Influence of gadolinium-induced kupffer cell blockade on portal venous tolerance in rat skin allograft transplantation

BACKGROUND: Intraportal injection of donor antigens delays rejection of allografts (portal venous tolerance). The study aimed to investigate the possible influence of prior gadolinium chloride (Gd)-induced Kupffer cell blockade on tolerance to non-vascularized skin allografts induced by means of donor-specific intraportal blood transfusion. MATERIALS AND METHODS: Wistar rats (n = 10) were used as donors and Sprague-Dawley rats (n = 70) as recipients of a non-vascularized skin graft. Recipients were divided into groups according to the manipulations prior to transplantation, as follows: (1) no manipulation; (2) donor-specific intrajugular blood transfusion; (3) donor-specific intraportal blood transfusion; (4) Gd administration and donor-specific intrajugular blood transfusion; (5) Gd administration and donor-specific intraportal blood transfusion; (6) Gd administration, and (7) intraportal saline infusion. In a first set of experiments, these manipulations were performed once. In a second set of experiments, the same manipulations were performed twice. Skin allograft was performed 7 days after the last manipulation in all groups. RESULTS: Group 3 showed the highest skin graft survival, particularly after repeated blood transfusion. Graft survival in this group was significantly higher than in any other group. Conversely, group 5 showed the lowest graft survival, particularly after repeated blood transfusion. Graft survival in this group was significantly lower than that of groups 1, 2, 3 and 7. CONCLUSIONS: In this model of skin allograft transplantation, Gd administration abrogates and can even reverse the tolerogenic effect of repeated donor-specific intraportal blood transfusion.