供体细胞嵌合率的动态定量检测在供体淋巴细胞回输中的应用

为了探究供体细胞嵌合率 (DC)的动态定量检测在确定供体淋巴细胞回输 (DLI)时机和预测DLI疗效中的作用 ,应用复合扩增荧光标记STR PCR结合毛细管电泳方法 ,对 6例接受异基因造血干细胞移植后早期复发或移植物被排斥并接受DLI治疗的白血病患者 ,进行了DC的动态定量检测。结果发现 ,复发或排斥发生时 6位患者DC均出现大幅度下降 ,介于 2 7.3% - 85 .7% ,4位患者从DC下降 (<90 % )到出现临床复发或排斥的中位时间为2 6天 ,提示DC进行性下降的患者为复发或排斥的高危患者 ,可早期实施DLI干预治疗。 2例患者出现治疗反应 ,治疗有效患者在DLI后短期内出现DC回升 ,供体细胞占优势 ,并转化为稳定的完全供体细胞嵌合状态 (FDC) ,临床上出现移植物抗宿主病 (GVHD)表现。无效患者DLI后DC均无稳定回升现象 ,并对 3例DLI无效患者进行了第二次DLI治疗。结论 :嵌合体检测可指导DLI的实施时机 ,预测DLI的临床疗效 ,而且对首次DLI治疗无效的患者的后继强化治疗提供重要的参考依据。

Application of Sequential and Quantitative Analysis of Donor Chimerism in Donor Lymphocyte Infusion

In order to study the value of sequential and quantitative analysis of chi merism in determination of optional time of donor lymphocyte infusion (DLI) and prediction of efficacy of DLI, six patients with leukemias who relapsed or failed of engraftmen t were treated with DLI. Serial and quantitative analyses of donor chimerism (DC ) both prior to and following DLI were performed by multiplex PCR amplification of STR markers (STR-PCR) and capillary electrophoresis with fluorescence detec ti on. The results showed that at the time of relapse or graft rejection, STR-PCR indicated the decreasing donor chimerism in all six patients, at levels ranging from 27.3% to 85.7%. The de clining value of DC (<90%) was detected in four patients at 26 days before relap se or graft rejection diagnosed clinically. Therefore the decrease of value of D C can be identified the high risk of relapse or graft failure and ca n be used to guide DLI implementation at early stage. In this study t he clinical response were seen in two patients, the value of DC in these patis ents increased with convertion to a predominant donor profile (>90%) or converte d to stable FDC shortly after DLI, while in the patients without clinical respon se, the level of DC decreased persistently or declined after transient increase . Three patients without response received second DLI. It is concluded that the monitoring of chimeri sm is proved to be a valuable to determine the optional time point of DLI and to early evaluate the efficacy of DLI. Furthermore, it can present a ra tional basis for treatment of intensification in the patients who did not respon d to first-line DLI treatment.