CD4 T cells in chronic myeloid leukemia present MHC class II-dependent and IFN-γ-dependent cytotoxic capacity.

At present, many therapeutic schemes have been used to improve the prognosis of patients with chronic myeloid leukemia (CML), but response remains poor in a small group of patients. CD4 T cell-mediated cytotoxicity has been found in various autoimmune diseases. This study analyzed the characteristics of CD4 T cell mediated cytotoxicity in CML patients and healthy people. The cytotoxicity of CD4 T cells was tested in using two CML cell lines, including the MHC class II-deficient K562 cells and the MHC class II-expressing KU812 cells. CD4 T cell-mediated lysis was minimal in K562 cells but was much higher in KU812 cells. In CML patients, the level of CD4 T cell-mediated lysis was limited to a certain level. Interestingly, pre-treating KU812 cells with IFN-γ could significantly elevate the expression of MHC class II and elevate the level of CD4 T cell-mediated lysis. Overall, these data indicated CD4 T cells could become a potential candidate for cytotoxic elimination of CML cells.

[Efficacy of Decitabine Combined with Pre-Excitation Chemotherapy in the Treatment of Middle-Aged and Elderly MDS Transformed Acute Myeloid Leukemia].

OBJECTIVE: To investigate the efficacy of domestic decitabine (D) combined with pre-excitation chemotherapy consisted of Ara-c, THP and G-CSF(CTG) in treatment of middle-aged and elderly patients with MDS-transformed AML and prognosis-related factors. METHODS: Seventy-six patients with MDS-transformed AML treated in our hospital from June 2013 to June 2015 were selected according to treatment regimens, 76 patients were divided into 2 groups: CTG group(36 cases) and D+CTG group(40 cases). The patients in CTG group received treatment with Ara-C, THP and G-CSF; the patients received the treatment with decitabine plus CTG. The patients in 2 groups all received 4 course treatment, then received maintaining treatment. The therapeutic efficacy and incidence of adverse reactions in 2 group were compared, at the same time, the risk factors affecting the prognos of patients treated with D+CTG were analyzed. RESULTS: There were no siginificant differences in age, sex, initial blood cell count, bone marrow blast ratio, disease types, chromosome karyotypes and FLT3-ITD gene mutation between 2 groups. The efficacy analysis showed that the efficacy of D+CTG was superior to CTG, ORR in D+CTG group was significantly higher than that in CTG group (72、52 vs 50%) (P<0.05), moreover, no significant differences in bone marrow inhibition digree infeetion, gastroinfestinal response and liver damage were found between 2 groups (P>0.05). The follow-np for 2 years showed that the median survival time in D+CTG group was significantly longer than that in CTG group (19.9 vs 11.0 months) (P<0.05). The multivariate analysis showed that the 1 course efficacy (RR=3.926, P=0.015) and FLT3-ITD gene mutation (RR=4.347, P=0.004) were independent risk factors affecting the efficacy of D+CTG treatment. CONCLUSION: The short-and long-term efficacy of domestic decitasine combined with preexcitation chenotherapy in treatment of middec-aged and eldery patients with MDS transformed AML is superior to single pre-excitation chenothrapy, moreover the incidence of adverse reactions did not increase. The 1 course efficacy and FLT-3 ITD gene mutation are the independent risk factors affecting the prognosis of patients. .