Transplantation of ABH incompatible bone marrow: gravity sedimentation of donor marrow.

A simple technique to separate erythrocytes from bone marrow by sedimentation under gravity after addition of hydroxyethyl starch is described. This method of removing red blood cells from the donor marrow was evaluated in 23 consecutive allogeneic bone marrow transplants between ABH-incompatible individuals. Infusion of the separated marrow was well tolerated, i.e. graft-rejection did not occur, and sustained engraftment was documented in all evaluable cases. This technique obviates the need for cumbersome and potentially hazardous large volume plasma exchange that is commonly utilized to deplete recipient isohaemagglutinins prior to transplantation.