Significance and methods of chimerism analysis after allogeneic hematopoietic stem cell transplantation

Abstract

Chimerism analysis is the crucial assay which confirms engraftment and surrogates relapse, or graft failure associated with immune rejection, after allogeneic hematopoietic stem cell transplantation. Salvage transplantation and／or donor lymphocyte infusion should be considered for cases with increasing recipient chimerism which warrants graft rejection or post-transplant relapse. On the other hand, cytopenias in multiple hematopoietic lineages despite complete donor chimerism indicate poor graft function. Fluorescence in situ hybridization(FISH)for sex chromosomes is the only method of chimerism analysis approved for coverage of Japanese public health insurance. However, short tandem repeat PCR (STR-PCR)and quantitative real-time PCR(qPCR)are more major methods for chimerism analysis in worldwide accredited laboratories as well as many Japanese laboratories. The advantages of PCR-based methods over FISH include higher informativity for discrimination of donor and recipients and requirement of fewer cells for an accurate assay. We are eager that the PCR-based methods will be publicly approved for chimerism analysis in Japan. (Japanese