[Clonal study on single apoptotic cells in myelodysplastic syndromes].

To investigate the clonal origin of the apoptotic hematopoietic cells in myelodysplastic syndromes (MDS).,Nineteen patients with MDS whose karyotypes had been analysed with G- or R-binding were studied. ISEL (DNA in situ end labelling) and FISH (fluorescence in situ hybridization) (simplified as ISEL/FISH) were performed simultaneously in a single nucleated cells on cytospin slides in 10/19 of the patients. The ratio of FISH positive cells to all nucleated cells and to apoptotic cells were counted. Eight slides from 4 normal donors induced apoptosis by Fas monoclonal antibody (McAb) were used as methodology control. For the rest 9 patients, different fractions of cells (PI-, Annexin V+PI-, Annexin V-PI-) were sorted by flow cytometry and then cytospined for FISH analysis (simplified as FCM/FISH).,The mean percentage of abnormal clonal cells in nuclear cells in the 10 cases detected by ISEL/FISH was 37.1%, whereas it was 24.0% in apoptotic cells. Induction by Fas McAb didn't lead to change of karyotype. Moreover, 8/9 patients analysed by FCM/FISH showed higher cell proportion with normal karyotypes in apoptosis-undergoing cells than that in non-apoptotic cells.,Over apoptotic hematopoietic cells in MDS are mainly residual normal hematopoietic cells.