Chemokine (C-X-C motif) ligand 4 (CXCL4) is a biomarker of unfavorable prognosis in Systemic Sclerosis (SSc), a potentially severe autoimmune condition, characterized by vasculitis, fibrosis and interferon (IFN)-I-signature. We recently reported that autoantibodies to CXCL4 circulate in SSc patients and correlate with IFN-α. Here, we used shorter versions of CXCL4 and CXCL4-L1, the CXCL4 non-allelic variant, to search for autoantibodies exclusively reacting to one or the other CXCL4 form. Moreover, to address whether anti-CXCL4/CXCL4-L1 antibodies were present before SSc onset and predicted SSc-progression, we longitudinally studied two VEDOSS (Very Early Diagnosis of Systemic Sclerosis) patient cohorts, separating SSc-progressors from SSc-non-progressors. We found that anti-CXCL4-specific autoantibodies were present in both SSc and VEDOSS patients (both SSc-progressors and SSc-non-progressors). Anti-CXCL4-L1-specific autoantibodies were especially detected in long-standing SSc (lsSSc). Anti-CXCL4/CXCL4-L1 antibodies correlated with IFN-α and with specific SSc-skin features but only in lsSSc and not in early SSc (eaSSc) or VEDOSS. Thus, a broader antibody response, with reactivity spreading to CXCL4-L1, is characteristic of lsSSc. The early anti-CXCL4 autoantibody response seems qualitatively different from, and likely less pathogenic than, that observed in advanced SSc. Lastly, we confirm that anti-CXCL4 autoantibodies are SSc-biomarkers and uncover that also CXCL4-L1 becomes an autoantigen in lsSSc.

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.

Background:Systemic sclerosis (SSc) is a rare and progressive autoimmune disease, whose diagnosis is difficult in the early stages because of the lack of specific signs and symptoms. Criteria for a Very Early Diagnosis of SSc (VEDOSS) have been proposed to identify those patients affected by undifferentiated connective tissue disease (UCTD) at risk to develop SSc [1]. For the diagnosis of SSc a strict clinical and laboratory follow up is mandatory [2]. CXCL4 chemokine recently proved to be higher in early SSc [3][4][5].Objectives:Aim of our study was to evaluate at baseline the main clinical-demographic and laboratory parameters in a group of VEDOSS patients, comparing these features during the follow-up, to detect any difference between progressors (P) and non-progressors (NP) into SSc. Furthermore, we dosed plasma levels of CXCL4.Methods:We included 27 VEDOSS patients, defined by EUSTAR 2011 Criteria and not fulfilling the 2013 ACR/EULAR classification criteria of SSc, attending the Rheumatology Unit of Policlinico Umberto I in Rome from 2009 to 2020. Demographic, laboratory and instrumental features were analyzed, and, after a mean follow-up of 5.7±1,7 years, we compared the P to NP patients. Having obtained written informed consent, blood samples were taken at baseline to measure plasma levels of CXCL4 chemokine using an ELISA assay.Results:At baseline the 27 VEDOSS patients (mean age 53.2±13.5 years, all females) had ANA positivity in 25 (93%) cases and Raynaud’s phenomenon in 25 (93%) cases. In a mean follow-up time of 43.5 ± 23.1 weeks from the first clinical examination, 15 (55%) patients were classified as P into SSc. These P patients showed a significant association with SSc specific antibodies such as anti-Centromere, anti-Scl70 and anti-RNAPIII (p=0.014) as well as with a specific “Scleroderma pattern” at the nailfold capillaroscopy (p=0.022) respect to those NP into SSc. A group of 6 P patients evolved in less than 24 months (mean 19,6 ± 6,8 weeks) and were defined “Fast Progressor”. They were also significantly associated with those autoantibodies considered as having a worse prognosis such as anti-Scl70 and anti-RNAPIII (p=0.005), and had a shorter duration of RP (88 vs 189.3 months) and a younger mean age (49.5 vs 55.4 years) respect to “Slow Progressor” (SSc evolving in >24 months). At baseline we detected significantly higher median plasma levels of CXCL4 in the 27 VEDOSS patients compared to 10 healthy subjects (9024±10559 pg/ml versus 348,5±684,3 pg/ml; p=0.0047). We also noticed a trend for lower CXCL4 levels in the “Fast Progressor” than in the “Slow Progressor” (3303 ± 6065 pg/ml vs 13300 ± 10308 pg/ml; p=0.052) without reaching a significant value, due probably to the low number of cases.Conclusion:Our study confirms that the presence of specific autoantibodies and capillaroscopic abnormalities correlate to an increased risk of developing SSc in patients with UCTD [6]. Beside we found significantly higher levels of CXCL4 in our 27 VEDOSS patients respect to controls, in agreement with other authors showing the association of this chemokine with early stages and specific organ involvement [4][5][7]. The finding of CXCL4 lower levels in “fast progressor” cases is consistent with our recent report of anti-CXCL4 antibodies in patients with early SSc, determining lower levels of this antigen [7]. We need deeper investigations to better evaluate the role of CXCL4 in the different stages of SSc.References:[1]J. Avouac et al., Ann. Rheum. Dis., 2011.[2]F. van den Hoogen et al., Ann. Rheum. Dis., 2013.[3]G. Valentini et al., Clin. Exp. Med., 2017.[4]R. Lande et al., Nat. Commun., 2019.[5]L. van Bon et al., N. Engl. J. Med., 2014.[6]M. Vasile et al., Clin. Exp. Rheumatol., 2018.[7]R. Lande et al., Int. J. Mol. Sci., 2020.Disclosure of Interests:None declared

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.

BackgroundSystemic sclerosis (SSc) is a rare and progressive autoimmune disease, that has been associated with an increased risk of osteoporosis (OP), but risk factors are still debated[1,2].ObjectivesThe aim of our study was to investigate the risk factors for osteoporosis in SSc and to evaluate if any feature of the disease could increase the risk of osteoporosis.MethodsIn this cross-sectional study we included 60 consecutive patients, fulfilling the 2013 ACR/EULAR classification criteria of SSc[3], attending our Rheumatology Unit from July to December 2022. All the 60 patients performed a Dual-energy X-ray absorptiometry (DXA) between 2020 and 2022. Osteoporosis was defined as a T score less than -2.5 SD and osteopenia as a T-score between -1.0 and -2.5 SD, according to WHO definitions. We divided patients in two groups according to the diagnosis of osteoporosis (OP+) and non osteoporosis including osteopenia (OP-). We collected the main clinical-demographic and laboratory features of the patients and we assess the presence of any association with OP.ResultsAll 60 patients were women with an average age (mean±SD) of 70.5±10.1 years, 35 had a diagnosis of osteoporosis (OP+ group) and 25 patients were included in OP- group, in which 17 patients had osteopenia. The two groups were comparable for age, disease duration, menopause and smoking habit. We found statistically significant differences between the two groups with BMI (21.97±3.47 in OP+ vs 24.04±3.63 in OP-, p=0.04), modified Rodnan Skin Score (mRSS) (8.91±12.19 vs 3.20±4.71, p=0.03) and presence of calcinosis (12 in OP+ vs 1 in OP-, p=0.005), pitting scars (17 vs 5, p=0.03) and telangiectasia (28 vs 13, p=0.02). Performing simple logistic regression analyses we confirmed the association of calcinosis (OR 12.52, CI 2.2-237.3, p=0.02), pitting scars (OR 2.02, CI 1.08-11.97, p=0.04) and telangiectasia (OR 2.24, CI 1.21-12.09, p=0.02) with the presence of OP. There was no difference between the two groups for NVC scleroderma pattern, autoantibodies and presence of digital ulcers. (Table 1).ConclusionThis retrospective study confirms the association of OP with lower BMI in SSc. An increased mRSS and the presence of calcinosis, telangiectasias and pitting scars were also associated to OP in our patients. These SSc features deserve to pinpoint an early evaluation of bone health in our patients and an early referral to DXA, independently from the traditional risk factors of OP. Of interest, in our opinion, is the rather high prevalence of calcinosis in the OP+ group, confirming data from other authors[4]and suggesting a possible common pathogenically pathway in calcinosis development.References[1]Tu X, et al.Clin Rheumatol. 2022[2]Marot M, et al.Oncotarget. 2015[3]van den Hoogen F, et al.Ann Rheum Dis. 2013[4]Valenzuela A, et al.Semin Arthritis Rheum. 2016Table 1.OP + (N=35)OP – (N=25)pSex (f/m)35/025/0nsAge (years) (mean±SD)70.03±11.5670.52±8.18nsBMI (mean±SD)21.97±3.4724.04±3.630.04Current smoking (N, %)3 (8)2 (8)nsMenopause (N, %)33 (94)24 (96)nsDisease duration (years) (mean ± SD)13.97±9.1511.68±7.19nsmRSS (mean ± SD)8.91±12.193.20±4.710.03DU (N, %)13 (37)6 (24)nsPitting scars (N, %)17 (49)5 (20)0.03Calcinosis (N, %)12 (34)1 (4)0.005Telangiectasia (N, %)28 (80)13 (26)0.02NVC Scleroderma pattern (N, %)32 (91)20 (80)nsACA (N, %)16 (46)13 (52)nsATA (N, %)9 (26)7 (28)nsPPI therapy (N, %)29 (83)21 (84)nsLumbar spine (T Score) (mean±SD)-2.33±0.81-0.69±1.18<0.0001Total hip (T Score) (mean±SD)-2.49±0.75-0.93±1.00<0.0001OP under treatment (N, %)31 (88)0 (0)<0.0001Pathological bone fractures (N, %)11 (31)0 (0)0.001Acknowledgements:NIL.Disclosure of InterestsNone Declared.