A Clinical Trial on Autologous NK Cells Combined With GD2 Monoclonal Antibody in the Treatment of Children With Newly Diagnosed High-risk or Relapsed/Refractory Neuroblastoma

Inclusion Criteria: 1. Age 1-18 years (including 18 years), gender not restricted; 2. Diagnosed with high-risk neuroblastoma and meeting the following conditions: high-risk neuroblastoma has undergone standardized treatment including induction therapy and consolidation therapy according to COG, SIOPEN or the expert consensus CCCG-NB-2021, and has entered the maintenance stage; high-risk neuroblastoma has undergone induction therapy with COG chemotherapy combined with GD2 immunotherapy and has entered the maintenance stage; any recurrence of high-risk neuroblastoma after standardized treatment; or the disease is initially determined to be in a refractory state. 3. If it is relapsed/refractory neuroblastoma, there must be at least one measurable lesion according to RECIST 1.1 criteria; 4. Normal major organ function, that is, meeting the following standards: (1) Blood routine test: hemoglobin \>= 80 g/L; absolute neutrophil count (ANC) \>=0.75×10\^9/L; platelet count \>= 75×10\^9/L; (2) Blood biochemistry test: serum albumin \>=28 g/L; total bilirubin \<= 2×upper limit of normal (ULN); aspartate aminotransferase (AST), alanine aminotransferase (ALT) \<= 3×ULN; alkaline phosphatase (ALP) \<= 3×ULN; creatinine \<= 1.5×ULN; (3) Coagulation function: international normalized ratio (INR) or prothrombin time (PT) \<= 1.5×ULN; activated partial thromboplastin time (APTT)\<=1.5×ULN; (4) Echocardiogram shows normal diastolic function of the heart, left ventricular ejection fraction (LVEF) \>= 50%, and no severe arrhythmia; (5) No severe lung or kidney disease, no active pulmonary infection. Indoor air oxygen saturation \>=92%; 5. Expected survival time \>= 6 months; 6. After obtaining full informed consent from the patient and guardian, sign the informed consent form. Exclusion Criteria: 1. Uncontrollable active infections, or expected to receive systemic anti-infection or immunosuppressive therapy during participation in this trial; 2. Any toxic reactions caused by previous anti-tumor treatments have not recovered to grade 1 or below (CTCAE 5.0 version) (hair loss is not restricted); 3. Have a history of organ transplantation or are expected to undergo organ transplantation during the trial period; 4. Highly allergic constitution; 5. HIV infection; 6. The researchers believe that there are other circumstances in which the subjects are not suitable to participate in this study.