Low-dose Cyclophosphamide or CNI in the Prevention of Acute Graft-versus-host Disease After gDLI

Assess the cumulative incidence of severe (III-IV) aGVHD after low-dose cyclophosphamide or CNI is used to after gDLI. Evaluate the overall survival rate (OS), non recurrent mortality rate (NRM), and recurrence rate (CIR) of two groups of patients; The complete response rate (CR) and partial response rate (PR) of patients with morphological/extramedullary recurrence, as well as the complete response rate and MRD response rate of patients with molecular recurrence. The incidence of adverse events such as infection, hemorrhagic cystitis, and cardiac events in two groups. Efficacy Evaluation: Follow up observation of the difference in efficacy and safety between two groups in preventing severe (III-IV) aGVHD. Primary Exploratory Endpoint: Assess the cumulative incidence of severe (III-IV) aGVHD after low-dose cyclophosphamide or CNI is used after gDLI. Secondary Exploratory Endpoints: 1. 1-year overall survival rate (OS); 2. 1-year recurrence rate (CIR); 3. 1-year non recurrent mortality rate (NRM); 4. The complete response rate (CR) and partial response rate (PR) of patients with morphological/extramedullary recurrence, as well as the complete response rate and MRD response rate of patients with molecular recurrent minimal residual disease (MRD); 5. The incidence of adverse events such as infection, hemorrhagic cystitis, and cardiac events in two groups.