Serial Analysis of Chimerism in Patients With Refractory Cytopenia (RC) Transplanted With Reduced Intensity Conditioning (RIC)

This is a prospective, non-randomized multi-center multi-national study to evaluate the chimerism measured by STR and SNP in patients with hypoplastic RC and normal karyotype transplanted with a preparative regimen of reduced intensity. Primary objectives: * To study hematopoietic chimerism in whole blood and different cell population (CD14, CD15, CD 56, CD3, CD19) as well as in dendritic cells and regulatory T-cells after SCT with RIC in patients with RC * To compare the results of chimerism obtained with standard STR PCR (sensitivity 1%) with those obtained with SNP PCR (sensitivity 0.1- 0.01%) Secondary objectives: * To evaluate the relationship between mixed chimerism and hematological engraftment, OS and EFS * To study the impact of mixed chimerism in plasmacytoid dendritic and regulatory T-cells on the incidence of acute and chronic GVHD