Diagnostic utility of flow cytometric immunophenotyping in myelodysplasticsyndrome

The myelodysplastic syndromes (MDSs) are characterized by bilineage or tril ineage dysplasia. Although diagnostic criteria are well established for MDS , a significant number of patients have blood and bone marrow findings that make diagnosis and classification difficult. Flow cytometric immunophenoty ping is an accurate and highly sensitive method for detection of quantitati ve and qualitative abnormalities in hematopoietic cells. Flow cytometry was used to study hematopoietic cell populations in the bone marrow of 45 pati ents with straightforward MDS. The results were compared with those obtaine d in a series of patients with aplastic anemia, healthy donors, and patient s with a history of nonmyeloid neoplasia in complete remission. The immunop henotypic abnormalities associated with MDS were defined, and the diagnosti c utility of flow cytometry was compared, with morphologic and cytogenetic evaluations in 20 difficult cases. Although morphology and cytogenetics wer e adequate for diagnosis in most cases, flow cytometry could detect immunop henotypic abnormalities in cases when combined morphology and cytogenetics were nondiagnostic. It is concluded that flow cytometric immunophenotyping may help establish the diagnosis of MDS, especially when morphology and cyt ogenetics are indeterminate. (C) 2001 by The American Society of Hematology .