Quantitative Monitoring Of Chimerism Following Multi-donor Hematopoietic Stem Cell Transplantation

Objective:To establish a model for detecting the donor chimerism rate following the multi-donor hematopoietic stem cell transplantations,using fluorescently labeled multiplex PCR of short tandem repeats (STR-PCR) and simplified calculation method at last.Methods:From February2010to June2012, patients with hematologic disease receiving hematopoietic stem cell transplantation including single-donor and multi-donor were selected in this study and the donor cell chimerism rate were detected, using STR-PCR combined with capillary electrophoresis.1. Selected peripheral blood or bone marrow samples following single-donor or multi-donor transplantations, in the mixed chimerism, compared peak areas of alleles coming from the same sources.2. In the mixed chimerism, compared the reference chimerism value and approximate chimerism value, using the hypothetical peak areas.Results:1. In the situation of mixed chimerism, the peaks of the sister alleles coming from the same individual were confirmed to have the approximate area.2. Based on the idea of "alternative", established a model for detecting the donor chimerism rate, and simplifying the arithmetic calculations for double-donor chimerism.3.In the calculation model, the value between reference chimerism and approximate chimerism have no significant difference using the hypothetical peak areas,and the result was confirmed to be accepted basing on typical measurement error between sister alleles(5%-20%). Conclusions:1. In the situation of mixed chimerism following single-donor or multi-donor transplantations, the peaks of the sister alleles coming from the same individual sources were confirmed to have the approximate area and height and could be substituted for each other.2.The characteristics for informative loci were easily defined, and highlighted the strategic importance of using and/or approximating the measurement for the R alleles. Of course, calculating%CHM requires information on D alleles as well, but the observation on the R alleles was particularly useful because it allowed simplifying the arithmetic calculations for%DD-CHM.