CD19 and mantle cell lymphoma: Primary analysis cohort (disease-specific)Adults (≥18 y) with relapsed/refractory B-cell lymphomas receiving CD19-directed CAR-T (e.g., Large B-cell Lymphomas subtypes, including Diffuse/high-grade B-cell lymphoma/transformed follicular lymphoma; ± mantle-cell lymphoma if using CD19 CAR-T).Baseline Eastern Cooperative Oncology Group (ECOG) performance status (0–4).Develop fever ≥38°C within 14 days post-infusion.Provide informed consent.