APPLICABILITY OF FLOW CYTOMETRY IN MYELODYSPLASTIC SYNDROMES DIAGNOSIS. CORRELATION BETWEEN FLOW CYTOMETRY, CYTOMORPHOLOGY AND CYTOGENETICS

Abstract

Introduction: Myelodysplastic syndrome (MDS) comprises a heterogeneous group of clonal hematopoietic stem cell diseases with variable clinical course and risk of evolution to acute leukemia. The diagnosis of MDS needs the combination of clinical and laboratorial criteria like clinical findings, bone marrow and peripheral blood cytomorphology (CM), cytogenetic (CG) and exclusion of other diseases. Although CM and CG are the gold standard parameters, flow cytometry (FC) has been used as an essential and important criterion for a better diagnosis, prognosis and therapeutic follow up in MDS. methods: In a period of 10 months (March 2012 to January 2013), our group studied 64 bone marrow samples by 4-colors FC protocols (Cytomics FC500, Beckman Coulter), characterizing the FC abnormalities according to the current recommendations of World Health Organization, 2008, such as aberrancies in myeloid progenitor’s cells and in granulocytes, erythrocytes and monocytes lineages. In addition, all the cases had CM and CG analyzed by a restricted laboratory team. The patients with clinical hypothesis of MDS were provided from Hospital Israelita Albert Einstein and Centro de Hematologia de São Paulo, São Paulo, Brazil. The median age was 70 (23-95) years old, and 59.4% (38/64) were male. Results: The aim of study was to evaluate FC abnormalities in MDS investigation and to verify the applicability of this technique in MDS diagnosis. Nine patients (14.1%) had no changes in FC analysis, and in four of them there were abnormalities in CM and CG consisted with MDS diagnosis. On the other hand, most of patients, 85.9% (55/64), had significant alterations in FC study. Stratifying these patients in groups that had or not changes in CM and CG, we observed that in 41.8% (23/55) there was concordance in the three methods, in 21 patients (38.2%) abnormalities in CM and CF, in only one case (1.8%) abnormalities in CF and CG, and in 10 patients (18.2%) only FC dysplasia. Conclusions: We could realize that in the most of patients we found dysplastic abnormalities by FC, but not always associated with findings in CM and CG analysis. However, in patients with suspected MDS the FC in association with CM and CG may add important information for a better diagnosis of MDS.