• Voluntary signing of the Informed Consent Form (ICF)

• Age range: At the time of signing the ICF, the age is between 18 and 60 years old (including 18 and 60 years old), regardless of gender.

• No systemic active infection within 2 weeks before screening.

• Contraceptive requirements for participants with child - bearing potential.

• Negative pregnancy test for women with child - bearing potential. Inclusion Criteria for SLE

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• Meet the EULAR/ACR 2019 SLE classification criteria with a disease history ≥ 6 months.

• Treatment and disease activity requirements:

• o Before screening, the participant must have received treatment with glucocorticoids combined with immunosuppressive agents (including cyclophosphamide, mycophenolate mofetil, tacrolimus, methotrexate, cyclosporine, leflunomide) and/or biological agents for ≥ 3 months, with a stable dose for ≥ 2 weeks, and the disease is still in an active state. Oral corticosteroid requirements at the time of screening:

• o If treated with corticosteroids alone, prednisone (or equivalent drug) ≥ 7.5 mg/day.

• o When used in combination with immunosuppressive agents and/or biological agents, there is no minimum daily dose requirement for corticosteroids.

• Positive antibody test at screening: Positive antinuclear antibody, and/or positive anti-ds-DNA antibody, and/or positive anti-Smith antibody.

• Disease activity score or organ damage: At the screening stage, the SLEDAI - 2K score is ≥ 7 points

• Active organ involvement at screening: isolated skin and mucous membrane involvement is not eligible for inclusion.

• Adequate organ function:

• o Renal function: Defined as a calculated creatinine clearance rate (Cockcroft - Gault) ≥ 50 mL/min without the need for hydration assistance.

• o Bone marrow function: Defined as absolute neutrophil count (ANC) ≥ 1.0×10⁹/L and hemoglobin (Hb) ≥ 60 g/L. Blood transfusion and growth factors should not be used to meet these requirements within 7 days before the inclusion and exclusion screening.

• o Liver function: Defined as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2× the upper limit of normal (ULN), and total bilirubin ≤ 2× the upper limit of normal (ULN).

• o Coagulation function: Defined as international normalized ratio (INR) or activated partial thromboplastin time (APTT) ≤ 1.5×ULN.

• o Lung function: Oxygen saturation (SpO₂) ≥ 92% (measured by pulse oximeter) in room air.

⁃ Cardiac function: Defined as a left ventricular ejection fraction (LVEF) ≥ 40% as evaluated by echocardiogram (ECHO) within 8 weeks before screening.

• Meet the 2013 EULAR/ACR classification criteria for systemic sclerosis and the diffuse - type manifestation simultaneously.

• Combined with interstitial pneumonia caused by SSc.

• Meet the definition of refractory or progressive disease:

• o Refractory disease definition: Ineffective after more than 6 months of conventional treatment, or disease recurrence after remission. Conventional treatment is defined as the use of glucocorticoids (more than 1 mg/kg/d) or cyclophosphamide, and one or more of the following immunomodulatory drugs: antimalarials, azathioprine, mycophenolate mofetil, methotrexate, leflunomide, tacrolimus, cyclosporine, and biological agents including Actemra, Rituxan, belimumab, tabitacicept, etc.

⁃ Progressive disease definition (in the past 6 months):

⁃ Skin progression: An increase in mRSS \> 10%.

⁃ Lung disease progression: A 10% decrease in FVC, or a 5% decrease in FVC accompanied by a 15% decrease in DLCO.

• Important organ function:

• o Renal function: Defined as a calculated creatinine clearance rate (Cockcroft - Gault) ≥ 50 mL/min without the need for hydration assistance.

• o Bone marrow function: Defined as absolute neutrophil count (ANC) ≥ 1.0×10⁹/L and hemoglobin (Hb) ≥ 90 g/L. Blood transfusion and growth factors should not be used to meet these requirements within 7 days before the inclusion and exclusion screening.

• o Liver function: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2× the upper limit of normal (ULN), and total bilirubin ≤ 2× the upper limit of normal (ULN).

• o Coagulation function: INR ≤ 1.5×ULN, prothrombin time (PT) ≤ 1.5×ULN.

• o Cardiac function: Good hemodynamic stability, left ventricular ejection fraction (LVEF) ≥ 40%.