Study On The Early Diagnosis Of Myelodysplastic Syndromes By Using Clonal Analysis

Myelodysplastic syndrome (MDS) is an acquired clonal hematologic disorder which derives from a defective maturation of hematopoietic stem cell, characterized by peripheral blood cytopenia, dyshemopoietic findings in several hemopoietic cell lines at bone marrow and peripheral blood and the high risk of transforming to acute leukemia. The diagnosis of MDS is mainly based on FAB criteria, which requests dyshemopoietic findings in at least two hemopoietic cell lines. However, there are some patients lack of obvious dyshemopoietic changes or having only one series dyspoiesis. Those patients often meet with missed diagnosis or misdiagnosis and can be correctly diagnosed only when the typical several series dyspoieses occur. This study is carried out to explore the early diagnosis of MIiI~S by utilizing clonal analysis on those patients not compatible with FAB criteria. Purpose: To study the value of clonal analysis to the early diagnosis of myelodysplastic syndrome (MIDS). Methods: Four types of clonal analyses were preformed on the bone marrow samples from 50 patients with suspected MDS: 0 Conventional Cytogenentics (CC) for clonal chromosomal abnormalities; 〣rdU-Sister Chromatid Differentiation (BrdU-SCD) for cell cycle analysis; ? Fluorescence in Situ Hybridization (FISH) for trisomy 8; ㏄CR-SSCP for N-RAS mutation. Results: OThe diagnosis of forty-three patients was compatible with MDS according to the FAB criteria, of which, eighteen cases had clonal chromosomal abnormalities, 26 cases had prolonged cell cycle patterns. Among twenty-six cases detected by FISH, eleven had trisomy 8. PCR-SSCP revealed exon I mutation of N-RAS in two patients and exon 2 mutation in 3 another two patients among analyzed twenty-three patients. Among other seven cases with only one series dyspoiesis or without obvious dysplastic changes, two were diagnosed morphologically as suspicious refractory anemia (RA), one as sideroblastic anemia, one as leukemoid reaction, one as hypercellular anemia and two as chronic aplastic anemia. Among these seven cases, six had clonal karyotype abnormalities, four had prolonged cell cycle patterns, two had trisomy 8 of different proportions, one had mutation of the exon 1 of N-RAS. Conclusion: the MDS patients with one series dyspoiesis or without obvious dysplastic changes can be diagnosed early by combining multiple clonal analysis techniques such as CC, SCD, FISH and PCR-SSCP.