并非骨髓增生低下引起的原因不明的血细胞减少,且呈现出血细胞形态异常的疾病过程叫做骨髓增生异常综合征(myelodysplasticsyndrome,MDS),虽主要见于中、老年人,常发生急性非淋巴细胞性白血病,但由于感染或出血等骨髓衰竭致死的亦多见,不亚于白血病化。不但血细胞减少,血细胞功能也异常,而且这种血细胞量和质的异常(异常克隆)常见于多种血细胞系统,所以考虑MDS是由多能造血干细胞的异常所致。其病程经过较缓慢,对通常的治疗反应不敏感是MDS的特点之一。MDS从外周血像的表现来看被称为难治性贫血或难治性血细胞减少等,从预后来看被称 It is not myelodysplastic syndrome (MDS) which is caused by unexplained cytopenia caused by low myeloproliferation and presents with an abnormal morphology of blood cells. Although it is mainly found in the middle and old aged people, acute non-lymphocytic leukemia often occurs, However, due to infection or bleeding and other bone marrow failure are also more common, as much as leukemia. Not only cytopenias and abnormal blood cell functions, but also abnormalities in blood cell mass and quality (abnormal cloning) are common in many blood cell systems. Therefore, MDS is considered to be caused by the abnormalities of pluripotent hematopoietic stem cells. One of the hallmarks of MDS is its slow course and insensitivity to usual therapeutic responses. MDS from the performance of peripheral blood is called refractory anemia or refractory cytopenia, etc., from the prognosis is called