Monoclonal antibody M195: a diagnostic marker for acute myelogenous leukemia.
Monoclonal antibody M195: a diagnostic marker for acute myelogenous leukemia.
复制标题
单克隆抗体 M195：急性髓性白血病的诊断标志物。
作者：
D. Scheinberg;M. Tanimoto;S. Mckenzie;A. Strife;Lloyd Old;B. Clarkson
单克隆抗体（mAb） M195是一种小鼠IgG2a抗体，与早期骨髓细胞和单核细胞中发现的髓单核细胞分化抗原反应。用流式细胞术测定了227例纪念医院患者血液或骨髓中M195对新鲜造血肿瘤的反应性。M195在61例髓母细胞白血病中有67%呈阳性。70%的tdt阴性ANLL和30%的tdt阳性ANLL呈阳性；CMMOL和CML在成髓细胞危象期和加速期均100%阳性。相比之下，M195在51例淋巴细胞白血病中仅为8%，在70例其他非髓细胞白血病中仅为1%。M195结合与ANLL的FAB分类相关性不强。在相同的病例中，M195的反应性模式与MY9 （CD33）相似，但不完全相同（一致性83%）。证实了MY9和L4F3 （CD33）交叉阻断M195的结合。M195可以与同一蛋白抗原上的不同表位结合。白血病样本中同时存在MY9和M195阳性，诊断ANLL的特异性为98%，高于单独使用MY9（88%）或单独使用M195（92%）。粒细胞-单核细胞和红细胞集落形成单位的测定显示M195存在于这些造血祖细胞上。M195的这种反应性模式，加上它对成熟粒细胞元素或成人组织缺乏反应性，使其成为体内治疗ANLL的候选药物。
Monoclonal antibody (mAb) M195 is a mouse IgG2a reactive with a myelomonocytic differentiation antigen found on early myeloid cells and monocytes. The reactivity of M195 with fresh hematopoietic neoplasms in the blood or bone marrow from 227 patients at Memorial Hospital was determined by flow cytometry. M195 was positive on 67% of 61 myeloblastic leukemias. Seventy percent of Tdt-negative ANLL and 30% of Tdt-positive ANLL were positive; 100% of CMMOL and 100% of CML in myeloblastic crisis or accelerated phase were positive. In contrast, M195 was positive on only 8% of 51 lymphoblastic leukemias and 1% of 70 other nonmyeloid samples. M195 binding did not correlate well with FAB classification of ANLL. The pattern of reactivity of M195 was similar but not identical to that of MY9 (CD33) on the same cases (83% concordance). Cross-blocking of M195 binding by MY9 and L4F3 (CD33) was demonstrated. M195 may bind to a different epitope on the same protein antigen. The presence of both MY9 and M195 positivity on a leukemia sample had a 98% specificity of diagnosing ANLL, which was greater than MY9 alone (88%) or M195 alone (92%). Assays of granulocytic-monocytic and erythroid colony-forming units showed M195 to be present on these hematopoietic progenitors. This pattern of reactivity of M195, together with its lack of reactivity with mature granulocytic elements or with adult tissues, make it a candidate for therapy of ANLL in vivo.