Association between trisomy 8 and the immunophenotype of blast cells from acute leukemias secondary to a myelodysplastic syndrome or chronic myeloproliferative disorders

 In the present study we have used FISH to analyze the incidence of trisomy 8 in acute leukemias following either a primary myeloproliferative disorder (MPD) or a myelodysplastic syndrome (MDS) and correlated it with both the immunophenotype and the cell-cycle distribution of the leukemic blast cells. Six of the 21 (28%) acute leukemias studied displayed trisomy 8 by FISH. The number of trisomic cells in these cases ranged from 20 to 84%, with a mean of 46±24%. Trisomy 8 was associated with a homogeneous population of leukemic cells, phenotypically characterized by CD34+ / HLADR+ / CD13+ / CD33+ / CD11b– / CD15– / CD14–. No significant differences were observed on the proliferative rate of cases with trisomy 8, as compared with blast cells from the remaining patients. Overall, our findings suggest that in acute leukemias secondary to MPD or MDS, trisomy 8 is associated with a blockade of myeloid maturation at an early step of the differentiation process. Received: 2 December 1996 / Accepted: 12 February 1997