Detection of dysplasia in peripheral blood: Proposal of an algorithm to detect myelodysplastic syndromes and chronic myelomonocytic leukemias on a high-speed technical platform using the Sysmex XN™ analyser.

INTRODUCTION: Chronic Myelomonocytic Leukemia (CMML) and Myelodysplastic Syndromes (MDS) are increasingly represented in the general population. We propose a screening strategy based on algorithms calculated from quantitative and analytical data from the XN analyser. MATERIALS AND METHODS: We tested the performance of previously published MDS and CMML scores on an evaluation cohort of 749 individual eligible patients over 50 years of age. These patients were classified into 3 groups as follows: 713 patients without MDS or CMML, 18 patients with MDS, and finally 18 patients with CMML. In a second step, a routine cohort of 37 828 samples was studied to evaluate the impact of this approach. RESULTS: The concordance rate between cytology and the two scores is 92.1%. The sensitivity and specificity of the CMML score are 100% and 96.2%, respectively. For the MDS score, they are 83.3% and 89.6% respectively. The ratio of platelets measured by fluorescence on board (PLT-F) as reflex tests generated is 1.5% after 6 months. The additional smear ratio for suspected MDS is calculated at 0.6%. CONCLUSION: We propose a flowchart using embedded artificial intelligence to help the cytologist in an optimized smear review and thus improve guidance to the clinician and the patients in the diagnosis process. This strategy permits a more comprehensive approach to MDS and CMML detection fitting with the new definition of CMML according to the recommendations of the World Health Organization (WHO) published in 2022.

Use of Sysmex XN-10 red blood cell parameters for screening of hereditary red blood cell diseases and iron deficiency anaemia.

INTRODUCTION: In daily practice in haematology laboratories, red blood cell (RBC) abnormalities are frequent and their management is a real challenge. The aim of this study is to establish a "decision tree" using RBC and reticulocyte parameters from the SYSMEX XN-10 analyser to distinguish between patients with a hereditary RBC disease from iron deficiency anaemia and other patients. METHODS: We analysed results of complete RBC counts in a cohort composed of 8217 adults divided into 5 different groups: iron deficiency anaemia (n = 120), heterozygous haemoglobinopathy (n = 92), sickle cell disease syndrome (n = 56), hereditary spherocytosis (n = 18) and other patients (n = 7931). A Classification And Regression Tree (CART) analysis was used to obtain a two-step decision tree in order to predict these previous groups. RESULTS: Five parameters and the calculated RBC score were selected by the CART method: mean corpuscular haemoglobin concentration, percentage of microcytes, distribution width of the RBC histogram, percentage of nucleated red blood cells, immature reticulocytes fraction and finally RBC Score. When applying the tree and recommended flowchart, 158/166 of the RBC hereditary disease patients and 114/120 iron deficiency anaemia patients are detected. Overall, the correct classification rate reached 99.4%. Sensitivity and specificity for RBC disease detection were 95.2% and 99.9%, respectively. These results were confirmed in an independent validation cohort. CONCLUSION: Based on the XN-10 RBC and reticulocyte parameters, we propose a two-step decision tree delivering a good prediction and classification of hereditary RBC diseases. These results can be used to optimize additional reticulocyte analysis and microscopy review.

Detection of Minimal Residual Disease in B Cell Acute Lymphoblastic Leukemia Using an Eight-Color Tube with Dried Antibody Reagents.

BACKGROUND: Flow cytometry is a powerful tool for the detection of minimal residual disease (MRD) of B cell precursor acute lymphoblastic leukemia (BCP-ALL) patients. However, the staining process and the choice of antibodies rely on laboratory expertise and may be source of variability or technical errors. Recently, Beckman Coulter commercialized a ready to use tube with dried format reagents for BCP-ALL MRD detection. The aim of this study is to evaluate the applicability of this tube and to compare it to a conventional (liquid format reagents) method. METHODS: Thirty-one samples from B ALL patients were analyzed: 19 bone marrow (BM) aspirations, 10 peripheral blood (PB) samples and 2 cerebrospinal fluids at different stages of the follow-up. In addition, we tested 5 bone marrow samples mixed into non-pathological (control) bone marrow. The dried format tube included seven antibodies: CD45Kro, CD58FITC, CD34ECD, CD10PC5.5, CD19PC7, CD38AA700, CD20AA750, with possibility of additional antibodies for blast markers identified at diagnosis. For comparison, a liquid format tube was prepared, and considered as the reference. RESULTS: This tube was validated for daily routine laboratory, with satisfying qualitative (MRD + or MRD-) and quantitative (MRD percentages) correlation with the reference tube. CONCLUSION: With this single dried format tube, we showed interesting results for BCP-ALL MRD detection in the aim of standardization and reliable interlaboratory results. It allows accurate MRD detection including low levels (10-4), and offers possibility to increase performance (supplementary antibody) within a preestablished effective antibody panel for BCP-ALL MRD. © 2018 International Clinical Cytometry Society.