study

OBJECTIVE

Pulmonary arterial hypertension (PAH) is a complication of SSc due to increased vascular resistance, and abnormal vascularity is a well-known feature of the disease as shown by nailfold videocapillaroscopy (NVC). This study investigated for specific NVC changes in SSc patients with and without PAH to assess any useful difference.

METHODS

Twenty-four SSc patients, 12 with PAH and 12 without, entered the study. Evidence of PAH was defined as increased systolic pulmonary artery pressure (PAP) (≥35 mmHg), indirectly assessed by echocardiography and confirmed by right heart catheterization (mPAP > 25 mmHg). NVC was performed, and a semi-quantitative rating scale, a rating system for avascular areas and a specific NVC pattern evaluation, namely early, active and late, were used.

RESULTS

An NVC score >1 was more frequently found in patients with PAH than those without, 11 cases (92%) vs 5 cases (42%) (P = 0.03); an avascular areas grade >1 was present in 10 (83%) and 2 (17%) cases, respectively (P = 0.003); and a more severe NC pattern (active/late) was described in 11 (92%) and 5 (42%) patients, respectively (P = 0.03). When we compared the mPAP with NVC parameters, we found significant correlations between mPAP values and the NVC score (P < 0.005) and with the avascular areas score (P < 0.001).

CONCLUSION

Our results underline the relevance of early microvascular assessment in patients at risk of developing a severe complication such as PAH that can amplify the systemic microvascular impairment in SSc. More severe NVC abnormalities should lead to strict cardiopulmonary surveillance and a complete NVC study is indicated.

High prevalence of capillary abnormalities in patients with diabetes and association with retinopathy

AIMS

To investigate the presence of capillary abnormalities in patients with Type 1 and Type 2 diabetes using nailfold videocapillaroscopy and to evaluate the possible correlation with the typical diabetes mellitus microangiopathic lesions detectable in retinal blood vessels.

METHODS

Forty-nine patients with diabetes mellitus (21 with Type 1 and 28 with Type 2 diabetes) and 39 subjects without diabetes were enrolled. Ophthalmoscopy was performed on all patients and was followed by retinal fluorangiography when indicated. Subjects underwent nailfold videocapillaroscopy to evaluate density, length, morphology and distribution of capillary loops, presence of ectasia, microbleedings and blood flow modifications. A score (0-3) was applied to quantify features of nailfold videocapillaroscopy.

RESULTS

Subjects with diabetes showed a significantly increased (P = 0.0001) nailfold videocapillaroscopy score and significantly greater alterations of capillary length (P = 0.004), distribution (P = 0.02), morphology (P = 0.0001), density (P = 0.02) and flux (P = 0.004), as well as presence of ectasic loops (P = 0.009) and of oedema/exudates (P = 0.03) compared with control subjects. In addition, patients with Type 1 diabetes had a significantly higher score (P = 0.01) and greater morphologic alterations (P = 0.03) compared with subjects with Type 2 diabetes. Nailfold videocapillaroscopy score also showed a positive correlation with retinopathy, detected by both ophthalmoscopy (P = 0.0001) and fluorangiography (P = 0.02), independently from sex, age, type of diabetes and all potential confounders. Moreover, nailfold videocapillaroscopy was capable of identifying alterations in almost 50% of patients with diabetes without retinopathy.

CONCLUSIONS

A high prevalence of nailfold capillary changes is detected in patients with diabetes using nailfold videocapillaroscopy. These abnormalities tightly correlate with retinal damage and may be expression of a generalized microvessel involvement in both Type 1 and Type 2 diabetes.

Potential role for the VDR agonist elocalcitol in metabolic control: Evidences in human skeletal muscle cells

Vitamin D plays a pivotal role to maintain skeletal muscle integrity and health. Vitamin D deficiency characterizes inflammatory myopathy (IM) and diabetes, often overlapping diseases involving skeletal muscle damage. Vitamin D receptor (VDR) agonists likely exert beneficial effects in both IM and metabolic disturbances. We aim to evaluate in vitro the effect of elocalcitol, a non-hypercalcemic VDR agonist, on the biomolecular metabolic machinery of human skeletal muscle cells (Hfsmc), vs. insulin (I). We analyzed GLUT4, Flotillin-1, Caveolin-3 and Caveolin-1 cell expression/localization; mTOR, AKT, ERK and 4E-BP1 phosphorylation; IL-6 myokine release; VDR expression. We investigated in vivo vitamin D status in IM subjects, evaluating VDR muscular expression and serum vitamin D with metabolism-related parameters, as glycemia, triglycerides, cholesterol, resistin and adiponectin. In Hfsmc, elocalcitol exerted an I-like effect, promoting GLUT4 re-localization in Flotillin-1, Caveolin-3 and Caveolin-1 positive sites and mTOR, AKT, ERK, 4E-BP1 activation; it enhanced IL-6 myokine release. IM subjects, all normoglycemic, showed VDR/vitamin D deficiency that, together with high lipidemic and resistin profile, possibly increases the risk to develop metabolic diseases. VDR agonists as elocalcitol may be therapeutic tools for skeletal muscle integrity/function maintenance, an indispensable condition for health homeostasis.

Elevated serum levels of macrophage migration inhibitory factor and stem cell growth factor β in patients with idiopathic and systemic sclerosis associated pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) can be idiopathic or secondary to autoimmune diseases, and it represents one of the most threatening complications of systemic sclerosis (SSc). Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine with proinflammatory functions that appears to be involved in the pathogenesis of hypoxia-induced PH. In SSc patients, high serum levels of MIF have been associated with the development of ulcers and PAH. Stem cell growth factor β (SCGF β) is a human growth factor that, together with MIF, is involved in the pathogenesis of chronic spinal cord injury. The aim of our study was to measure serum levels of MIF in patients with idiopathic and SSc-associated PAH. We enrolled 13 patients with idiopathic PAH and 15 with SSc-associated PAH. We also selected 14 SSc patients without PAH and 12 normal healthy controls, matched for sex and age. PAH was confirmed by right hearth catheterism (mPAP>25 mmHg). MIF and SCGF β levels were measured by ELISA. We found significantly higher circulating levels of MIF and of SCGF β in patients with idiopathic PAH (P=0.03 and P=0.004) and with PAH secondary to SSc (P=0.018 and P=0.023) compared to SSc patients without PAH. Higher levels of MIF were found in those patients with an higher New York Heart Association (NYHA) class (P=0.03). We can hypothesize that MIF and SCGF β are able to play a role in PAH, both idiopathic or secondary, and in the future they may be evaluated as useful biomarkers and prognostic factors for this serious vascular disease.

CXCL4-RNA Complexes Circulate in Systemic Sclerosis and Amplify Inflammatory/Pro-Fibrotic Responses by Myeloid Dendritic Cells

CXCL4 is an important biomarker of systemic sclerosis (SSc), an incurable autoimmune disease characterized by vasculopathy and skin/internal organs fibrosis. CXCL4 contributes to the type I interferon (IFN-I) signature, typical of at least half of SSc patients, and its presence is linked to an unfavorable prognosis. The mechanism implicated is CXCL4 binding to self-DNA, with the formation of complexes amplifying TLR9 stimulation in plasmacytoid dendritic cells (pDCs). Here, we demonstrate that, upon binding to self-RNA, CXCL4 protects the RNA from enzymatic degradation. As a consequence, CXCL4-RNA complexes persist in vivo. Indeed, we show for the first time that CXCL4-RNA complexes circulate in SSc plasma and correlate with both IFN-I and TNF-α. By using monocyte-derived DCs (MDDCs) pretreated with IFN-α as a model system (to mimic the SSc milieu of the IFN-I signature), we demonstrate that CXCL4-RNA complexes induce MDDC maturation and increase, in particular, pro-inflammatory TNF-α as well as IL-12, IL-23, IL-8, and pro-collagen, mainly in a TLR7/8-dependent but CXCR3-independent manner. In contrast, MDDCs produced IL-6 and fibronectin independently in their CXCL4 RNA-binding ability. These findings support a role for CXCL4-RNA complexes, besides CXCL4-DNA complexes, in immune amplification via the modulation of myeloid DC effector functions in SSc and also during normal immune responses.

The Prostacyclin Analogue Iloprost Modulates CXCL10 in Systemic Sclerosis

The prostacyclin analogue iloprost is used to treat vascular alterations and digital ulcers, the early derangements manifesting in systemic sclerosis (SSc), an autoimmune disease leading to skin and organ fibrosis. Bioindicator(s) of SSc onset and progress are still lacking and the therapeutic approach remains a challenge. The T helper 1 (Th1) chemokine interferon (IFN)γ-induced protein 10 (IP-10/CXCL10) associates with disease progression and worse prognosis. Endothelial cells and fibroblasts, under Th1-dominance, release CXCL10, further enhancing SSc’s detrimental status. We analyzed the effect of iloprost on CXCL10 in endothelial cells, dermal fibroblasts, and in the serum of SSc patients. Human endothelial cells and dermal fibroblasts activated with IFNγ/Tumor Necrosis Factor (TNF)α, with/without iloprost, were investigated for CXCL10 secretion/expression and for intracellular signaling cascade underlying chemokine release (Signal Transducer and Activator of Transcription 1, STAT1; Nuclear Factor kappa-light-chain-enhancer of activated B cells, NF-kB; c-Jun NH₂-terminal kinase, JNK: Phosphatidyl-Inositol 3-kinase (PI3K)/protein kinase B, AKT; Extracellular signal-Regulated Kinase 1/2, ERK1/2). CXCL10 was quantified in sera from 25 patients taking iloprost, satisfying the American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2013 classification criteria for SSc, and in sera from 20 SSc sex/age-matched subjects without therapy, previously collected. In human endothelial cells and fibroblasts, iloprost targeted CXCL10, almost preventing IFNγ/TNFα-dependent cascade activation in endothelial cells. In SSc subjects taking iloprost, serum CXCL10 was lower. These in vitro and in vivo data suggest a potential role of iloprost to limit CXCL10 at local vascular/dermal and systemic levels in SSc and warrant further translational research aimed to ameliorate SSc understanding/management.

Subclinical atherosclerosis in systemic sclerosis: Different risk profiles among patients according to clinical manifestations

INTRODUCTION

Like other autoimmune diseases, systemic sclerosis (SSc) has been described to be associated with accelerated atherosclerosis (ATS). Before clinical manifestations of cardiovascular disease (CVD) occur, subclinical ATS can be investigated in different ways.

AIM

To evaluate the presence of subclinical ATS in a group of patients with SSc, and to identify different risk profiles among patients.

METHODS

Subclinical ATS was reviewed in 43 SSc patients and 27 healthy controls, using 2 methods: carotid ultrasound and flow mediated dilation (FMD) of the brachial artery.

RESULTS

Plaques were statistically more frequent in SSc patients than in controls (65% vs 30%, P = .006); intima-media thickness of common carotid artery (CCA-IMT) resulted in statistically higher (median value 0.8 mm vs 0.55 mm; P < .0001) while FMD was significantly lower (median value 9% vs 14%; P = .0086) in patients compared to healthy controls. Among the SSc patients, thickening of CCA-IMT was significantly associated with the presence of diastolic dysfunction of left ventricle (absence of diastolic dysfunction: odds ratio [OR] 0.2, 95% CI 0.04-0.92, P = .038) and with a higher Framingham score (OR 1.3, 95% CI 1.03-1.6], P = .024). The diffuse cutaneous form was slightly protective against pathological FMD (OR 0.12, 95% CI 0.022-0.71, P = .019).

CONCLUSIONS

This study confirms the involvement of macrocirculation in SSc patients, detecting the presence of subclinical ATS markers more frequently in patients compared to healthy controls. Framingham score, diastolic dysfunction of left ventricle and limited cutaneous form of the disease appeared to be associated with a higher risk of developing ATS.

COVID-19 and systemic sclerosis: analysis of lifestyle changes during the SARS-CoV-2 pandemic in an Italian single-center cohort

The outbreak of SARS-CoV-2 has changed the habits and lives of people worldwide. Patients affected by systemic sclerosis (SSc) experienced constant fear because of their immunocompromised status. The aim of this study was to investigate the prevalence of SARS-CoV-2 infection and to analyze the lifestyle changes in a single-center cohort of SSc patients and if these changes were more severe than in the general population. During the Italian lockdown, we supplied two surveys to our 184 SSc patients. In the first one, filled by 110 patients, we asked if SARS-CoV-2 had infected them or if they experienced signs and symptoms consistent with COVID-19. The second survey, performed by 79 SSc patients and 63 healthy subjects, included questions about the lifestyle adopted during this specific period. Among our patients, COVID-19 was diagnosed only in one case, while three other subjects reported signs and symptoms suggestive for the disease. Regarding the second survey, our patients greatly changed their lifestyle during the pandemic, adopting more restrictive isolation measures, because of their awareness of frailty. To date, we do not dispose of enough data to speculate about the risk of COVID-19 among immunocompromised patients, although in our SSc patients their frailty seems to have been their shelter. Pending more accurate epidemiological studies, it is essential to share as much data as possible to better understand the impact of COVID-19 on SSc patients' health. Key points • The lifestyle adopted by SSc patients during the first months of COVID-19 pandemic was characterized by more stringent isolation rules than general population. • The prudential behavior of patients with SSc during Italian lockdown should be considered as a possible bias when analyzing the risk of SARS-CoV-2 disease in these subjects, as well as a protective factor against infection.

POS0475 ROLE OF IL-33/ST2 AXIS IN SYSTEMIC SCLEROSIS PATIENTS WITH ELECTROCARDIOGRAPHIC ABNORMALITIES

Background

Electrocardiographic (EKG) abnormalities are described in 25-75% Systemic Sclerosis (SSc) patients and they are associated with other systemic manifestations1 as well as with a worse prognosis.2 There is an increasing need for clinical and laboratory biomarkers to ameliorate the diagnostic approaches to patients with EKG abnormalities.3

In the last decade, many studies focused on the components of the interleukin (IL)-33/ST2 axis. Under physiological conditions, IL-33 is released by apoptotic cardiac cells, promoting a protective mechanism of cell survival, thanks to the binding with its transmembrane receptor ST2.4 During pathological cardiovascular events, an abnormal secretion of the IL-33 soluble receptor (sST2) by Th2 cells occurs. It binds IL-33 not allowing the physiological mechanism driven by the IL-33/ST2 binding previously described.4 For these reasons, sST2 has been proposed as a biomarker of cardiac injury in a variety of diseases.5

Objectives

Aim of this study was to analyse clinical and demographical parameters in a group of SSc patients, trying to define any possible feature associated with EKG abnormalities. Furthermore, the role of IL-33/ST2 axis components as biomarkers of cardiac injury in patients with SSc-related EKG abnormalities was evaluated, also assessing the possible correlation with serum concentration of NT-pro-BNP, a well-known cardiac injury biomarker in SSc.

Methods

Data from 277 SSc patients, fulfilling the 2013 ACR/EULAR classification criteria,6 attending our Scleroderma Clinic were retrospectively analysed. We selected patients with EKG trace and a blood sample available, collected after the SSc diagnosis. The sera levels of sST2 (ELISA Kit, Abcam), IL-33 (ELISA kit, RayBiotech) and NT-pro-BNP (ELISA Kit, Abcam) were measured. Patients with a history of heart diseases occurring before the diagnosis of SSc or features of secondary cardiac involvement (pulmonary arterial hypertension, severe interstitial lung disease or renal disease) were excluded.

Results

Forty-six SSc patients showed significant EKG abnormalities (rhythm and conduction disorders). Thirty-one SSc patients without pathologic finding at EKG traces were recruited as the control group.

From the analysis of the clinical characteristic of the disease at the moment of serum collection, patients with EKG anomalies have more frequently both a diffuse form of disease (n°-%: 23-50 vs 7-23; p 0.01), with a mean value of mRSS higher than controls (11±9 vs 6±6; p 0.01), and a scleroderma “late” pattern at the nailfold capillaroscopy (n°-% 23-50 vs 6-19; p 0.027).

Significantly higher median values of serum levels of sST2 in SSc patients with EKG disorders compared to the control group (4289pg/mL, IQR 2383 vs 2560 pg/mL, IQR 1455; p 0.0002) were detected, while opposite results were found analyzing serum levels of IL-33 (2.89 pg/mL IQR 101 vs 9 pg/mL IQR 277; p 0.032) (Graph 1). Serum NT-pro-BNP median values were significantly higher in the group of patients with EKG abnormalities than in the control group (149 pg/mL, IQR 354 vs 26 pg/mL, IQR 62; p 0.0007). These values correlated with sST2 serum levels (rho Spearman correlation 0.37; p 0.0006).

Conclusion

SSc patients with EKG abnormalities showed an increased skin and vascular involvement with respect to the control group. These associations could help clinicians in clinically stratifying SSc patients at risk of EKG abnormalities. To our knowledge, this is the first report evaluating the serum concentration of sST2 in SSc patients. Based on these results, we can speculate on the role of this molecule as potential biomarkers of early cardiac injury during SSc, although further studies involving a larger cohort of patients are needed.

References

[1]Vacca et al. Rheumatol 2014

[2]Tyndall et al. Ann Rheum Dis 2010

[3]Muresan et al. Clin Rheumatol 2018

[4]Vianello et al. Int J Biochem Cell Biol 2019

[5]Dudek et al. Adv Clin Exp Med 2020

[6]van den Hoogen et al. Arthritis Rheum 2013

Figure 1:

Graph 1. Serum sST2 (a) and IL-33 (b) concentrations in patients with EKG abnormalities (EKG+) vs control group (EKG)

Disclosure of Interests

None declared.

Lung ultrasound compared to computed tomography detection and automated quantification of systemic sclerosis-associated interstitial lung disease: preliminary study

BACKGROUND

Lung ultrasound (LUS) is a promising tool for detecting SSc-associated interstitial lung disease (SSc-ILD). Currently, consensus on the best LUS findings and execution technique is lacking.

OBJECTIVES

To compare qualitative and quantitative assessment of B-lines and pleural line (PL) alterations in SSc-ILD with chest CT analysis.

METHODS

During 2021-2022, consecutive SSc patients according to 2013 ACR/EULAR classification criteria underwent pulmonary functional tests (PFTs). On the same day, if a CT was performed over a ± 6 months period, LUS was performed by two certified blinded operators using a 14-scans method. The ≥10 B-lines cut-off proposed by Tardella and the Fairchild's PL criteria fulfilment were selected as qualitative findings. As quantitative assessment, total B-lines number and the quantitative PL score adapted from the semi-quantitative Pinal-Fernandez score were collected. CT scans were evaluated by two thoracic radiologists for ILD presence, with further processing by automated texture analysis software (QCT).

RESULTS

Twenty-nine SSc patients were enrolled. Both qualitative LUS scores were significantly associated to ILD presence on CT, with Fairchild's PL criteria resulting in slightly more accuracy. Results were confirmed on multivariate analysis. All qualitative and quantitative LUS findings were found to be significantly associated with QCT ILD extension and radiological abnormalities. Mid and basal PL quantitative score correlated with mid and basal QCT ILD extents. Both B-lines and PL alterations differently correlated with PFTs and clinical variables.

CONCLUSION

This preliminary study suggests the utility of a comprehensive LUS assessment for SSc-ILD detection compared with CT and QCT.

Psychological Fragility in an Italian Cohort of Systemic Sclerosis Patients During COVID-19 Pandemic Category: Short Communication

Objective

This work aims to evaluate the prevalence of anxiety and COVID-19-related fear in systemic sclerosis (SSc) patients during the second and third waves of the SARS-CoV-2 pandemic in Italy and their possible associated factors.

Methods

A cohort study was carried out on 114 SSc patients referred to our Scleroderma Clinic, matched for sex and age. Twenty-eight of them had missed scheduled examinations during the October 2020-March 2021 period and 86 has attended regular outpatient visits during the same period. Both groups were administered (by telephone for cases and in-person for controls) the Generalized Anxiety Disorder Scale-7 (GAD-7) questionnaire and the validated on SSc patients COVID-19 Fears Questionnaire for Chronic Medical Conditions (COVID-19 Fears). Concurrent factors related to higher scores were investigated in patients who did not have an outpatient follow-up.

Results

The missing group had significantly more patients scoring ≥8 on the GAD-7 questionnaire [22 (78.6%) vs 16 (18.6%), p < 0.0001] and significantly higher scores on the COVID-19 Fears questionnaire (median [quartiles] 31.5 [26.25;37.25] vs 20 [13.75;28], p < 0.0001) than the attending group. Multivariate analysis performed on the missing patients group showed a significant association of the lack of work and ongoing therapy for anxiety/depression with GAD-7 (p = 0.0275 and p = 0.0188) and COVID-19 Fears score (p = 0.0016 and p = 0.0099).

Conclusion

Anxiety disorder and COVID-19-related fear were greater in SSc patients who missed regular follow-ups and are associated with a lack of work activity. These findings aim to identify a subgroup deserving attention regarding risk factors for missed periodic controls.

Helicobacter pylori and Upper Endoscopy in Systemic Sclerosis: A Cross-sectional Study in the Real World

BACKGROUND/AIMS

A role for Helicobacter pylori in triggering systemic sclerosis (SSc) has been proposed, but data are conflicting. In previous studies, infection has been generally searched for by using serology. We designed this study to assess H. pylori prevalence in SSc patients with histology of gastric mucosa, considered the criterion standard for infection diagnosis.

METHODS

This cross-sectional study enrolled 30 SSc patients who complained of upper gastrointestinal symptoms. All underwent upper endoscopy with gastric biopsies. Endoscopic alterations were recorded, and gastric mucosa biopsies were used for both histological examination and searching for H. pylori. The role for proton-pump inhibitor (PPI) therapy was considered. Fisher exact test was used for statistical analysis.

RESULTS

Data of 28 SSc patients were available, 14 with ongoing PPI therapy. Helicobacter pylori infection at histology was detected in 14.3% patients, and it equally occurred in patients with or without PPI therapy. Erosive esophagitis/Barrett esophagus was detected in 26.6% of cases. Among patients with PPI therapy, 30% received half dose only. The prevalence of intestinal metaplasia was low (14.3%). Endoscopic esophageal alterations were significantly more frequent in those patients showing anti-Scl70 antibody positivity.

CONCLUSIONS

This study showed that prevalence of H. pylori is very low in SSc patients, so that it seems not having a role in triggering SSc. Management of gastroesophageal diseases in SSc patients needs to be improved, and looking to the autoimmune profile may be of help. Thus, collaboration between rheumatologist and gastroenterologist is highly recommended.

POS1185 IMPACT OF LOCKDOWN DURING COVID-19 PANDEMIC ON THE ONSET OF POST-TRAUMATIC STRESS DISORDER (PTSD) IN SYSTEMIC SCLEROSIS PATIENTS: A CASE-CONTROL STUDY

Background:

Social distancing due to COVID-19 pandemic had a major impact on the mental health of general population, with a high prevalence of post-traumatic stress disorder (PTSD) related symptoms1, 2. Psychological repercussions were notably found in people with chronic diseases, including systemic sclerosis (SSc) patients, where an increasing of anxiety symptoms, related also to low financial resources, emerged3.

Objectives:

To evaluate the impact of COVID-19 lockdown on the onset of PTSD in patients with SSc, firstly during the total confinement period (March-April 2020) and then at the time of less restrictive government measures, following the RT index lowering (June-July 2020)4.

Methods:

We carried out a case-control study on 57 SSc patients, according to the ACR/EULAR 2013 criteria, and on 57 healthy subjects as control group (HC), matched by sex and age. At T0 (March-April) and T1 (June-July) both populations received the “Impact of Event Scale Revised” questionnaire (IES-R) by e-mail, with a cut-off of ≥ 33 defining probable diagnosis of PTSD5. A multivariate analysis of possible factors influencing IES-R score, such as age, number of cohabitating people and weekly outings count, was performed in SSc patients at both times of the survey.

Results:

At T0 we found a significantly greater number of SSc patients with IES-R score ≥ 33 compared to HC (26/45.6% vs 13/22.8%; median value [quartiles] 31 [19.5;42.5] vs 24 [15.5; 32]; p-value 0.046). At T1, we obtained data from 44 SSc patients and 35 HC but no significant difference was noticed (18 / 40.9% vs 8 / 23.5%; 26 [15.25; 38] vs 26.5 [20.75; 32.5]; p> 0.05). SSc patients also had significantly fewer weekly outings than HC, both at T0 (p <0.001) and T1 (p <0.001) (Table 1). The multivariate analysis performed at T0 on SSc patients showed a significant association of IES-R ≥33 score with age (p 0.025) and with a lower count of weekly outings (p 0.002). The latter data negatively correlated with an IES-R ≥33 score in SSc patients (r -0.267, p 0.004).

Conclusion:

We found a significantly higher prevalence of PTSD in SSc patients compared to HC at the strictest lockdown time, turning into comparable when government measures were less restrictive, due to the minimum RT index values recorded in Italy. Older age and lower count of weekly outings were associated with PTSD in SSc patients during the lockdown, whereas the count of weekly outings was lower than in HC during both the examined periods. The results of this study indicate that COVID-19 lockdown had a worse impact in SSc patients, where the fewer weekly outings may depend on their clinical condition and on a greater concern about their health6. These findings strengthen the World Scleroderma Foundation recommendations regarding care to the psychological frailty of SSc patients7.

References:

[1]Wang C, Brain Behav Immun. 2020.

[2]Dubey S, Psychiatr Pol. 2020.

[3]Thombs BD, J Psychosom Res. 2020 Dec.

[4]https://covid19.infn.it/grafici/?chart=italia,rt,covidstat

[5]Weiss, D. S., & Marmar, C. R. (1996). The Impact of Event Scale - Revised, Assessing. psychological trauma and PTSD (pp. 399-411).

[6]Orlandi M, Clin Rheumatol. 2020

[7]Matucci-Cerinic M, Ann Rheum Dis. 2020

Table 1.

Descriptive analysis of study population: T0 (Time 0), T1 (Time 1), SD (Standard Deviation), IES-R (Impact of Event Scale-Revised).

SSc patient groupHS groupFemale:male ratio at T046:746:7Mean age ± SD at T059±12.851±8.7IES-R ≥33 score n°/% at T026/45.6%*13/22.8%IES-R ≥33 score n°/% at T118/40.9%8/23.5%IES-R score at T0, median value [quartiles]31 [19.5;42.5]24 [15.5;32]IES-R score at T1, median value [quartiles]26 [15.25; 38]26.5 [20.75; 32.5]N° of weekly outings at T0, median value [quartiles]2 [1;3.5]4 [2;10]**N° of weekly outings at T1, median value [quartiles]5 [3;6]14 [6.75;15]**

*p<0.046; **p<0.001

Disclosure of Interests:

None declared.

POS0433 CAN INTERLEUKIN 33 (IL-33) BE CONSIDERED A VALUABLE BIOMARKER IN THE EARLY STAGES OF SYSTEMIC SCLEROSIS? ANALYSIS OF A MONOCENTRIC COHORT

Background:

The ScS approach has changed considerably in recent years especially concerning the very early diagnosis of the disease (VEDOSS) at the time when the patient is still in an undifferentiated form (UCTD) at risk of developing SSc (1, 2). Of great value are different clinical, instrumental and laboratory findings, such as specific autoantibodies and Nailfold VideoCapillaroscopy (NVC), able to identify those cases progressing into overt SSc. IL-33 cytokine is known to exert pro-fibrotic effects through its membrane receptor ST2 on immune cells and myofibroblasts and recent studies suggest that it can be released following endothelial cell activation at the onset of SSc (3, 4).

Objectives:

Our aim has been to evaluate IL-33 serum levels in a monocentric cohort of VEDOSS patients, looking for the possible association with clinical phenotype and disease progression, focusing on the microvascular capillaroscopic changes.

Methods:

Fourty-seven VEDOSS patients underwent a complete clinical, instrumental and laboratory evaluation, including NVC and specific SSc autoantibodies. At baseline serum IL-33 levels were measured using an ELISA assay. In 32 of them we also had a second serum sample at a follow-up time of at least 24 months (range 24 to 96 months).

Results:

During the follow-up time, 17 patients were subsequently reclassified as having ScS whereas 30 remained VEDOSS. The “progressor” subjects positively correlated with the presence of anti-Topoisomerase I antibodies (p>0,004). IL-33 concentrations had a median value of 427.2 pg/ml (IQR 967.9 pg/ml) at baseline and of 130.4 pg/ml (IQR 399 pg/ml) at the follow up, showing a statistically significant difference independently from the progression of the disease (p=0.03). Besides significantly higher levels were detected in those patients with more severe NVC changes, defined as “active” pattern (p<0.05). Among the 47 VEDOSS patients, 12 started some kind of vascular therapy. In these patients serum IL-33 concentrations significantly lowered during the follow-up respect to those without any treatment (p<0.03)

Conclusion:

The analysis of our data confirms previous report (5) on higher IL-33 serum levels in the very early stages of UCTD patients at risk for SSc, regardless of their progression in established SSc, although related to more severe microvascular NVC involvement. The lowering of IL-33 serum levels that we detected in the follow up of our patients, may be linked to the well-known endothelial changes during the progression of the SSc and seems also to be partially affected by treatments. Investigation on a greater number of patients are needed to better understand our findings.

References:

[1]J. Avouac et al. Ann Rheum Dis 2011

[2]G Valentini et al. Clin Exp Med 2017

[3]Manetti M, et al. Ann Rheum Dis 2010

[4]Terras S et al. Ann Rheum Dis 2013

[5]Vettori S, et al. J Clin Immunol 2014

Disclosure of Interests:

None declared

AB0170 PHENOTYPIC CHARACTERIZATION OF ENDOTHELIAL PROGENITORS CELLS OF SYSTEMIC SCLEROSIS (SSC) PATIENTS: ROLE IN ENDOTHELIAL-TO-MESENCHIMAL TRANSITION PROCESS

Background:

Endothelial-to-mesenchymal transition (EndoMT), a newly recognized type of cellular transdifferentiation, seems to be involved in Systemic Sclerosis (SSc) pathogenesis. In this process endothelial cells lose their specific markers, and acquire a mesenchymal phenotype, thus expressing cell products such as alpha smooth muscle actin (α-SMA) (1,2).Circulating endothelial progenitors cells (EPCs) derive from bone marrow stem cells and contribute tode novovessels formation. Several studies, although with conflicting results, have shown that EPCs in the peripheral blood of patients with SSc are impaired in their number and function (3).

Objectives:

to assess phenotypic characteristics of EPCs fromSSc patients and from patients with Very Early Diagnosis of SSc (VEDOSS) compared with healthy controls (HC). In particular we want to evaluate the expression of α-SMA, as marker of a pro-mesenchymal switch (EndoMT) in:

Methods:

we enrolled 11 patients (6 SSc and 5 VEDOSS), classified according to the classification criteria for SSc (4) and for VEDOSS not fulfilling SSc criteria (5), and 5 HC. Phenotypic characterization was performed as previously described by Vasa et al. using a FACS Calibur (BD Immunocytometry Systems). EPCs number was expressed as a percentage of cells within the lymphocyte gate. 5*106 PBMCs were plated on human fibronectin-precoated (10 μg/ml Sigma-Aldrich) 6-well plates and cultured for 7-12 days to obtain EPCs. PBMCs from one HC were also cultured with 20% SSc patient serum. Collected EPCs were lysed and a Western blot analysis for α-SMA detection was performed.

Results:

we found a significant higher percentage of α-SMA positive Early EPCs in all patients respect to HC (0,06% ±0,03 vs 0,03% ± 0,01; p=0,0149) particularly in VEDOSS patients (0,07%±0,01 vs 0,03%±0,01 p=0,008). Similarly we found a significant higher expression of α-SMA protein in all patients and VEDOSS patients respect to HC (0,1895±0,16 vs 0,07± 0,06 p= 0,0342; 0,3075 ± 0,14 vs 0,07± 0,06 p=0,0159). After the incubation of HC PBMCs with SSc serum, the α-SMA protein expression seems to be increased respect to its expression in thePBMCs of the same HC cultured without SSc serum (0,33 vs 0,1).

Conclusion:

we found higher percentage of Early α-SMA positive EPCs and a higher expression of α-SMA protein in cultured EPCs in patients group (SSc and VEDOSS) than in HC. So we hypothesized a predominant pro-mesenchymal phenotype of this kind of EPCs. This could be considered the expression of the involvement of EPCs in the EndoMT process and it better explain the controversial role of EPCs in SSc pathogenesis. Moreover the modified expression of α-SMA in HC EPCs co-cultured with 20% SSc serum could suggest the presence of a factor inducing the EndoMT process in the disease.

References:

[1]Corallo C et al Arthritis Res Ther 2016;

[2]Manetti M et al AnnRheumDis 2017;

[3]Del Papa N et al Front. Immunol 2018;

[4]Van den Hoogen F et al AnnRheumDis 2013.

[5]Avouac J et al Ann Rheum Dis 2011;

Disclosure of Interests:

Katia Stefanantoni Consultant of: Italfarmaco

Boehringer Ingelheim, cristiana barbati: None declared, Tania Colasanti: None declared, Carlotta Angelelli: None declared, Greta Pellegrino: None declared, cristiano alessandri Grant/research support from: Pfizer, Guido Valesini: None declared, Valeria Riccieri: None declared

POS0879 LUNG ULTRASOUND FOR INTERSTITIAL LUNG DISEASE DETECTION IN A COHORT OF SYSTEMIC SCLEROSIS PATIENTS: ROLE OF B-LINE AND PLEURAL LINE MODIFICATIONS

Background

Lung ultrasound (LUS) is a technique that showed a high diagnostic accuracy for interstitial lung disease (ILD) detection in systemic sclerosis (SSc) patients and currently in progress of standardization. Traditionally, B-lines represented the finding of ILD, with the ≥10 total cut-off reported by Tardella et al. resulting to be closely related to moderate ILD detected on high resolution chest computed tomography (HRCT). Recently, Fairchild et al. proposed novel LUS criteria for the evaluation of pleural line, disclosing high accuracy and reproducibility.

Objectives

To compare B lines cut-off with novel pleural line criteria and the respectively associated variables.

Methods

We enrolled 55 consecutive patients affected by SSc according to ACR/EULAR 2013 criteria who underwent respiratory functional tests (RFTs) during 2021, excluding smokers and those with arterial pulmonary hypertension. Twenty-four of them carried out a HRCT during a ± 6-months’ time. In the same day of RFTs, two certified blinded operators performed LUS for each patient applying the 14-areas technique proposed by Gutierrez et al., looking for the presence of total ≥10 cumulative B lines and the fulfilling of Fairchild’s criteria for pleural line. A 3-13 MHz operating linear probe was used. Clinical-demographic data and ongoing therapies were collected.

Results

Among 55 total SSc patients, the agreement between the two operators for Fairchild’s criteria was almost perfect (Cohen’s kappa (k) =0.81) and substantial for ≥10 cumulative B-lines count (k=0.74). Fairchild’s criteria showed a higher diagnostic accuracy compared with ILD detected on HRCT, with an overall specificity (SP) and a positive predicted value (PPV) of 100% (Table 1). A negative correlation emerged between total lung capacity values (TLC%) and both B lines cut-off [first operator (IO): p 0.04, r -0.27; second operator (IIO): p 0.042, r-0.28] and pleural line criteria (IO: p 0.009, r -0.35; IIO: p 0.08, r – 0.36), but only the latter negatively correlated also with forced vital capacity values (FVC%) (IO: p 0.04, r – 0.27; IIO p 0.03, r -0.28). The ≥10 total B lines amount correlated positively with concurrent mycophenolate therapy (IO: p 0.09, r 0.28; IIO: p 0.005, r 0.37) and negatively with anti-centromere antibodies (IO: p 0.002, r -0.3; IIO p 0.009, r -0.34). The presence of digital ulcers showed a positive correlation with pleural line criteria (IO: p 0.03, r 0.29; IIO: p 0.005, r 0.37), with a significant association on multivariate analysis (IO: p 0.03, IIO: p 0.01).

Table 1.

Overall sensitivity, specificity, positive predictive value, negative predictive value of LUS compared to ILD detected on HRCT. C.I. 95% confidence interval.

SE (C.I.)SP (C.I.)PPV (C.I.)NPV (C.I.)Fairchild’s criteria fulfilling0.91 (0.76 - 0,97)1 (0.78 – 1.000)1 (0.88 -1.00)0.82 (0,59 – 0.94)≥10 cumulative B-lines count0.73 (0.56 – 0.85)0.8 (0.55 – 0.93)0.89 (0.72 – 0.96)0.57 (0.36 – 0.75)

Conclusion

We confirmed the feasibility and reliability of Fairchild’s recently proposed pleural line LUS criteria, that showed a higher diagnostic accuracy versus ≥10 cumulative B-lines count for ILD detected on HRCT, presenting SP and PPV values of 100% in SSc. Furthermore, these LUS features seem to differently associate with other aspects of the disease such as autoantibody specificity and vascular lesions, thus deserving future deeper evaluations. For the first time, we found that Fairchild’s criteria were associated with a clinical variable such as digital ulcers. Our results highlight the relevance of pleural line evaluation for ILD detection in SSc on LUS and its possible role towards a standardization of this diagnostic technique.

References

[1]Gutierrez M et al., Radiol Med, 2019.

[2]Xie, H.Q et al. Arthritis Res Ther, 2019.

[3]Tardella M et al., Medicine (Baltimore), 2018.

[4]Fairchild R et al. Arthritis Care Res, 2021.

Disclosure of Interests

None declared

Heparin-Independent and Heparin-Dependent Anti-CXCL4 Antibodies Have a Reciprocal Expression in a Systemic Sclerosis Patients' Cohort

Systemic sclerosis (SSc) is a chronic disease characterized by skin/internal organ fibrosis, vasculopathy and autoimmunity. Chemokine (C-X-C motif) ligand 4 (CXCL4) is an early SSc biomarker that predicts worse disease outcome. We previously reported that CXCL4 is an autoantigen in SSc, and anti-CXCL4 antibodies correlated with IFN-I and were more abundant in patients with lung fibrosis. However, it is unclear whether antibodies to CXCL4 in SSc are only directed to CXCL4 or recognize complexes formed by CXCL4 and heparin. Here, by analyzing an SSc cohort, we addressed the occurrence of circulating heparin-dependent VS heparin-independent anti-CXCL4 antibodies and their relationship with a few disease parameters. We found that heparin-dependent, like the heparin-independent antibodies, are higher in SSc as compared to healthy donors; they are detectable in 24% and 30% of the SSc patients, respectively, and appear inversely correlated and mutually exclusive. Like the heparin-independent antibodies, heparin-dependent antibodies correlated with digital ulcers. However, in contrast to heparin-independent antibodies, heparin-dependent antibodies did not correlate with IFN-I, but were largely expressed in patients with pulmonary arterial hypertension. This pilot study indicates that heparin-dependent antibodies are worth studying in larger SSc cohorts to address whether they discriminate SSc sub-groups with different pathological characteristics and outcomes.