Progress and Priorities in Systemic Sclerosis: The Next 10 Years – Report from the World Scleroderma Foundation

Osteopontin Links Myeloid Activation and Disease Progression in Systemic Sclerosis

Progressive lung fibrosis is a major cause of mortality in systemic sclerosis (SSc) patients, but the underlying mechanisms remain unclear. We demonstrate that immune complexes (ICs) activate human monocytes to promote lung fibroblast migration partly via osteopontin (OPN) secretion, which is amplified by autocrine monocyte colony stimulating factor (MCSF) and interleukin-6 (IL-6) activity. Bulk and single-cell RNA sequencing demonstrate that elevated OPN expression in SSc lung tissue is enriched in macrophages, partially overlapping with CCL18 expression. Serum OPN is elevated in SSc patients with interstitial lung disease (ILD) and prognosticates future lung function deterioration in SSc cohorts. Serum OPN levels decrease following tocilizumab (monoclonal anti-IL-6 receptor) treatment, confirming the connection between IL-6 and OPN in SSc patients. Collectively, these data suggest a plausible link between autoantibodies and lung fibrosis progression, where circulating OPN serves as a systemic proxy for IC-driven profibrotic macrophage activity, highlighting its potential as a promising biomarker in SSc ILD.

Immune complexes induce osteopontin (OPN) secretion from macrophages via MCSF and IL-6

OPN is expressed predominantly by macrophages in fibrotic interstitial lung disease

Circulating OPN levels are elevated and predict disease progression in systemic sclerosis

IL-6 receptor blockade reduces levels of circulating OPN in systemic sclerosis patients

Systemic Sclerosis Trial Design Moving Forward

The 2013 ACR-EULAR classification criteria for systemic sclerosis (SSc) have shifted the construct of SSc. The new reality is that patients recruited for trials may not be so severe and not so advanced. We can now look for therapeutics that might stop disease evolution and/or prevent organ involvement. This article highlights recent advances in research methodology, and broadens the potential range of design and analytic considerations when planning a SSc trial.

Effect of endothelin-1 receptor antagonists on skin fibrosis in scleroderma patients from the EUSTAR database

Introduction

The aim of the study was to evaluate the effect of endothelin-1 receptor antagonists (ETRAs) on skin fibrosis in systemic sclerosis (SSc) patients from the (EULAR Scleroderma Trials and Research) EUSTAR cohort.

Methods

SSc patients from the EUSTAR cohort with at least three visits (pre-study visit without ETRA treatment, baseline and follow-up visit with ETRA treatment) were included. The control group consisted of SSc patients with the same inclusion criteria, but without ETRA treatment. The primary endpoint was the comparison of the delta change of the modified Rodnan skin score (mRSS) between baseline and follow-up in the ETRA versus the control group.

Results

Data on 75 ETRA treated (68 bosentan, 1 sitaxentan, 6 ambrisentan) and 969 control patients were included. The delta change of mRSS was not significantly different between the ETRA group and the control group (n = 969; 0 (-2-1) vs. n = 75; 0 (-2-1); p = 0.4). Similarly, subgroup analysis on patients with diffuse, extended SSc disease (mRSS ≥16) did not show differences in the delta change of mRSS between the ETRA group and the control group (n = 125; −1 [-7-0] vs. n = 23; −1 [-7-2], p = 0.8). Likewise, diffuse SSc patients with mRSS 7-21 at baseline, reflecting recently identified enrichment criteria for clinical trials, did not show any difference between the ETRA and the control group (n = 219; −1 [-3-1] vs. n = 27; −1 [-3-2]; p = 0.5).

Conclusions

This controlled, observational, real-life cohort study with a large sample size did not show effects of ETRAs on skin fibrosis in patients with SSc.