Biological characteristics of blasts from patiente with myelodysplastic syndromes : an application of a new blast-enrichment method

我们从许多骨髓增生异常综合征（MDS）或由MDS转化的急性白血病（AL-MDS）患者的血液和骨髓样本中制备了富含blast的标本（使用一种新的密度离心试剂用于收集blast），并检测了blast的特征。主要发现如下。(1)几乎所有病例的原细胞均为CD34^+CD38^+HLA-DR^+CD13^+CD33^+，与疾病亚型无关。58%的病例骨髓过氧化物酶细胞化学反应为阴性。因此，MDS的细胞表型比新生急性髓系白血病更不成熟。(2)母细胞常不同步表达干细胞抗原和晚期髓系抗原，但很少表达T和b淋巴细胞特异性抗原。(3)骨髓细胞成熟标志物（CD10和CD15）在低危MDS（难治性贫血[RA]和伴环状铁母细胞的RA）的母细胞中更为普遍，而骨髓细胞不成熟标志物（CD7和CD117）在高危MDS（慢性髓单细胞白血病，伴过多母细胞的RA [RAEB]和转化中的RAEB）和AL-MDS的母细胞中更为普遍。同一患者的顺序表型也记录了细胞向更不成熟表型的转变，伴随疾病进展。(4)骨髓中表达CD7、CD56和CD117的细胞比例增加，表达CD10、CD11b和CD15的细胞比例减少。骨髓母细胞免疫表型改变的百分比分别为5%、10%和20%。母细胞免疫表型有可能为目前MDS的分类提供生物学基础。(5)原细胞cd7阳性是MDS患者预后不良的自变量。(6)部分患者存在CD45^- cd34 ^- cd38 ^- lin ^-胚样细胞染色体畸变。当与基质细胞共培养时，CD45^-CD34^- cd38 ^- lin ^-细胞仅表现出较弱的增殖/分化潜能，可分化为CD34^+细胞，进而分化为成熟的骨髓细胞。这个细胞群代表了迄今为止在造血谱系中发现的最不成熟的免疫表型。少

We prepared blast-rich specimens (using a new density-centrifugation reagent for harvesting blasts) from blood and marrow samples of many patients with myelodysplastic syndromes(MDS) or acute leukemia transformed from MDS(AL-MDS) and examined blast characteristics. Key findings are the following. (1)The blasts from almost all cases were CD34^+CD38^+HLA-DR^+CD13^+CD33^+, regardless of the disease subtype. The cytochemical reaction for myeloperoxidase was negative in 58% of the cases. Thus, the blast phenotype is more immature in MDS than in de novo acute myeloid leukemia. (2)The blasts often coexpressed stem-cell antigens and late-stage myeloid antigens asynchronously, but rarely expressed T- and B-lymphoid cell-specific antigens. (3)Markers for myeloid-cell maturation (CD10 and CD15) were more prevalent on blasts from low-risk MDS (refractory anemia [RA] and RA with ringed sideroblasts), while markers for myeloid-cell immaturity (CD7 and CD117) were more prevalent on blasts from high-r … More isk MDS (chronic myelomonocytic leukemia, RA with excess blasts [RAEB] and RAEB in transformation) and AL-MDS. A shift to a more immature phenotype of blasts, accompanying disease progression, was also documented by sequential phenotyping of the same patients. (4)When the blast percentage in the marrow increased, cases whose blasts expressed CD7,CD56 and CD117 increased whereas cases whose blasts expressed CD10,CD11b and CD15 decreased. The marrow blast percentages where the blast immunophenotype changed were 5%,10% and 20%. Blast immunophenotypes have the potential to provide a biological basis for the present MDS classifications. (5)CD7-positivity of blasts was an independent variable for a poor prognosis in MDS. (6)CD45^-CD34^-CD38^-Lin^- blastoid cells having chromosomal aberration were detected in some patients. When co-cultured with stroma cells, CD45^-CD34^-CD38^-Lin^- cells showed only weak potential for proliferation/differentiation, yet differentiated into CD34^+ cells and then mature myeloid cells. This cell population represents the most immature immunophenotype so far identified in the hematopoietic lineage. Less