Follow up of hemopoietic chimerism in individuals given allogeneic hemopoietic stem cell allografts using an immunosuppressive, non-myeloablative conditioning regimen: a prospective study in a single institution.

Thirty consecutive patients were given non-myeloablative stem cell transplants (NST) and posttransplant chimerism was studied by several methods. In 16 individuals definitive proofs of chimerism have been shown: In 10 cases sex chimerism, in 7 cases chimerism shown by means of microsatellites, in 4 cases ABO chimerism, in two cases Rh chimerism and in one HLA-DR chimerism. In addition, in 9 individuals the disappearance of the molecular marker of the leukemia is an indirect evidence of the chimerism, as well as the presence of graft versus host disease (GVHD) in 17 allografted patients.