中文摘要：

骨髓增生异常综合征（MDS）是一组起源于造血干／祖细胞的获得性、克隆性、异质性疾患。中国与西方国家MDS患者具有不同的遗传学特征。以砷剂青黄散为主治疗MDS已取得肯定临床疗效。疗效机制研究表明含砷中药治疗不能改变MDS患者已有的染色体异常，但MDS患者异常增高的甲基化显著减低，含砷中药治疗的主要作用机制是去甲基化。血砷浓度测定表明有效血砷质量浓度为（19．39±10．36）μg／L，明显低于砷剂治疗急性早幼粒细胞白血病所需血砷浓度。进一步研究砷剂的去甲基化机制、进行个体化血砷浓度检测和疗效关系的研究是今后研究的方向。

英文摘要：

The myelodysplastic syndromes （MDS） are a group of clonal heterogeneous disorders of hematopoietic/progenitor. There are differences between Chinese and Western on cytogenetic typing of MDS. The arsenic-containing Chinese herbal formula Qinghuang powder is exact effective in the treatment of MDS. The clinical effect mechanism research indicated that treatment with arsenic-containing Chinese herbal formula had no effect on karyotype status, but resulted in a significant genome wide demethylation. The effective arsenic-concentration in blood is （19.39±10.36）μg/L, which is obviously lower than that in treating APL.