OBJECTIVETo investigate the myeloperoxidase (cMPO) expression pattern by flow cytometry (FCM) in patients with acute myeloid leukemia (AML) and its role in classifying AML.

METHODSEight- color multiparametric FCM with CD45/SSC gating was used to determine the cMPO expression in 502 AML patients.

RESULTSThe positive rate of cMPO in all patients was 58.0%, in which the proportion of normal positivity, dim positivity and partial positivity was 21.5%, 34.1% and 2.4%, respectively. The remaining case (42.0%) were all negative. In AML with t (15;17）(q22;q12)/PMLRARα, the positive rate was the highest (100%) and the intensity was similar to that of the normal granular leukocytes, followed by AML with t (8;21（q22;q22/RUNX1-RUNX1T1, the positive rate was 91.4% and the intensity was mostly dim. AML with minimal differentiation and acute megakaryoblastic leukemia were all cMPO negative. The positive rates of cMPO in the remaining subtypes were between 22.7% and 76.2%.

CONCLUSIONThe positive rate and intensity of cMPO were significantly different among different subtypes of AML.

Cell Differentiation ; Flow Cytometry ; Granulocytes ; Humans ; Leukemia, Myeloid, Acute ; classification ; genetics ; Peroxidase ; genetics

5' nucleotides (5'NT), a purine degradative enzyme, is capable of hydrolyzing nucleotide and acting as a phosphotransferase simultaneously. It has critical role in maintaining nucleotide metabolism balance. The present study was aimed to investigate the expression of 5'NT in bone marrow granulocytes (BMGs) from patients with acute myeloid leukemia (AML) and healthy donors comparatively. The BMGs were isolated from bone marrow of 33 patients with AML and 6 healthy donors by using lymphocyte isolating solution. The reactivity of 5'NT was detected by electron microscope and cytochemistry of cytidine monophosphate (CMP). The positive BMG ratio and their index were calculated on the base of ultrastructural observation semiquantitatively. The results indicated that electron microscopy revealed plasma membrane reacting pattern of CMP. Most BMGs from normal donors were CMP negative or exhibited lower active degree. All cases of M(0), M(1), M(2) and t (8; 21) showed high positive percentages and high indexes of BMGs, but no statistic differences between them. APL of t (15; 17) shared lower percentages and indexes than other subtypes. There was no significant difference between APL and normal donors statistically. In conclusions, the results suggested the expression of 5'NT may be associated with BMG differentiation in AML, and APL of t (15; 17) may be a highly differentiated leukemia subtype.
5'-Nucleotidase ; metabolism ; ultrastructure ; Adolescent ; Adult ; Aged ; Bone Marrow Cells ; cytology ; enzymology ; Child ; Female ; Granulocytes ; enzymology ; Humans ; Leukemia, Myeloid, Acute ; classification ; enzymology ; Male ; Middle Aged ; Young Adult

BACKGROUND: Despite the diagnostic utility of immunophenotyping for myelodysplastic syndromes (MDS), it has not been widely performed, and reports on this are absent in Korea. We aimed to evaluate the immunophenotypic features of non-blastic granulocytes, monocytes, and blasts in patients with MDS and non-clonal disorders using routine flow cytometry (FCM). Moreover, we evaluated the phenotypic abnormalities of mature cells in leukemic patients. METHODS: Marrow aspirates from 60 patients, including 18 with MDS, 18 with leukemia, and 24 with non-clonal disorders (control group), were analyzed using FCM. Blasts, non-blast myeloid cells, and monocytes were gated based on CD45 expression and side scatter (SSC). The phenotypes were then compared among the 3 groups. RESULTS: Compared to non-clonal disorders, the granulocytic lineages of MDS showed decreased SSC (P=0.005), increased CD45 intensity (P=0.020), decreased CD10-positive granulocytes (P= 0.030), and a higher CD56-positive rate (P=0.005). It is noteworthy that similar results were obtained in the leukemia group, and these findings were not related to the phenotypes of the leukemic cells. Using blast and monocytic gating, useful parameters for generating a differential diagnosis were not found. CONCLUSIONS: Gating the granulocytic region is a relatively easy method for MDS immunophenotyping. Among the parameters studied, SSC, CD10, and CD56 were the most useful for differentiating MDS from non-clonal disorders. While immunophenotypic changes in MDS appear to be useful for differentiating MDS from non-clonal disorders, these changes were also noted in the mature cells of leukemic patients.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Antigens, CD45/metabolism ; Antigens, CD56/metabolism ; Bone Marrow Cells/cytology ; Cell Lineage ; Child ; Child, Preschool ; Diagnosis, Differential ; Female ; Flow Cytometry ; Granulocytes/*classification ; Humans ; *Immunophenotyping ; Leukemia/diagnosis/pathology ; Male ; Middle Aged ; Monocytes/*classification ; Myelodysplastic Syndromes/*diagnosis ; Neprilysin/metabolism ; Phenotype