First-line Treatment of P53 Mutation With PD-L1 Expression in DLBCL With Anti-PD-1 Mab and R-CHOP

Inclusion Criteria: 1. Ages≥18 years, ≤ 80 years. 2. Patients with primary treatment of DLBCL. 3. Histopathologically confirmed diagnosis of diffuse large B-cell lymphoma. 4. At least one measurable lesion according to the 2014 Lugano criteria. 5. ECOG physical status score of 0, 1 or 2. 6. Laboratory tests meet the following criteria unless judged to be due to lymphoma: 1. Routine blood tests: (in the absence of growth factor support therapy or blood transfusion within 7 days) haemoglobin ≥ 90 g/L, absolute neutrophil value ≥ 1.5 x 109/L, platelet count ≥ 90 x 109/L. 2. Liver biochemistry: serum creatinine ≤ 1.5 x upper limit of normal; total bilirubin ≤ 1.5 x upper limit of normal; glutamate transaminase and glutamic oxalacetic transaminase ≤ 2.5 x upper limit of normal. 3. Coagulation: INR and APTT ≤ 2.5 times the upper limit of normal values. 7. Consent to use contraception during the trial and for 3 months after its completion. 8. Expected survival ≥ 3 months. Exclusion Criteria: 1. Suffering from other untreated malignant tumours. 2. Cardiovascular disease that remains unstable under pharmacological control . 3. With severe interstitial lung disease. 4. With cognitive impairment. 5. Patients with uncontrolled autoimmune disease. 6. Presence of uncontrolled active infection. 7. Expected survival time \< 3 months. 8. Lactating women and subjects of childbearing age who do not wish to use contraception. 9. With poor adherence or unable to follow up regularly.