Background:
We evaluated the efficacy and feasibility of performing prolonged donor type fresh frozen plasma (FFP) infusion for the in vivo adsorption of isohemagglutinins (IHGs) in major ABO-incompatible allogeneic stem cell transplantation.
Methods: Forty-five patients underwent allogeneic stem cell transplantation. Major ABO incompatibility was observed in 23 patients. 18 patients of these 23 patients had IHGs directed towards the donor ABO antigens and they received donor type FFP; in 5 patients, the bone marrow grafts were minor incompatible; in 17 patients, the grafts were compatible.
Results: The engraftment times of the granulocytes and platelets and the transfusion requirements for red blood cells in the FFP-transfused recipients of the major ABO-incompatible allografts were not different from those of therecipients of ABO-compatible allografts (P＞0.1) and these factors were not different from those for the FFP-treated recipients of the major ABO-incompatible allografts. The median duration of FFP infusion and the number of FFP units were 23.5 days (range 8∼39) and 47 units (range 16∼78), respectively. The median IgG titers decreased from 1：64 to 1：4 over a median of 22.5 days (range 8∼36) in the FFP-treated groups, compared with a median of 61 days (range 19∼116) in the non-FFP-treated groups.
Conclusion: The infusion of donor-type FFP with red cell depletion represents a more feasible, effective alternative strategy to achieve in vivo immunoadsorption of IHGs and to prevent late immunohematologic complications.

Keywords: Fresh frozen plasma, Isohemagglutinins, Major ABO incompatible bone marrow transplantation