Decrease of LL-37 in systemic sclerosis: a new marker for interstitial lung disease?

Area of Science:

• Immunology
• Pulmonology
• Rheumatology

Background:

• Interstitial lung disease (ILD) is a major complication of systemic sclerosis (SSc).
• LL-37 peptide, a human antimicrobial and immunomodulatory protein, exhibits anti-fibrotic and anti-apoptotic properties relevant to SSc.
• The role of LL-37 in SSc-ILD pathogenesis is not well understood.

Purpose of the Study:

• To investigate circulating LL-37 peptide levels in SSc patients.
• To determine the association between LL-37 levels and clinical, laboratory, and instrumental parameters, particularly pulmonary involvement (ILD).

Main Methods:

• Fifty-eight SSc patients (30 with ILD, 28 without ILD) and 28 healthy controls were enrolled.
• Pulmonary involvement was diagnosed via High-Resolution Computed Tomography (HRCT).
• Serum LL-37 concentrations were quantified using ELISA.

Main Results:

• SSc patients with ILD exhibited significantly lower serum LL-37 levels (1.36 ng/ml) compared to SSc patients without ILD (4.62 ng/ml) and healthy controls (5.53 ng/ml).
• No significant difference in LL-37 levels was observed between SSc patients without ILD and healthy controls.
• No significant correlations were found between LL-37 levels and other clinical, serological, or instrumental features.

Conclusions:

• Serum LL-37 levels are significantly reduced in SSc patients with ILD.
• Lower LL-37 levels may be associated with the development or progression of ILD in SSc.
• Further research in larger cohorts is needed to validate LL-37 as a potential biomarker for SSc-ILD.