Immunophenotypic characteristics of acute leukaemia after myelodysplastic syndromes.

PURPOSE

To analyse the immunophenotype of acute leukaemia (AL) after myelodysplastic syndromes (MDS) (MDS-AL) and to compare the immunophenotypic profile of acute myeloblastic leukaemia (AML) secondary to MDS (MDS-AML) with that of "de novo"-AML.

PATIENTS AND METHODS

Twenty patients with MDS-AL and 29 patients with "de novo"-AML were studied. Morphocytochemical and flow cytometric studies were done in each case.

RESULTS

All the MDS-AL studied displayed a myeloid phenotype (MDS-AML). The main difference between MDS-AML and "de novo"-AML was a significantly higher frequency of CD34 expression in the first group. Differences concerning the expression of other non-lineage related or myeloid-associated markers were not statistically significant, although the percentage of cases CD15(+) was lower in MDS-AML. The overall frequency of expression of lymphoid-associated markers was similar in both groups, T-cell markers being more frequently detected.

CONCLUSIONS

Our findings support the usefulness of immunophenotyping studies to characterize MDS-AL and suggest some immunophenotyping differences between MDS-AML and "de novo"-AML which might have biological and prognostic significance.