Study on cytological characteristics of myelodysplastic syndrome (MDS) in children.

用电镜和细胞化学方法研究了儿童和成人MDS患者的成红细胞、粒细胞和巨核细胞系列。本研究共纳入43例儿童、成人及继发性MDS患者。粒细胞的主要异常为核袋，在唐氏综合征患者的细胞中最常见（7例中有4例）。粒细胞的其他异常表现为细胞核变形、奥尔体样细长颗粒和chediak - higashi样大颗粒。在红母细胞中，海绵状核染色质变形主要发生在儿童身上。多核和畸形核红细胞也被发现。巨核细胞和血小板的变化，如微核细胞和巨血小板，不常被观察到。难治性贫血主要表现为红细胞改变，11例患者中有5例出现含铁线粒体，11例患者中有4例出现海绵状细胞核改变。RAEB-T以粒细胞改变为主。该亚型MDS 11例中有8例可见核袋。所有MDS亚型的红细胞和粒细胞系列细胞均出现凋亡。细胞化学方面，MIDS细胞髓过氧化物酶阳性颗粒数量减少。MDS中部分未成熟细胞出现血小板过氧化物酶反应，提示原细胞具有巨核细胞特征。电镜和细胞化学方法有助于发现光镜技术无法检测到的MDS细胞异常，儿童的MiDS与成人不相同。

Erytliroblast, granulocyte and megakaryocyte series of cells from MDS in children and adults were studied by electron microscopic and cytochemical methods. Fourty three patients of child, adult and secondary cases of MDS were included in this study. Major abnormal finding of granulocytes was nuclear pocket, which was most frequently observed in the cells from patients with Down's syndrome (4 out of 7 cases). Other abnormal findings in granulocytes were deformation of nucleus, Auer body-like elongated granules, and Chediak-Higashi-like large granules. In erythroblasts, sponge-like deformation of nuclear chromatin was predominant in children. Polynudear and deformed nuclear erytliroblasts were also noted. Megakaryocyte and platelet changes, such as microinegakaryocytes and giant platelets, 'were not frequently observed. Refractory anemia revealed predominant erythroblastic changes, that is, iron-loaded mitochondda was observed in 5 out of 11 patients, and sponge-like change of nucleus in 4 out of 11 cases. RAEB-T showed most predominant granulocytic changes. Nuclear pockets were obseved in 8 out of 11 cases in this sub-type of MDS.Apoptosis was observed in erythroblast and granulocyte series of cells in all MDS sub-types.Cytochemically, the number of myeloperoxidase-posilive granules were decreased in MIDS.Some of immature cells in MDS showed platelet peroxidase reaction, suggesting that the blasts had megakaryocyte characteristics. Electron microscopic and cytochemical methods were useful to find abnormalities in MDS cells which could not detect by lightmicroscopic techniques, and MiDS of children was not identical to that of adults.