Immunotherapy With CD19 CAR T-cells for B-Cell Leukemia

Inclusion Criteria: 1. Relapsed or refractory B cell Leukemia. 2. KPS\>60. 3. Life expectancy\>3 months. 4. Gender unlimited, age from 2 years to 70 years. 5. CD19 expression must be detected on greater than 15% of the malignant cells by immunohistochemistry or greater than 30% by flow cytometry. 6. Patients who have failed at least one line of a standard treatment. 7. No serious mental disorder. 8. Patients must have adequate cardiac function(no cardiac disease, LVEF≥40% ), adequate pulmonary function as indicated by room air oxygen saturation of \>94%, and adequate renal function(Cr≤133umol/L). 9. No other serious diseases(autoimmune disease, immunodeficiency etc.). 10. No other tumors. 11. Patients volunteer to participate in the research. 12. Patients with history of allogeneic stem cell transplantation are eligible if at least 100 days post-transplant, if there is no evidence of active GVHD and no longer taking immunosuppressive agents for at least 30 days prior to trial Exclusion Criteria: 1. KPS\<50. 2. Patients are allergic to cytokines. 3. Uncontrolled active infection. 4. Acute or chronic GVHD. 5. Treated with T cell inhibitor. 6. Pregnancy and nursing females. 7. HIV/HBV/HCV Infection. 8. Other situations we think improper for the research.