⁃ Willing and able to provide written informed consent.

⁃ Aged ≥18 years and ≤75 years.

⁃ Adequate organ function defined as:

∙ Bone marrow function: Defined as absolute neutrophil count (ANC) ≥1500/μL, absolute lymphocyte count (ALC) ≥100/μL, hemoglobin (Hb) ≥80 g/L, and platelet count (PLT) ≥50,000/μL. Transfusions and growth factors must not have been used within 7 days prior to screening to meet these criteria.

‣ Liver function: Defined as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤3 × upper limit of normal (ULN), and total bilirubin \<1.5 × ULN (or \<3.0 × ULN for subjects with Gilbert's syndrome).

‣ Coagulation function: Defined as international normalized ratio (INR) or partial thromboplastin time (PTT) ≤1.5 × ULN.

‣ Pulmonary function: Defined as dyspnea ≤ Grade 1 per CTCAE and oxygen saturation (SpO₂) ≥92% on room air (by pulse oximetry).

⁃ Female subjects of childbearing potential must have a negative serum or urine pregnancy test. Females who are surgically sterile or postmenopausal for at least 2 years are considered not of childbearing potential.

⁃ From the time of signing the informed consent form until 6 months after the completion of RD06-05 infusion, female subjects of childbearing potential and male subjects with partners of childbearing potential must use highly effective methods of contraception.

• Diagnosis of anti-GBM disease according to the 2012 Chapel Hill Consensus Conference definitions, meeting both of the following criteria:

⁃ Positive for anti-GBM antibody (based on historical or screening test results);

⁃ Evidence of renal involvement at screening, defined as:

∙ Presence of active, pathologically confirmed anti-GBM disease (renal biopsy must have been performed within 1 year prior to the screening visit or during the screening period); and

‣ Accompanied by proteinuria and hematuria.

⁃ Diagnosis of SLE according to the 2019 European Alliance of Associations for Rheumatology (EULAR)/American College of Rheumatology (ACR) classification criteria or the 2012 Systemic Lupus International Collaborating Clinics (SLICC) classification criteria.

⁃ Positive for antinuclear antibody (ANA), and/or anti-double-stranded DNA (anti-dsDNA) antibody, and/or anti-Smith (anti-Sm) antibody at screening.

⁃ SLEDAI-2K score \> 6 points at screening.

⁃ Diagnosis of microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) according to the 2022 ACR/EULAR classification criteria for ANCA-associated vasculitis.

⁃ Positive for anti-myeloperoxidase (MPO-ANCA) antibody or anti-proteinase 3 (PR3-ANCA) antibody at screening or based on historical testing.

⁃ For AAV without renal involvement: A Birmingham Vasculitis Activity Score (BVAS) version 3 score of ≥3 at screening, indicating active vasculitis.

⁃ Diagnosis of primary (idiopathic) membranous nephropathy confirmed by renal biopsy pathology (the renal biopsy must have been performed within 2 years prior to screening or during the screening period).

⁃ Meeting the criteria for high-risk or relapsed/refractory membranous nephropathy:

• High-risk patients, defined as meeting any of the following criteria:

⁃ Normal eGFR with urine protein \>3.5g/24h, a reduction of \<50% in urine protein after 6 months of ACEI/ARB treatment, and serum albumin \<25 g/L or anti-PLA2R antibody \>50 RU/mL;

⁃ eGFR \<60 mL/min/1.73m² and/or urine protein \>8g/24h for more than 6 months.

• Refractory/Relapsed patients:

• Refractory patients are defined as those resistant to prior immunosuppressive therapy (persistent urine protein ≥3.5g/24h with a \<50% reduction from baseline).

• Relapsed patients are defined as those who achieved complete or partial remission with prior immunosuppressive therapy but subsequently developed recurrent urine protein ≥3.5g/24h.

⁃ Diagnosis of systemic sclerosis (SSc) according to the 2013 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) classification criteria.

⁃ Diagnosis of diffuse cutaneous SSc at screening.

• Diagnosis of idiopathic inflammatory myopathy (IIM) according to the 2017 ACR/EULAR classification criteria (including probable or definite diagnosis, corresponding to a probability score of ≥55%). The subtypes include dermatomyositis (DM), anti-synthetase syndrome (ASS), and immune-mediated necrotizing myopathy (IMNM).