Molecular basis for clinical diversity between autoantibody subsets in diffuse cutaneous systemic sclerosis

Area of Science:

• Immunology
• Genomics
• Proteomics

Background:

• Systemic sclerosis (SSc) exhibits significant clinical heterogeneity.
• SSc-specific autoantibodies are crucial for diagnosis and predict organ complications.
• Understanding molecular diversity is key to SSc pathogenesis and patient stratification.

Purpose of the Study:

• To elucidate molecular differences between diffuse cutaneous SSc subgroups.
• To investigate the molecular basis of clinical diversity in SSc.
• To explore differences linked to hallmark antinuclear autoantibody (ANA) reactivities.

Main Methods:

• High-dimensional transcriptional and proteomic analysis of blood and skin.
• Analysis of a cohort of 52 SSc patients and 16 healthy controls.
• Individual patient pathway analysis to define overlapping and distinct disease processes.

Main Results:

• A molecular spectrum of SSc was defined using skin gene expression and serum protein analysis, correlating with clinical subgroups.
• Antitopoisomerase-1 and anti-RNA polymerase III antibody specificities showed distinct longitudinal changes in fibrosis markers and gene expression.
• Overlapping and distinct molecular pathways were identified across patient subgroups.

Conclusions:

• Findings offer insights into SSc clinical diversity and pathogenetic differences between ANA-based subgroups.
• Supports stratification of SSc patients by ANA antibody subtype in clinical trials.
• May explain differential outcomes in trials targeting specific pathogenic mechanisms.