Testing a candidate composite serum protein marker of skin severity in systemic sclerosis.

Objectives: Using an integrated multi-omic analysis, we previously derived a candidate marker that estimates the modified Rodnan Skin Score (mRSS) and thus the severity of skin involvement in SSc. In the present study we explore technical and biological validation of this composite marker in a well-characterized cohort of SSc patients. Methods: Cartilage oligomeric matrix protein (COMP), collagen type IV (COL4A1), tenascin-C (TNC) and spondin-1 (SPON1) were examined in serum samples from two independent cohorts of patients with dcSSc. The BIOlogical Phenotyping of diffuse SYstemic sclerosis cohort had previously been used to derive the composite marker and Molecular Determinants to Improve Scleroderma (SSc) treatment (MODERNISE) was a novel validation cohort. Multiple regression analysis derived a formula to predict the mRSS based on serum ELISA protein concentration. Results: The serum concentration of two of the proteins-COMP and TNC-positively correlated with the mRSS, particularly in early dcSSc patients. Interpretable data could not be obtained for SPON1 due to technical limitations of the ELISA. COL4A1 showed a correlation with disease duration but not overall mRSS. Patients receiving MMF showed lower serum concentrations of COMP, COL4A1 and TNC and a lower composite biomarker score not established on treatment. A revised ELISA-based three-protein composite formula was derived for future validation studies. Conclusions: Although more validation is required, our findings represent a further step towards a composite serum protein assay to assess skin severity in SSc. Future work will establish its utility as a predictive or prognostic biomarker.

Gerald P Rodnan.

Dr Gerald Rodnan was a man of many talents who developed a single-minded fascination with the disease systemic sclerosis. His passion and vision led to numerous important research contributions to our understanding of the natural history of this disease and his extensive travel and teaching stimulated many other investigators in the United States and throughout the world to devote their careers to this uncommon but serious disorder. He indeed was a "Giant" in rheumatology and those of us who had the opportunity to train under him have been inspired to carry it forward.

Tocilizumab in systemic sclerosis treatment: a case report.

Introduction: In the United States, tocilizumab was approved for the treatment of scleroderma and scleroderma-related interstitial lung disease because it inhibited the decrease in forced expiratory volume, so scleroderma treatment is entering a new era. Case presentation: A 44-year-old female patient with systemic scleroderma, diagnosed 6 years ago, presented with breathlessness over the last week. The modified Rodnan's score was 18. Tocilizumab 162 mg subcutaneously once every 2 weeks was prescribed. After 4 weeks, a decrease in Rodnan score was observed. Tocilizumab was stopped after 6 months without any side effects due to treatment. Discussion: Treatment with tocilizumab may maintain lung function nearly unchanged. Its effect on perfecting skin fibrosis seems promising. Tocilizumab may be fairly safe to use. Conclusion: Tocilizumab may be effective and fairly safe to use. Further exploration is anticipated to advance a new period of systemic sclerosis treatment.

Scleroderma Skin: How Is Treatment Best Guided by Data and Implemented in Clinical Practice?

As skin involvement is the hall mark of systemic sclerosis (SSc) and changes of skin involvement have shown to correlate with internal organ involvement, assessing the extend of skin involvement is key. Although the modified Rodnan skin score is a validated tool used to evaluate the skin in SSc, it has its drawbacks. Novel imagine methods are promising but should be further evaluated. As for molecule markers for skin progression there are conflicting data on the predictive significance of baseline SSc skin gene expression profiles, but immune cell type signature in SSc skin correlates with progression.

New Era in Systemic Sclerosis Treatment: Recently Approved Therapeutics.

Systemic sclerosis (SSc) is a chronic autoimmune disease with a poor prognosis. Among the various complications of SSc, treatment options for the fibrotic lesions, skin sclerosis, and SSc-associated interstitial lung disease (SSc-ILD) have been limited. However, since 2019, the efficacy and safety of nintedanib, tocilizumab, and rituximab for SSc or SSc-ILD have been demonstrated in double-blind, randomized, placebo-controlled trials, respectively. The antifibrotic agent nintedanib was approved for SSc-ILD in all regions of the United States, Europe, and Japan after the SENSCIS study confirmed that it suppressed the reduction in forced vital capacity (FVC), a measure of SSc-ILD. Tocilizumab, an anti-interleukin-6 receptor antibody, was approved for the treatment of SSc-ILD in the United States after the FocuSSced study showed that it inhibited the decrease in FVC. Rituximab, an anti-CD20 antibody, showed improvement in both modified Rodnan skin score, a measure of skin sclerosis, and FVC in the DESIRES study, and was approved in Japan for the treatment of SSc itself. With the development of these three drugs, SSc treatment is entering a new era. This paper outlines the latest advances in SSc therapeutics, focusing on nintedanib, tocilizumab, and rituximab.

Predictors of rituximab effect on modified Rodnan skin score in systemic sclerosis: a machine-learning analysis of the DesiReS trial.

OBJECTIVES: The double-blind, parallel-group comparison, investigators initiated phase II clinical trial of IDEC-C2B8 (Rituximab) in patients with Systemic sclerosis (DesiReS) trial showed that rituximab is effective in treating skin sclerosis in SSc. However, which patient groups are likely to benefit from rituximab is unknown. METHODS: We performed post-hoc analysis of prospective data from 54 patients who received rituximab or placebo in the DesiReS trial. Twenty-seven baseline factors were used to investigate subpopulations with different magnitudes of rituximab effect on modified Rodnan skin score (mRSS) change at 24 weeks. Based on a machine-learning algorithm called the causal tree, we explored the combination of predictors needed to identify subpopulations that would respond to rituximab and have good treatment outcomes. RESULTS: Three factors were identified as branches of the decision tree: peripheral blood CD19-positive cell counts', 'mRSS', and 'serum surfactant protein D (SP-D) levels'. It was only in the subpopulation of patients with CD19-positive cell counts of <57/µl that rituximab did not show a significant improvement in mRSS vs placebo. In the subpopulation of patients with CD19-positive cell counts of ≥57/µl and mRSS ≥ 17, mRSS was most improved with rituximab [difference -17.06 (95% CI: -24.22, -9.89)]. The second greatest improvement in mRSS with rituximab was in the subpopulation with CD19-positive cell counts of ≥57/µl, mRSS < 17, and serum SP-D levels of ≥151 ng/ml [difference -10.35 (95% CI: -14.77, -5.93)]. CONCLUSION: SSc patients who have high CD19-positive cell counts and high mRSS are expected to have greater improvement in mRSS with rituximab. When the patients with high CD19-positive cell counts show low mRSS, serum SP-D levels may modify the treatment effect. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT04274257 and UMIN-CTR; https://center6.umin.ac.jp, UMIN000030139.

Circulating Collagen Metabolites and the Enhanced Liver Fibrosis (ELF) Score as Fibrosis Markers in Systemic Sclerosis.

Background: Serum fibrosis markers for systemic sclerosis (SSc) remain limited. The Enhanced Liver Fibrosis (ELF) score is a collagen marker set consisting of procollagen type III amino terminal propeptide (PIIINP), tissue inhibitor of metalloproteinases 1 (TIMP-1), and hyaluronic acid (HA). This longitudinal study aimed to examine the performance of the ELF score and its single analytes as surrogate outcome measures of fibrosis in SSc. Methods: Eighty-five SSc patients fulfilling the 2013 ACR/EULAR criteria with the absence of chronic liver diseases were enrolled. Serum PIIINP, TIMP-1, HA, and the ELF score were measured and correlated with clinical variables including the modified Rodnan skin score (mRSS) and interstitial lung disease (ILD). Twenty SSc patients underwent a follow-up serological testing and mRSS evaluation during treatment with immunosuppressants and/or anti-fibrotic drugs. Results: Serum PIIINP, TIMP-1, and ELF score were significantly higher in patients with SSc than in healthy controls [PIIINP: 10.31 (7.83-14.10) vs. 5.61 (4.69-6.30), p < .001; TIMP-1: 110.73 (66.21-192.45) vs. 61.81 (48.86-85.24), p < .001; ELF: 10.34 (9.91-10.86) vs. 9.68 (9.38-9.99), p < .001]. Even higher levels of PIIINP, TIMP-1, and ELF score were found in patients with diffuse cutaneous SSc than those with limited cutaneous SSc. At baseline, both PIIINP and ELF score showed good correlation with mRSS (PIIINP: r = .586, p < .001; ELF: r = .482, p < .001). Longitudinal analysis showed that change in PIIINP positively correlated with change in mRSS (r = 0.701, p = .001), while change in ELF score were not related, in a statistical context, to the change in mRSS (ELF: r = .140, p = .555). Serum TIMP-1 was significantly higher in SSc patients with ILD, compared to the matched group of patients without ILD [109.45 (93.05-200.09) vs. 65.50 (40.57-110.73), p = 0.007]. Conclusion: In patients with SSc, the ELF score well correlates with the extent of skin fibrosis, while serum PIIINP is a sensitive marker for longitudinal changes of skin fibrosis. In the future, circulating collagen metabolites may potentially be used to evaluate therapeutic effects of anti-fibrotic treatments in the disease.

The Levels of Serum Serotonin Can Be Related to Skin and Pulmonary Manifestations of Systemic Sclerosis.

Background and Objective: The most prominent feature of systemic sclerosis (SSc), besides vasculopathy and autoimmune disorders, is excessive fibrosis. Serotonin affects hemostasis and can induce vasoconstriction, which is presumed to be one of the pathophysiological patterns in SSc that leads to fibrosis. Our aim was to explore the possible association of serotonin with some of the clinical features of SSc in our cohort of patients. Materials and Methods: We measured serotonin levels in sera of 29 female SSc patients. Patients were 41-79 years old, their average disease duration was 9 years. Serotonin values were analyzed in correlation with clinical and laboratory parameters, such as modified Rodnan skin score (mRSS), digital ulcers (DU), and spirometry parameters-forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), and lung diffusion capacity of carbon monoxide (DLCO). Statistical analyses were performed using statistical software Statistica. Results: We found correlation of serotonin level with mRSS (r = 0.388, p = 0.038). The highest values of serotonin were documented in patients with refractory DU, but this was not statistically significant. We also found a negative correlation between serotonin and FVC (r = -0.397), although it did not reach the level of significance (p = 0.114). Conclusions: Our study suggests that levels of serum serotonin could affect the course of skin fibrosis and partially restrictive pulmonary dysfunction in patients with SSc. We assume that serotonin might have influence on several features of SSc, but more studies are needed to reveal those relations.

Thyroid Volume in Systemic Sclerosis Patients: A Cross-Sectional Study.

INTRODUCTION: Systemic sclerosis (SSc) is a multisystemic disease. Thyroid involvement in systemic sclerosis is an overlooked issue. Our study aimed to evaluate the decreased thyroid volume in SSc. Also, we aimed to show the relationship between patients' thyroid volume and clinical and laboratory parameters. METHOD: This was a single-center, cross-sectional study. Eighty-six patients were included in the study. A radiologist evaluated patients' thyroid volumes by ultrasonography. Demographic and clinical characteristics of the patients were recorded. Skin thickness was evaluated by the modified Rodnan skin score (mRSS) and the disease severity by the Medsger severity score (MSS). Findings were analyzed statistically. RESULTS: Thyroid volume was in the atrophic range in 53.5% of the patients. There was a significant negative correlation between thyroid volume and mRSS, MSS, and disease duration. Logistic regression analysis showed that mRSS and disease duration were risk factors for thyroid atrophy. CONCLUSIONS: Many studies point out that thyroid autoantibodies are a cause of thyroid dysfunction in patients with SSc. However, in most of these studies, thyroid volume was not evaluated. As a result of our study, we saw that the major cause of thyroid dysfunction in our SSc patients was thyroid atrophy. Also, we observed that thyroid atrophy was more common in patients with interstitial lung disease. We would like to draw attention to the fact that thyroid dysfunction and volume changes increase with the disease's duration and severity in systemic sclerosis.

Correlation between Interstitial Lung Disease Morphology Scores Based on High-resolution Computed Tomography Chest and Skin Fibrosis Degree Based on Modified Rodnan's Skin Score on Systemic Sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a systemic autoimmune disease involving a multisystem. Modified Rodnan's Skin Score (MRSS) is a gold standard for measuring skin fibrosis in SSc. In SSc, lung fibrosis disorders, especially interstitial lung disease (ILD), are the leading cause of mortality and often late in diagnosis. High-Resolution Computed Tomography (HRCT) Chest scan is a gold standard for evaluating ILD morphology, but its availability is limited. The degree of skin fibrosis based on MRSS in SSc can predict the presence of ILD in several studies but has not been widely studied in Indonesia. This study aimed to determine the relationship of the ILD morphology based on thoracic HRCT scan with the degree of skin fibrosis based on MRSS in SSc. METHODS: This study is a retrospective analytic observational study with a cross-sectional design. The subjects of this study are SSc patients who had data of MRSS and HRCT chest scan from July 2019 to March 2020. Statistical analysis uses Spearman's correlation test. RESULTS: There were 42 study subjects, consisting of 41 women (97.6%) and one man (2.4%) with an average age of 39.50 years old (age range of 19 years to 60 years old). Correlation test results based on Spearman's show a moderate correlation between the morphological score of ILD with MRSS with R = 0.429, which is significant (p = 0.005). CONCLUSION: There is a significant moderate correlation between the morphological scores of ILD based on HRCT chest and the degree of skin fibrosis based on MRSS in SSc.

Immunological Adverse Events After Autologous Hematopoietic Stem Cell Transplantation in Systemic Sclerosis Patients.

Autologous hematopoietic stem cell transplantation (aHSCT) represents an effective treatment for systemic sclerosis (SSc), but it also can cause immunological adverse events (iAEs). Therefore, we aimed to determine the frequency of iAEs [engraftment syndrome (ES) and secondary autoimmune disorder (sAD)] and to identify potential risk factors for their development in a retrospective analysis on 22 patients similarly transplanted due to SSc. While nine patients (41%) suffered from ESs, seven sADs occurred in six patients (27%). Patients who developed ES were older in our cohort (52.45 vs. 42.58 years, p = .0433, Cohen's d = 0.86), and cardiac involvement by SSc was associated with development of ES (OR = 40.11, p = .0017). Patients with manifestation of sAD had a higher modified Rodnan skin score (mRSS) reduction after aHSCT (90.50% vs. 60.00%, p = .0064, r = .65). Thus, IAEs are common after aHSCT for SSc and can occur in different stages during and after aHSCT with characteristic clinical manifestations. Good cutaneous response after aHSCT might be considered as a risk factor for sAD, and higher age at aHSCT and cardiac involvement might be considered as risk factors for the development of ES.

Arterial evaluation of systemic sclerosis patients with Doppler ultrasound: What did we find?

AIM: The aim of this study was to detect macrovascular findings in systemic sclerosis (SSc) by means of color Doppler ultrasonography (CDUS) and to evaluate the relationship between the laboratory and clinical findings in the setting of the disease. METHODS: This was a cross-sectional study. Eighty-eight patients were included in the study. CDUS examinations of the bilateral carotid, vertebral, and peripheral arteries were performed. The presence of macrovascular involvement was investigated and recorded, and its relationships with the clinical, laboratory, and cardiovascular risk factors were evaluated. RESULTS: An atheromatous plaque was found in 67.7% of the 1936 arteries examined by CDUS. Of these 1936 arteries, 37.4% demonstrated a narrowing of the intraluminal diameter. On the other hand, the carotid intima-media thickness (CIMT) was found to have increased in 55.7% of the patients. This increase was found to be statistically correlated with disease duration, the modified Rodnan Skin Thickness Score, and the Medsger Disease Activity Score. But no relation existed with the disease subtype, age, or cardiovascular risk factors. Arterial occlusion was detected in 10 patients. An association was found between the CIMT values and arterial occlusion. CONCLUSIONS: In this study, we examined the arteries by means of CDUS, and we detected structural alterations in the peripheral and carotid arteries. We witnessed that these macrovascular changes had a close association with certain features of SSc. We think there is a need for broader prospective studies in order to evaluate the contribution of these factors to the macrovascular changes stated in the article.

HDL cholesterol efflux capacity and lipid profile in patients with systemic sclerosis.

OBJECTIVE: It is well established that patients with systemic sclerosis (SSc) have a disrupted lipid profile and an increased cardiovascular risk. Cholesterol efflux capacity (CEC), the ability of high-density lipoprotein (HDL)-cholesterol to accept cholesterol from macrophages, has been linked to cardiovascular events. The aim of this study was to establish whether CEC and lipid profile were impaired in SSc patients with respect to controls and whether these changes were associated with disease-related data. METHODS: Cross-sectional study encompassed 188 individuals: 73 SSc patients and 115 controls. CEC, using an in vitro assay, and lipoprotein serum concentrations were assessed in patients and controls. A multivariable analysis was performed to study the differences in CEC between patients and controls, and if SSc-related data could explain such differences. RESULTS: The multivariable analysis adjusted for demographic characteristics, cardiovascular risk factors, and lipid-related molecules showed that total cholesterol (beta coefficient: - 22 [95%CI - 37 to - 7], p = 0.004), triglycerides (beta coefficient: 24 [95%CI 2-47], p = 0.033), lipoprotein A (beta coefficient: 22 [95%CI 2-43], p = 0.033), and CEC (beta coefficient: - 6 [95%CI - 10 to - 2]%,p = 0.002) were significantly different between patients and controls. Skin thickness, as assessed by modified Rodnan skin score, was independently associated with a lower CEC (beta coefficient: - 0.21 [95%CI - 0.37 to - 0.05]%, p = 0.011) after multivariable adjustment. CONCLUSION: SSc patients show an abnormal lipid profile with respect to controls including CEC. Skin thickness is independent and inversely associated with CEC in SSc patients.

Efficacy and safety of rituximab on lung and skin involvement in systemic sclerosis: a systematic review and metaanalysis.

OBJECTIVE: To evaluate the efficacy and safety of rituximab (RTX), an antiB cell monoclonal antibody, on lung and skin involvement in systemic sclerosis (SSc). METHODS: All literature published in Embase and Medline before September 2019 were comprehensively searched. Two independent reviewers selected eligible studies, extracted relevant data, and assessed the quality of the included studies. We only considered randomized, controlled trials (RCTs), cohort studies, and case-control studies that compared RTX with a placebo, other immunosuppressive agents, or corticosteroids. All analyses were performed using RevMan (version 5.3). RESULTS: A total of 8 studies (3 RCTs and 5 cohort studies) met our inclusion criteria. The pooled analysis showed a significant improvement of modified Rodnan skin score in the RTX group only in the cohort studies (mean difference [SD] - 3.31 [- 4.95, - 1.68]; I2 = 82%). As to the PFT, the RTX group showed a significant improvement in the forced vital capacity only in 3 RCTs (mean difference [SD] 6.59 [3.51, 9.68]; I2 = 0%). Additionally, the RTX group demonstrated a statistically significant improvement in the diffuse capacity of carbon monoxide only in the cohort studies (mean difference [SD] 7.42 [1.08, 13.76]; I2 = 97%). There were no significant differences in the AEs of the RTX and control groups. CONCLUSIONS: RTX may be effective for lung and skin involvement in SSc, with no serious AEs. However, further studies with high quality and a large sample size are necessary to firmly establish the efficacy and safety of the use of RTX with SSc patients. Key Points • RTX may be an alternative treatment for cutaneous and pulmonary manifestations in patients with SSc with a favorable safety profile. • However, further studies with a high quality and large sample size are necessary to firmly establish its efficacy and safety.

Tocilizumab therapy in juvenile systemic sclerosis: a retrospective single centre pilot study.

To evaluate the efficacy and safety of anti-interleukin (IL)-6 receptor antibody tocilizumab (TCZ) as a treatment option of juvenile systemic sclerosis (JSS). Nine JSS patients were assigned to a TCZ, additionally to conventional treatment (steroids, methotrexate, mycophenolate-mofetil). The modified Rodnan skin score (mRSS), carbon-monoxide diffusion capacity (DLCO), thorax high-resolution tomography (HRCT), patient global assessment (PGA) and Juvenile Systemic Sclerosis Severity (J4S) score were used to explore the efficacy of treatment. Nine JSS patients were treated with TCZ with a median treatment duration of 10 (1-21) months. Nine patients (77.8%) had radiologically confirmed improvement on thorax HRCT, 7 (77.8%) had decreased PGA (mean pre-treatment PGA 3.7 vs. 2.3 post-treatment PGA 2), 6 (66.7%) had increased DLCO (mean pre-treatment DLCO 69.14% vs. post-treatment DLCO 79.50%) after the TCZ treatment. In all patients mRSS and the J4S decreased: 26.1 vs. 19.7 and 8.2 vs. 4.7, respectively. Changes in mRSS, DLCO, PGA and J4S were statistically significant: p = 0.012, 0.04, 0.026 and 0.007, respectively. All patients tolerated well TCZ treatment. JSS is a rare condition characterized with skin fibrosis and internal organ involvement. Tocilizumab represents a potential treatment option for patients unresponsive to conventional treatment. Long-term prospective studies with higher number of patients are needed to provide more relevant data.

The first composite score predicting Digital Ulcers in systemic sclerosis patients using Clinical data, Imaging and Patient history-CIP-DUS.

BACKGROUND: Digital ulcers (DU) present a challenging complication in systemic sclerosis (SSc). The aim of this study was to combine clinical characteristics and imaging methods to a composite score for the prediction of DU in SSc patients. METHODS: Seventy-nine SSc patients received clinical examination, their patient history was taken and nailfold capillaroscopy (NC), colour Doppler ultrasonography (CDUS) and fluorescence optical imaging (FOI) of the hands were performed at baseline. Newly developed DU over a period of approximately 12 months were registered. We used criteria with area under the curve (AUC) of at least 0.6 in regard to the development of these new DU to create the score (CIP-DUS, clinical features, imaging, patient history-digital ulcer score). RESULTS: Twenty-nine percent of all SSc patients developed new DU during follow-up (48.1% diffuse, 18.4% limited SSc). Based on the cross-validated (cv) AUC, a weight (cvAUC > 0.6 and ≤ 0.65: 1; cvAUC > 0.65 and ≤ 0.7: 2; cvAUC > 0.7: 3) was assigned to each selected parameter. The performance of the final CIP-DUS was assessed with and without the CDUS/FOI component. For the scleroderma patterns in NC, three points were appointed to late, two to active and one point to early capillaroscopy pattern according to Cutolo et al. The CIP-DUS including the CDUS and FOI parameters resulted in a good diagnostic performance (AUC after cross-validation: 0.83, 95%CI 0.74 to 0.92) and was well calibrated (chi-square = 12.3, p = 0.58). The cut-off associated with the maximum of sensitivity and specificity was estimated at ≥ 10 points resulting in a sensitivity of 100% and specificity of 74% for new DU during follow-up. Excluding CDUS and FOI parameters leads to a non-statistically significant lower performance (AUC after cross-validation: 0.81, 95%CI 0.72 to 0.91). However, including CDUS and FOI resulted in a better classification of patients in respect to the outcome new DU in follow-up due to significantly better reclassification performance (NRI = 62.1, p = 0.001) and discrimination improvement (IDI = 9.7, p = 0.01). CONCLUSION: A new score was introduced with the aim to predict digital ulcers. If applied correctly and with the new imaging techniques proposed, all patients at risk of digital ulcers throughout 12 months could be identified.

Ultrasound Surface Wave Elastography for Assessing Scleroderma.

Scleroderma, or systemic sclerosis (SSc), is a multi-organ connective tissue disease characterized by immune dysregulation and tissue fibrosis. Skin disease is both a disabling feature of SSc and a predictor of visceral involvement and increased mortality. The Modified Rodnan Skin Score (MRSS) is currently the most common clinical method for assessing skin. We developed ultrasound surface wave elastography (USWE) techniques to measure skin surface wave speeds and analyze skin viscoelasticity. The objective of this research was to determine the correlations of skin surface wave speed and skin viscoelasticity with MRSS. Twenty-six SSc patients were studied using USWE and the MRSS. The subject was tested in a sitting position while his or her left or right forearm and upper arm were placed horizontally on a pillow in a relaxed state. The skin of both left and right forearms and upper arms of patients was tested using USWE. Surface wave speeds are positively correlated with the MRSS. Skin elasticity is also positively correlated with the MRSS. However, there was no correlation between skin viscosity and the MRSS for these SSc patients. We will further study if skin viscosity is sensitive enough to detect early edema from inflammation changes of SSc.

High-throughput quantitative histology in systemic sclerosis skin disease using computer vision.

BACKGROUND: Skin fibrosis is the clinical hallmark of systemic sclerosis (SSc), where collagen deposition and remodeling of the dermis occur over time. The most widely used outcome measure in SSc clinical trials is the modified Rodnan skin score (mRSS), which is a semi-quantitative assessment of skin stiffness at seventeen body sites. However, the mRSS is confounded by obesity, edema, and high inter-rater variability. In order to develop a new histopathological outcome measure for SSc, we applied a computer vision technology called a deep neural network (DNN) to stained sections of SSc skin. We tested the hypotheses that DNN analysis could reliably assess mRSS and discriminate SSc from normal skin. METHODS: We analyzed biopsies from two independent (primary and secondary) cohorts. One investigator performed mRSS assessments and forearm biopsies, and trichrome-stained biopsy sections were photomicrographed. We used the AlexNet DNN to generate a numerical signature of 4096 quantitative image features (QIFs) for 100 randomly selected dermal image patches/biopsy. In the primary cohort, we used principal components analysis (PCA) to summarize the QIFs into a Biopsy Score for comparison with mRSS. In the secondary cohort, using QIF signatures as the input, we fit a logistic regression model to discriminate between SSc vs. control biopsy, and a linear regression model to estimate mRSS, yielding Diagnostic Scores and Fibrosis Scores, respectively. We determined the correlation between Fibrosis Scores and the published Scleroderma Skin Severity Score (4S) and between Fibrosis Scores and longitudinal changes in mRSS on a per patient basis. RESULTS: In the primary cohort (n = 6, 26 SSc biopsies), Biopsy Scores significantly correlated with mRSS (R = 0.55, p = 0.01). In the secondary cohort (n = 60 SSc and 16 controls, 164 biopsies; divided into 70% training and 30% test sets), the Diagnostic Score was significantly associated with SSc-status (misclassification rate = 1.9% [training], 6.6% [test]), and the Fibrosis Score significantly correlated with mRSS (R = 0.70 [training], 0.55 [test]). The DNN-derived Fibrosis Score significantly correlated with 4S (R = 0.69, p = 3 × 10- 17). CONCLUSIONS: DNN analysis of SSc biopsies is an unbiased, quantitative, and reproducible outcome that is associated with validated SSc outcomes.

Early trajectories of skin thickening are associated with severity and mortality in systemic sclerosis.

BACKGROUND: Systemic sclerosis (SSc) is a severe and highly heterogeneous disease. The modified Rodnan skin score (mRSS) is a widely used tool for the assessment of the extent and degree of skin thickness. This study aimed to identify the classes of patients with early similar skin thickening trajectories without any a priori assumptions and study their associations with organ involvement and survival. METHODS: From the French SSc national cohort, patients with a disease duration of less than 2 years at inclusion and with at least 2 mRSS available within the first 4 years of follow-up were enrolled. Classes of patients with similar mRSS trajectories were identified based on a latent class mixed model. The clinical characteristics and survival rate were compared between the obtained classes. RESULTS: A total of 198 patients fulfilled the inclusion criteria, with a total of 641 mRSS available. The median disease duration and follow-up were 0.8 (interquartile range 0.4; 1.2) and 6.3 (3.8; 8.9) years, respectively. Individual trajectories of mRSS were highly heterogeneous between patients. Models with 1-6 latent classes of trajectories were sequentially assessed, and the 5-class model represented the best fit to data. Each class was characterized by a unique global trajectory of mRSS. The median disease duration did not differ significantly between classes. Baseline organ involvement was more frequent in classes with significant change over time (classes 2-5) than in class 1 (low baseline mRSS without significant change over time). Using Cox regression, we observed a progressively increasing risk of death from classes 1 to 5. CONCLUSIONS: Early identification of clinical phenotype based on skin thickening trajectories could predict morbi-mortality in SSc. This study suggested that mRSS trajectories characterization might be pivotal for clinical practice and future trial designs.

Performance of ultra-high-frequency ultrasound in the evaluation of skin involvement in systemic sclerosis: a preliminary report.

OBJECTIVE: High frequency ultrasound allows visualization of epidermis, dermis and hypodermis, precise measurement of skin thickness, as well as assessment of skin oedema, fibrosis and atrophy. The aim of this pilot cross-sectional observational study was to assess the performance and multiobserver variability of ultra-high-frequency (UHF) (50 MHz) ultrasound (US) in measuring skin thickness as well as the capacity of UHF-derived skin features to differentiate SSc patients from healthy controls. METHODS: Twenty-one SSc patients (16 limited and five diffuse SSc) and six healthy controls were enrolled. All subjects underwent US evaluation by three experts at three anatomical sites (forearm, hand and finger). Dermal thickness was measured and two rectangular regions of interest, one in dermis and one in hypodermis, were established for texture feature analysis. RESULTS: UHF-US allowed a precise identification and measurement of the thickness of the dermis. The dermal thickness in the finger was significantly higher in patients than in controls (P < 0.05), while in the forearm it was significantly lower in patients than in controls (P < 0.001). Interobserver variability for dermal thickness was good to excellent [forearm intraclass correlation coefficient (ICC) = 0.754; finger ICC = 0.699; hand ICC = 0.602]. Texture computed analysis of dermis and hypodermis was able to discriminate between SSc and healthy subjects (area under the curve >0.7). CONCLUSION: These preliminary data show that skin UHF-US allows a very detailed imaging of skin layers, a reliable measurement of dermal thickness, and a discriminative capacity between dermis and hypodermis texture features in SSc and healthy subjects.