Nebulized MSC-Exos for Anti-MDA5+ RP-ILD: Safety and Efficacy Trial

Inclusion Criteria: * Patients are eligible for inclusion if they meet all of the following criteria: 1. Positive for anti-MDA5 antibody dermatomyositis (according to the "Chinese Expert Consensus on the Diagnosis and Treatment of Anti-MDA5 Positive Dermatomyositis (2023 Edition)"); 2. Pulmonary lesions meet the diagnostic criteria for RP-ILD. Exclusion Criteria: * Patients who meet any of the following criteria will be excluded from this study: 1. Pregnant or breastfeeding women, or women planning pregnancy during the study, or men unwilling to use contraceptive measures throughout the trial period; 2. History of severe allergies or allergies to the main active ingredients of the trial medication; 3. Currently suffering from severe pulmonary infections, pneumothorax, or large pleural effusions; 4. Currently diagnosed with pulmonary embolism; 5. Currently undergoing mechanical ventilation through tracheal intubation; 6. Currently undergoing extracorporeal life support treatments such as ECMO, CRRT, PMX-DHP, or plasma exchange; 7. Currently suffering from severe heart failure, liver, or kidney insufficiency; 8. Expected to undergo lung transplantation in the near future; 9. Currently suffering from lung cancer or pulmonary nodules suspected to be early-stage lung cancer; 10. Suffering from primary immunodeficiency diseases; 11. Currently suffering from active infectious diseases, including but not limited to HIV positivity, active tuberculosis, etc., and deemed unsuitable for this trial by the researcher; 12. Use of other trial medications within 28 days before starting treatment, which the researcher judges may interfere with the safety and efficacy assessment of this trial medication; 13. Other situations deemed not in the best interest of the subject or unsuitable for participation in this study by the researcher, such as poor compliance.