Concanavalin a: modification of kidney graft immunogenicity in a double transplant model

This study determines the effectiveness of flush graft pretreatment with concanavalin A (Con A) in minimally immunosuppressed recipients receiving double kidney transplantation. Significant prolongation of survival was seen when both kidneys from the same unrelated donor were treated with Con A, when both kidneys from different unrelated donors were treated with Con A, or when the allogeneic kidney was treated with Con A, and the syngeneic kidney was untreated. There was no significant prolongation in kidney allograft survival when one of the two allogeneic kidneys was treated with Con A, whether they came from the same, or different donors. If only the syngeneic kidney was treated with Con A and no treatment was given to the allogeneic kidney, also no prolongation of survival was observed. Thus, this study fully agrees with previous data indicating that Con A is not acting by systemic immunosuppression, but by local changes that modify the kidney immunogenicity. The theoretical implications associated with the prolongation of graft survival after flush pretreatment with Con A are activation of suppressor T cells, enhancement, physico-chemical modifications of the cell membrane and/or others.