急性单核细胞白血病M5a和M5b染色体核型及免疫表型的差异

Differences of karyotype and immunophenotype between M5a, and M5b of acute monocytic leukemia

目的研究60例急性单核细胞白血病的细胞遗传学、免疫表型和临床特点，分析亚型M5a和M5b之间的差异。方法采用骨髓直接法和24h短期培养法制备染色体标本，用G显带技术对60例成年人初发急性单核细胞白血病进行核型分析，用免疫荧光标记法及流式细胞术进行免疫表型检测，同时对其临床资料进行回顾性分析。结果60例患者中正常核型29例，异常核型31例，其中，正常核型在M5b中出现率高于M5a（P〈0．01），异常核型中11q23异常和＋8染色体在M5a中均较M5b常见（P〈0．01）；单核白血病细胞的免疫表型差异有统计学意义，其中CD68和CD11b在M5a中的表达高于M5b（P〈0．01）；然而，M5a和M5b患者的髓外浸润、外周血白细胞计数、弥散性血管内凝血（DIC）的出现、完全缓解率以及无病生存期（〉1年）之间差异无统计学意义（P〉0．05）。结论急性单核细胞白血病是一种异质性疾病，其两亚型之间具有各自的细胞生物学特征。

Objective Acute monocytic leukemia （AML-M5） is a distinct subtype of acute myeloid leukemia （AML）with characteristic biology and clinical features. This study was designed to identify differences in M5a and M5b. Method A total of 60 cases of de novo adult AML M5 was identified. Chromosome preparations of bone marrow cells were made using direct and 24 hours short-term culture method. Karyotypes were analyzed by G-banding. Immunofluresence analysis by flow cytometry was perforemed to detect the immunophenotype of the leukemic cells in all cases. Meanwhile, clinical data of these cases were studied retrospectively. Results There were 29 cases with normal karyotype and 31 cases with aberrant karyotype. The frequency of normal karyotype in Msb was higher than that in M5a（P =0.0001）. The 1 1q23 aberrations and the trisomy 8 were common in M5a, in comparison with M5b （P 〈0.01）. CD5a and CD11b were the leukemic cell antigens expressed differently in M5a. compared with M5b to a significant degree（P 〈0.01）. The immunophenotypes of monocytic leukemic cells in patients with AML M5 were heterogeneous. However, a signifigant difference did not exist in clinical characteristics of the two categories. Conclusions The individual cytobiological features can be detected between patients with AML M5a and M5b.