CD34+-selected stem cell boost for delayed or insufficient engraftment after allogeneic stem cell transplantation

Background Poor graft function without rejection may occur after stem cell transplantation (SCT). CD34 stem cell boost (SCB) can restore marrow function but may induce or exacerbate GvHD. We therefore investigated the feasibility and efficacy of CD34-selected SCB in some patients with poor graft function. We present the results for eight patients (median age 46 years) transplanted initially for myelofibrosis, acute leukemia, myeloma and NHL. Six patients had received HLAmatched and two mismatched grafts (PB, BM; n /5, 3). After a median of 128 days post-transplant, the median leukocyte and platelet counts were, respectively, 2.05/nL and 18/nL. None had achieved platelet counts � /50/nL even though donor chimerism was � /95% in seven recipients.