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Introduction Systemic sclerosis-associated interstitial lung disease (SSc-ILD) is one of the leading causes of mortality in patients with SSc. To aid differential diagnosis, prognosis and assessment of disease progression in SSc-ILD, reliable and reproducible biomarkers remain urgently needed. Extracellular vesicles (EVs) are membrane-coated structures containing protein and nucleic acid cargo, which act as mediators of intercellular communication. Recent research has shown they may have a role in SSc-ILD pathophysiology and as biomarkers of SSc-ILD. We conducted a proteomic study of plasma EV content in SSc-ILD in order to analyse pathophysiological mechanisms and potential biomarkers.Material and Methods The study included a total of N=50 subjects: N=30 SSc patients, divided into a SSc-ILD group (N=12) and SSc without (w/o) ILD group (N=18), as well as N=20 age and sex matched controls. EVs were isolated from blood plasma samples by ultracentrifugation and lysed to release protein content. Purified peptides were analysed using liquid chromatography and tandem mass spectrometry (LC-MS/MS). MS data was processed and differentially expressed proteins (DEPs) were identified using LIMMA statistical test. Proteins with an adjusted p-value < 0.05 and fold change > 2 were considered significantly changed. Enrichment analysis of the DEPs was done using FunRich 3.1.3 software.Results DEP analysis between groups showed 14 significantly upregulated and 1 downregulated protein when comparing the SSc-ILD to the SSc w/o ILD group, 222 upregulated and 257 downregulated proteins between the SSc-ILD and control group, as well as 362 upregulated and 492 downregulated proteins between the SSc w/o ILD and control group. Enrichment analysis of upregulated DEPs from the SSc-ILD group showed several enriched processes and pathways, such as: immune response and complement activation when compared to the SSc w/o ILD group, as well as cadherin binding, positive regulation of NF-kB signaling, negative regulation of apoptosis and pathways related to neutrophil degranulation when compared to controls. Within the set of upregulated DEPs identified in comparison between SSc-ILD and SSc without ILD, several proteins emerge as promising candidate biomarkers for SSc-ILD, including pulmonary surfactant-associated protein B (SP-B), caveolin-1 (CAV1), and sialic acid-binding immunoglobulin-like lectin 5 (Siglec-5).Conclusions Proteomic profiling of EV cargo revealed a substantial number of DEPs in the SSc-ILD group compared with both SSc without ILD and healthy controls. Preliminary analyses highlighted several proteins as potential candidate biomarkers for SSc-ILD. However, further validation studies are required, including the assessment of their circulating plasma levels, to enhance biomarker accessibility and translational applicability.