Can transfusion-associated graft-versus-host disease (TA-GvHD) be prevented with leukoreduction alone?

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare but devastating disease with a very high mortality rate. Because of the high mortality and lack of effective treatments, the current state of the art is aimed at preventing TA-GvHD and this can be accomplished via irradiation of all cellular blood products (red blood cells, granulocytes, and platelets). However, given that TA-GvHD is driven by contaminating white blood cells, and the fact that the international transfusion community has largely embraced leukoreduction, this raises the question as to whether the quantitative reduction of leukocytes via filtration can itself prevent TA-GvHD, thus allowing hospitals to skip irradiation steps? In this paper, we review the medical literature to determine how many leukocytes are needed to be removed to prevent TA-GvHD, while providing brief overviews of this entity itself and current irradiation strategies.