CD19 CAR T Cells in Patients With Relapsed or Refractory CD19 Positive B-cell Lymphoma

Inclusion Criteria: * Patients aged 18 to 70 years with relapsed or refractory CD19 positive B-cell lymphoma. * Eastern Cooperative Oncology Group (ECOG) Performance status 0-2. * Adequate end organ function as defined by: Total bilirubin ≤ 1.5 x upper limit of normal（ULN）; Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) ≤ 2.5 x ULN; Creatinine ≤ 1.5 x ULN or any serum creatinine level associated with a measured or calculated creatinine clearance of ≥ 40ml/min. * Male and female of reproductive potential must agree to use birth control during the study and for at least 6 weeks post study. * Patients should sign informed consent form. Exclusion Criteria: * Patients with central nervous system involvement by lymphoma. * Prior chemotherapy within 2 weeks before enrollment with the following exceptions: steroids, hydroxyurea, oral mercaptopurine, methotrexate, vincristine and thioguanine are permitted within 2 weeks of enrollment as maintenance or to reduce tumor load. * Prior allogeneic hematopoietic stem cell transplant (HSCT) ≤ 4 months before enrollment. Patients must have completed immunosuppression therapy prior to enrollment. At enrollment, patients must not have≥ grade 2 acute GVHD, or either moderate or severe limited chronic GVHD, or extensive GVHD of any severity. * Known systemic vasculitides, primary or secondary immunodeficiency(such as HIV infection or severe inflammatory disease). * Major surgery within 4 weeks before enrollment. * Impaired cardiac function:Ejection fraction ≤45 % on MUGA scan. QTc interval \> 450msecs on baseline ECG. Myocardial infarction within 6 months prior to starting study; other clinically significant heart disease (e.g. unstable angina, congestive heart failure or uncontrolled hypertension, uncontrolled arrhythmias). * Administration of live vaccine ≤ 4 weeks before enrollment. * Other concurrent severe and/or uncontrolled medical conditions: Patients with another primary malignant disease, except those that do not currently require treatment; acute or chronic liver, pancreatic or severe renal disease; another severe and/or life-threatening medical disease.