[1274] The Sensitivity and Specificity of Granulocyte and Monocyte Immunophenotype Abnormalities in the Detection of Myeloid Neoplasms

JM Polski. University of South Alabama, Mobile, AL

Background: Flow cytometric immunophenotyping (FCI) of peripheral blood and bone marrow is a useful and widely utilized technique for diagnosis and classification of hematopoietic neoplasms. However, routine FCI is usually limited to analysis of lymphocytes, blasts, and plasma cells. Granulocytes and monocytes are less commonly studied, but compelling evidence exists that detection of granulocyte and monocyte abnormalities can be useful in diagnosis of myelodysplastic syndrome (MDS) and chronic myeloproliferative disease (CMD).
Design: Consecutive cases of peripheral blood (n=47) and bone marrow (n=56) specimens submitted for FCI due to various clinical indications were included in this prospective study. A four-color flow cytometry data was collected. The granulocyte and monocyte immunophenotype was compared to normal controls.
Results: Granulocyte and monocyte abnormalities were common in peripheral blood (46.8%) and bone marrow aspirate (26.8%) specimens. The abnormalities included the following. Monocytes (number of cases): increased expression of CD56 (20), CD2 (5), CD23 (5), CD7 (3), CD22 (1), HLA-DR (1), and lack of expression of HLA-DR (1). Granulocytes (number of cases): lack of significant granulocyte maturation (7), decreased side light scatter (4), lack of expression of CD61 (2), expression of CD25 (3), and CD56 (1). The number of abnormalities ranged from 0 to 4 per case. Only 19 of 38 abnormal cases had evidence of myeloid neoplasia such as acute myeloid leukemia (AML), MDS, or CMD (specificity of 50%). The overall sensitivity was 73%. The specificity of individual abnormalities ranged from 20-100%. Three or more abnormalities had specificity of 100%, but were present in only 2 cases.
Conclusions: The results confirmed the published data showing high prevalence of granulocyte and monocyte abnormalities in MDS and CMD. Similar abnormalities were present in many cases of AML. This study also documented additional, not previously reported, granulocyte and monocyte abnormalities such as expression of CD25 in granulocytes, lack of expression of CD61 in granulocytes, and expression of CD22 in monocytes. These findings can be useful in clinical flow cytometry.
Category: Hematopathology

Wednesday, March 11, 2009 1:00 PM

Poster Session VI # 195, Wednesday Afternoon