CD3⁻cd(16+56)⁺ Cell Dose Is An Important Factor Determining Clinical Outcomes in Patients Undergoing Unmanipulated HLA-Identical Sibling Hematopoietic Stem Cell Transplantation

Background: It has been suggested that the dose of the cellular components in the graft may influence the outcome of transplantation, especially CD3 ^|CD(16+56)⁺ cell(NK cell) is believed to play an important role in improving the transplant outcome in terms of preventing graft-versus-host disease(GVHD) and graft rejection, and as a mediator of the graft-versus-leukemia(GVL) effect. The current study attempted to evaluate the role of CD3⁻CD(16+56)⁺ cell dose on the outcome of HLA-identical sibling hematopoietic stem cell transplantation.

Methods: We retrospective analyzed the outcomes of 72 patients receiving HLA-identical sibling hematopoietic stem cell transplantation between July 2005 and May 2008 in the first Affiliated Hospital of Soochow University. Diagnoses of these patients included acute leukemia(AL)(n=34), chronic myeloid leukemia(CML) (n=29), aplastic anemia(AA) (n=4), malignant lymphoma (n=3) and multiple myeloma (n=2). The median follow-up time is 19 months (range 0.5–36 months) after transplantation. Transplanted doses of CD3 ^|CD(16+56)⁺ cell were analyze in relation to engraftment, GVHD, infectious events, relapse and survival.

Result: The median dose of NK cell in bone marrow grafts from patients receiving G-CSF-mobilized was 0.91× 10⁷/Kg. Therefore the group received a dose of CD3 ^|CD(16+56)⁺ cell above 0.91×10⁷/Kg wass a higher group. There were no significant difference between two groups for neutrophil and platelet recovery. The incidence of II°-‡W°aGVHD in low group was much more than that of high group(41%VS 18.2%, P<0.05). and there was a significantly higher incidence of infection in patients receiving a lower dose of CD3 |CD(16+56)+ cell (46.1%VS 21.2%, P<0.05). However there was no significant association between CD3-CD(16+56)+ cell and either cGVHD or relapse.

Conclusions: High dose of CD3⁻CD(16+56)⁺ cell may play an important role in improving the outcome of transplantation in terms of reducing aGVHD and infection.