急性淋巴细胞白血病T细胞受体γ、δ链基因的重组

Rearrangements of the T Cell Receptorγand δchain Genes in Acute Lymphoblastic Leukemia

本文对３７例形态学上确认为急性淋巴细胞白血病患者（ＡＬＬ）的免疫表型、Ｔ细胞受体（ＴＣＲ）γ、δ链基因以及免疫球蛋白重链（ＩｇＨ）基因的重组进行了研究。根据免疫表型分析，有２６例为Ｂ系ＡＬＬ，８例为Ｔ－ＡＬＬ，２例为急性未分化白血病（ＡＵＬ）及１例粒系白血病。发现在Ｔ－ＡＬＬ中ＴＣＲ基因的重组有时序性，δ基因的重组先于γ基因；在Ｂ系ＡＬＬ中，绝大多数均发生γ和δ基因的重组和（或）缺失，且重组类型与Ｔ－ＡＬＬ不同；相反，ＩｇＨ基因的重组仅见于Ｂ系ＡＬＬ。ＡＬＬ基因型分析是非常有用的克隆标志，并为了解人类早期的淋巴细胞分化提供了重要资料。另外还证实ＴＣＲγ基因Ｖ－Ｊ接头部顺序的测定可以作为检测临床缓解期患者微小残余病变的克隆标志。

The immunophenotype rearrangements of the T Cell receptor (TCR)γand δchain genes as well as the immunoglobulin heavy chain (IgH)gene were studies in 37 cases of morphologically defined acute lymphoblastic leukemia (ALL).According to the expression of differentiation antigens,8 cases were classified as T-ALL,26 as B lineage ALL,2 as acute undifferentiated leukemia (AUL)while one exhibited a myeloid phenotype.A temporal order of TCR gene rearrangements was observed in T-ALL,with the δgene preceding the γ gene.Bothe genes were also found frequently rearrange and/or deleted in high proportion of ALLL of B cell lineage. However, the patterns of gene rearrangements were somewhat different between the T and B lineage ALLs.In contract,the IgH gene rearrangements were observed only in the B lineage ALL.The immunogenotype analysis of ALL was proved to be a useful marker of the clonality and provided us important informations on the early lymphoid differentiation in humans.We also demonstrated that the determination of TCRγ gene V-J junctional sepuence can be used as a clonal marker for detecting minimal residual disease during clinical remissions.