This is a single-center real-world study aiming to explore predictive factors for the efficacy of CAR-T therapy in patients with relapsed/refractory large B-cell lymphoma (R/R LBCL).

This single-center, prospective, single-arm phase II observational study aims to investigate multidimensional correlations between clinical baseline characteristics, tumor biological profiles, dynamic changes in CAR-T cell subsets, immune microenvironment features, and therapeutic outcomes in patients with relapsed/refractory diffuse large B-cell lymphoma (LBCL). The study will enroll 80 participants who will receive a standardized 90-day CAR-T therapy regimen. Post-intervention management will be stratified based on the results of treatment efficacy and transplant evaluation: patients failing to achieve complete remission (CR) or exhibiting progressive disease (PD) during therapy may receive investigator-determined salvage therapies, while responders will transition to long-term follow-up. The primary endpoint is to explore predictors of CAR-T efficacy through multivariate analysis of patients' clinical baseline characteristics, tumor characteristics, CAR-T cell subsets and their dynamic changes, and immune microenvironment.

Inclusion Criteria:

1. Pathological diagnosis confirmed as large B-cell lymphoma
2. Patients with relapsed or refractory large B-cell lymphoma (R/R DLBCL) after receiving second-line or above systemic treatment
3. Intend to use CAR-T products approved by NMPA for the treatment of R/R LBCL.
4. Understand and voluntarily sign a written informed consent form. For patients without full civil capacity, their guardians must be informed and sign the corresponding informed consent form and note the date, as for the patient himself, informed consent may be obtained based on the specific circumstances.

Exclusion Criteria:

1. Poor patient compliance
2. During pregnancy or lactation
3. After judgment by the researcher, the patient has other unsuitable conditions for inclusion in the study.

The investigators identified patients with Relapsed/refractory large B-cell lymphoma who could be used and who were willing to receive CAR-T