急性淋巴细胞白血病患儿化疗结束后T淋巴细胞克隆谱系分析

目的了解急性淋巴细胞白血病(ALL)患儿化疗结束后T淋巴细胞免疫重建情况。方法逆转录-聚合酶链反应(RT-PCR)高压变性聚丙烯酰胺凝胶电泳法检测8例正常对照及44例化疗结束后的ALL患儿外周血T细胞受体(TCR)β链可变区(BV)第三互补决定区(CDR3)的克隆谱系。结果白血病化疗结束至48个月TCRBV家族仍可见表达增高或降低(P均0.05)。化疗结束后TCRBVCDR3谱型多态性基本恢复,但寡克隆增生情况仍明显高于正常对照组(P均0.05),小于6个月组差异最明显(P均0.05)。16例普通B细胞急淋(c-ALL)BV8、BV5.1、BV5.2和BV12发生克隆性增生的频率较高,9例前B细胞急淋(pre-B)BV6家族发生克隆性增生较多。结论白血病患儿化疗结束至48个月T细胞免疫尚未完全恢复;T细胞克隆谱系异常以寡克隆增生为主。

T-cell repertoire analysis of children with acute lymphoblastic leukemia after chemotherapy

Objective To elucidate the reconstitution of immune function of T cells and to look for anti-leukemic T cell clones,and T cell repertoires of children with acute lymphoblastic leukemia in long-term survival were analyzed. Methods A method combined RT-PCR with polyacrylamide sequencing gel electrophoresis,was used to detect 44 long-term disease-free survivors and 8 age-matched healthy control donors' complementarity determining region 3 (CDR3) repertoires of T cell receptor (TCR) beta chain V (BV) region. Results Compared with that of controls,TCR BV usage of patients who had finished chemotherapy within 48 months were biased,including overexpressed or underexpressed of some TCR BV families(P<0.05). Some CDR3 repertoire of TCR BV was restricted in ALL patients finished chemotherapy from less than 6 months to more than 48 months,even though most TCR BV families' CDR3 repertoire had returned to normally Gaussian distribution. TCR CDR3 oligoclonal expansion of each group was significantly more than controls (P<0.05). Less than 6 months group had more oligoclonal expansions than the other 4 groups (P<0.05),and there were no significant difference among the other 4 groups (P<0.05). Oligoclonality often occurred in BV3,BV5.1,BV6,BV7,BV8,BV17,BV9 and BV11 in 44 patients. BV8,BV5.1,BV5.2 and BV12 had oligoclonality more often in common B cell leukemia(c-ALL) than in other types. BV6 often present oligoclonality in pre-B cell leukemia. Conclusion TCR BV CDR3 repertoire of leukemia children in long term survival from less than 6 months to more than 48 months (the longest is 72 months) is still abnormal,especially for oligoclonality,which suggested there might be anti-leukemic T cell clones in long term survivors of ALL children.