儿童特发性血小板减少性紫癜骨髓巨核细胞的研究

Study on Bone Marrow Megakaryocytes in Children Patients with Idiopathic Thrombocytopenic Purpura

本研究观察特发性血小板减少性紫癫 (ITP)患儿骨髓巨核细胞形态与造血功能的改变 ,初步分析其血小板减少的发生机制。采用巨核细胞CD4 1α单克隆抗体免疫酶标染色观察骨髓涂片中小巨核细胞的计数与分类 ,采用血浆凝块法体外培养骨髓单个核细胞 ,用免疫酶标法进行巨核细胞集落检测 ,计数巨核细胞集落形成单位 (CFU MK)和爆式巨核细胞集落形成单位 (BFU MK)。结果表明 :ITP患儿骨髓小巨核细胞检出率与对照组无显著差异 ,而I型淋巴样小巨核细胞很少见 ;小巨核细胞总数及CFU MK和BFU MK集落形成率明显高于对照组 ;在培养体系中可以观察到正在释放血小板的成熟的巨核细胞。发现 1例慢性ITP患儿骨髓巨核细胞集落形成率降低。结论 :Ⅱ、Ⅲ、Ⅳ型小巨核细胞增多是ITP的病理特征 ,这些小巨核细胞在体外培养条件下可发育成熟为正常的巨核细胞 ,并释放血小板 ;免疫损伤导致血小板减少及巨核细胞成熟障碍可能并不是ITP发病的唯一机制 ,部分病例尤其是慢性ITP ,其发病可能与患者巨核细胞本身质的异常有关。

To observe the morphological characteristics and hematopoietic function of bone marrow megakaryocyte (MK) in children patients with idiopathic thrombocytopenic purpura (ITP),and to preliminary analyse the cause and mechanism of thrombocytopenia. CD41 McAb immunohistochemical technique was used to detect micromegakaryocyte in bone marrow smear. Plasma clot culture and CD41 McAb immunohistochemical technique were used for the MK-colony forming assay. The results showed that there was no statistical difference of the positive rate of micromegakaryocyte between groups of ITP and control,but type I lymphocyte-like micromegakaryocyte was infrequent. The number of micromegakaryocyte and the formation rates of CFU-MK and BFU-MK in ITP group were significantly higher than those in control group. The normal MK releasing platelet could be easily found in the culture system. The MK colony formation rate was decreased in a patient with chronic ITP. In conclusion,the increment of type Ⅱ,Ⅲ,Ⅳ micromegakaryocytes is one of pathologic phenomenon of ITP. These small megakaryocytes can develop and mature to normal megakaryocytes in the condition of ex vivo culture. The developmental abnormity of MK is a possible reason for thrombocytopenia among partial patients with ITP,especially the chronic cases.