Research On The Value Of Improved Flow Cytometry Score In Myelodysplastic Syndromes Diagnosis

Background Myelodysplastic syndrome(MDS) are a group of heterogeneity characterized by peripheral cytopenias and dysplasia in one or more myeloid cell lines in bone marrow,and are classified by the WHO as myeloid neoplasms. Ineffective hematopoiesis leads to a high risk of progression to leukemia being observed. The incidence rate is about 5cases per 100 000 persons per year in the general population, but increases to 20 to 50 cases per 100000 persons per year after age 60 year. According to WHO criteria,the classification of myelodysplastic syndromes is based on peripheral cytopenias and morphological evaluation of bone marrow dysplasia,as well as other evidences, such as clonal cytogenetic abnormalities and/or ringsideroblasts. However, in clinical practice,when patients lack specific diagnostic markers above, the diagnosis MDS is not always straightforward. Therefore, we need more auxiliary diagnosis of MDS. Flow cytometric analysis of hematopoietic cells in the qualitative and quantitative is already very mature and play a very important role in the diagnosis and evaluation of blood system diseases.At present, has not yet found signs of patients with MDS specific antigen or combination of signs, but flow cytometry has significance in the reactive changes in bone marrow and clonal myeloid tumor differential diagnosis. This technique can serve as the auxiliary tool for the diagnosis of MDS. 2012 Della Porte et al proposed a flow cytometric score(FCM-score) was published for MDS patients by integrating four parameters capable of distinguish between low-grade MDS and non clonal cytopenias.The proposed FCM score showed a high sensitivity and specificity, and clinically significant positive and negative likelihood ratios.Objective Our research reference for this method and do a minor modification to test the clinical practicability of FCM- score. At the same time, we evaluated the diagnostic effectiveness of an improved FCM-score in MDS.Methods A total of 118 patients suspected diagnosis of MDS because of peripheral blood cytopenia from the Second Affiliated Hospital, Anhui Medical University, China, were enrolled in this study. The diagnosis and classification were performed in accordance with the minimum diagnostic criteria established by the Conference on MDS(Vienna,2006) and the 2008 WHO criteria respectively. Accordingly, morphological evaluation and cytogenetic analysis was carried out as well as iron stain and biopsy when the morphology was difficult to distinguish. If there was no evidence of clonality by genetic studies, the patient is classified as having idiopathic cytopenia of undetermined significance(ICUS) and need to be observed clinically for 6 months before MDS was diagnosed. According to the final diagnosis patients were divided into two categories: 1proven MDS(n=54), 2 non-clonal cytopenias(n=41). We use a set of antibody combination: CD34/CD19/CD33/CD45 to analysis of the four parameters. Compared with the published method using low SSC and CD45 expression to separate progenitor B-cell blasts and myeloblasts, our minor modified FCM-Score using CD19 and CD33 separate progenitor B-cell blasts and myeloblasts from myeloid blasts. The minor modified FCM-score were compared with the originally proposed FCM-score. Study population was analyzed by two kinds of schemes, and respectively calculated their specificity and sensitivity, analyzed of their differences to evaluate efficacy of the modified FCM-score.Results1. Analysis of MDS and Non-MDS patient population data and the four parameters of the modified FCM-score. The median score MDS group and the median parameter 1 MDS group was obviously higher than that of the Non- MDS group, and the median parameters 2 and 4 were significantly lower than the Non-MDS group, two groups of the median parameter 3 no statistical difference.2. Two kinds of schemes were calculated respectively in the diagnosis of MDS specificity, sensitivity, positive and negative likelihood ratio diagnostic parameters, chi square test to compare two kinds of integral diagnostic performance of no statistical difference, two options have good diagnosis of alignment.Conclusion The modified FCM-score affirmation of the effectiveness of the diagnosis of MDS.The improved scheme is simple, convenient operation, can better separation progenitor B-cell blasts and myeloblasts, only need a set of antibody combination with four color flow cytometry instrument can realize the analysis of the four parameters.