Early Recognition of Progressive Lung Fibrosis in Systemic Rheumatic Diseases

Inclusion Criteria: * Female and male aged between 18 and 75 years. * Signature of informed consent * A clinical diagnosis of SSc, RA, SS, IIM, or UCTD that must adhere to internationally accepted classification criteria \[Aletha 2010, Van Der Hoogen 2013, Lundberg 2017, Shiboski 2016, Bottai 2017, Antunes 2019\]. * A high risk of ILD based on autoantibody profile, specifically: anti-Scl70+ or anti-RNAPIII+ for SSc, anti-CCP+ and/or RF+ for RA, anti-RoSSA+ and anti-LaSSB+ for primary SS, anti-synthetase+ for IIM. For UCTD patients, the enrollment criteria will be adapted to match those of Interstitial Pneumonia with Autoimmune Features (IPAF) \[Fernandes 2019\], with patients exhibiting one clinical feature of CTD and one serological domain criterion (e.g., ANA positive with nucleolar pattern, RF and anti-CCP positivity, anti-RoSSA and anti-LaSSB positivity, anti-Scl70 positivity) while not meeting the classification criteria for any other CTD. * Evidence of ILD based on an HRCT documenting the presence of interstitial changes involving at least 10% of the parenchyma within the previous 6 weeks. An HRCT scan completely negative for ILD changes performed up to 6 weeks before enrollment will be evaluated for the group of CTD patients without ILD. * Either naive to immunosuppressants or having been on a stable immunosuppressive regimen for the three months preceding blood collection for EV characterization. Treatment with rituximab must be not administered in the previous 24 weeks. Exclusion Criteria: * Current treatment with corticosteroids \>10 mg of prednisone. * Poor peripheral venus access that would interfere with blood sampling