PB1949 CHRONIC MYELOID LEUKEMIA PATIENTS WITH BOTH HIGH TH1 AND HIGH CD8+ T‐CELL LEVELS SHOW THE BETTER REMISSION, AND THE GOOD THERAPEUTIC RESPONSE ACCOMPANIES WITH THE HIGHER TH1 LEVEL

Background: The immune mornitoring on chronic myeloid leulemia (CML) patients may provide valuable guidence for the therapeutic strategies and prognosis prediction of this hematological malignancy. Aims: To investigate the correlation of Th1 and CD8+T‐based immunological characteristics of CML patients with the clinical efficacy. Methods: To analyze the Th1 proportion (Th1/CD4+T) and the CD8+T proportion (CD8+T/Lymphocyte) in the peripheral blood of all the CML patients diagnosed in our center. And the remission status at the same timepoint of the blood test are evaluated. The data is further statistically analyzed in different groups. Results: 70% of the patients in newly‐diagnosed group (n = 10), 15.38% of the patients in complete cytogenetic response(CCyR) group (n = 13) and 15.15% of the patients in molecular response 4.5(MR4.5) group (n = 67) respectively show a Th1 level below the lower limit of normal, therefore, the low‐Th1 percentage of the newly‐diagnosed group is significantly higher than that of the CCyR group and that of the MR4.5group ( P  = 0.01; P  = 0.00). On the other hand, the average of the actual Th1 value in the newly‐diagnosed group is also significantly lower than that in the CCyR group and that in the MR4.5 group ( P  = 0.01; P  = 0.00). As we have observed in clinic work that those patients with both high‐Th1 and high‐CD8+T levels (both higher than the upper limit of normal) mostly obtain better remission situations, furthermore, we analyze the relevant groups of CML patients statistically in this study. The results show: The MR4.5 rate in the high‐Th1 and high‐CD8+T group (n = 15) is significantly higher than that in the high‐Th1 and not‐high‐CD8+T group (n = 17) ( P  = 0.03), while the un‐remission rate in these two groups doesn’t show a statistically significant difference ( P  = 0.74). On the other hand, the MR4.5 rate in the high‐Th1 and high‐CD8+T group is also significantly higher than that in the low‐Th1 and high‐CD8+T group (here “low‐Th1” represents that the Th1 level is below the lower limit of normal; n = 10) ( P  = 0.00), while the un‐remission rate in the high‐Th1 and high‐CD8+T group is significantly lower than that in the low‐Th1 and high‐CD8+T group ( P  = 0.00). Summary/Conclusion: The good therapeutic efficacy of CML patients after treatment shows a significantly higher Th1 level compared with the level at diagnosis. And those patients with a Th1 level and a CD8+T level both higher than the upper limit of normal show the higher remission rate and the deeper remission level.