OBJECTIVE: To study the immunosupression efficacy an specific anti-antilymphocytic serum prepared in goats in a model of cardiac allografts in rats. METHODS: Three rabbits were immunized with lymphoid cells obtained from mesenteric lymphatic nodes of Wistar rats. Each one received subcutaneously 3x10(9) cells mixed with Freund's adjuvant. After 2 weeks, they were injected with the same amount of cells at weekly intervals for 4 additional times. In the 5th week they were bled and their serum were mixed. This serum, which had a cytotoxic titer of 1:1024, was used to immunize 2 goats that gave rise to the anti-antilymphocytic serum (AAS-1 and AAS-2). As control we immunized 1 additional goat with normal rabbit serum (ANS). The gel diffusion technique (AAS x rabbit serum) showed precipitation bands against till the following dilution: AAS-1 - 1/64, AAS-2 - 1/128 and ANS 1/124. Both AAS were able to block the in vitro lymphocytotoxity of goat antilymphocytic serum till dilution of 1:2 while ANS did not. The hearts from Wistar rats (donors) were transplanted in Holtzman rats. The transplanted rats were divide in groups: C1 - 11 animals (control that received no serum); C2 - 5 animals (control that received 1ml of goat normal serum); A- 19 animals - A1 with 5 rats injected intravenously in the day of surgery with 0.5ml of AAS-1, A2 with 7 rats injected with 1ml of AAS-1 only in the of surgery, and A3 with 7 rats that received 1ml of AAS-1 in days 0, 1 and 2 postoperatively; and group B with 19 rats (B1, B2 and B3) treated as group A except with the AAS-2 serum. RESULTS: Mean heart survival in groups C1 and C2 was respectively 11.9 and 14.6 days Survival range in the subgroups A1 and A2 were respectively 9 to 230 days and 23 to 230 days. In subgroup A3 heart survival was prolonged till 29 to 190 days in 5 animals. In group B only 3 animals had prolonged (120, 130 and 129 days) heart survival in comparison with the control groups. CONCLUSION: Anti-antilymphocytic serum against donor antigen is able to suppress rejection of cardiac allograft in rats.
Cardiac allograft; cardiac transplant; antilymphocytic serum; rejection
