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MDS转化的急性白血病(AL-MDS)患者的血液和骨髓标本中制备了富原始细胞标本(使用一种新的密度离心剂收集原始细胞)，并检测了原始细胞的特性。主要发现如下。(1)无论疾病亚型如何，几乎所有病例的原始细胞均为CD34^+CD38^+HLA-DR^+CD13^+CD33^+。髓过氧化物酶细胞化学反应阴性者占58%。因此，MDS的原始表型比初治的急性髓系白血病更不成熟。(2)原始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、B淋巴细胞特异性抗原。(3)髓系细胞成熟的标志物(CD10和CD15)在低风险MDS(难治性贫血[RA]和RA伴环状铁粒母细胞)的原始细胞中更常见，而髓系细胞不成熟的标志(CD7和CD117)在高r-…的原始细胞中更常见更多的是ISK MDS(慢性粒单核细胞白血病，RA原始细胞增多[RAEB]和RAEB在转化中)和AL-MDS。同一患者的连续表型也记录了向更不成熟的原始细胞表型的转变，伴随着疾病的进展。(4)随着骨髓原始细胞百分率的增加，表达CD7、CD56、CD117的病例增多，表达CD10、CD11b、CD15的病例减少。原始细胞免疫表型改变的骨髓原始细胞百分率分别为5%、10%和20%。原始免疫表型有可能为目前的MDS分类提供生物学基础。(5)原始细胞CD7阳性是MDS预后不良的独立变量。(6)部分患者检测到CD45^-CD34^-CD38^-LIN^-胚样细胞存在染色体异常。与基质细胞共培养时，CD45^-CD34^-CD38^-LIN^-细胞仅表现出微弱的增殖/分化潜能，但可分化为CD34^+细胞和成熟的髓系细胞。这一细胞群体代表了迄今为止在造血系中发现的最不成熟的免疫表型。较少

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