Quantitative analysis of chimerism after allogeneic hematopoietic stem cell transplantation with molecular genetic methods

Abstract

Quantitative monitoring of chimerism after allogeneic hematopoietic stem cell transplantation (HSCT) by molecular methods has becomea significant diagnostic tool in detection of engraftment / graft failure, predicting rejection and disease relapse. Despite the great utility of chimerism analysis there is not a unique standard method for its quantification. The objective of the present investigation was to compare perspective methods multiplex short tandem repeat polymerase chain reaction (STR-PCR) and real-time PCR insertion / deletion polymorphisms (InDel-PCR) for the quantification of chimerism after HSCT. We performed a study analyzing the chimerism status in 60 patients by STR-PCR and by InDel-PCR. Recipient / donor discrimination was possible with STR-PCR in all patient-donor pairs (100 %), whereas informative alleles for recipient were found in 88 % pairs with InDel-PCR. The sensitivity (detection limit) of STR-PCR and InDel-PCR was 1–5 % and more than 0.01 % donor cells correspondingly. The accuracy of quantification was higher for STR-PCR than for InDel-PCR, when level of donor chimerism was 3–97 %. These methods can be successfully used to determine chimerism after allogeneic HSCT. Considering the higher sensitivity and quantification accuracy of InDel-PCR it should be chosen if donor chimerism level less 5 % or more 95 % and in other cases STR-PCR should be chosen.

Keywords

• chimerism
• short tandem repeats
• insertion / deletion polymorphisms
• polymerase chain reaction
• fluorescence in situ hybridization
• hematopoietic stem cell transplantation