RESUMO
<p><b>OBJECTIVE</b>To investigate the total in situ apoptotic cell number and the apoptotic situation in erythroid cell and megakaryocytes in patients with myelodysplastic syndromes (MDS).</p><p><b>METHODS</b>Apoptosis cell number and the apoptotic situation of erythroid cell and megakaryocytes were analysed on cold embedded bone marrow sections from 25 MDS patients by DNA in situ end labelling (ISEL)/alkaline phosphatase anti-alkaline phosphatase (APAAP) double stained techniques. Fourteen cases of iron deficiency anemia (IDA) were taken as control.</p><p><b>RESULTS</b>Mean apoptotic cell numbers in MDS and control group were (39.44 +/- 29.34)/mm(2) and (13.43 +/- 8.39)/mm(2) respectively (P < 0.01). RA/RAS subtypes had a higher apoptosis ratio (47.56 +/- 32.86/mm(2)) than that in RAEB/RAEB-t subtypes (21.87 +/- 13.65/mm(2)) (P < 0.05). Double staining showed similar apoptosis percentage in erythroid cell and megakaryocytes in MDS patients comparing with that of controls (P > 0.05). Some apoptotic cells showing erythroid or megakaryocytic morphologic characteristics expressed no cluster differentiation antigen.</p><p><b>CONCLUSION</b>Overapoptosis existed in MDS, RA/RAS group had a higher apoptosis ratio than RAEB/RAEB-t group. No obvious increased apoptosis in erythroid cell and megakaryocytes was observed in MDS perhaps due to the loss of surface antigens in later stages of apoptotic cells.</p>