Chimeric antigen receptor T cell therapy (CART) has achieved excellent results in the past 10 years for treating of leukemia. Treatment of B cell acute lymphoblastic leukemia by anti-CD19 CART can reach a complete remission rate of 90%. Although CART has greatly improved the treatment of patients with leukemia and lymphoma, as many as one-third of the patients can suffer disease relapse after CART. The tumor surface marker CD19 is negative in most the patients who relapse, and these patients display high expression of CD19 before treatment. In this review, the current causes of CD19-negative relapses after CD19 CART against leukemia, and the mechanisms of target escape are briefly summarized. Also, methods and strategies for treating relapse to provide references for the treatment of leukemia relapse are also discussed.
Keywords: CART; CD19; leukemia; relapse mechanism; treatment.