末端脱氧核苷酸转移酶(TdT)为造血系统中不成熟淋巴细胞特异性强的细胞内标记。此酶最先山 Bullum 等在正常胸腺细胞内测得,随后 Coleman 等发现正常骨髓的少量淋巴细胞内亦有此酶的活性,而外周血淋巴细胞中则缺乏。自1979年 McCaffrey 等首次在1例急性淋巴细胞白血病(ALL)患者的外周血 Terminal deoxynucleotidyl transferase (TdT) is an intracellular marker that is immature lymphocytes specific in the hematopoietic system. The enzyme first Hill Bullum and other measured in normal thymocytes, then Coleman found that a small number of normal bone marrow lymphocytes also have this enzyme activity, while the lack of peripheral blood lymphocytes. Since 1979, McCaffrey and other first time in 1 case of acute lymphoblastic leukemia (ALL) patients with peripheral blood