Clinical Trial of Human Umbilical Cord Mesenchymal Stem Cells (IxCell hUC-MSC-P) in the Treatment of CTD-ILD

Inclusion Criteria: 1. Both sexes, aged 18-80 years; 2. SSc diagnosed according to the 2013 American College of Rheumatology and European League Against Rheumatism (ACR/EULA) criteria: 3. Pulmonary fibrosis ≥10% was confirmed by high-resolution chest computed tomography (HRCT); 4. The diffusion capacity for carbon monoxide (DLco) was 30%-89% of the expected value, and progression of interstitial lung disease was found. Progression was confirmed if one of the following criteria was met: 1. A decline of 10% or more in the percentage of predicted forced vital capacity (FVC%p) within 24 months (significant decline in ventilatory function) despite treatment; 2. A decline of ≥5% in FVC%p + a decline of ≥15% in DLco (a decline in ventilation function + a decline in diffusion capacity) within 24 months despite treatment; 3. Within 24 months, high resolution CT (HRCT) showed worsening of pulmonary fibrosis + ≥5% decline in FVC%p (deterioration of lung imaging + decline in ventilatory function), despite treatment. 4. Despite the treatment, 24 months reduced FVC % p + 5% or higher clinical symptoms (reduced ventilation function + symptoms); 5. Worsening of pulmonary fibrosis on HRCT + worsening of clinical symptoms (worsening of lung imaging + worsening of symptoms) within 24 months despite treatment; 5. Forced Vital Capacity (FVC) was greater than 40% of expected vital capacity; 6. The patient was able to complete the 6-Minute Walk Test (6MWT); 7. Be able to understand and complete pulmonary function test procedures. 8. Fully informed experiment purposes, methods, and possible uncomfortable, willing to medicine and follow-up inspection on time, according to the requirements of plan agreed to participate in trials, and sign the informed consent. Exclusion Criteria: 1. The patients were diagnosed with other lung diseases other than SSc-ILD, such as COPD, lung abscess, lung cancer and other types of connective tissue disease-related interstitial lung disease. 2. Have obvious acute lung infection requiring anti-infection treatment (treatment of 4 weeks prior to the start of the respiratory tract infection and systemic infection); 3. History of severe pulmonary hypertension, including right heart failure, cardiac intubation, and parenteral administration of prostaglandin analogues; 4. History of myocardial infarction or angina pectoris within 6 months before enrollment; 5. Patients with 3 or more fingertip ulcers when signing the informed consent form or unable to accurately observe fingertip ulcers due to other reasons of the hand; 6. Allergic to any component of the medication; 7. Life expectancy of less than 1 year due to diseases other than SSc; 8. Planned surgical procedures during the trial; 9. Has a history of scleroderma kidney crisis; 10. Patients who had used glucocorticoids within 2 weeks before enrollment but could not maintain the dosage ≤10mg/ d equivalent prednisone; 11. Patients who had used methotrexate within 2 months before enrollment, or failed to maintain a stable dosage while using other immunosuppressants; 12. Into groups of 2 months before used anti fibrosis drug (such as pyrazole ketone, dani, cloth, etc.); 13. Patients treated with rituximab, tocilizumab and mesenchymal stem cells within 2 months before enrollment; 14. Patients with other systemic diseases and organ dysfunction (ALT\>1.5 times upper limit of normal; Cr\>1.5 times upper limit of normal; LVEF≤40%; Other progressive or uncontrolled diseases); 15. Active hepatitis, tuberculosis, HIV infection; 16. Patients with malignant tumors or a history of cancer; 17. Pregnant or lactating women or those who have recently planned to have children and cannot take effective contraceptive measures; 18. People with a history of alcohol or drug abuse; 19. Enrolled in another drug trial within 3 months before enrollment; 20. Unable to complete all assessors; 21. And anyone who was deemed by the investigator to be ineligible for inclusion.