Expression Of PD-1 In Peripheral Blood Lymphocyte Of Chronic Myeloid Leukemia Patients And Its Clinical Significance

Purpose:To study the expression of PD-1 on the T lymphocyte of chronic myeloid leukemia at different stages of treatment,and analyzes the immune status of chronic myeloid leukemia patients.Method:Including chronic myeloid leukemia patients and healthy volunteers who met the inclusion and exclusion criteria in the the first affiliated hospital of Gannan Medical College from November 30,2021 to November 30,2022,there were 7 newly diagnosed CML patients,12 CML patients with major molecular response,20 CML patients with molecular response 4.5 and 30 healthy volunteers.Peripheral blood samples were collected from all subjects and Flow cytometry were used to detect the expression of PD-1 on CD3+T lymphocyte,CD4+T lymphocyte and CD8+T lymphocyte,to further analysis of the immune status of chronic myeloid leukemia patients.Results:1.In patients with newly diagnosed CML,PD-1 levels on CD3+ T cells were9.2%(7.5-12.7%)(9.2% as Median,7.5% as first quartile,and 12.7% as third quartile);It was significantly higher than that CML patients who achieved MMR(4.1%,3.37-4.47%,p = 0.003)and CML patients who achieved MR4.5(3.45%,2.75-5.62%,p = 0.001).Similarly,PD-1 levels on CD4+ T cells were significantly lower in CML patients who achieved MR4.5 response(4.35%,2.15-7.67%)than in newly diagnosed CML patients(8.6%,6.8-10.6%,p = 0.038).however,there was no significant difference in CML patients who achieved MMR response(4.25%,2.35-6.75%)compared wit newly diagnosed CML patients on CD4+ T cells(P = 0.071).PD-1 levels of CD8+ T lymphocyte were significantly lower in CML patients who achieved MMR response(4.8%,3.57-7.57%,p = 0.009)and CML patients who achieved MR4.5 response(5.85%,4.17-6.97%,p = 0.004)than in newly diagnosed CML patients(9.4%,8.8-15.5%).2.The levels of PD-1 on CD3+ T cells in CML patients who achieved MR4.5response after TKIS treatment was 3.45%(2.75-5.62%),significantly lower than healthy adults(5.6%,3.80-6.85%,p = 0.033).Among the CD4+ T cells,the PD-1levels in MR4.5 group was 4.35%(2.15-7.67%),which was significantly lower than healthy adults(6.5%,5.27-10.32%,p = 0.028).Similarly,among CD8+ T cells,PD-1 levels were significantly lower in MR4.5 patients(5.85%,4.17-6.97%)than healthy adults(8.25%,6.37-11.45%,p = 0.018).3.On the other hand,the levels of PD-1 were 9.2%(7.5-12.7%),8.6%(6.8-10.6%),and 9.4%(8.8-15.5%)in the lymphocyte subgroups of newly diagnosed CML patients respectively,which were higher than healthy adults,but no statistical significance.Conclusion:1.The expression of PD-1 on CD3+ T lymphocyte,CD4+ T lymphocyte,and CD8+ t lymphocyte were decreased in CML patients who achieved remission after TKIS treatment,but there was no significant change in CD4+ T lymphocyte in the MMR group.At the same time,only the PD-1 levels of CML patients with molecular response 4.5 were significantly lower than the healthy population.2.The levels of PD-1 in chronic myeloid leukemia patients vary from stage to stage of treatment,this suggests that the expression of PD-1 in lymphocyte may reflect the development of the disease and the immune status in advance.3.CML Patients who achieve the DMR response(Molecular reaction4.5 and above),as a target population for discontinuation,have a state of lower expression of PD-1 in vivo,which prompts PD-1 may be used as a biological marker to predict treatment-free remission.4.For relapsed or resistant CML patients,the use of PD-1 inhibitors may be helpful in the future.