CAR-T Combined With ASCT in the Treatment of Relapsed/Refractory Large B-cell Lymphoma With High-risk Factors.

Inclusion Criteria: 1. Age ≥ 18 years 2. Histopathologically confirmed large B-cell lymphoma, including diffuse large B-cell lymphoma (DLBCL), high-grade B-cell lymphoma (HGBL), central nervous system lymphoma (CNSL), primary mediastinal large B-cell lymphoma (PMBCL), and transformed follicular lymphoma (tFL) 3. Must have received first-line treatment with a regimen containing anti-CD20 monoclonal antibody and anthracycline 4. Meet one of the following clinical high-risk factors or molecular biological high-risk factors: 1. Clinical high-risk factors: Failure to achieve partial response (PR) after 4 cycles of first-line immunochemotherapy; or relapse within 12 months after achieving complete response (CR) with first-line immunochemotherapy; or relapse after autologous hematopoietic stem cell transplantation (ASCT); or central nervous system involvement at the time of disease relapse or progression 2. Molecular biological high-risk factors: TP53 gene mutation; or high-grade B-cell lymphoma (HGBL) with MYC and Bcl-2 rearrangements, with or without Bcl-6 rearrangement 5. ECOG 0 to 2 6. Eligible for high-dose chemotherapy/autologous hematopoietic stem cell transplantation (HDCT/ASCT) per the investigator's assessment, and planned to receive a sequential regimen of ASCT followed by CAR-T therapy 7. Hepatic and renal function meet the following criteria: Serum alanine aminotransferase (ALT)/aspartate aminotransferase (AST) ≤ 3 × upper limit of normal (ULN); total bilirubin ≤ 1.5 mg/dL; serum creatinine ≤ 1.5 × ULN, or creatinine clearance (calculated using the Cockcroft-Gault formula) ≥ 30 mL/min 8. Left ventricular ejection fraction (LVEF) ≥ 40% 9. Life expectancy ≥ 3 months Exclusion Criteria: 1. Patients who have previously received any CD19-targeted therapy 2. Patients with CD19 negativity confirmed by immunohistochemistry (IHC) 3. Active hepatitis B virus (HBV) or hepatitis C virus (HCV) infection, defined as HBV DNA or HCV RNA level above the upper limit of normal (ULN), with or without liver function abnormalities 4. Presence of uncontrolled infection, cardio-cerebrovascular diseases, coagulopathy, or connective tissue diseases 5. History of human immunodeficiency virus (HIV) infection 6. Pregnant or lactating patients