Application of short tandem repeat in monitoring engraftment of allo-hematopoietic stem cell transplantation

Hongyan ZOU; Zhen LI; Ge SUN; Qian LI; Tianli WEI; Lianghong CHENG; Zhihui DENG

ABSTRACT

BACKGROUND:

The judgment of the engraftment of hematopoietic stem cells after transplantation mainly depends on various genetic labeling in vivo, which are different in sensitivity and effectiveness, thus a method with powerful differential ability, high sensitivity and not restricted by sex is to be established.

OBJECTIVE:

To observe the DNA genetic loci of short tandem repeat in the blood samples of both donors and recipients before allo-hematopoietic stem cell transplantation and those of recipients at different time points after transplantation.

DESIGN:

An observation measurement.

SETTING:

Laboratory of Immunogenetics, Shenzhen Institute of Transfusion Medicine, Shenzhen Blood Center.

PARTICIPANTS:

Blood samples of 18 pairs of donors and recipients, who were successfully matched and accepted hematopoietic stem cell transplantation, were selected from the Laboratory of Immunogenetics, Shenzhen Institute of Transfusion Medicine, Shenzhen Blood Center from February 2004 to December 2005. Among the 18 patients, there were 10 males and 8 females, with a mean age of 35 years old, including 6 cases of them were donated by relatives with blood relationship, and 12 cases by volunteers without blood relationship. Informed consents were obtained from all the participants.

METHODS:

The blood samples of both donors and recipients before transplantation and the blood samples of recipients after transplantation were collected, and the fluorescence labeling short tandem repeat technique was used to detect the 15 loci for short tandem repeat and Amelogenin sex locus, so that the differential loci between the donor and recipient could be screened. The engraftment and dynamic changes of the short tandem repeat genes of the donors in the recipients after transplantation were observed, the times for the earliest occurrences of short tandem repeat genes of the donors and the complete chimerism were recorded.MAIN OUTCOME

MEASURES:

① Differential genes between the donors and recipients before transplantation;②Times for the earliest occurrences of short tandem repeat genes of the donors and the complete chimerism.

RESULTS:

All the 18 pairs of donors and recipients were involved in the final analysis of results. Satisfactory results of the typing at the 15 loci for short tandem repeat and 1 sex locus in the 18 pairs of samples of both donors and recipients before transplantation and the sample of the recipients after transplantation respectively. Averagely 12.4 (8-15) differential loci for short tandem repeat could be distinguished between the donors and recipients. ②After transplantation, short tandem repeat genes could be detected the earliest at 8 (5-14) days averagely, It took 14 (9-23) days averagely for short tandem repeat loci to convert from recipient type completely into donor type, and the engraftment converted from the recipient chimerism types completely into the donor types.

CONCLUSION:

The fluorescence labeling compound amplification of short tandem repeat technique can precisely measure the number of PCR products, describe the engraftment of hematopoietic stem cells and the whole process of development. It can also provide accurate and timely information for the early judgement of engraftment, predicting failure of transplantation and controlling recurrence.