Analysis of post-transplant chimerism by using a single amplification reaction of 38 Indel polymorphic loci

In order to detect chimerism after allogeneic hematopoietic SCT (HSCT), several methods have been developed. In this study we describe the use of a set of insertion/deletion (Indel) polymorphic loci to determine the level of donor cell engraftment. We analyzed 50 DNA samples from patients who had undergone HSCT, and also several artificial chimeric samples created by mixing different DNA specimens from non-transplanted donors in various proportions. A specific set of 38 autosomic Indel polymorphisms were analyzed. For comparison purposes, a set of 15 short tandem repeats (STRs) were analyzed using the Identifiler Plus Amplification Kit. Our results suggest that Indel-based and STR-based procedures behave similarly in most cases. However, Indel analysis may provide additional information in some cases with a small minor chimeric component or when the presence of stutter bands complicates chimerism estimation.