Interpretations And Significance Of Flow Cytometry Scatter Plot Of T Lymphocyte Subsets In Peripheral Blood Of Leukemia Patients

Objective: Leukemia is a malignant clonal disease of hematopoietic stem cells,characterized by the high morbidity and poor survival.The clinical development of leukemia is also fast.The quantitation of T lymphocyte subsets is valuable for diagnosis,evaluation of prognosis,and treatment efficacy in patients with leukemia,which is available for clinician to choose treatment schemes.However,due to the abnormal morphology,size and immunophenotypic features of T cell subsets in some leukemia patients,the cell populations were not separated clearly when T lymphocyte subsets were detected by flow cytometry,which may lead some problems in the interpretation of the results.In this study,we analysed those abnormal flow cytometry scatter plots of T lymphocyte subsets in peripheral blood of leukemia patients with different types and disease processes,which aimed to identify which types and disease processes of leukemia patients are suitable to detect T lymphocyte subsets,and to provide evidence for the development of strategies about the detection of clinical leukemia patients.Methods: A retrospective analysis of 194 patients with leukemia who underwent T lymphocyte subsets detection in the hospital from January 2018 to January 2023,with a total of 415 T lymphocyte subsets detection results,studied the abnormal flow cytometry scatter plots.According to various types of leukemia,the subjects were divided into four groups: acute myelogenous leukemia,acute lymphoblastic leukemia,chronic myelogenous leukemia,chronic lymphocytic leukemia.According to various disease processes,the patients were divided into four groups: first-diagnosed patients,patients undergone first chemotherapy treatment,patients undergone multiple chemotherapy treatments(≥ 2 times),and patients undergone allogeneic hematopoietic stem cell transplantation.Firstly,the results of manual gate for T lymphocyte subsets of leukemia patients were compared with automatic gate’s results,to analyze whether there was statistical difference between these two analysis results.Then,the autoverification passing rate of T lymphocyte subsets of leukemia patients was analyzed and compared with historical lymphocyte subsets results in the laboratory.Furthermore,The characteristics of flow cytometry scatter plots of T lymphocyte subsets in leukemia patients were analyzed,and those abnormal flow cytometry scatter plots were dividedinto mild abnormalities and severe abnormalities according to whether they affected docimasters to set manual gate to separate those blasts.The proportion of severe abnormalities in flow cytometry scatter plots of leukemia patients with different disease types and different disease processes was analyzed,which aimed to find out which types and disease processes of leukemia patients are suitable to undergo T lymphocyte subsets detection.Results: 1.Firstly,statistical analysis was compared between the results of automatic gate setting and manual gate setting in the flow cytometry scatter plots of T lymphocyte subsets in leukemia patients.There was statistical difference between manual gate setting and automatic gate setting in leukemia,including acute myelogenous leukemia,acute lymphoblastic leukemia and chronic myelogenous leukemia.Therefore,the flow cytometry automatic gate could not accurately separate T lymphocyte subsets in patients with leukemia,acute myelogenous leukemia,acute lymphoblastic leukemia,and chronic myelogenous leukemia.2.All results of manual gate setting for leukemia patients’ T lymphocyte subsets were intercepted by the autoverification system that we had established.The autoverification passing rate of T lymphocyte subsets of leukemia patients was only9.94%,much lower than the autoverification passing rate of laboratory historical data which was 67.93%.Therefore,most leukemia patients need manual verification.3.Finally,the disease types and progresses of abnormal flow cytometry scatter plots were analyzed.Acute myeloid leukemia has the highest proportion of severe abnormal flow cytometry scatter plots among different types of leukemia.In different disease progresses of acute leukemia,the proportion of severe abnormal flow cytometry scatter plots in first-diagnosed leukemia patients was the highest,followed by acute leukemia patients after first chemotherapy treatments.In addition,more than 70% of leukemia patients’ T lymphocyte subsets results can be interpreted through manual gate,which is suitable for T lymphocyte subsets detection.Conclusion: The automatic gate setting of flow cytometry can not accurately separate T lymphocyte subsets in leukemia patients,and the autoverification passing rate of T lymphocyte subsets of leukemia patients is low.The interpretation of T lymphocyte subsets in leukemia patients needs manual verification after manual gate setting.Those Tlymphocyte cell populations of first-diagnosed leukemia patients may not be separated clearly by manual gate,followed by those leukemia patients who undergone first chemotherapy.However,more than 70% of leukemia patients could have accurate interpretation of results by manual gate,which is suitable for the detection of T lymphocyte subsets.