Study On The Immunophenotype Of Myeloid Cells In Myelodsplastic Syndromes And Aplastic Anemia

OBJECTIVE The aim of this study was to determine whether immunophenotype of myeloid cells was different in AA patients from that of MDS.METHODS Take 3 ml bone marrow from 22 patients with MDS,12 patients with AA and 10 healthy controls by routine bone marrow puncture.A panel of monoclonal antibodies(including CD10/CD34/CD45,HLA-DR/CD33/CD45,CD15/CD13/CD45,and IgG1 cntrols),direct immunofluorescence and flow cytometry using CD45/SSC gating strategies were used for the immunophenotype in the bone marrow nucleated cells.RESULTS1.The percentages of CD 13~+ cells,CD33~+ cells,CD34~+ cells and HLA-DR~+ cells in patients with MDS were significantly higher than in normal controls,the percentages of CD15~+ cells and CD10~+ cells were significantly lower than in normal controls(P＜0.05).Abnormal granularity of MDS was characterized by a decrease in SSC as compared with normal mature neutrophils.As RA progressing to RAEB,the percentages of CD13~+ cells,CD33~+ cells,CD34~+ cells and HLA-DR~+ cells were significantly increased,the percentage of CD15~+ cells was significantly decreased(P＜0.05).2.There was no significant difference according to the surface expression ratio of all immunophenotypes analyzed between AA group and normal control(P＞0.05). Compared with normal controls,the SSC of cells in AA patients have no difference.3.The percentages of CD13~+ cells,CD33~+ cells,CD34~+ cells and HLA-DR~+ cells were significantly lower in patients with AA than in MDS,RA and RAEB patients (P＜0.05).The percentages of CD15~+ cells and CD10~+ cells were significantly higher in patients with AA than in MDS,RA and RAEB patients(P＜0.05).CONCLUSIONS1.The percentages of CD13~+ cells,CD33~+ cells,CD34~+ cells and HLA-DR~+ cells in patients with MDS were significantly higher than in normal controls,the percentages of CD15~+ cells and CD10~+ cells were significantly lower than in normal controls.Our data indicate abnormal maturation and antigenic aberrancy,a typical biological feature of MDS.This is coincided with the theory that MDS was malignant tumor.2.The percentages of CD34~+ cells and HLA-DR~+ cells in patients with MDS were significantly higher than in normal controls,the inappropriate expressions of CD34 and HLA-DR support the hypothesis that myeloid cells in MDS aberrantly expressing antigens usually restricted to the borderline of myeloblast-promyelocyte maturation.3.The percentages of CD13~+ cells,CD33~+ cells,CD34~+ cells and HLA-DR~+ cells were significantly higher in patients with RAEB than those in RA patients.The percentage of CD15~+ cells was significantly lower in patients with RAEB than in RA patients and normal controls.Patients with RAEB also tended to have a lower percentage of CD10~+ cells than the control patients,although this was not statistically significant.These findings indicate that the aberrancy of immunophenotype on the surface of myeloid cells in the higher-grade MDS is more serious than lower-grade MDS.4.There were no significant differences in the expression of these markers between patients with AA and normal controls.The quality of cells from AA patients was normal and the differentiation from stem cells to cells was normal in AA patients.5.All the markers we tested showed significant differences between MDS and AA.Flow cytometric immunophenotyping can be helpful to distinguish MDS from AA.6.MDS patients have high incidence of infection because of hypogranularity, decreased percentage of CD15~+ granulocytes and CD10~+ granulocytes.