CD19 CAR-T Cells for Patients With Relapse and Refractory CD19+ B-ALL.

Inclusion Criteria:

* 1\. 2 years to 70 years, expected survival \> 3 months;
* 2\. CD19 positive B-cell acute lymphoblastic leukemia;
* 3\. ECOG \< 2；
* 4\. The tumor load in the bone marrow is less than 60%;
* 5\. Cardiac function: 1-2 levels; Liver: TBIL≤3ULN，AST ≤2.5ULN，ALT ≤2.5ULN; kidney: Cr≤1.25ULN; Peripheral Blood: WBC ≥ 2.0×109/L, Hb ≥80 g/L, PLT ≥ 30×109/L）;
* 6\. No leukemia cells in the central nervous system;
* 7\. No serious allergic constitution;
* 8\. No other serous diseases that conflicts with the clinical program;
* 9\. No other cancer history;
* 10\. No serious mental disorder;
* 11\. female participants of reproductive potential must have a negative serum pregnancy test;
* 12\. Informed consent is signed by a subject or his lineal relation.

Exclusion Criteria:

* 1\. Pregnant or lactating women;
* 2\. Uncontrolled active infection, HIV infection, syphilis serology reaction positive;
* 3\. Active hepatitis B or hepatitis C infection;
* 4\. Recent or current use of glucocorticoid or other immunosuppressor;
* 5\. With severe cardiac, liver, renal insufficiency, diabetes and other diseases;
* 6\. Participate in other clinical research in the past three months; previously treatment with any gene therapy products;