Prospects for Stratified and Precision Medicine in Systemic Sclerosis Treatment

Purpose of review Precision medicine is an evolving field stemming from Oncology research, with an increasingly important role in autoimmune diseases. The heterogeneity, both of clinical presentations of systemic sclerosis and differing response to treatment, emphasises the importance of developing means of patient stratification to ensure that the correct patients are managed with the most appropriate treatments at a disease duration when this will have meaningful impact on disease course and resolution. This review aims to discuss the different means explored so far in stratifying patients with systemic sclerosis. We highlight recent clinical trials which have applied stratification techniques in order to provide a form of precision medicine in the management of systemic sclerosis. Recent findings Advances have focused on utilising gene expression techniques on whole skin biopsies or fibroblasts to understand which groups of patients are more likely to respond to which treatments. This technique has been used successfully to understand the effect of tocilizumab, abatacept, and fresolimumab on systemic sclerosis, and helped identify those that are more likely to respond to treatment. Summary Utilising high output platforms to stratify patients for targeted treatment is still in its infancy but has huge potential for ensuring the patients most likely to respond to a specific therapy are put forward to trials. It has already been shown to be successful in those with a high IL-6 profile and will most likely prove hugely informative in the future

Health visiting - the end of a UK wide service?

In 1997 Health Visiting was deemed by New Labour to be an important player in reducing health inequalities. It was acknowledged that if Health Visiting was to fulfill this vision it would have to work out with its traditional child health role and also engage with groups, communities and populations to tackle the determinants of ill health. Twelve years on, external factors such as, NHS cut backs, recent changes to how Health Visitors are regulated throughout the UK and devolved Health Visiting policy making structures have led to the rapid demise in status and legitimacy of Health Visiting and its wider public health role. This article argues that the unintended consequences of devolved Health Visiting policy has resulted in 3 recent community nursing and health-visiting reviews in Scotland and England which have made divergent policy recommendations about the role of the Health Visitor in tackling health inequalities. The recommendations outlined in the Scottish review in particular threatened to jeopardise the very future provision of a UK wide Health Visiting service. If Health Visiting is to survive as a UK wide entity, a radical independent rethink as to its future direction and its public health role is urgently required

Using autoantibodies and cutaneous subset to develop outcome-based disease classification in systemic sclerosis

OBJECTIVE: To describe the associations between autoantibodies, presentation and outcome among systemic sclerosis (SSc) patients. We propose a new SSc classification incorporating antibodies and cutaneous subset. METHODS: Survival analysis was used to assess the effect of antibodies on organ disease and death. RESULTS: The study included 1325 subjects. The ACA+ limited cutaneous (lc)SSc group (n=374) had the highest 20-year survival (65.3%), lowest incidence of clinically-significant pulmonary fibrosis (csPF, 8.5%) and scleroderma renal crisis (SRC, 0.3%), low cardiac SSc incidence (4.9%), while pulmonary hypertension (PH) frequency was similar to the cohort average. The anti-Scl70+ lcSSc (n=138) and diffuse cutaneous (dc)SSc groups (n=149) had the highest csPF incidence (86.1% and 84% at 15 years). The dcSSc group had the lowest survival (32.4%) and the second highest incidence of cardiac SSc (12.9%) at 20 years, while in the lcSSc group other complications were rare, demonstrating the lowest incidence of PH (6.9%) and second highest survival (61.8%). The anti-RNA polymerase+ group (n=147) had the highest incidence of SRC (28.1%). The anti-U3RNP+ group (n=56) had the highest PH (33.8%) and cardiac SSc incidence (13.2%). Among lcSSc patients with other autoantibodies (n=295), risk of SRC and cardiac SSc was low, while other outcomes were similar to the cohort average. DcSSc patients with other antibodies (n=166) had poor prognosis, with the second lowest survival (33.6%) and frequent organ complications. CONCLUSION: We highlight the importance of autoantibodies, cutaneous subset and disease duration when assessing SSc morbidity and mortality. Our classification may benefit disease monitoring and clinical trial design

Outcomes linked to eligibility for stem cell transplantation trials in diffuse cutaneous systemic sclerosis

Objectives: The aim of this study was to explore outcomes in a cohort of diffuse cutaneous systemic sclerosis (dcSSc) patients fulfilling eligibility criteria for stem cell transplantation (SCT) studies but receiving standard immunosuppression. Methods: From a large single-centre dcSSc cohort (n = 636), patients were identified using the published SCT trials’ inclusion criteria. Patients meeting the trials’ exclusion criteria were excluded. Results: Of the 227 eligible patients, 214 met the inclusion criteria for ASTIS, 82 for SCOT and 185 for the UPSIDE trial, and 66 were excluded based on age > 65 years, low DLco, pulmonary hypertension or creatinine clearance <40ml/min. The mean follow-up time was 12 years (SD 7). Among the eligible patients, 103 (45.4%) died. Survival was 96% at 2-, 88% at 5-, 73% at 10- and 43% at 20 years. Compared with this ‘SCT-eligible’ cohort, those patients who would have been excluded from SCT trials had a worse long-term survival (97% at 2-, 77% at 5-, 52% at 10- and 15% at 20 years, log rank p< 0.001). Excluded patients also had a significantly worse long-term event free survival. Hazard of death was higher in patients with higher age at onset (HR 1.05, p< 0.001), higher ESR at baseline (HR 1.01, p= 0.025) and males (HR 2.12, p= 0.008). Conclusion: SCT inclusion criteria identify patients with poor outcome despite current best practice treatment. Patients meeting the inclusion criteria for SCT but who would have been excluded from the trials because of age, pulmonary hypertension, poor kidney function or DLco <40%, had worse outcomes

Skin biopsy analysis of concurrent keloidal morphoea and systemic sclerosis confirms overlapping pathogenic pathways

OBJECTIVES: Although localised forms of scleroderma (morphoea) have very different clinical features and outcomes from systemic sclerosis the two conditions can occur together in some patients. In this study we have explored skin gene expression in a series of patients with keloidal morphoea, a distinct clinical variant, concurrently with systemic sclerosis. METHODS: We have compared skin gene expression from the keloidal lesions with that from skin elsewhere. We have also examined a series of patients with diffuse or limited cutaneous SSc without morphoea and some healthy control skin biopsies. RESULTS: Keloidal morphoea has a distinct gene expression signature that is mainly driven by differential expression of fibroblast related genes compared with other cell types. Indeed, the signature reflects a profibrotic pattern seen in diffuse cutaneous SSc but is much more extreme. We propose that keloidal morphoea skin provides a unique insight into the profibrotic population of cells driving dcSSc. CONCLUSIONS: Understanding the biology of keloidal morphoea may give valuable insight into the molecular and cellular pathology of systemic sclerosis. The discrete nature of keloidal lesions raises the possibility of haematogenous spread and we suggest that the driving cells could represent blood derived cells derived from circulating progenitors

TGFβ activation primes canonical Wnt signaling through the downregulation of AXIN2

OBJECTIVES: Aberrant activation of Wnt signaling has been observed in systemic sclerosis (SSc) affected tissues. This study aimed to determine the role of transforming growth factor (TGF)β in driving the increased Wnt signaling, through modulation of AXIN2, a critical regulator of Wnt canonical pathway. METHODS: Canonical Wnt signaling activation was analyzed by TOPFlash TCF/LEF promoter assays. AXIN2 was evaluated in vitro by analysis of AXIN2 primary/mature transcripts expression and decay, TβRI blockade, siRNA-mediated TTP-1 depletion and through XAV-939-mediated AXIN2 stabilisation. In vivo, Axin2 mRNA and protein expression was determined in skin and lung biopsies from TβRIIΔk-fib transgenic mice and littermate controls. RESULTS: SSc fibroblasts display increased response to canonical Wnt ligands despite basal levels of Wnt signaling comparable to healthy control (HC) fibroblasts in vitro. Notably, we show that SSc fibroblasts express reduced basal expression of AXIN2, which is caused by endogenous TGFβ-dependent increase of AXIN2 mRNA decay. Accordingly, we observed that TGFβ decreased AXIN2 expression both in vitro in HC fibroblasts and in vivo, employing TβRIIΔk-fib transgenic mice. Additionally, we demonstrate by AXIN2 loss and gain of function experiments, that the TGFβ-induced increased response to Wnt activation characteristic of SSc fibroblasts is dependent on reduced AXIN2 bioavailability. CONCLUSIONS: This study highlights the importance of reduced AXIN2 bioavailability in mediating the increased canonical Wnt response observed in SSc fibroblasts. This novel mechanism extends our understanding of the processes involved in Wnt/β-catenin-driven pathology and supports the rationale for targeting the TGFβ pathway to regulate the aberrant Wnt signaling observed during fibrosis. This article is protected by copyright. All rights reserved

The pan-PPAR agonist lanifibranor reduces development of lung fibrosis and attenuates cardiorespiratory manifestations in a transgenic mouse model of systemic sclerosis

Background: The TβRII∆k-fib transgenic (TG) mouse model of scleroderma replicates key fibrotic and vasculopathic complications of systemic sclerosis through fibroblast-directed upregulation of TGFβ signalling. We have examined peroxisome proliferator-activated receptor (PPAR) pathway perturbation in this model and explored the impact of the pan-PPAR agonist lanifibranor on the cardiorespiratory phenotype. Methods: PPAR pathway gene and protein expression differences from TG and WT sex-matched littermate mice were determined at baseline and following administration of one of two doses of lanifibranor (30 mg/kg or 100 mg/kg) or vehicle administered by daily oral gavage up to 4 weeks. The prevention of bleomycin-induced lung fibrosis and SU5416-induced pulmonary hypertension by lanifibranor was explored. Results: Gene expression data were consistent with the downregulation of the PPAR pathway in the TβRII∆k-fib mouse model. TG mice treated with high-dose lanifibranor demonstrated significant protection from lung fibrosis after bleomycin and from right ventricular hypertrophy following induction of pulmonary hypertension by SU5416, despite no significant change in right ventricular systolic pressure. Conclusions: In the TβRII∆k-fib mouse strain, treatment with 100 mg/kg lanifibranor reduces the development of lung fibrosis and right ventricular hypertrophy induced by bleomycin or SU5416, respectively. Reduced PPAR activity may contribute to the exaggerated fibroproliferative response to tissue injury in this transgenic model of scleroderma and its pulmonary complications

Integrated analysis of dermal blister fluid proteomics and genome-wide skin gene expression in systemic sclerosis: an observational study

Background: Skin fibrosis is a hallmark feature of systemic sclerosis. Skin biopsy transcriptomics and blister fluid proteomics give insight into the local environment of the skin. We have integrated these modalities with the aim of developing a surrogate for the modified Rodnan skin score (mRSS), using candidate genes and proteins from the skin and blister fluid as anchors to identify key analytes in the plasma. Methods: In this single-centre, prospective observational study at the Royal Free Campus, University College London, London, UK, transcriptional and proteomic analyses of blood and skin were performed in a cohort of patients with systemic sclerosis (n=52) and healthy controls (n=16). Weighted gene co-expression network analysis was used to explore the association of skin transcriptomics data, clinical traits, and blister fluid proteomic results. Candidate hub analytes were identified as those present in both blister and skin gene sets (modules), and which correlated with plasma (module membership >0·7 and gene significance >0·6). Hub analytes were confirmed using RNA transcript data obtained from skin biopsy samples from patients with early diffuse cutaneous systemic sclerosis at 12 months. Findings: We identified three modules in the skin, and two in blister fluid, which correlated with a diagnosis of early diffuse cutaneous systemic sclerosis. From these modules, 11 key hub analytes were identified, present in both skin and blister fluid modules, whose transcript and protein levels correlated with plasma protein concentrations, mRSS, and showed statistically significant correlation on repeat transcriptomic samples taken at 12 months. Multivariate analysis identified four plasma analytes as correlates of mRSS (COL4A1, COMP, SPON1, and TNC), which can be used to differentiate disease subtype. Interpretation: This unbiased approach has identified potential biological candidates that might be drivers of local skin pathogenesis in systemic sclerosis. By focusing on measurable analytes in the plasma, we generated a promising composite plasma protein biomarker that could be used for assessment of skin severity, case stratification, and as a potential outcome measure for clinical trials and practice. Once fully validated, the biomarker score could replace a clinical score such as the mRSS, which carries substantial variability. Funding: GlaxoSmithKline and UK Medical Research Council