Autologous fat‑derived regenerative cell injections for hand problems in systemic sclerosis

Inclusion Criteria:

1. Age 18-70 years old (inclusive), gender not restricted;
2. According to the 2013 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) systemic sclerosis (SSc) diagnostic criteria, diagnosed as diffuse cutaneous type or localized cutaneous type;
3. Thickened hand skin, modified Rodnan skin score ≥ 8 points and ≤ 35 points;
4. Cochin Hand Function Scale (CHFS) ≥ 20 (total score 90), with or without skin ulcers;
5. Capable of safely undergoing liposuction to obtain sufficient adipose tissue (the preferred fat extraction sites are the abdomen, followed by the lateral abdomen, inner and outer thighs, posterior thighs, and anterior thighs; multiple sites can be selected for liposuction to obtain sufficient adipose tissue);
6. Voluntary participation in this clinical trial and signing the informed consent form by the subject.

Exclusion Criteria:

1. Subject's body mass index (BMI) \< 17 kg/m\^2;
2. Hand skin lesions are in the atrophic stage, and the investigator determines that they are not suitable for hand drug injection;
3. Any finger contracture or injection site ulcer that makes it unsafe to complete the injection;
4. Any proximal to distal interphalangeal joint amputation of any finger, or amputation of more than one finger;
5. Concurrent other rheumatic immune diseases, such as RA, SLE, dermatomyositis, etc. (existing rheumatic immune diseases that do not affect the safety and efficacy evaluation of the hand and do not affect the safety of the hand and efficacy evaluation, excluding Sjögren's syndrome);
6. Active infectious diseases or patients who have used antibiotics within 3 months before the screening visit due to active infectious diseases;
7. Patients with unstable systemic sclerosis who have received cell therapy before the screening visit;
8. Patients who have undergone chemotherapy or resection of malignant cancer within 5 years before the screening visit;
9. Abnormal tumor markers detected during the screening period, and the investigator determines that there is a tumor risk;
10. Patients who have received CD20 monoclonal antibody treatment within 1 year before the screening visit, or have used other biologic drugs or taken small molecule targeted drugs within 3 months before the screening visit (excluding those who have maintained a stable dose of ≥ 3 months at the time of enrollment for systemic sclerosis treatment);
11. Have received hand cell injection therapy before, or are intolerant to cell therapy, or have received systemic cell injection therapy within 6 months before the screening visit;
12. Patients with positive human immunodeficiency virus antibody (anti-HIV-Ab) test results, active syphilis, active hepatitis C (HCV-RNA positive, and hepatitis C antibody positive), hepatitis B (HBsAg positive and HBV-DNA positive) during the screening period;
13. There is evidence indicating that the subject currently has possible safety-related diseases in the digestive system, urinary system, cardiovascular system, hematological system, nervous system, mental state, and metabolism, such as poorly controlled diabetes, poorly controlled hypertension, etc.;
14. Any of the following laboratory test results during the screening period: ① Abnormal blood routine: hemoglobin \< 80 g/L; white blood cell count \< 3.0 × 10\^9/L; absolute neutrophil count \< 1.2 × 10\^9/L; platelet count \< 100 × 10\^9/L; ② Abnormal liver and kidney function: aspartate transaminase (AST), alanine aminotransferase (ALT), activated partial thromboplastin time (APTT) prolonged \> 1.5 times the upper limit of the reference value; ③ Coagulation dysfunction: prothrombin time (PT) and partial thromboplastin time (APTT) prolonged \> 1.8 times the upper limit of the reference value, or international normalized ratio (INR) \> 2;
15. Allergic to any component of human albumin, anesthetic drugs, or human adipose-derived mesenchymal stem cell injection solution, or the investigator determines that the subject is not suitable for enrollment due to a severe allergy history;
16. Patients whose screening visit is within 3 months before the general anesthesia surgery planned during the study period;
17. Patients who have participated in other clinical studies within 3 months before the screening visit, or are currently participating in other clinical studies;
18. Pregnant women, lactating women, those with positive pregnancy test results, or those who do not agree to use effective contraceptive measures during the study period and within 6 months after the trial;
19. Patients judged by the investigator to be unsuitable to participate in this study.