Exploring the complexity of systemic sclerosis etiology by trio whole genome sequencing.

Systemic sclerosis (SSc) is a heterogeneous rare autoimmune fibrosing disorder affecting connective tissue. The etiology of systemic sclerosis is largely unknown and many genes have been suggested as susceptibility loci of modest impact by genome-wide association study (GWAS). Multiple factors can contribute to the pathological process of the disease, which makes it more difficult to identify possible disease-causing genetic alterations. In this study, we have applied whole genome sequencing (WGS) in 101 indexed family trios, supplemented with transcriptome sequencing on cultured fibroblast cells of four patients and five family controls where available. Single nucleotide variants (SNVs) and copy number variants (CNVs) were examined, with emphasis on de novo variants. We also performed enrichment test for rare variants in candidate genes previously proposed in association with systemic sclerosis. We identified 42 exonic and 34 ncRNA de novo SNV changes in 101 trios, from a total of over 6000 de novo variants genome wide. We observed higher than expected de novo variants in PRKXP1 gene. We also observed such phenomenon along with increased expression in patient group in NEK7 gene. Additionally, we also observed significant enrichment of rare variants in candidate genes in the patient cohort, further supporting the complexity/multi-factorial etiology of systemic sclerosis. Our findings identify new candidate genes including PRKXP1 and NEK7 for future studies in SSc. We observed rare variant enrichment in candidate genes previously proposed in association with SSc, which suggest more efforts should be pursued to further investigate possible pathogenetic mechanisms associated with those candidate genes.

Minimal Detectable Changes of the HAQ-DI, PROMIS-29v2.0 Domains, and PHQ-8 in Systemic Sclerosis: A SPIN Cohort Cross-Sectional Study.

OBJECTIVE: Systemic sclerosis (SSc) is a rare, chronic, autoimmune disorder associated with disability, diminished physical function, fatigue, pain, and mental health concerns. We assessed minimal detectable changes (MDCs) of the Health Assessment Questionnaire-Disability Index (HAQ-DI), Patient Reported Outcomes Measurement Information System-29 Profile version 2.0 (PROMIS-29v2.0) domains, and Patient Health Questionnaire-8 (PHQ-8) in SSc. METHODS: Scleroderma Patient-centered Intervention Network Cohort participants completed the HAQ-DI, PROMIS-29v2.0 domains, and PHQ-8 at baseline assessments from April 2014 until August 2023. We estimated MDC95 and MDC90 with 95% confidence intervals (CI) generated via the percentile bootstrapping method resampling 1000 times. We compared MDC estimates by age, sex and SSc subtype. RESULTS: A total of 2,571 participants were included. Most were female (N = 2,241; 87%), and 38% (N = 976) had diffuse SSc. Mean (SD) age was 54.9 (12.7) years and duration since onset of first non-Raynaud phenomenon symptom 10.8 (8.7) years. MDC95 estimate was 0.41 points (95% CI: 0.40 to 0.42) for the HAQ-DI, between 4.88 points (95% CI: 4.72 to 5.05) and 9.02 points (95% CI: 8.80 to 9.23) for the 7 PROMIS-29v2.0 domains, and 5.16 points (95% CI: 5.06 to 5.26) for the PHQ-8. MDC95 estimates were not materially different across subgroups. CONCLUSION: MDC95 and MDC90 estimates were precise and similar across age, sex and SSc subtype groups. HAQ-DI MDC95 and MDC90 were substantially larger than previous estimates of HAQ-DI minimal important difference from several small studies. Minimally important differences of all measures should be evaluated in large studies using anchor-based methods.

The association of resilience and positive mental health in systemic sclerosis: A Scleroderma Patient-centered Intervention Network (SPIN) cohort cross-sectional study.

OBJECTIVE: A previous study using Scleroderma Patient-centered Intervention Network (SPIN) Cohort data identified five classes of people with systemic sclerosis (also known as scleroderma) based on patient-reported somatic (fatigue, pain, sleep) and mental health (anxiety, depression) symptoms and compared indicators of disease severity between classes. Across four classes ("low", "normal", "high", "very high"), there were progressively worse somatic and mental health outcomes and greater disease severity. The fifth ("high/low") class, however, was characterized by high disease severity, fatigue, pain, and sleep but low mental health symptoms. We evaluated resilience across classes and compared resilience between classes. METHODS: Cross-sectional study. SPIN Cohort participants completed the 10-item Connor-Davidson-Resilience Scale (CD-RISC) and PROMIS v2.0 domains between August 2022 and January 2023. We used latent profile modeling to identify five classes as in the previous study and multiple linear regression to compare resilience levels across classes, controlling for sociodemographic and disease variables. RESULTS: Mean CD-RISC score (N = 1054 participants) was 27.7 (standard deviation = 7.3). Resilience decreased progressively across "low" to "normal" to "high" to "very high" classes (mean 4.7 points per step). Based on multiple regression, the "high/low" class exhibited higher resilience scores than the "high" class (6.0 points, 95% confidence interval [CI] 4.9 to 7.1 points; standardized mean difference = 0.83, 95% CI 0.67 to 0.98). CONCLUSIONS: People with worse disease severity and patient-reported outcomes reported substantially lower resilience, except a class of people with high disease severity, fatigue, pain, and sleep disturbance but positive mental health and high resilience.

Myeloablation Followed by Hematopoietic Stem Cell Transplantation and Long-Term Normalization of Systemic Sclerosis Molecular Signatures.

OBJECTIVE: In the randomized Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial, myeloablation, followed by hematopoietic stem cell transplantation (HSCT), led to the normalization of systemic sclerosis (SSc) peripheral blood cell (PBC) gene expression signature at the 26-month visit. Herein, we examined long-term molecular changes ensuing 54 months after randomization for individuals receiving an HSCT or 12 months of intravenous cyclophosphamide (CYC). METHODS: Global PBC transcript studies were performed in study participants at pretreatment baseline and at 38 months and 54 months after randomization, as well as in healthy controls using Illumina HT-12 arrays. RESULTS: Thirty (HSCT = 19 and CYC = 11) participants had 38-month samples available, and 26 (HSCT = 16 and CYC = 11) had 54-month samples available. In the paired comparison to baseline, a significant down-regulation of interferon modules and an up-regulation of cytotoxic/natural killer module were observed at the 38-month and 54-month visits in the HSCT arm, indicating a long-term normalization of baseline SSc gene expression signature. No differentially expressed modules were detected in the CYC arm. In comparison to samples from healthy controls, 38-month visit samples in the HSCT arm showed an up-regulation of B cell and plasmablast modules and a down-regulation of myeloid and inflammation modules. Importantly, 54-month HSCT samples did not show any differentially expressed modules compared to healthy control samples, suggesting completion of immune reconstitution. Participants in the CYC arm continued to show an SSc transcript signature in comparison to controls at both time points. CONCLUSION: Paralleling the observed clinical benefit, HSCT leads to durable long-term normalization of the molecular signature in SSc, with completion of immune resetting to 54 months after HSCT.

Factors associated with physical function among people with systemic sclerosis: a SPIN cohort cross-sectional study.

OBJECTIVES: To compare physical function in systemic sclerosis (SSc, scleroderma) to general population normative data and identify associated factors. METHODS: Scleroderma Patient-centered Intervention Network Cohort participants completed the Physical Function domain of the Patient-Reported Outcomes Measurement Information System Version 2 upon enrolment. Multivariable linear regression was used to assess associations of sociodemographic, lifestyle, and disease-related variables. RESULTS: Among 2,385 participants, mean physical function T-score (43.7, SD = 8.9) was ∼2/3 of a standard deviation (SD) below the US general population (mean = 50, SD = 10). Factors associated in multivariable analysis included older age (-0.74 points per SD years, 95% CI -0.78 to -1.08), female sex (-1.35, -2.37 to -0.34), fewer years of education (-0.41 points per SD in years, -0.75 to -0.07), being single, divorced, or widowed (-0.76, -1.48 to -0.03), smoking (-3.14, -4.42 to -1.85), alcohol consumption (0.79 points per SD drinks per week, 0.45-1.14), BMI (-1.41 points per SD, -1.75 to -1.07), diffuse subtype (-1.43, -2.23 to -0.62), gastrointestinal involvement (-2.58, -3.53 to -1.62), digital ulcers (-1.96, -2.94 to -0.98), moderate (-1.94, -2.94 to -0.93) and severe (-1.76, -3.24 to -0.28) small joint contractures, moderate (-2.10, -3.44 to -0.76) and severe (-2.54, -4.64 to -0.44) large joint contractures, interstitial lung disease (-1.52, -2.27 to -0.77), pulmonary arterial hypertension (-3.72, -4.91 to -2.52), rheumatoid arthritis (-2.10, -3.64 to -0.56) and idiopathic inflammatory myositis (-2.10, -3.63 to -0.56). CONCLUSION: Physical function is impaired for many individuals with SSc and associated with multiple disease factors.

Factors associated with satisfaction with social roles and activities among people with systemic sclerosis: a Scleroderma Patient-centered Intervention Network (SPIN) cohort cross-sectional study.

OBJECTIVE: The objectives were to (1) compare satisfaction with social roles and activities in a large multinational systemic sclerosis (SSc) cohort to general population normative data and (2) identify sociodemographic, lifestyle and SSc disease factors associated with satisfaction with social roles and activities. METHODS: Participants in the Scleroderma Patient-centered Intervention Network Cohort completed the Patient Reported Outcomes Information System Version 2 satisfaction with social roles and activities domain questionnaire. Multivariable regression was used to assess associations with sociodemographic, lifestyle and disease factors. RESULTS: Among 2385 participants, mean satisfaction with social roles and activities T-score (48.1, SD=9.9) was slightly lower than the US general population (mean=50, SD=10). Factors independently associated with satisfaction were years of education (0.54 per SD, 95% CI 0.14 to 0.93); non-White race or ethnicity (-1.13, 95% CI -2.18 to -0.08); living in Canada (-1.33, 95% CI -2.40 to -0.26 (reference USA)) or the UK (-2.49, 95% CI -3.92 to -1.06); body mass index (-1.08 per SD, 95% CI -1.47 to -0.69); gastrointestinal involvement (-3.16, 95% CI -4.27 to -2.05); digital ulcers (-1.90, 95% CI -3.05 to -0.76); moderate (-1.62, 95% CI -2.78 to -0.45) or severe (-2.26, 95% CI -3.99 to -0.52) small joint contractures; interstitial lung disease (-1.11, 95% CI -1.97 to -0.25); pulmonary arterial hypertension (-2.69, 95% CI -4.08 to -1.30); rheumatoid arthritis (-2.51, 95% CI -4.28 to -0.73); and Sjogren's syndrome (-2.42, 95% CI -3.96 to -0.88). CONCLUSION: Mean satisfaction with social roles and activities is slightly lower in SSc than the general population and associated with multiple sociodemographic and disease factors.

Moderators of Loneliness Trajectories in People with Systemic Sclerosis During the COVID-19 Pandemic: A SPIN COVID-19 Cohort Longitudinal Study.

BACKGROUND: Many individuals with systemic sclerosis (SSc) are at heightened risk for COVID-19 related morbidity and isolation due to interstitial lung disease, frailty, and immunosuppressant use. Minimal research has explored loneliness predictors in individuals with chronic illnesses during COVID-19. This study evaluated moderators of loneliness trajectories in individuals with SSc during COVID-19. METHODS: Longitudinal data were analyzed across 30 timepoints from April 2020 to May 2022 from 775 adults in the Scleroderma Patient-centered Intervention Network (SPIN) COVID-19 Cohort. Hierarchical linear modeling evaluated cross-level moderators of loneliness trajectories, including marital status, baseline number of household members, number of virtual or telephone one-on-one or virtual group conversations, number of hours spent enjoying in-person household conversations or activities, and satisfaction with quality of in-person household conversations (all in the past week). Level-1 moderation analyses assessed effects of conversation, activity, and satisfaction means and slopes over time. RESULTS: Baseline values were not statistically significant moderators of loneliness trajectories. Higher mean (averaged over time) virtual or telephone one-on-one and in-person household conversations, in-person household activity, and in-person household conversation satisfaction were associated with lower loneliness trajectories (ps < .05). The relationship between in-person household conversation satisfaction and loneliness trajectory was statistically significantly but minimally attenuated over time (p < .001). CONCLUSIONS: For people with SSc, higher mean conversation, activity, and satisfaction variables were associated with lower levels of loneliness during the pandemic, but changes in these social variables were generally not predictive of changes in loneliness.

A Prospective Observational Study of Disease Severity and Mortality in Hispanic American Patients With Systemic Sclerosis.

OBJECTIVE: To characterize disease manifestations in Hispanic American patients with systemic sclerosis (SSc) in comparison with non-Hispanic White and Black patients. METHODS: Longitudinal clinical characteristics were collected prospectively in the Genetics versus Environment in Scleroderma Outcome Study cohort. All patients fulfilled the classification criteria for SSc and had a disease duration less than five years at enrollment. RESULTS: A cohort of 427 patients, consisting of 124 Hispanic, 220 non-Hispanic White, and 83 non-Hispanic Black participants were examined. At enrollment, Hispanic patients were significantly younger but had longer disease duration, higher frequency of U1-RNP positivity as well as concurrent systemic lupus erythematosus (SLE) diagnosis, and lower income and educational levels in comparison to non-Hispanic White patients. Compared with non-Hispanic Black patients, Hispanic patients had more frequently limited cutaneous involvement and anticentromere antibodies. In the longitudinal analysis, Hispanic patients had significantly lower forced vital capacity percents predicted (point estimate, -9.3%; P < 0.001) than non-Hispanic White but not Black patients. Hispanic patients had similar longitudinal modified Rodnan Skin Scores like non-Hispanic White patients but lower measurements than non-Hispanic Black patients (point estimate, -3.2; P = 0.029). Hispanic patients had significantly higher serially obtained perceived functional disability scores than White patients (point estimate, 0.29; P < 0.001). Hispanic patients also had higher mortality rates than White Americans even after adjustment for age, gender, and socioeconomic statuses. CONCLUSION: Hispanic patients have higher likelihood of having U1-RNP positivity and SLE overlap, more severe restrictive lung disease, as well as higher rate of mortality than non-Hispanic White patients.

Validity, Reliability, and Differential Item Functioning of English and French Versions of the 10-Item Connor-Davidson Resilience Scale in Systemic Sclerosis: A Scleroderma Patient-Centered Intervention Network Cohort Study.

OBJECTIVE: Some individuals with systemic sclerosis (SSc) report positive mental health, despite severe disease manifestations, which may be associated with resilience, but no resilience measure has been validated in SSc. This study was undertaken to assess the validity, reliability, and differential item functioning (DIF) between English- and French-language versions of the 10-item Connor-Davidson Resilience Scale (CD-RISC-10) in SSc. METHODS: Eligible participants were enrolled in the Scleroderma Patient-centered Intervention Network Cohort and completed the CD-RISC-10 between August 2022 and January 2023. We used confirmatory factor analysis (CFA) to evaluate the CD-RISC-10 factor structure and conducted DIF analysis across languages with Multiple Indicators Multiple Causes models. We tested convergent validity with another measure of resilience and measures of self-esteem and depression and anxiety symptoms. We assessed internal consistency and test-retest reliability using Cronbach's alpha and intraclass correlation coefficient (ICC). RESULTS: A total of 962 participants were included in this analysis. CFA supported a single-factor structure (Tucker-Lewis index = 0.99, comparative fit index = 0.99, root mean square error of approximation = 0.08 [90% confidence interval (90% CI) 0.07, 0.09]). We found no meaningful DIF. Internal consistency was high (α = 0.93 [95% CI 0.92, 0.94]), and we found that correlations with other measures of psychological functioning were moderate to large (|r| = 0.57-0.78) and confirmed study hypotheses. The scale showed good 1-2-week test-retest reliability (ICC 0.80 [95% CI 0.75, 0.85]) in a subsample of 230 participants. CONCLUSION: The CD-RISC-10 is a valid and reliable measure of resilience in SSc, with score comparability across English and French versions.

Efficacy and Safety of Lenabasum, a Cannabinoid Type 2 Receptor Agonist, in a Phase 3 Randomized Trial in Diffuse Cutaneous Systemic Sclerosis.

OBJECTIVE: This phase 3 study was undertaken to investigate the efficacy and safety of lenabasum, a cannabinoid type 2 receptor agonist, in patients with diffuse cutaneous systemic sclerosis (dcSSc). METHODS: A multinational double-blind study was conducted in 365 dcSSc patients who were randomized and dosed 1:1:1 with lenabasum 20 mg, lenabasum 5 mg, or placebo, each twice daily and added to background treatments, including immunosuppressive therapies (IST). RESULTS: The primary end point, the American College of Rheumatology combined response index in dcSSc (CRISS) at week 52 for lenabasum 20 mg twice a day versus placebo, was not met, with CRISS score of 0.888 versus 0.887 (P = 0.4972, using mixed models repeated measures [MMRM]). The change in the modified Rodnan skin thickness score (MRSS) at week 52 for lenabasum 20 mg twice a day versus placebo was -6.7 versus -8.1 (P = 0.1183, using MMRM). Prespecified analyses showed higher CRISS scores, greater improvement in MRSS, and lower decline in forced vital capacity in patients on background mycophenolate and those who were taking IST for ≤1 year. No deaths or excess in serious or severe adverse events related to lenabasum were observed. CONCLUSION: A benefit of lenabasum in dcSSc was not demonstrated. Most patients were treated with background IST, and treatment with mycophenolate mofetil in particular was associated with better outcomes. These findings support the use of IST in the treatment of dcSSc and highlight the challenge of demonstrating a treatment effect when investigational treatment is added to standard of care IST. These findings have relevance to trial design in SSc, as well as to clinical care.

Qualitative Interviews to Assess the Content Validity and Usability of the Electronic Raynaud Diary in Patients with Systemic Sclerosis.

OBJECTIVE: To better understand the symptoms and impacts of Raynaud phenomenon (RP) in patients with systemic sclerosis (SSc) and to evaluate the content validity and usability of a new electronic patient-reported outcome (PRO) measure for RP: the Raynaud Diary. METHODS: The Raynaud Diary was developed as a daily eDiary for assessing the number and duration of symptomatic Raynaud attacks; worst pain, numbness, tingling, and discomfort in the fingers; and overall disease severity, captured using the Raynaud's Condition Score. The Raynaud Diary was debriefed in two waves of qualitative interviews with adults with self-reported RP secondary to SSc. All interviews included open-ended questions about participants' experiences of RP. RESULTS: Participants (N = 39) had a mean age of 55.1 years, and 87% were female. Frequently reported RP symptoms were color change (reported by all participants), numbness (90%), tingling (82%), pain (77%), and discomfort (72%). Common attack triggers included temperature-related factors and stress. Participants reported being unable to be outside or do outdoor activities and had problems gripping objects. All participants demonstrated understanding of the Raynaud Diary instructions. Most participants indicated that they would be able to use the Raynaud Diary to record the worst severity of individual RP symptoms in the previous 24 hours. CONCLUSION: Patients with RP secondary to SSc bear a heavy symptom burden. The Raynaud Diary is a content valid PRO measure that captures the most frequent symptoms of RP in patients with SSc.

Percutaneous revascularization for the treatment of refractory digital ischemia in systemic sclerosis.

Objective: The objective of this study is to explore the role of adjunctive percutaneous revascularization of the hand in the management of patients with systemic sclerosis-associated refractory digital ischemia. Methods: We present our initial experience of using percutaneous upper extremity interventions to treat patients with systemic sclerosis and symptomatic Raynaud's phenomenon who presented with either refractory digital ischemia or non-healing ulcers. We discuss patient characteristics, procedural findings, and short-term clinical outcomes of these interventions. Results: We performed 14 interventions in 6 patients with non-healing digital ulcers or refractory ischemia secondary to systemic sclerosis. Angioplasty was performed at or below the wrist in conjunction with intravenous prostaglandin therapy, started prior to or immediately after the revascularization procedure. All patients experienced symptomatic relief and demonstrated accelerated wound healing. Two patients required an additional procedure to treat recurrent ischemia (without new ulceration) in the treated digit. Three of the patients underwent multiple procedures during the study period to treat new ischemic lesions or Raynaud's phenomenon symptoms, highlighting the progressive nature of the vascular occlusions in systemic sclerosis. There were no adverse events related to the interventions. Conclusions: Our retrospective analysis suggests that percutaneous revascularization in combination with vasodilator therapy in systemic sclerosis-associated digital ischemia is safe and can facilitate the healing of long-standing ulcers. Its role in the management of refractory digital ischemia in patients with systemic sclerosis should be explored further.

A 24-Week, Phase IIa, Randomized, Double-Blind, Placebo-Controlled Study of Ziritaxestat in Early Diffuse Cutaneous Systemic Sclerosis.

OBJECTIVE: We undertook this study to explore the efficacy, safety, and tolerability of ziritaxestat, a selective autotaxin inhibitor, in patients with early diffuse cutaneous systemic sclerosis (dcSSc). METHODS: NOVESA was a 24-week, multicenter, phase IIa, double-blind, placebo-controlled study. Adults with dcSSc were randomized to oral ziritaxestat 600 mg once daily or matching placebo. The primary efficacy end point was change from baseline in modified Rodnan skin score (MRSS) at week 24. Secondary end points assessed safety and tolerability; other end points included assessment of skin and blood biomarkers. Patients in NOVESA could enter a 104-week open-label extension (OLE). RESULTS: Patients were randomized to ziritaxestat (n = 21) or placebo (n = 12). Reduction in MRSS was significantly greater in the ziritaxestat group versus the placebo group (-8.9 versus -6.0 units, respectively; P = 0.0411). Placebo patients switching to ziritaxestat in the OLE showed similar reductions in MRSS to those observed for ziritaxestat patients in the parent study. Ziritaxestat was well tolerated; the most frequent treatment-related treatment-emergent adverse events were headache and diarrhea. Circulating lysophosphatidic acid (LPA) C18:2 was significantly reduced, demonstrating ziritaxestat target engagement, and levels of fibrosis biomarkers were reduced in the blood. No differentially expressed genes were identified in skin biopsies. Significant changes in 109 genes were identified in blood samples. CONCLUSION: Ziritaxestat resulted in significantly greater reduction in MRSS at week 24 than placebo; no new safety signals emerged. Biomarker analysis suggests ziritaxestat may reduce fibrosis. Modulation of the autotaxin/LPA pathway could improve skin involvement in patients with dcSSc. A plain language summary is provided in the Supplementary Material, available on the Arthritis & Rheumatology website at https://onlinelibrary.wiley.com/doi/10.1002/art.42477.

STAT6 suppression prevents bleomycin-induced dermal fibrosis.

Fibrosis of the skin and internal organs is a hallmark of systemic sclerosis (SSc). Although the pathogenesis of SSc is poorly understood, increasing evidence suggests that interleukins (IL)-4 and - 13 contribute to the pathogenesis of skin fibrosis by promoting collagen production and myofibroblast differentiation. Signal transducers and activators of transcription 6 (STAT6) is one of the most important downstream transcription factors activated by both IL-4 and IL-13. However, it is not completely understood whether STAT6 plays a role during the pathogenesis of skin fibrosis in SSc. In this study, we observed increased STAT6 phosphorylation in fibrotic skin samples collected from SSc patients as well as bleomycin-injected murine mice. Knockout of Stat6 in mice significantly (1) suppressed the expression of fibrotic cytokines including Il13, Il17, Il22, Ccl2, and the alternatively activated macrophage marker Cd206; (2) reduced the production of collagen and fibronectin, and (3) attenuated late-stage skin fibrosis and inflammation induced by bleomycin. Consistently, mice treated with STAT6 inhibitor AS1517499 also attenuated skin fibrosis on day 28. In addition, a co-culture experiment demonstrated that skin epithelial cells with STAT6 knockdown had reduced cytokine expression in response to IL-4/IL-13, and subsequently attenuated fibrotic protein expression in skin fibroblasts. On the other side, STAT6 depletion in skin fibroblasts attenuated IL-4/IL-13-induced cytokine and fibrotic marker expression, and reduced CXCL2 expression in co-cultured keratinocytes. In summary, our study highlighted an important yet not fully understood role of STAT6 in skin fibrosis by driving innate inflammation and differentiation of alternatively activated macrophages in response to injury.

Expert consensus on the management of systemic sclerosis-associated interstitial lung disease.

BACKGROUND: Systemic sclerosis (SSc) is a rare, complex, connective tissue disorder. Interstitial lung disease (ILD) is common in SSc, occurring in 35-52% of patients and accounting for 20-40% of mortality. Evolution of therapeutic options has resulted in a lack of consensus on how to manage this condition. This Delphi study was initiated to develop consensus recommendations based on expert physician insights regarding screening, progression, treatment criteria, monitoring of response, and the role of recent therapeutic advances with antifibrotics and immunosuppressants in patients with SSc-ILD. METHODS: A modified Delphi process was completed by pulmonologists (n = 13) and rheumatologists (n = 12) with expertise in the management of patients with SSc-ILD. Panelists rated their agreement with each statement on a Likert scale from - 5 (complete disagreement) to + 5 (complete agreement). Consensus was predefined as a mean Likert scale score of ≤ - 2.5 or ≥ + 2.5 with a standard deviation not crossing zero. RESULTS: Panelists recommended that all patients with SSc be screened for ILD by chest auscultation, spirometry with diffusing capacity of the lungs for carbon monoxide, high-resolution computed tomography (HRCT), and/or autoantibody testing. Treatment decisions were influenced by baseline and changes in pulmonary function tests, extent of ILD on HRCT, duration and degree of dyspnea, presence of pulmonary hypertension, and potential contribution of reflux. Treatment success was defined as stabilization or improvement of signs or symptoms of ILD and functional status. Mycophenolate mofetil was identified as the initial treatment of choice. Experts considered nintedanib a therapeutic option in patients with progressive fibrotic ILD despite immunosuppressive therapy or patients contraindicated/unable to tolerate immunotherapy. Concomitant use of nintedanib with MMF/cyclophosphamide can be considered in patients with advanced disease at initial presentation, aggressive ILD, or significant disease progression. Although limited consensus was achieved on the use of tocilizumab, the experts considered it a therapeutic option for patients with early SSc and ILD with elevated acute-phase reactants. CONCLUSIONS: This modified Delphi study generated consensus recommendations for management of patients with SSc-ILD in a real-world setting. Findings from this study provide a management algorithm that will be helpful for treating patients with SSc-ILD and addresses a significant unmet need.

Reduced digestion of circulating genomic DNA in systemic sclerosis patients with the DNASE1L3 R206C variant.

OBJECTIVES: Polymorphism in a coding region of deoxyribonuclease I-like III (DNASE1L3), causing amino acid substitution of Arg-206 to Cys (R206C), is a robustly replicated heritable risk factor for SSc and other autoimmune diseases. DNASE1L3 is secreted into the circulation, where it can digest genomic DNA (gDNA) in apoptosis-derived membrane vesicles (AdMVs). We sought to determine the impact of DNASE1L3 R206C on digestion of circulating gDNA in SSc patients and healthy controls (HCs). METHODS: The ability of DNASE1L3 to digest AdMV-associated gDNA was tested in vitro. The effect of R206C substitution on extracellular secretion of DNASE1L3 was determined using a transfected cell line and primary monocyte-derived dendritic cells from SSc patients. Plasma samples from SSc patients and HCs with DNASE1L3 R206C or R206 wild type were compared for their ability to digest AdMV-associated gDNA. The digestion status of endogenous gDNA in plasma samples from 123 SSc patients and 74 HCs was determined by measuring the proportion of relatively long to short gDNA fragments. RESULTS: The unique ability of DNASE1L3 to digest AdMV-associated gDNA was confirmed. Extracellular secretion of DNASE1L3 R206C was impaired. Plasma from individuals with DNASE1L3 R206C had reduced ability to digest AdMV-associated gDNA. The ratio of long: short gDNA fragments was increased in plasma from SSc patients with DNASE1L3 R206C, and this ratio correlated inversely with DNase activity. CONCLUSION: Our results confirm that circulating gDNA is a physiological DNASE1L3 substrate and show that its digestion is reduced in SSc patients with the DNASE1L3 R206C variant.

Characterising the autoantibody repertoire in systemic sclerosis following myeloablative haematopoietic stem cell transplantation.

OBJECTIVES: Results from the SCOT (Scleroderma: Cyclophosphamide Or Transplantation) clinical trial demonstrated significant benefits of haematopoietic stem cell transplant (HSCT) versus cyclophosphamide (CTX) in patients with systemic sclerosis. The objective of this study was to test the hypothesis that transplantation stabilises the autoantibody repertoire in patients with favourable clinical outcomes. METHODS: We used a bead-based array containing 221 protein antigens to profile serum IgG autoantibodies in participants of the SCOT trial. RESULTS: Comparison of autoantibody profiles at month 26 (n=23 HSCT; n=22 CTX) revealed antibodies against two viral antigens and six self-proteins (SSB/La, CX3CL1, glycyl-tRNA synthetase (EJ), parietal cell antigen, bactericidal permeability-increasing protein and epidermal growth factor receptor (EGFR)) that were significantly different between treatment groups. Linear mixed model analysis identified temporal increases in antibody levels for hepatitis B surface antigen, CCL3 and EGFR in HSCT-treated patients. Eight of 32 HSCT-treated participants and one of 31 CTX-treated participants had temporally varying serum antibody profiles for one or more of 14 antigens. Baseline autoantibody levels against 20 unique antigens, including 9 secreted proteins (interleukins, IL-18, IL-22, IL-23 and IL-27), interferon-α2A, stem cell factor, transforming growth factor-ß, macrophage colony-stimulating factor and macrophage migration inhibitory factor were significantly higher in patients who survived event-free to month 54. CONCLUSIONS: Our results suggest that HSCT favourably alters the autoantibody repertoire, which remains virtually unchanged in CTX-treated patients. Although antibodies recognising secreted proteins are generally thought to be pathogenic, our results suggest a subset could potentially modulate HSCT in scleroderma.

Clinical and Molecular Findings After Autologous Stem Cell Transplantation or Cyclophosphamide for Scleroderma: Handling Missing Longitudinal Data.

OBJECTIVE: Among individuals with systemic sclerosis (SSc) randomized to cyclophosphamide (CYC) (n = 34) or hematopoietic stem cell transplantation (HSCT) (n = 33), we examined longitudinal trends of clinical, pulmonary function, and quality of life measures while accounting for the influence of early failures on treatment comparisons. METHODS: Assuming that data were missing at random, mixed-effects regression models were used to estimate longitudinal trends for clinical measures when comparing treatment groups. Results were compared to observed means and to longitudinal trends estimated from shared parameter models, assuming that data were missing not at random. Longitudinal trends for SSc intrinsic molecular subsets defined by baseline gene expression signatures (normal-like, inflammatory, and fibroproliferative signatures) were also studied. RESULTS: Available observed means for pulmonary function tests appeared to improve over time in both arms. However, after accounting for participant loss, forced vital capacity in HSCT recipients increased by 0.77 percentage points/year but worsened by -3.70/year for CYC (P = 0.004). Similar results were found for diffusing capacity for carbon monoxide and quality of life indicators. Results for both analytic models were consistent. HSCT recipients in the inflammatory (n = 20) and fibroproliferative (n = 20) subsets had superior long-term trends compared to CYC for pulmonary and quality of life measures. HSCT was also superior for modified Rodnan skin thickness scores in the fibroproliferative subset. For the normal-like subset (n = 22), superiority of HSCT was less apparent. CONCLUSION: Longitudinal trends estimated from 2 statistical models affirm the efficacy of HSCT over CYC in severe SSc. Failure to account for early loss of participants may distort estimated clinical trends over the long term.

Blood Neutrophil Count and Neutrophil-to-Lymphocyte Ratio for Prediction of Disease Progression and Mortality in Two Independent Systemic Sclerosis Cohorts.

OBJECTIVE: To assess the predictive significance of blood neutrophil count and the ratio between neutrophil and lymphocyte count (neutrophil-to-lymphocyte ratio [NLR]) for disease severity and mortality in systemic sclerosis (SSc). METHODS: Neutrophil and lymphocyte counts were prospectively measured in the Genetics versus Environment in Scleroderma Outcome Study (GENISOS) and the Scleroderma Lung Study II (SLS II). Forced vital capacity percent predicted (FVC%) and modified Rodnan skin thickness score (MRSS) were used as surrogate measures for disease severity. Longitudinal analyses were performed using generalized linear mixed models. Cox proportional hazards models evaluated the predictive significance of these cell counts for mortality. RESULTS: Of the 447 SSc patients in the GENISOS cohort at the time of analysis, 377 (84.3%) had available baseline blood neutrophil and lymphocyte counts. Higher baseline neutrophil count and NLR predicted lower serially obtained FVC% (b = -4.74, P = 0.009 and b = -2.68, P = 0.028, respectively) and higher serially obtained MRSS (b = 4.07, P < 0.001 and b = 2.32, P < 0.001, respectively). Longitudinal neutrophil and NLR measurements also significantly correlated with lower concurrently obtained FVC% measurements and higher concurrently obtained MRSS. Baseline neutrophil count and NLR predicted increased risk of long-term mortality, even after adjustment for baseline demographic and clinical factors (hazard ratio [HR] 1.42, P = 0.02 and HR 1.48, P < 0.001, respectively). The predictive significance of higher baseline neutrophil count and NLR for declining FVC% and increased long-term mortality was confirmed in the SLS II. CONCLUSION: Higher blood neutrophil count and NLR are predictive of more severe disease course and increased mortality, indicating that these easily obtainable laboratory studies might be a reflection of pathologic immune processes in SSc.