[Complement system and lymphocytotoxic antibodies in presensitized dogs after homologous lung transplantation ].

Left side orthotopic homotransplantation of the lung was performed in 8 mongrel dogs pre-sensitized by full-thickness skin transplants. The degree of sensitization was assessed by control of the lymphocytotoxic antibody titre. The behaviour of haemolytic complement activity, as well as the alterations in antibody titre were recorded up to 60 minutes after opening of the anastomoses. Evaluation was performed by analyses of significance. A significant decrease in lymphocytotoxic antibody titre (p less than 0.001), as well as a significant diminution in complement activity (p less than 0.01) was observed in blood samples from the pulmonary vein of the graft during the first five minutes following recirculation. This resulted from an interaction of both systems in the immune reaction. The further complement consumption by the graft in contrast to the constancy of the lymphocytotoxic antibody titre in the subsequent post-transplantation period can be explained by antibody-independent complement activation. Vena cava-- pulmonary vein differences in the lymphocytotoxic antibody titre and complement activity are correlated only five minutes after opening of the anastomoses (r = 0.75), which confirms the independence of both systems during later course of the reaction.