Serial Analysis of Chimerism in Patients With Refractory Cytopenia (RC) Transplanted With Reduced Intensity Conditioning (RIC)
- To study hematopoietic chimerism in whole blood and different cell populations (i.e.,
CD14, CD15, CD 56, CD3, and CD19) as well as in dendritic cells and regulatory T cells
after allogeneic hematopoietic stem cell transplantation with reduced intensity
conditioning in patients with refractory cytopenia.
- To compare the results of chimerism obtained with standard short tandem nucleotide
polymorphism PCR (sensitivity 1%) with those obtained with single nucleotide
polymorphisms PCR (sensitivity 0.1- 0.01%).
- To evaluate the relationship between mixed chimerism and hematological engraftment,
overall survival, and event-free survival.
- To study the impact of mixed chimerism in plasmacytoid dendritic and regulatory T cells
on the incidence of acute and chronic graft-versus-host-disease.
OUTLINE: This is a multicenter study.
Peripheral blood is collected from patients and donors prior to hematopoietic stem cell
transplantation (HSCT). Patients also undergo blood sample collection on days 30, 60, 100,
and 180 after transplantation. Peripheral blood cells are enriched and separated into
lineage-specific subpopulations (i.e., CD3, CD14, CD15, CD19, and CD56) which are then
divided equally for either DNA isolation via PCR or for flow cytometry. DNA concentrations
in pre-HSCT donor and patient samples and in post-HSCT subpopulation samples are determined
using quantitative real-time PCR. Samples are also analyzed for quantification of chimerism
and detection of genetic markers via short tandem repeats- and sequence nucleotide
polymorphism-based chimerism analyses.
Number of patients with complete chimerism as measured by standard short tandem nucleotide polymorphism PCR in whole blood and the different cell populations
Peter Bader, MD
European Working Group of MDS in Childhood