Allogeneic Anti-CD19/BCMA CAR-T for Refractory Graves' Disease

Inclusion Criteria (Participants must meet all of the following inclusion criteria to be eligible for this study): * Refractory Graves' disease, defined as meeting at least one of the following: a) Continuous treatment with antithyroid drugs (ATDs) for ≥3 years without achieving criteria for drug discontinuation. b) Meeting criteria for drug discontinuation but experiencing ≥2 relapses after withdrawal. * Positive serum TRAb. * Willing to voluntarily participate in this clinical study, able to sign informed consent, and compliant with follow-up requirements. Exclusion Criteria (Participants will be excluded if any of the following conditions apply): * History of severe drug allergies or allergic constitution. * Presence or suspected presence of uncontrolled or active infections (including bacterial, fungal, viral, or other pathogens) requiring systemic or intravenous treatment. * Presence of central nervous system disorders (including epilepsy, psychosis, cerebrovascular accident, encephalitis, CNS vasculitis, etc). * Presence of clinically significant heart diseases (e.g., angina pectoris, myocardial infarction, heart failure, severe arrhythmias, etc). * Subjects with congenital immunoglobulin deficiency. * Subjects with malignancy (current or past), except for conditions deemed cured and with no risk of recurrence based on investigator assessment. * Positive viral serology, including any of the following: Hepatitis B surface antigen (HBsAg)-positive, or hepatitis B core antibody (HBcAb)-positive with HBV DNA above the upper limit; Hepatitis C virus (HCV) antibody-positive with detectable HCV RNA; Human immunodeficiency virus (HIV) antibody-positive; Positive syphilis test. * Severe psychiatric disorder or significant cognitive impairment that may affect compliance. * Hematologic dysfunction, including: a) White blood cell count \< 3.5 × 10⁹/L; b) Neutrophil count \< 1.8 × 10⁹/L; c) Hemoglobin \< 110 g/L. * Hepatic dysfunction, defined as any of the following: Alanine aminotransferase (ALT) \> 3 × ULN; Aspartate aminotransferase (AST) \> 3 × ULN; Total bilirubin (TBIL) \> 2.5 × ULN. * Renal dysfunction: creatinine clearance rate (CrCl) \< 60 mL/min (Cockcroft-Gault formula). * Left ventricular ejection fraction (LVEF) \< 55%. * Coagulation abnormalities, defined as either: International normalized ratio (INR) \> 1.5 × ULN; Prothrombin time (PT) \> 1.5 × ULN. * Participation in another clinical trial within 3 months prior to enrollment. * Pregnant or breastfeeding women, or women planning to become pregnant. * Any other condition that, in the opinion of the investigator, would make the participant unsuitable for the study.