Systemic sclerosis: changes in the incidence rates in the Finnish population during the years 1999-2018.

OBJECTIVE: The aim of our study was to examine changes in the incidence of systemic sclerosis (SSc) in Finland using two different classification criteria. METHOD: Medical records of patients who had been registered with ICD-10 code M34 from 1999 to 2018 in two university hospitals were reviewed retrospectively. This period was divided into 5 year periods: 1999-2003, 2004-2008, 2009-2013, and 2014-2018. Using American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) 2013 criteria and clinical findings, we reclassified patients into four groups: diffuse SSc, limited SSc, sine SSc, or early SSc. In the same population, we also investigated whether the ACR 1980 criteria were fulfilled. RESULTS: In 1999-2018, 246 new patients with SSc and 45 patients with early SSc were identified using ACR/EULAR 2013 criteria. Of these patients, 70 fulfilled the ACR 1980 criteria. Using ACR/EULAR 2013 criteria, the increase in new diagnoses was statistically significant when comparing the fourth period with the first period (p = 0.0012). The increase was due to a rise in limited SSc. Mean annual incidence rates in these groups were 0.9, 1.2, 1.9, and 2.8 per 100 000 inhabitants ≥ 16 years old. An increasing trend was also seen when using ACR 1980 criteria, but this was not statistically significant. CONCLUSION: The incidence of SSc increased during the period between 1999-2003 and 2014-2018 using ACR/EULAR 2013, but not using ACR 1980 criteria. The increase was detected within a limited SSc subclass, owing to more sensitive classification criteria.

Gut microbiome profiling in systemic sclerosis: a metagenomic approach.

OBJECTIVES: The early gastrointestinal (GI) manifestation of systemic sclerosis (SSc) suggests a possible GI microbiota engagement in the pathophysiology and/or progression of SSc. Previous studies have revealed dysbiosis among Caucasian SSc patients. This study extends these findings to Asian SSc patients. METHODS: Adult SSc patients, stratified according to 1) on immunosuppressive (On-IS) drugs or 2) no immunosuppressive drugs (No-IS), and age-and-sex-matched healthy controls (HC) were recruited. Metagenomic sequencing of stool DNA was compared between SSc patients and HC, and between SSc (On-IS) and (No-IS) patients. Alpha and beta-diversity, taxonomic and functional profiling were evaluated. RESULTS: Twenty-three female SSc patients (12 On-IS; 11 No-IS; 5 diffuse and 18 limited SSc subtype) and 19 female HC, with median age of 54 years and 56 years, respectively, were recruited. Median SSc disease duration was 3.3 years. Alpha diversity was significantly higher in SSc versus HC (p=0.014) and in SSc (No-IS) versus HC (p=0.006). There was no significant difference in beta diversity between SSc and HC (p=0.307). At the phyla level, there were significantly increased abundance of Firmicutes and Actinobacteria in SSc versus HC, and reduced abundance of Bacteroidetes (all p<0.001). At the species level, there were significantly increased abundance of several Lactobacillus, Bifidobacterium, and Coprococcus species in SSc, and increased abundance of Odoribacter, Bacteroides and Prevotella species in HC. KEGG pathway analysis demonstrated distinct differences between SSc versus HC, and between SSc (No-IS) and SSc (On-IS). CONCLUSIONS: Using metagenomic sequencing, our study further underlines distinct alterations in microbiota profiling among Asian SSc patients.

Phenotype of limited cutaneous systemic sclerosis patients with positive anti-topoisomerase I antibodies: data from the EUSTAR cohort.

OBJECTIVES: To characterize patients with positive anti-topoisomerase I (ATA) in lcSSc. METHODS: SSc patients enrolled in the EUSTAR cohort with a disease duration of ≤3 years at database entry were considered. We assessed the risk of major organ involvement in the following groups: ATA-lcSSc vs ACA-lcSSc and vs ANA without specificity (ANA)-lcSSc, and ATA-lcSSc vs ATA-dcSSc. Cox regression models with time-dependent covariates were performed with the following outcomes: new-onset interstitial lung disease (ILD), ILD progression [forced vital capacity (FVC) decline ≥10% and ≥5% vs values at ILD diagnosis), primary myocardial involvement (PMI), pulmonary hypertension (PH), any organ involvement and all-cause mortality. RESULTS: We included 1252 patients [194 ATA-lcSSc (15.5%)], with 7.7 years (s.d. 3.5) of follow-up. ILD risk was higher in ATA-lcSSc vs ACA- and ANA-lcSSc and similar to ATA-dcSSc, although with less frequent restrictive lung disease. The risk of FVC decline ≥10% (35% of ATA-lcSSc) was lower in ATA-lcSSc than in ATA-dcSSc, whereas FVC decline ≥5% occurs similarly between ATA-lcSSc (58% of patients) and other SSc subsets, including ATA-dcSSc. The risk of PMI was similar in ATA-lcSSc and ANA-lcSSc but lower than in ACA-lcSSc; no difference in PH and mortality risk was observed among lcSSc subsets. The risk of any organ involvement, PMI and PH was lower and the mortality tended to be lower in ATA-lcSSc vs ATA-dcSSc. CONCLUSION: ATA-lcSSc patients have a high risk of ILD, albeit with a lower risk of progression compared with ATA-dcSSc, supporting careful screening for ILD in this subgroup.

Perifollicular Hypopigmentation in Systemic Sclerosis: Associations With Clinical Features and Internal Organ Involvement.

OBJECTIVE: To determine whether perifollicular hypopigmentation in systemic sclerosis (SSc) is associated with demographics, distinct clinical features, and autoantibody profiles. METHODS: Patients with SSc were prospectively enrolled, with a standardized data form used to collect anatomic distribution of perifollicular hypopigmentation. Associations between hypopigmentation and features of SSc were assessed. RESULTS: Of 179 adult patients with SSc, 36 (20%) patients had perifollicular hypopigmentation. Of these 36 patients, 94% (n = 34) were female and 33% (n = 12) had limited cutaneous SSc. In univariable logistic regression, Black race (odds ratio [OR] 15.63, 95% CI 6.6-37.20, P < 0.001), diffuse cutaneous SSc (dcSSc; OR 4.62, 95% CI 2.11-10.09, P < 0.001), higher maximum modified Rodnan skin score (mRSS; OR 1.05, 95% CI 1.02-1.08, P = 0.003), myopathy (OR 3.92, 95% CI 1.80-8.57, P < 0.001), pulmonary fibrosis (OR 2.69, 95% CI 1.20-6.02, P = 0.02), lower minimum forced vital capacity % predicted (OR 0.96, 95% CI 0.94-0.99, P = 0.001), and lower minimum diffusing capacity for carbon monoxide % predicted (OR 0.97, 95% CI 0.95-0.99, P = 0.009) were associated with hypopigmentation. Anticentromere antibodies inversely associated with hypopigmentation (OR 0.24, 95% CI 0.07-0.86, P = 0.03). After adjusting for age, race, and disease duration, dcSSc (OR 4.28, 95% CI 1.46-12.53, P = 0.008) and increased mRSS (OR 1.07, 95% CI 1.02-1.12, P = 0.009) were significantly associated with hypopigmentation. CONCLUSION: Perifollicular hypopigmentation is observed in a subset of patients with SSc and associated with diffuse subtype. Larger prospective studies determining whether perifollicular hypopigmentation precedes end-organ involvement and whether specific patterns associate with internal organ involvement are needed.

Domains and outcome measures for the assessment of limited cutaneous systemic sclerosis: an international collaborative scoping review.

OBJECTIVES: The aim of this study was to comprehensively identify instruments within relevant domains employed to assess lcSSc since the endorsement of its consensus definition in 1988. The overall objective is to inform the creation of a Combined Response Index for Scleroderma Trials Assessing lcSSc (CRISTAL). METHODS: MEDLINE and Embase were searched using terms selected to comprehensively retrieve titles and abstracts mentioning both lcSSc and dcSSc, along with those only mentioning lcSSc, SSc sine scleroderma, limited SSc and/or CREST/CRST. Because our initial assessment of the literature revealed that very few studies included only lcSSc subjects, we also assessed literature that included both cutaneous subsets. A total of 3964 titles and abstracts were screened by two reviewers, and 270 articles were selected for data extraction. RESULTS: We identified 27 domains encompassing 459 instruments. Instruments from 'Skin involvement', 'Pulmonary involvement' and 'Health-related quality of life and general functioning' were the most frequently retrieved. Among the 15 most represented instruments announced as primary end points in efficacy or effectiveness studies, 7 were clinician-reported outcomes (ROs), 7 were patient ROs, and one was a performance outcome (6 min-walk test). The mean proportion of lcSSc patients in studies of lcSSc, including studies that mention both lcSSc and dcSSc, was 56.4%, demonstrating that this subset is underrepresented in the literature, given that the prevalence of lcSSc ranges from 60% to 80% in national registries and international cohorts. CONCLUSION: This scoping literature review provides a comprehensive identification of domains and outcomes used to assess lcSSc. Our results also highlight that lcSSc is underrepresented in the literature.

Symptom experience of limited cutaneous systemic sclerosis from the Patients' perspective: A qualitative study✰,✰✰,☠,☠☠.

OBJECTIVES: Limited cutaneous systemic sclerosis (lcSSc) is the largest subgroup of people with SSc, but little is known about symptom experience from the patients' perspective. This study aimed to comprehensively identify domains and symptoms reported as bothersome by patients with lcSSc and to analyze themes and sub-themes capturing symptom experience in this population. METHODS: Focus groups of patients with lcSSc were conducted using a structured guide. Patients were recruited based on an a priori purposive framework to include men and women with SSc. Focus groups were recorded, transcribed, anonymized, and analyzed using the RADaR technique (rigorous and accelerated data reduction) combined with iterative, deductive and inductive approaches. RESULTS: Four 2-hour Focus groups comprising participants with lcSSc were conducted (N = 26). Ninety-four symptoms were identified with 22 domains. Symptoms from the following domains were mentioned in all Focus groups: skin, musculoskeletal (MSK), cardiac, pulmonary, gastro-intestinal (GI) manifestations, fatigue, sleep, Raynaud's phenomenon (RP), pain, and digital ulcers. The three most cited domains in a pre-meeting survey were GI, RP and MSK. Seven themes defining symptom experience were identified: difficulty attributing symptoms to this complex systemic disease, influence of symptom temporality, impairment of emotional well-being, limitations in functioning (including several sub-themes of functioning), survival, symptoms management and uncertainty. CONCLUSION: This study comprehensively identified domains and symptoms considered bothersome from the perspective of patients with lcSSc and summarized patient experience of lcSSc-related symptoms. This study is the first step in the design of a future combined response index dedicated to lcSSc that could foster specific research on this subpopulation of patients.

Localized scleroderma: actual insights and new biomarkers.

Localized scleroderma (LS, morphea, limited scleroderma, focal scleroderma) is a chronic autoimmune disease characterized by a progressive damage to the connective tissue with a predominance of fibrosclerotic disorders in the skin and the subcutaneous tissue. In addition surrounding structures may be affected: fascia, muscle, and bone tissues. This review reflects the current understanding about limited scleroderma, its pathogenesis, diagnosis, new biomarkers, and information about the possibilities of its transition to systemic scleroderma. The following new biomarkers have been identified: galactosylated IgG (Ig-Gal), progranulin (PGRN), chemokine CCXL 18, various types of microRNA (miRNA-let-7a, miRNA-7, miRNA-196a, miRNA-155, miRNA-483-5p), periostin, and myelin basic protein (MBP). Knowledge about new biomarkers of LS will help us to explore the patients' predisposition to the development of systemic scleroderma. In addition, by acting on these biomarkers, it is possible to prevent the progression of LS in the early stages and its transition to systemic scleroderma. The review also presents the current understanding of autoantibodies in LS and their correlation with clinical signs of the disease.

Clinical features and prognostic factors of systemic sclerosis in Guangxi, China: Retrospective, single-center study of long-term survival in 470 patients.

OBJECTIVE: Systemic sclerosis (SSc) is an autoimmune disease the prevalence of which varies among populations. We analyzed SSc patients from Guangxi to improve the clinical understanding of this disease. METHODS: Data of 470 SSc patients admitted to our institution from October 1,2012 to January 1,2019 were examined. The characteristics of these patients were analyzed using Kaplan-Meier survival analysis. Cox proportional-hazard regression was used to identify prognostic factors. RESULTS: The average age was 50.44 ± 12.31 years, 285 patients (60.6%) were women, 2.1% had pneumoconiosis, 58.2% had pulmonary interstitial disease (ILD), 18.7% had pulmonary hypertension (PH), and 3.6% had renal crisis. These patients had diffuse cutaneous systemic sclerosis (dcSSc, 70.2%) or limited cutaneous systemic sclerosis (29.7%), and PH and renal crisis were more common in the dcSSc group. Patients 50 years old or more had greater prevalences of ILD, PH, and musculoskeletal damage, greater positivity of laboratory biomarkers, and increased mortality (all P < .05). Seventy-four patients (15.7%) died. The non-survivors were older, had longer disease duration, had higher prevalences of ILD, restrictive ventilation dysfunction, PH, and renal crisis, and had higher levels of creatine kinase myocardial band (CK-MB), C-reactive protein, and immunoglobin A (all P < .05). Renal crisis, PH, and high CK-MB were independent risk factors for death. CONCLUSIONS: Pneumoconiosis was more common in SSc patients than the general population from this region. Our patients had a 10-year cumulative survival rate of 74.9%, higher than reported for patients from the US. Renal crisis, PH, and high CK-MB level were independent risk factors for death.

Sine scleroderma, limited cutaneous, and diffused cutaneous systemic sclerosis survival and predictors of mortality.

BACKGROUND: Systemic sclerosis (SSc) is associated with a variability of mortality rates in the literature. OBJECTIVE: To determine the mortality and its predictors in a long-term follow-up of a bi-centric cohort of SSc patients. METHODS: A retrospective observational study by systematically analyzing the medical records of patients diagnosed with SSc in Toulouse University Hospital and Ducuing Hospital. Standardized Mortality Ratio (SMR), mortality at 1, 3, 5, 10, and 15 years of disease and causes of death were described. Predictors of mortality using Cox regression were assessed. RESULTS: Three hundred seventy-five patients were included: 63 with diffuse cutaneous SSc, 279 with limited cutaneous SSc, and 33 with sine scleroderma. The SMR ratio was 1.88 (95% CI 1.46-1.97). The overall survival rates were 97.6% at 1 year, 93.4% at 3 years, 87.1% at 5 years, 77.9% at 10 years, and 61.3% at 15 years. Sixty-nine deaths were recorded. 46.4% were SSc related deaths secondary to interstitial lung disease (ILD) (34.4%), pulmonary hypertension (31.2%), and digestive tract involvement (18.8%). 53.6% were non-related to SSc: cardiovascular disorders (37.8%) and various infections (35.1%) largely distanced those from cancer (13.5%). Four significant independent predictive factors were identified: carbon monoxide diffusing capacity (DLCO) < 70% (HR=3.01; p=0.0053), C-reactive protein (CRP) >5 mg/l (HR=2.13; p=0.0174), cardiac involvement (HR=2.86; p=0.0012), and the fact of being male (HR=3.25; p=0.0004). CONCLUSION: Long-term data confirmed high mortality of SSc. Male sex, DLCO <70%, cardiac involvement, and CRP> 5mg/l were identified as independent predictors of mortality.

Oral Health Experiences of the Limited Scleroderma Patient.

Purpose: Limited scleroderma is associated with significant risks to the orofacial complex. The purpose of this mixed methods study was to investigate the experiences of participants with limited scleroderma related to oral health quality of life and oral health.Methods: A sequential mixed methods study was used in a population of individuals diagnosed with limited scleroderma. Participants were recruited through rheumatology specialists, referral, and social media; purposive sampling was used to recruit participants to be interviewed. The validated Oral Health Impact profile (OHIP) and Mouth Handicap in Systemic Sclerosis (MHISS) instruments and semi-structured interviews were used for data collection. Quantitative data were analyzed using descriptive statistics and the qualitative data were reported through thematic analysis.Results: Forty-eight (n=48) qualifying participants participated in the quantitative phase, and 12 (n=12) participated in the qualitative phase. Based on a Likert Scale from 0-4, mean OHIP-14 scores ranged from 2.76 to 2.85, with anxiety over oral condition, embarrassed by oral problems, and oral self-consciousness having the greatest negative impact on quality of life. Mean MHISS scores ranged from 2.13 to 3.11. The highest OHRQoL scores were related to dry mouth symptoms. Factors influencing oral health-related quality of life were varied; dry mouth and microstomia were the prevalent complaints. Thematic analysis revealed challenges to oral health included self-care and professional dental care factors, both of which depended upon individual disease expression. Financial and emotional burdens also influenced participants' oral health.Conclusion: The oral health-related quality of life of those with limited scleroderma is impacted by multiple factors and oral health care professionals must seek out improved treatment modalities to address the needs of these vulnerable individuals. Future studies related to interprofessional collaborative care with scleroderma specialists are recommended.

Evaluation of endothelial dysfunction and clinical events in patients with early-stage vasculopathy in limited systemic sclerosis.

OBJECTIVES: Limited cutaneous systemic sclerosis (lcSSc) is characterised by vasculopathy contributing to vascular apoptosis, structural and functional changes. The aim of this study was to investigate parameters of endothelial dysfunction and their association to clinical events in lcSSc patients with early-stage vasculopathy. METHODS: Patients with lcSSc and early-stage vasculopathy defined as absent pre-existing pulmonary arterial hypertension (PAH), digital ulcers, and symptomatic cardiovascular diseases were recruited together with age-, race- and sex-matched controls with primary Raynaud's phenomenon. All subjects underwent measurements of flow-mediated (FMD) and nitroglycerine-mediated dilation (NMD), pulse-wave analysis, and biochemical analysis, including arginine, homoarginine, citrulline, ornithine, asymmetric dimethylarginine (ADMA), symmetric dimethylarginine (SDMA), and endothelial microparticles (EMP). Clinical events, including EUSTAR index, sicca symptoms, microvascular, skin, renal, gastrointestinal, and pulmonary involvement, were recorded by medical history, physical examination, laboratory parameters, disease-specific questionnaire, electrocardiogram, diagnostic imaging and spirometry. RESULTS: 38 patients with lcSSc and 38 controls were included after screening for eligibility. There was no difference in FMD (p=0.775), NMD (p=0.303), aortic pulse-wave velocity (p=0.662) or in augmentation index (p=0.600) between patients with lcSSc and controls. Higher values of ADMA (p=0.030), SDMA (p=0.025) and borderline significantly higher values for CD31+/CD42b- EMP (p=0.062) were observed in lcSSc patients, also with positive correlations between those parameters. ADMA, SDMA and CD31+/CD42b- were correlated with subclinical PAH, nephropathy and capillary changes. CONCLUSIONS: Selected parameters of endothelial dysfunction contribute to clinical events in lcSSc patients with early-stage vasculopathy and endothelial dysfunction seems to be primarily present in microvasculature, while its impact on macrovascular changes in lcSSc is still indistinct.

Evaluation of limited hand mobility in systemic sclerosis patients by using "prayer sign" and "tabletop sign".

OBJECTIVES: To determine limited joint mobility (LJM) of the hand in patients with systemic sclerosis (SSc). METHODS: LJM was evaluated with "prayer sign" and "tabletop sign" tests. LJM staging was done by Rosenbloom classification method. LJM (+) and LJM (-) patients were compared in terms of demographic findings (gender, age and duration of disease), laboratory results (ESR, CRP, anti-nuclear antibody (ANA), anti-topoisomerase I and anti-centromere), and modified Rodnan skin score (mRss) results. RESULTS: In our study, a total of 217 patients, including 113 patients with a diagnosis of SSc, and 104 as a healthy control group with similar age and gender distribution to these patients, were included. A total of 113 (F=98, M=15) patients (limited cutaneous SSc (lcSSc=71), diffuse cutaneous SSc (dcSSc=42)) were included in this study and LJM positivity was found in 66.4% (lcSSc=38, dcSSc=37). A statistically significant difference was observed in between lcSSc and dcSSc patients according to the presence of LJM (p<0.001). There was a moderate positivity relationship between LJM and mRss (lcSSc r=0.449, p<0.001; dcSSc r=0.565, p<0.001). CONCLUSIONS: In our study, it was found that LJM staging correlated with mRss and dcSSc patients had more severe LJM findings than lcSSc. We conclude that "prayer sign" and "tabletop sign" tests used in hand evaluation in SSc patients have similar clinical results with mRss and can be simple bedside tests in daily practice. Key Points • This is the first study examining limited joint mobility (LJM) with "prayer sign" and "tabletop sign" tests in systemic sclerosis (SSc) patients. • "Prayer sign" and "tabletop sign" tests can be easily performed in daily practice. • We found Rosenbloom LJM staging correlated with modified Rodnan skin score. LJM of the hand can be a good prognostic indicator for early stage SSc patients.

Impact of concomitant obstructive sleep apnea on pulmonary involvement and main pulmonary artery diameter in adults with scleroderma.

PURPOSE: Pulmonary involvement is common in adults with scleroderma. The effect of concomitant obstructive sleep apnea (OSA) on risk for pulmonary hypertension in scleroderma is unknown. An enlarged main pulmonary artery diameter (mPAD) derived from chest computer tomography (CT) is a useful predictor of pulmonary hypertension. We addressed the effect of OSA on pulmonary involvement and enlarged mPAD in adults with scleroderma. METHODS: All participants underwent pulmonary function testing, carbon monoxide diffusion capacity, chest CT, and overnight sleep recording with home sleep apnea testing. OSA diagnosis was based on an apnea-hypopnea index (AHI) ≥ 15/h. Oxygen desaturation index (ODI) was also recorded. Scleroderma involvement of the lungs was defined as the Warrick score ≥ 7 based on the CT findings. Enlarged mPAD was defined as an mPAD ≥ 29 mm in men and ≥ 27 mm in women. RESULTS: After exclusions, 62 patients (58 women) were included. OSA was found among 20 (32%), 17/42 (38%) in the limited cutaneous type, and 3/20 (15%) in the diffuse cutaneous type (p = 0.08). Scleroderma involvement of the lungs was observed in 40 participants (65% in OSA vs 64% in no-OSA; n.s.). Enlarged mPAD was measured in 16 participants, 10 of 20 (50%) in the OSA group and 6 of 17 (14%) in the no-OSA group (p = 0.003). OSA was associated with enlarged mPAD (odds ratio 4.7, 95% confidence interval 1.1-20.9; p = 0.042) independent of age, body mass index, and pulmonary involvement. There was a linear relationship between mPAD and AHI (r = 0.37; p = 0.003) as well as ODI (r = 0.41; p < 0.001). CONCLUSIONS: In this cohort, OSA was associated with risk for pulmonary hypertension independent of pulmonary involvement. These findings suggest that assessing the effect of therapy for concomitant OSA in patients with scleroderma is warranted. TRIAL REGISTRATION: NCT02740569.

Antifibrogenic Activities of CYP11A1-derived Vitamin D3-hydroxyderivatives Are Dependent on RORγ.

Previous studies showed that noncalcemic 20(OH)D3, a product of CYP11A1 action on vitamin D3, has antifibrotic activity in human dermal fibroblasts and in a bleomycin mouse model of scleroderma. In this study, we tested the role of retinoic acid-related orphan receptor γ (RORγ), which is expressed in skin, in the action of CYP11A1-derived secosteroids using murine fibroblasts isolated from the skin of wild-type (RORγ +/+), knockout (RORγ -/-), and heterozygote (RORγ +/-) mice. CYP11A1-derived 20(OH)D3, 20,23(OH)2D3, 1,20(OH)2D3, and 1,20,23(OH)3D3 inhibited proliferation of RORγ +/+ fibroblasts in a dose-dependent manner with a similar potency to 1,25(OH)2D3. Surprisingly, this effect was reversed in RORγ +/- and RORγ -/- fibroblasts, with the most pronounced stimulatory effect seen in RORγ -/- fibroblasts. All analogs tested inhibited TGF-ß1-induced collagen synthesis in RORγ +/+ fibroblasts and the expression of other fibrosis-related genes. This effect was curtailed or reversed in RORγ -/- fibroblasts. These results show that the antiproliferative and antifibrotic activities of the vitamin D hydroxy derivatives are dependent on a functional RORγ. The dramatic changes in the transcriptomes of fibroblasts of RORγ -/- versus wild-type mice following treatment with 20(OH)D3 or 1,20(OH)2D3 provide a molecular basis to explain, at least in part, the observed phenotypic differences.

Genomic Risk Score impact on susceptibility to systemic sclerosis.

OBJECTIVES: Genomic Risk Scores (GRS) successfully demonstrated the ability of genetics to identify those individuals at high risk for complex traits including immune-mediated inflammatory diseases (IMIDs). We aimed to test the performance of GRS in the prediction of risk for systemic sclerosis (SSc) for the first time. METHODS: Allelic effects were obtained from the largest SSc Genome-Wide Association Study (GWAS) to date (9 095 SSc and 17 584 healthy controls with European ancestry). The best-fitting GRS was identified under the additive model in an independent cohort that comprised 400 patients with SSc and 571 controls. Additionally, GRS for clinical subtypes (limited cutaneous SSc and diffuse cutaneous SSc) and serological subtypes (anti-topoisomerase positive (ATA+) and anti-centromere positive (ACA+)) were generated. We combined the estimated GRS with demographic and immunological parameters in a multivariate generalised linear model. RESULTS: The best-fitting SSc GRS included 33 single nucleotide polymorphisms (SNPs) and discriminated between patients with SSc and controls (area under the receiver operating characteristic (ROC) curve (AUC)=0.673). Moreover, the GRS differentiated between SSc and other IMIDs, such as rheumatoid arthritis and Sjögren's syndrome. Finally, the combination of GRS with age and immune cell counts significantly increased the performance of the model (AUC=0.787). While the SSc GRS was not able to discriminate between ATA+ and ACA+ patients (AUC<0.5), the serological subtype GRS, which was based on the allelic effects observed for the comparison between ACA+ and ATA+ patients, reached an AUC=0.693. CONCLUSIONS: GRS was successfully implemented in SSc. The model discriminated between patients with SSc and controls or other IMIDs, confirming the potential of GRS to support early and differential diagnosis for SSc.