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.
