Biomarker patterns across skin-lung-gut burden in systemic sclerosis

Area of Science:

• Immunology
• Rheumatology
• Clinical Biomarkers

Background:

• Systemic sclerosis (SSc) is a multisystem autoimmune disease.
• Skin, lung, and gastrointestinal involvement frequently co-occur in SSc patients.
• The relationship between increasing organ co-involvement and circulating biomarker patterns in SSc is not well understood.

Purpose of the Study:

• To characterize immune, inflammatory, and nutritional biomarker patterns in relation to the burden of skin, lung, and gut involvement in SSc.
• To investigate how the number of affected organs influences specific biomarker levels.

Main Methods:

• A retrospective cross-sectional study of 314 SSc patients was conducted.
• Patients were categorized into groups based on the number of involved organ systems (0-Axis, 1-Axis, 2-Axis, 3-Axis) using modified Rodnan skin score (mRSS), interstitial lung disease (ILD), and broad gastrointestinal involvement (bGI).
• Biomarker distributions (including Anti-Scl-70, hs-CRP, albumin, and total cholesterol) were compared across groups using multinomial logistic regression and unsupervised clustering.

Main Results:

• Anti-Scl-70 positivity significantly increased with higher organ burden (51.4% in 0-Axis to 91.3% in 3-Axis).
• Lower albumin levels were associated with increased organ co-involvement (3-Axis vs. 0-Axis).
• Higher total cholesterol was linked to the 3-Axis group, while hs-CRP showed complex associations across burden levels.

Conclusions:

• Increasing skin-lung-gut co-involvement in SSc is associated with distinct circulating biomarker patterns.
• Anti-Scl-70 positivity and decreased albumin are key biomarkers reflecting higher organ burden in SSc.
• These findings offer a biomarker-informed perspective on multisystem involvement in SSc, complementing existing classifications.