Systemic Sclerosis: Can Breathomics Monitor Interstitial Lung Disease?

Systemic sclerosis (SSc) is an autoimmune disease causing inflammation, blood vessel damage, and collagen deposition. Interstitial lung disease (ILD) is common in SSc, leading to significant mortality. Early detection of SSc-ILD is crucial, but current biomarkers are limited. Our previous research identified distinct volatile organic compound (VOC) patterns in SSc patients' breath. This study aims to establish standardized breath analysis procedures, and assess VOCs' potential in predicting SSc-ILD. Two expert medical centers, the University Hospital of Liège (CHU), Belgium, and Maastricht University Medical Center (MUMC+), the Netherlands, collaborated in studying and recruiting 21 SSc patients and 21 SSc-ILD patients. Nine VOCs were identified as discriminatory between SSc and SSc-ILD, outperforming traditional blood markers. The statistical model based on these markers achieved an AUC of 0.82, accuracy of 85%, sensitivity of 77% and a specificity of 100% for indentifying ILD phenotype, comparable to traditional lung function tests. A correlation was also observed between the functional respiratory parameters (i.e., DLco and FVC% predicted value) and the VOCs. Additionally, our study confirmed the potential of four terpenes, observed in both studies, in distinguishing SSc patients. Methodological SOPs for multi-center studies were developed and validated. This study demonstrates the potential of breath analysis and in particular markers discovery in understanding SSc metabolic changes and could aid prompt ILD treatment. Future research will explore VOC changes in early-stage SSc-ILD and treatment response. This study paves the way for improved diagnosis and management of SSc-ILD.