Myeloablation followed by autologous stem cell transplantation normalises systemic sclerosis molecular signatures

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.

Distinct molecular subtypes of systemic sclerosis and gene signature with diagnostic capability

Background

As Systemic Sclerosis (SSc) is a connective tissue ailment that impacts various bodily systems. The study aims to clarify the molecular subtypes of SSc, with the ultimate objective of establishing a diagnostic model that can inform clinical treatment decisions.

Methods

Five microarray datasets of SSc were retrieved from the GEO database. To eliminate batch effects, the combat algorithm was applied. Immune cell infiltration was evaluated using the xCell algorithm. The ConsensusClusterPlus algorithm was utilized to identify SSc subtypes. Limma was used to determine differential expression genes (DEGs). GSEA was used to determine pathway enrichment. A support vector machine (SVM), Random Forest(RF), Boruta and LASSO algorithm have been used to select the feature gene. Diagnostic models were developed using SVM, RF, and Logistic Regression (LR). A ROC curve was used to evaluate the performance of the model. The compound-gene relationship was obtained from the Comparative Toxicogenomics Database (CTD).

Results

The identification of three immune subtypes in SSc samples was based on the expression profiles of immune cells. The utilization of 19 key intersectional DEGs among subtypes facilitated the classification of SSc patients into three robust subtypes (gene_ClusterA-C). Gene_ClusterA exhibited significant enrichment of B cells, while gene_ClusterC showed significant enrichment of monocytes. Moderate activation of various immune cells was observed in gene_ClusterB. We identified 8 feature genes. The SVM model demonstrating superior diagnostic performance. Furthermore, correlation analysis revealed a robust association between the feature genes and immune cells. Eight pertinent compounds, namely methotrexate, resveratrol, paclitaxel, trichloroethylene, formaldehyde, silicon dioxide, benzene, and tetrachloroethylene, were identified from the CTD.

Conclusion

The present study has effectively devised an innovative molecular subtyping methodology for patients with SSc and a diagnostic model based on machine learning to aid in clinical treatment. The study has identified potential molecular targets for therapy, thereby offering novel perspectives for the treatment and investigation of SSc.

Longitudinal global transcriptomic profiling of preclinical systemic sclerosis reveals molecular changes associated with disease progression

OBJECTIVE

To investigate peripheral blood cell (PBCs) global gene expression profile of SSc at its preclinical stage (PreSSc) and to characterize the molecular changes associated with progression to a definite disease over time.

MATERIAL AND METHODS

Clinical data and PBCs of 33 participants with PreSSc and 16 healthy controls (HCs) were collected at baseline and follow-up (mean 4.2 years). Global gene expression profiling was conducted by RNA sequencing and a modular analysis was performed.

RESULTS

Comparison of baseline PreSSc to HCs revealed 2889 differentially expressed genes. Interferon signalling was the only activated pathway among top over-represented pathways. Moreover, 10 modules were significantly decreased in PreSSc samples (related to lymphoid lineage, cytotoxic/NK cell, and erythropoiesis) in comparison to HCs. At follow-up, 14 subjects (42.4%) presented signs of progression (evolving PreSSc) and 19 remained in stable preclinical stage (stable PreSSc). Progression was not associated with baseline clinical features or baseline PBC transcript modules. At follow-up stable PreSSc normalized their down-regulated cytotoxic/NK cell and protein synthesis modules while evolving PreSSc kept a down-regulation of cytotoxic/NK cell and protein synthesis modules. Transcript level changes of follow-up vs baseline in stable PreSSc vs evolving PreSSc showed 549 differentially expressed transcripts (336 up and 213 down) with upregulation of the EIF2 Signalling pathway.

CONCLUSIONS

Participants with PreSSc had a distinct gene expression profile indicating that molecular differences at a transcriptomic level are already present in the preclinical stages of SSc. Furthermore, a reduced NK signature in PBCs was related to SSc progression over time.

Differentially expressed genes in systemic sclerosis: Towards predictive medicine with new molecular tools for clinicians

Systemic sclerosis (SSc) is a rare and chronic autoimmune disease characterized by a pathogenic triad of immune dysregulation, vasculopathy, and progressive fibrosis. Clinical tools commonly used to assess patients, such as the modified Rodnan skin score, difference between limited or diffuse forms of skin involvement, presence of lung, heart or kidney involvement, or of various autoantibodies, are important prognostic factors, but still fail to reflect the large heterogeneity of the disease. SSc treatment options are diverse, ranging from conventional drugs to autologous hematopoietic stem cell transplantation, and predicting response is challenging. Genome-wide technologies, such as high throughput microarray analyses and RNA sequencing, allow accurate, unbiased, and broad assessment of alterations in expression levels of multiple genes. In recent years, many studies have shown robust changes in the gene expression profiles of SSc patients compared to healthy controls, mainly in skin tissues and peripheral blood cells. The objective analysis of molecular patterns in SSc is a powerful tool that can further classify SSc patients with similar clinical phenotypes and help predict response to therapy. In this review, we describe the journey from the first discovery of differentially expressed genes to the identification of enriched pathways and intrinsic subsets identified in SSc, using machine learning algorithms. Finally, we discuss the use of these new tools to predict the efficacy of various treatments, including stem cell transplantation. We suggest that the use of RNA gene expression-based classifications according to molecular subsets may bring us one step closer to precision medicine in Systemic Sclerosis.

Myeloablative autologous haematopoietic stem cell transplantation resets the B cell repertoire to a more naïve state in patients with systemic sclerosis

OBJECTIVES

Myeloablative autologous haematopoietic stem cell transplant (HSCT) was recently demonstrated to provide significant benefit over cyclophosphamide (CYC) in the treatment of diffuse cutaneous systemic sclerosis (dcSSc) in the Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial. As dysregulation of the B cell compartment has previously been described in dcSSc, we sought to gain insight into the effects of myeloablative autologous HSCT as compared with CYC.

METHODS

We sequenced the peripheral blood immunoglobulin heavy chain (IGH) repertoires in patients with dcSSc enrolled in the SCOT trial.

RESULTS

Myeloablative autologous HSCT was associated with a sustained increase in IgM isotype antibodies bearing a low mutation rate. Clonal expression was reduced in IGH repertoires following myeloablative autologous HSCT. Additionally, we identified a underusage of immunoglobulin heavy chain V gene 5-51 in patients with dcSSc, and usage normalised following myeloablative autologous HSCT but not CYC treatment.

CONCLUSIONS

Together, these findings suggest that myeloablative autologous HSCT resets the IGH repertoire to a more naïve state characterised by IgM-expressing B cells, providing a possible mechanism for the elimination of pathogenic B cells that may contribute to the benefit of HSCT over CYC in the treatment of dcSSc.

Type I interferon pathway assays in studies of rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

OBJECTIVES

To systematically review the literature for assay methods that aim to evaluate type I interferon (IFN-I) pathway activation and to harmonise-related terminology.

METHODS

Three databases were searched for reports of IFN-I and rheumatic musculoskeletal diseases. Information about the performance metrics of assays measuring IFN-I and measures of truth were extracted and summarised. A EULAR task force panel assessed feasibility and developed consensus terminology.

RESULTS

Of 10 037 abstracts, 276 fulfilled eligibility criteria for data extraction. Some reported more than one technique to measure IFN-I pathway activation. Hence, 276 papers generated data on 412 methods. IFN-I pathway activation was measured using: qPCR (n=121), immunoassays (n=101), microarray (n=69), reporter cell assay (n=38), DNA methylation (n=14), flow cytometry (n=14), cytopathic effect assay (n=11), RNA sequencing (n=9), plaque reduction assay (n=8), Nanostring (n=5), bisulphite sequencing (n=3). Principles of each assay are summarised for content validity. Concurrent validity (correlation with other IFN assays) was presented for n=150/412 assays. Reliability data were variable and provided for 13 assays. Gene expression and immunoassays were considered most feasible. Consensus terminology to define different aspects of IFN-I research and practice was produced.

CONCLUSIONS

Diverse methods have been reported as IFN-I assays and these differ in what elements or aspects of IFN-I pathway activation they measure and how. No 'gold standard' represents the entirety of the IFN pathway, some may not be specific for IFN-I. Data on reliability or comparing assays were limited, and feasibility is a challenge for many assays. Consensus terminology should improve consistency of reporting.

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.

Association between type I interferon pathway activation and clinical outcomes in rheumatic and musculoskeletal diseases: a systematic literature review informing EULAR points to consider

BACKGROUND

Type I interferons (IFN-I) contribute to a broad range of rheumatic and musculoskeletal diseases (RMDs). Compelling evidence suggests that the measurement of IFN-I pathway activation may have clinical value. Although several IFN-I pathway assays have been proposed, the exact clinical applications are unclear. We summarise the evidence on the potential clinical utility of assays measuring IFN-I pathway activation.

METHODS

A systematic literature review was conducted across three databases to evaluate the use of IFN-I assays in diagnosis and monitor disease activity, prognosis, response to treatment and responsiveness to change in several RMDs.

RESULTS

Of 366 screened, 276 studies were selected that reported the use of assays reflecting IFN-I pathway activation for disease diagnosis (n=188), assessment of disease activity (n=122), prognosis (n=20), response to treatment (n=23) and assay responsiveness (n=59). Immunoassays, quantitative PCR (qPCR) and microarrays were reported most frequently, while systemic lupus erythematosus (SLE), rheumatoid arthritis, myositis, systemic sclerosis and primary Sjögren's syndrome were the most studied RMDs. The literature demonstrated significant heterogeneity in techniques, analytical conditions, risk of bias and application in diseases. Inadequate study designs and technical heterogeneity were the main limitations. IFN-I pathway activation was associated with disease activity and flare occurrence in SLE, but their incremental value was uncertain. IFN-I pathway activation may predict response to IFN-I targeting therapies and may predict response to different treatments.

CONCLUSIONS

Evidence indicates potential clinical value of assays measuring IFN-I pathway activation in several RMDs, but assay harmonisation and clinical validation are urged. This review informs the EULAR points to consider for the measurement and reporting of IFN-I pathway assays.

Distinct genome-wide DNA methylation and gene expression signatures in classical monocytes from African American patients with systemic sclerosis

BACKGROUND

Systemic sclerosis (SSc) is a multisystem autoimmune disorder that has an unclear etiology and disproportionately affects women and African Americans. Despite this, African Americans are dramatically underrepresented in SSc research. Additionally, monocytes show heightened activation in SSc and in African Americans relative to European Americans. In this study, we sought to investigate DNA methylation and gene expression patterns in classical monocytes in a health disparity population.

METHODS

Classical monocytes (CD14+ + CD16-) were FACS-isolated from 34 self-reported African American women. Samples from 12 SSc patients and 12 healthy controls were hybridized on MethylationEPIC BeadChip array, while RNA-seq was performed on 16 SSc patients and 18 healthy controls. Analyses were computed to identify differentially methylated CpGs (DMCs), differentially expressed genes (DEGs), and CpGs associated with changes in gene expression (eQTM analysis).

RESULTS

We observed modest DNA methylation and gene expression differences between cases and controls. The genes harboring the top DMCs, the top DEGs, as well as the top eQTM loci were enriched for metabolic processes. Genes involved in immune processes and pathways showed a weak upregulation in the transcriptomic analysis. While many genes were newly identified, several other have been previously reported as differentially methylated or expressed in different blood cells from patients with SSc, supporting for their potential dysregulation in SSc.

CONCLUSIONS

While contrasting with results found in other blood cell types in largely European-descent groups, the results of this study support that variation in DNA methylation and gene expression exists among different cell types and individuals of different genetic, clinical, social, and environmental backgrounds. This finding supports the importance of including diverse, well-characterized patients to understand the different roles of DNA methylation and gene expression variability in the dysregulation of classical monocytes in diverse populations, which might help explaining the health disparities.

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.

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-β, 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.

Alterations of the Primary Cilia Gene SPAG17 and SOX9 Locus Noncoding RNAs Identified by RNA-Sequencing Analysis in Patients With Systemic Sclerosis

OBJECTIVE

Systemic sclerosis (SSc) is characterized by immune activation, vasculopathy, and unresolving fibrosis in the skin, lungs, and other organs. We performed RNA-sequencing analysis on skin biopsy samples and peripheral blood mononuclear cells (PBMCs) from SSc patients and unaffected controls to better understand the pathogenesis of SSc.

METHODS

We analyzed these data 1) to test for case/control differences and 2) to identify genes whose expression levels correlate with SSc severity as measured by local skin score, modified Rodnan skin thickness score (MRSS), forced vital capacity (FVC), or diffusing capacity for carbon monoxide (DLco).

RESULTS

We found that PBMCs from SSc patients showed a strong type I interferon signature. This signal was found to be replicated in the skin, with additional signals for increased extracellular matrix (ECM) genes, classical complement pathway activation, and the presence of B cells. Notably, we observed a marked decrease in the expression of SPAG17, a cilia component, in SSc skin. We identified genes that correlated with the MRSS, DLco, and FVC in SSc PBMCs and skin using weighted gene coexpression network analysis. These genes were largely distinct from the case/control differentially expressed genes. In PBMCs, type I interferon signatures negatively correlated with the DLco. In SSc skin, ECM gene expression positively correlated with the MRSS. Network analysis of SSc skin genes that correlated with clinical features identified the noncoding RNAs SOX9-AS1 and ROCR, both near the SOX9 locus, as highly connected, "hub-like" genes in the network.

CONCLUSION

These results identify noncoding RNAs and SPAG17 as novel factors potentially implicated in the pathogenesis of SSc.

Hematopoietic Cell Transplantation for Systemic Sclerosis-A Review

Systemic sclerosis (SSc) is an autoimmune, multi-organ, connective tissue disease associated with significant morbidity and mortality. Conventional immunosuppressive therapies demonstrate limited efficacy. Autologous hematopoietic stem cell transplantation (HCT) is more efficacious but carries associated risks, including treatment-related mortality. Here, we review HCT as a treatment for SSc, its efficacy and toxicity in comparison to conventional therapies, and the proposed mechanisms of action. Furthermore, we discuss the importance of and recent developments in patient selection. Finally, we highlight the knowledge gaps and future work required to further improve patient outcomes.

Type 1 interferon activation in systemic sclerosis: a biomarker, a target or the culprit

PURPOSE OF REVIEW

Activation of the type 1 interferon (T1 IFN) pathway has been implicated in the pathogenesis of systemic sclerosis (SSc) by an increasing number of studies, most of which share key findings with similar studies in systemic lupus erythematosus (SLE). Here we will focus on the evidence for T1 IFN activation and dysregulation in SSc, and the rationale behind targeting the pathway going forward.

RECENT FINDINGS

An increased expression and activation of T1 IFN-regulated genes has been shown to be present in a significant proportion of SSc patients. TI IFN activation markers have been found to predict and correlate with response to immunosuppressive treatment as well as severity of organ involvement. As inhibition of the IFN-α receptor has been proven to be effective in active SLE, benefit may be seen in targeting the IFN pathway in SSc.

SUMMARY

The role played by T1 IFN and its regulatory genes in SSc is becoming increasingly evident and strikingly similar to the role observed in SLE. This observation, together with the benefit of type 1 IFN targeting in SLE, supports the notion of a potential therapeutic benefit in targeting T1 IFN in SSc.

Cellular-Based Therapies in Systemic Sclerosis: From Hematopoietic Stem Cell Transplant to Innovative Approaches

Systemic sclerosis (SSc) is a systemic disease characterized by autoimmune responses, vasculopathy and tissue fibrosis. The pathogenic mechanisms involve a wide range of cells and soluble factors. The complexity of interactions leads to heterogeneous clinical features in terms of the extent, severity, and rate of progression of skin fibrosis and internal organ involvement. Available disease-modifying drugs have only modest effects on halting disease progression and may be associated with significant side effects. Therefore, cellular therapies have been developed aiming at the restoration of immunologic self-tolerance in order to provide durable remissions or to foster tissue regeneration. Currently, SSc is recommended as the 'standard indication' for autologous hematopoietic stem cell transplantation by the European Society for Blood and Marrow Transplantation. This review provides an overview on cellular therapies in SSc, from pre-clinical models to clinical applications, opening towards more advanced cellular therapies, such as mesenchymal stem cells, regulatory T cells and potentially CAR-T-cell therapies.

Reconstitution of the immune system and clinical correlates after stem cell transplantation for systemic sclerosis

Systemic sclerosis (SSc) is a chronic autoimmune disease that includes fibrosis, diffuse vasculopathy, inflammation, and autoimmunity. Autologous hematopoietic stem cell transplantation (auto-HSCT) is considered for patients with severe and progressive SSc. In recent decades, knowledge about patient management and clinical outcomes after auto-HSCT has significantly improved. Mechanistic studies have contributed to increasing the comprehension of how profound and long-lasting are the modifications to the immune system induced by transplantation. This review revisits the immune monitoring studies after auto-HSCT for SSc patients and how they relate to clinical outcomes. This understanding is essential to further improve clinical applications of auto-HSCT and enhance patient outcomes.

Assessment of disease outcome measures in systemic sclerosis

The assessment of disease activity in systemic sclerosis (SSc) is challenging owing to its heterogeneous manifestations across multiple organ systems, the variable rate of disease progression and regression, and the relative paucity of patients in early-phase therapeutic trials. Despite some recent successes, most clinical trials have failed to show efficacy, underscoring the need for improved outcome measures linked directly to disease pathogenesis, particularly applicable for biomarker studies focused on skin disease. Current outcome measures in SSc-associated interstitial lung disease and SSc skin disease are largely adequate, although advancing imaging technology and the incorporation of skin mRNA biomarkers might provide opportunities for earlier detection of the therapeutic effect. Biomarkers can further inform pathogenesis, enabling early phase trials to act as reverse translational studies through the incorporation of routine high-throughput sequencing.

Role of B-Cell in the Pathogenesis of Systemic Sclerosis

Systemic sclerosis (SSc) is a rare multisystem autoimmune disease, characterized by fibrosis, vasculopathy, and autoimmunity. Recent advances have highlighted the significant implications of B-cells in SSc. B-cells are present in affected organs, their subpopulations are disrupted, and they display an activated phenotype, and the regulatory capacities of B-cells are impaired, as illustrated by the decrease in the IL-10+ producing B-cell subpopulation or the inhibitory membrane co-receptor density. Recent multi-omics evidence highlights the role of B-cells mainly in the early stage of SSc and preferentially during severe organ involvement. This dysregulated homeostasis partly explains the synthesis of anti-endothelial cell autoantibodies (AECAs) or anti-fibroblast autoantibodies (AFAs), proinflammatory or profibrotic cytokines (interleukin-6 and transforming growth factor-β) produced by B and plasma cells. That is associated with cell-to-cell interactions with endothelial cells, fibroblasts, vascular smooth muscle cells, and other immune cells, altogether leading to cell activation and proliferation, cell resistance to apoptosis, the impairment of regulatory mechanisms, and causing fibrosis of several organs encountered in the SSc. Finally, alongside these exploratory data, treatments targeting B-cells, through their depletion by cytotoxicity (anti-CD20 monoclonal antibody), or the cytokines produced by the B-cell, or their costimulation molecules, seem interesting, probably in certain profiles of early patients with severe organic damage.

Peripheral blood gene expression profiling shows predictive significance for response to mycophenolate in systemic sclerosis-related interstitial lung disease

OBJECTIVES

To characterise the peripheral blood cell (PBC) gene expression changes ensuing from mycophenolate mofetil (MMF) or cyclophosphamide (CYC) treatment and to determine the predictive significance of baseline PBC transcript scores for response to immunosuppression in systemic sclerosis (SSc)-related interstitial lung disease (ILD).

METHODS

PBC RNA samples from baseline and 12-month visits, corresponding to the active treatment period of both arms in Scleroderma Lung Study II, were investigated by global RNA sequencing. Joint models were created to examine the predictive significance of baseline composite modular scores for the course of forced vital capacity (FVC) per cent predicted measurements from 3 to 12 months.

RESULTS

134 patients with SSc-ILD (CYC=69 and MMF=65) were investigated. CYC led to an upregulation of erythropoiesis, inflammation and myeloid lineage-related modules and a downregulation of lymphoid lineage-related modules. The modular changes resulting from MMF treatment were more modest and included a downregulation of plasmablast module. In the longitudinal analysis, none of the baseline transcript module scores showed predictive significance for FVC% course in the CYC arm. In contrast, in the MMF arm, higher baseline lymphoid lineage modules predicted better subsequent FVC% course, while higher baseline myeloid lineage and inflammation modules predicted worse subsequent FVC% course.

CONCLUSION

Consistent with the primary mechanism of action of MMF on lymphocytes, patients with SSc-ILD with higher baseline lymphoid module scores had better FVC% course, while those with higher myeloid cell lineage activation score had poorer FVC% course on MMF.

Safety and Efficacy of Mesenchymal Stromal Cells and Other Cellular Therapeutics in Rheumatic Diseases in 2022: A review of what we know so far

Although there are a number of new immunosuppressives and biologics approved for treating various autoimmune/inflammatory rheumatic diseases, there remain a substantial number of patients who have no clinical response or limited clinical response to these available treatments. Use of cellular therapies is a novel approach for the treatment of autoimmune/inflammatory rheumatic diseases with perhaps enhanced efficacy and less toxicity than current therapies. Autologous hematopoietic stem cell transplants were the first foray into cellular therapies with proven efficacy in scleroderma and multiple sclerosis. Newer yet unproven cellular therapies include allogenic mesenchymal stromal cells, shown effective in graft vs host disease and in healing of Crohn's fistulas. CAR-T cells are effective in various malignancies with possible usage in rheumatic diseases, as shown in preclinical studies in murine lupus and recently in human lupus. T regulatory cells are one of the master controllers of the immune response and are decreased in number and/or effectiveness in specific autoimmune diseases. Expansion of autologous T regulatory cells is an attractive approach to controlling autoimmunity. There are a number of other regulatory cells in the immune system including regulatory B cells, dendritic cells, macrophages, and other T cell types that are early in development. In this review, the current evidence for efficacy and mechanisms of actions of cellular therapies already in use or in clinical trials in human autoimmune diseases will be discussed including limitations of these therapies and potential side effects.

Cellular and Molecular Diversity in Scleroderma

With the increasing armamentarium of high-throughput tools available at manageable cost, it is attractive and informative to determine the molecular underpinnings of patient heterogeneity in systemic sclerosis (SSc). Given the highly variable clinical outcomes of patients labelled with the same diagnosis, unravelling the cellular and molecular basis of disease heterogeneity will be crucial to predicting disease risk, stratifying management and ultimately informing a patient-centered precision medicine approach. Herein, we summarise the findings of the past several years in the fields of genomics, transcriptomics, and proteomics that contribute to unraveling the cellular and molecular heterogeneity of SSc. Expansion of these findings and their routine integration with quantitative analysis of histopathology and imaging studies into clinical care promise to inform a scientifically driven patient-centred personalized medicine approach to SSc in the near future.

Dysregulation of Type 1 Interferon Signaling in Systemic Sclerosis: a Promising Therapeutic Target?

Purpose of review

There are several lines of evidence at the genetic and gene expression levels linking type I interferon (IFN) activation to systemic sclerosis (SSc) pathogenesis. Herein, we summarize the potential role of type I IFN signaling components as therapeutic targets.

Recent findings

All type I IFN cytokines signal through the interferon-α/β receptor (IFNAR). Early phase studies indicate that anifrolumab (a human monoclonal antibody against IFNAR subunit 1) has an acceptable safety profile and can attenuate transforming growth factor beta (TGF-β)-mediated fibrosis in SSc skin, supporting its further clinical development. Janus kinase (JAK) signaling pathways are downstream from IFNAR. Building on their efficacy in hereditary interferonopathies, JAK inhibitors have the potential to block the deleterious IFN and other profibrotic cytokine activation in SSc and are promising drug targets. Moreover, interferon regulator factor (IRF) 5, 7, and 8 have been linked to the profibrotic response in SSc preclinical studies, underscoring their potential as therapeutic targets. Lastly, depletion of plasmacytoid dendritic cells (pDCs) attenuates the IFN activation and fibrotic response in vitro and murine model experiments and can be studied as a viable drug target in future clinical studies.

Summary

There is increasing evidence linking the prominent type I IFN activation to the observed exaggerated fibrotic response in SSc. Key components of type I IFN signaling are druggable therapeutic targets that can be pursued in future randomized clinical trials, in order to develop more effective therapeutic options for SSc.

Multiomic study of skin, peripheral blood, and serum: is serum proteome a reflection of disease process at the end-organ level in systemic sclerosis?

BACKGROUND

Serum proteins can be readily assessed during routine clinical care. However, it is unclear to what extent serum proteins reflect the molecular dysregulations of peripheral blood cells (PBCs) or affected end-organs in systemic sclerosis (SSc). We conducted a multiomic comparative analysis of SSc serum profile, PBC, and skin gene expression in concurrently collected samples.

METHODS

Global gene expression profiling was carried out in skin and PBC samples obtained from 49 SSc patients enrolled in the GENISOS observational cohort and 25 unaffected controls. Levels of 911 proteins were determined by Olink Proximity Extension Assay in concurrently collected serum samples.

RESULTS

Both SSc PBC and skin transcriptomes showed a prominent type I interferon signature. The examination of SSc serum profile revealed an upregulation of proteins involved in pro-fibrotic homing and extravasation, as well as extracellular matrix components/modulators. Notably, several soluble receptor proteins such as EGFR, ERBB2, ERBB3, VEGFR2, TGFBR3, and PDGF-Rα were downregulated. Thirty-nine proteins correlated with severity of SSc skin disease. The differential expression of serum protein in SSc vs. control comparison significantly correlated with the differential expression of corresponding transcripts in skin but not in PBCs. Moreover, the differentially expressed serum proteins were significantly more connected to the Well-Associated-Proteins in the skin than PBC gene expression dataset. The assessment of the concordance of between-sample similarities revealed that the molecular profile of serum proteins and skin gene expression data were significantly concordant in patients with SSc but not in healthy controls.

CONCLUSIONS

SSc serum protein profile shows an upregulation of profibrotic cytokines and a downregulation of soluble EGF and other key receptors. Our multilevel comparative analysis indicates that the serum protein profile in SSc correlates more closely with molecular dysregulations of skin than PBCs and might serve as a reflection of disease severity at the end-organ level.

Autologous stem-cell transplantation in systemic sclerosis-associated interstitial lung disease: early action in selected patients rather than escalation therapy for all

Systemic sclerosis (SSc) is a rare rheumatic disease characterised by inflammation, vasculopathy and fibrosis of skin and internal organs. A common complication and a leading cause of death in SSc is interstitial lung disease (ILD). The current armamentarium of treatments in SSc-ILD mainly includes immunosuppressive therapies and has recently been expanded with anti-fibrotic agent nintedanib. Autologous stem cell transplantation (SCT) is increasingly used in progressive diffuse cutaneous SSc. This intensive treatment has been studied in three randomised trials and demonstrated to improve survival and quality of life. In the subsets of patients with SSc-ILD, SCT resulted in stabilisation and modest improvement of lung volumes and disease extent on high resolution computed tomography, but less impact was seen on diffusion capacity. Comparison of SCT outcomes with results from SSc-ILD trials is difficult though, as lung involvement per se was not an inclusion criterion in all SCT trials. Also, baseline characteristics differed between studies. The risk of severe treatment-related complications from SCT is still considerable and patients with extensive lung disease are particularly at risk of complications during transplantation. Therefore SCT should only be provided by experienced multidisciplinary teams in carefully selected patients. Future research needs to include comprehensive pulmonary evaluation and establish whether SCT early in the disease might prevent irreversible pulmonary damage and reduce treatment-related complications. Also, more insight in mechanisms of action of SCT in the lung and predictors for response will improve the use of this treatment in SSc-ILD. In this review the role of SCT in the treatment of SSc-ILD is summarised.

[Autologous hematopoietic cells for severe autoimmune diseases: Guidelines of the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) for immune monitoring and biobanking]

Autologous hematopoietic cell transplantation (AHCT) is a new treatment option for patients with severe autoimmune diseases (AD), based on the use of intensive or myeloablative chemotherapy to eradicate the pathogenic autoreactive immune cells and to allow the installation of a new and tolerant immune system during immune reconstitution process. Immune reconstitution analysis after AHCT is required for patients clinical follow-up and to further identify biological and immunological markers of the clinical response to develop individualized AHCT protocols. These MATHEC-SFGM-TC good clinical practice guidelines were developed by a multidisciplinary group of experts including members of the french reference center for stem Cell Therapy in Auto-immune Diseases (MATHEC), hematologists from the French speaking Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) and experts in immune monitoring and biobanking. The objectives are to provide practical recommandations for immune monitoring and biobanking of samples in patients with AD undergoing AHCT, for routine care purposes and investigational studies.

Predictive Significance of Serum Interferon-Inducible Protein Score for Response to Treatment in Systemic Sclerosis-Related Interstitial Lung Disease

OBJECTIVE

Response to immunosuppression is highly variable in systemic sclerosis (SSc)-related interstitial lung disease (ILD). This study was undertaken to determine whether a composite serum interferon (IFN)-inducible protein score exhibits predictive significance for the response to immunosuppression in SSc-ILD.

METHODS

Serum samples collected in the Scleroderma Lung Study II, a randomized controlled trial of mycophenolate mofetil (MMF) versus cyclophosphamide (CYC), were examined. Results were validated in an independent observational cohort receiving active treatment. A composite score of 6 IFN-inducible proteins IFNγ-inducible 10-kd protein, monokine induced by IFNγ, monocyte chemotactic protein 2, β₂ -microglobulin, tumor necrosis factor receptor type II, and macrophage inflammatory protein 3β) was calculated, and its predictive significance for longitudinal forced vital capacity percent predicted measurements was evaluated.

RESULTS

Higher baseline IFN-inducible protein score predicted better response over 3 to 12 months in the MMF arm (point estimate = 0.41, P = 0.001) and CYC arm (point estimate = 0.91, P = 0.009). In contrast, higher baseline C-reactive protein (CRP) levels were predictive of a worse ILD course in both treatment arms. The predictive significance of the IFN-inducible protein score and CRP levels remained after adjustment for baseline demographic and clinical predictors. During the second year of treatment, in which patients in the CYC arm were switched to placebo, a higher IFN-inducible protein score at 12 months showed a trend toward predicting a worse ILD course (point estimate = -0.61, P = 0.068), while it remained predictive of better response to active immunosuppression in the MMF arm (point estimate = 0.28, P = 0.029). The predictive significance of baseline IFN-inducible protein score was replicated in the independent cohort (r_s = 0.43, P = 0.028).

CONCLUSION

A higher IFN-inducible protein score in SSc-ILD is predictive of better response to immunosuppression and could potentially be used to identify patients who may derive the most benefit from MMF or CYC.

A randomised, open-label trial to assess the optimal treatment strategy in early diffuse cutaneous systemic sclerosis: the UPSIDE study protocol

INTRODUCTION

Systemic sclerosis (SSc) is a chronic, autoimmune connective tissue disease associated with high morbidity and mortality, especially in diffuse cutaneous SSc (dcSSc). Currently, there are several treatments available in early dcSSc that aim to change the disease course, including immunosuppressive agents and autologous haematopoietic stem cell transplantation (HSCT). HSCT has been adopted in international guidelines and is offered in current clinical care. However, optimal timing and patient selection for HSCT are still unclear. In particular, it is unclear whether HSCT should be positioned as upfront therapy or rescue treatment for patients refractory to immunosuppressive therapy. We hypothesise that upfront HSCT is superior and results in lower toxicity and lower long-term medical costs. Therefore, we propose this randomised trial aiming to determine the optimal treatment strategy for early dcSSc by comparing two strategies used in standard care: (1) upfront autologous HSCT versus (2) immunosuppressive therapy (intravenous cyclophosphamide pulse therapy followed by mycophenolate mofetil) with rescue HSCT in case of treatment failure.

METHODS AND ANALYSIS

The UPSIDE (UPfront autologous hematopoietic Stem cell transplantation vs Immunosuppressive medication in early DiffusE cutaneous systemic sclerosis) study is a multicentre, randomised, open-label, controlled trial. In total, 120 patients with early dcSSc will be randomised. The primary outcome is event-free survival at 2 years after randomisation. Secondary outcomes include serious adverse events, functional status and health-related quality of life. We will also evaluate changes in nailfold capillaroscopy pattern, pulmonary function, cardiac MR and high-resolution CT of the chest. Follow-up visits will be scheduled 3-monthly for 2 years and annually in the following 3 years.

ETHICS AND DISSEMINATION

The study was approved by the Dutch Central Committee on Research Concerning Human Subjects (NL72607.041.20). The results will be disseminated through patient associations and conventional scientific channels.

TRIAL REGISTRATION NUMBERS

NCT04464434; NL 8720.

Systemic sclerosis (scleroderma): remaining challenges

Despite progress in treating internal organ involvement in systemic sclerosis (scleroderma) (SSc), such as pulmonary disease, effective treatments for the hallmark of the disease, cutaneous fibrosis, remain elusive. None of the disease-modifying antirheumatic drugs (DMARDS) have shown proven efficacy for SSc skin fibrosis, and there remain no FDA-approved medications, all of which are off-label, for cutaneous fibrosis in SSc. This review article will briefly summarize conventional therapies, biologics and hematopoietic stem cell transplants and select ongoing clinical trials in SSc. The gold standard for measuring skin fibrosis in SSc is the modified Rodnan skin score (MRSSS). This is a validated test that measures skin thickness (0 to 3) at 17 locations for a total score of 51. Improvements in skin score over time are used in clinical trials to quantitate skin fibrosis. Although recording the Rodnan skin score is technically straightforward, requiring no special equipment, and noninvasive, the fluctuating natural history of the disease includes improvement over time without interventions, rendering meaningful trials difficult to assess. Understanding of the basic molecular mechanisms driving pathologic fibrosis in SSc remains lacking, and underpins the often empiric nature and likely the lack of efficacy of many therapeutics that have been tried. Although repeated skin biopsies might be a more precise way to follow disease progression and regression, this is necessarily invasive and requires special tools. Here, this review will look at conventional therapies, biologics, autologous hematopoietic stem cell transplantation, and catalog some of the ongoing clinical trials in SSc with a focus on cutaneous fibrosis.

Large-Scale Characterization of Systemic Sclerosis Serum Protein Profile: Comparison to Peripheral Blood Cell Transcriptome and Correlations With Skin/Lung Fibrosis

OBJECTIVE

To provide a large-scale assessment of serum protein dysregulation in diffuse cutaneous systemic sclerosis (dcSSc) and to investigate serum protein correlates of SSc fibrotic features.

METHODS

We investigated serum protein profiles of 66 participants with dcSSc at baseline who were enrolled in the Scleroderma: Cyclophosphamide or Transplant Trial and 66 age- and sex-matched healthy control subjects. A panel of 230 proteins, including several cytokines and chemokines, was investigated. Whole blood gene expression profiling in concomitantly collected samples was performed.

RESULTS

Among the participants with dcSSc, the mean disease duration was 2.3 years. All had interstitial lung disease (ILD), and none were being treated with immunosuppressive agents at baseline. Ninety proteins were differentially expressed in participants with dcSSc compared to healthy control subjects. Similar to previous global skin transcript results, hepatic fibrosis, granulocyte and agranulocyte adhesion, and diapedesis were the top overrepresented pathways. Eighteen proteins correlated with the modified Rodnan skin thickness score (MRSS). Soluble epidermal growth factor receptor was significantly down-regulated in dcSSc and showed the strongest negative correlation with the MRSS, being predictive of the score's course over time, whereas α₁ -antichymotrypsin was significantly up-regulated in dcSSc and showed the strongest positive correlation with the MRSS. Furthermore, higher levels of cancer antigen 15-3 correlated with more severe ILD, based on findings of reduced forced vital capacity and higher scores of disease activity on high-resolution computed tomography. Only 14 genes showed significant differential expression in the same direction in serum protein and whole blood RNA gene expression analyses.

CONCLUSION

Diffuse cutaneous SSc has a distinct serum protein profile with prominent dysregulation of proteins related to fibrosis and immune cell adhesion/diapedesis. The differential expression for most serum proteins in SSc is likely to originate outside the peripheral blood cells.

Hematopoietic stem cell transplantation for systemic sclerosis: Brazilian experience

BACKGROUND

In the past 20 years, hematopoietic stem cell transplantation (HSCT) has been investigated as treatment for systemic sclerosis (SSc). The goal of HSCT is to eradicate the autoreactive immune system, which is replaced by a new immune repertoire with long-lasting regulation and tolerance to autoantigens. Here, we describe the clinical outcomes of severe and refractory SSc patients that underwent HSCT at a single Brazilian center.

PATIENTS AND METHODS

This is a longitudinal and retrospective study, including 70 adult SSc patients, with an established diagnosis of SSc, and who underwent autologous HSCT from 2009 to 2016. The procedure included harvesting and cryopreservation of autologous hematopoietic progenitor cells, followed by administration of an immunoablative regimen and subsequent infusion of the previously collected cells. Patients were evaluated immediately before transplantation, at 6 months and then yearly until at least 5-years of post-transplantation follow-up. At each evaluation time point, patients underwent clinical examination, including modified Rodnan's skin score (mRSS) assessment, echocardiography, high-resolution computed tomography of the lungs and pulmonary function.

RESULTS

Median (range) age was 35.9 (19-59), with 57 (81.4%) female and median (range) non-Raynaud's disease duration of 2 (1-7) years. Before transplantation, 96% of the patients had diffuse skin involvement, 84.2%, interstitial lung disease and 67%, positive anti-topoisomerase I antibodies. Skin involvement significantly improved, with a decline in mRSS at all post-transplantation time points until at least 5-years of follow-up. When patients with pre-HSCT interstitial lung disease were analyzed, there was an improvement in pulmonary function (forced vital capacity and diffusing capacity of lung for carbon monoxide) over the 5-year follow-up. Overall survival was 81% and progression-free survival was 70.5% at 8-years after HSCT. Three patients died due to transplant-related toxicity, 9 patients died over follow-up due to disease reactivation and one patient died due to thrombotic thrombocytopenic purpura.

CONCLUSIONS

Autologous hematopoietic progenitor cell transplantation improves skin and interstitial lung involvement. These results are in line with the international experience and support HSCT as a viable therapeutic alternative for patients with severe and progressive systemic sclerosis.

Mesenchymal stromal cells for systemic sclerosis treatment

Systemic sclerosis (SSc) is a rare chronic autoimmune disease characterized by vasculopathy, dysregulation of innate and adaptive immune responses, and progressive fibrosis. SSc remains an orphan disease, with high morbity and mortality in SSc patients. The mesenchymal stromal cells (MSC) demonstrate in vitro and in vivo pro-angiogenic, immuno-suppressive, and anti-fibrotic properties and appear as a promising stem cell therapy type, that may target the key pathological features of SSc disease. This review aims to summarize acquired knowledge in the field of :1) MSC definition and in vitro and in vivo functional properties, which vary according to the donor type (allogeneic or autologous), the tissue sources (bone marrow, adipose tissue or umbilical cord) or inflammatory micro-environment in the recipient; 2) preclinical studies in various SSc animal models , which showed reduction in skin and lung fibrosis after MSC infusion; 3) first clinical trials in human, with safety and early efficacy results reported in SSc patients or currently tested in several ongoing clinical trials.

Biomarkers as an opportunity to stratify for outcome in systemic sclerosis

Systemic sclerosis (SSc) is a highly complex disease whose heterogeneity includes multiple aspects of the condition, such as clinical presentation, progression, extent and type of organ involvement, and clinical outcomes. Thus far, these features remain not easily predictable both at the patient group level and in a given patient with regard to age at onset and clinical course. The unpredictable clinical course represents an obstacle to focusing potentially effective treatment in patients that need it the most. At the time of organ involvement and clinical diagnosis, most of the clinical manifestations are irreversible; therefore, predicting outcomes becomes crucial. This can explain the multiple attempts to identify prognostic, predictive, and monitoring-both soluble and imaging-biomarkers over the past years. They range from the currently most used biomarkers, the autoantibodies associated with disease-specific clinical features and course, to the single recently proposed skin, lung, cardiac involvement biomarkers and to the composite scores capturing multiple aspects of the disease. This review will focus on soluble and imaging biomarkers that recently showed promising evidence for outcome stratification in patients with SSc.

Machine learning predicts stem cell transplant response in severe scleroderma

OBJECTIVE

The Scleroderma: Cyclophosphamide or Transplantation (SCOT) trial demonstrated clinical benefit of haematopoietic stem cell transplant (HSCT) compared with cyclophosphamide (CYC). We mapped PBC (peripheral blood cell) samples from the SCOT clinical trial to scleroderma intrinsic subsets and tested the hypothesis that they predict long-term response to HSCT.

METHODS

We analysed gene expression from PBCs of SCOT participants to identify differential treatment response. PBC gene expression data were generated from 63 SCOT participants at baseline and follow-up timepoints. Participants who completed treatment protocol were stratified by intrinsic gene expression subsets at baseline, evaluated for event-free survival (EFS) and analysed for differentially expressed genes (DEGs).

RESULTS

Participants from the fibroproliferative subset on HSCT experienced significant improvement in EFS compared with fibroproliferative participants on CYC (p=0.0091). In contrast, EFS did not significantly differ between CYC and HSCT arms for the participants from the normal-like subset (p=0.77) or the inflammatory subset (p=0.1). At each timepoint, we observed considerably more DEGs in HSCT arm compared with CYC arm with HSCT arm showing significant changes in immune response pathways.

CONCLUSIONS

Participants from the fibroproliferative subset showed the most significant long-term benefit from HSCT compared with CYC. This study suggests that intrinsic subset stratification of patients may be used to identify patients with SSc who receive significant benefit from HSCT.

Haematopoietic stem cell transplantation in systemic sclerosis: Challenges and perspectives

Systemic Sclerosis is chronic progressive autoimmune disease, characterised by microangiopathy and fibrosis. Due to disease heterogeneity, in terms of extent, severity, and rate of progression, optimal therapeutic interventions are still lacking. Haematopoietic stem cells may be a new therapeutic option in this disease and, although the results of the first trials are encouraging, several issues remain to be addressed. On these bases, the stem cells transplantation is an area of active investigation, and an overview of the current available literature may help to define the role of this therapeutic strategy. Although the promising results, some unmet needs remain, including the transplantation protocols and their effects on immune system, the selection of the ideal patient and the pre-transplant cardiopulmonary evaluations. An improvement in these fields will allow us to optimize the haematopoietic stem cell therapies in SSc.

[Autologous hematopoietic stem cell transplantation for autoimmune diseases : Current indications and mode of action, a review on behalf of the EBMT Autoimmune Diseases Working Party (ADWP)]

The recent introduction of biologic and targeted synthetic disease-modifying drugs has led to more specificity in the treatment of autoimmune diseases; however, they require continuous or intermittent administration, are associated with cumulative risks for side effects, result in high costs and provide no cure. In contrast, high-dose chemotherapy followed by transplantation of autologous hematopoietic stem cells (AHSCT) has been demonstrated to induce clinical remission in various autoimmune diseases that can persist over many years without continued maintenance therapy. The principle behind AHSCT is an elimination of important components of the autoreactive immunological memory with subsequent regeneration of the complete immune system. Several studies have indicated that such an immune reset is associated with fundamental changes in the immune repertoire leading to an induction of tolerance against self-antigens. This article presents the current indications of AHSCT for autoimmune diseases based on the registry data of the European Society of Blood and Marrow Transplantation (EBMT) and discusses the results from mechanistic studies, which provide detailed insights into the mode of action of this treatment.

The basic and translational science year in review: Confucius in the era of Big Data

Personalized medicine is an important goal for the treatment of rheumatic disease that seeks to improve outcomes by matching therapy more precisely with the underlying pathogenetic disturbances in the individual patient. Realization of this goal requires actionable biomarkers to identify these disturbances as well as pathways that can be targeted for novel therapy. Among advances in characterizing pathogenesis, Big Data provides an unprecedented picture of pathogenesis, with analysis of tissue lesions revealing disturbances that may not be apparent in blood. Big Data approaches include single cell RNAseq (scRNAseq) which can elucidate patterns of gene expression by individual cells. Galvanized by the Accelerating Medicines Partnership, a public-private initiative of the NIH, investigative teams have analyzed gene expression in cells in the synovium for rheumatoid arthritis and kidney for systemic lupus erythematosus. A review of basic and translational research for 2018-2019 provides the progress in these areas. Thus, the studies on rheumatoid arthritis have identified subpopulations of immune cells and fibroblasts implicated in synovitis. For lupus, transcriptomic studies have provided evidence for widespread effects of type 1 interferon. Studies in progressive sclerosis have demonstrated changes associated with stem cell therapy as well as potential new targets for anti-fibrotic agents. Other studies using molecular approaches have defined new mechanisms for vasculitis as well as the potential role of the microbiome in inflammatory arthritis and systemic lupus erythematosus. Future studies with Big Data will incorporate the spatial relationships of cells in inflammation as well as changes in gene expression over time.

The role of innate immune cells in systemic sclerosis in the context of autologous hematopoietic stem cell transplantation

Systemic sclerosis (SSc) is a complex, heterogeneous autoimmune connective tissue disease. Autologous hematopoietic stem‐cell transplantation (AHSCT) has emerged as a valuable treatment option for rapidly progressive diffuse cutaneous SSc (dcSSc) patients, and thus far is the only treatment that has been shown to have a long‐term clinical benefit. AHSCT is thought to reintroduce immune homeostasis through elimination of pathogenic self‐reactive immune cells and reconstitution of a new, tolerant immune system. However, the mechanism of action underlying this reset to tolerance remains largely unknown. In this study we review the immune mechanisms underlying AHSCT for SSc, with a focus on the role of the innate immune cells, including monocytes and natural killer (NK) cells, in restoring immune balance after AHSCT.

Interstitial Lung Disease in Systemic Sclerosis: Focus on Early Detection and Intervention

Systemic sclerosis (SSc) is a progressive and often devastating disease characterized by autoimmune dysfunction, vasculopathy, and fibrosis. Interstitial lung disease (ILD) is identified in the majority of patients with SSc and is the leading cause of SSc-related mortality. Although clinical manifestations and ILD severity vary among patients, lung function typically declines to the greatest extent during the first 3-4 years after disease onset. We aim to provide an overview of SSc-associated ILD (SSc-ILD) with a focus on current and emerging tools for early diagnosis of ILD and current and novel treatments under investigation. Early detection of ILD provides the opportunity for early therapeutic intervention, which could improve patient outcomes. Thoracic high-resolution computed tomography is the most effective method of identifying ILD in patients with SSc; it enables detection of mild lung abnormalities and plays an important role in monitoring disease progression. Cyclophosphamide and mycophenolate mofetil are the most commonly prescribed treatments for SSc-ILD. Recently, nintedanib (an antifibrotic) was approved by the Food and Drug Administration for patients with SSc-ILD; it is indicated for slowing the rate of decline in pulmonary function. However, there is a need for additional effective and well-tolerated disease-modifying therapy. Ongoing studies are evaluating other antifibrotics and novel agents. We envision that early detection of lung involvement, combined with the emergence and integration of novel therapies, will lead to improved outcomes in patients with SSc-ILD.