Herstellung und Wirkung heterologer Antihundelymphocytenseren

[Long-term therapy using horse anti-dog lymphocyte globulin without sensitization against horse protein]

Eight mongrel dogs received a standard daily i.v. infusion of 20 mg/kg b.w. deaggregated horse-anti-dog-lymphocyte-globulin (ALG) and additional prednisolone (1 mg/kg b.w. daily i.v.) over a maximum period of 82 days following pretreatment with deaggregated normal horse IgG. No sensitization against horse protein was observed during therapy of afterwards as proved by lack of humoral antibodies against horse antigens, maintained lymphopenia, good compatibility, longterm prolongation of xenogeneic skin graft survival (85.6+/-20.6 days, n=8' untreated controls 12.5+/-1.3 days, n=4) and longterm suppression of cytotoxic antibodies against donor lymphocytes. The level of preformed agglutinating antibodies against horse erythrocytes was significantly reduced, while preformed antibodies against other species remained normal. The immune response to a challenge injection of anti-lymphocyte-serum (ALS) 6-11 weeks after termination of treatment was significantly lower in the ALG treated animals as compared to the control group. These results suggest the involvement of a specific mechanism of unresponsiveness against ALG other than immunosuppression only. It is concluded, that by the described method sensitization against ALG can be prevented during longterm treatment.

[Long-term graft survival in the xenogeneic system wolf-dog (author's transl)]

In contrast to the zoological definition that wolf and dog belong to different species, it is shown by this study that in terms of immunology both species appear to be even closer related than DL-A compatible and MLC negative unrelated dogs. However, this close relationship is not expressed in DL-A or MLC tissue typing. Wolf skin-graft survival time in untreated dogs was 12,5, in ALG-treated dogs 85,6 days. The survival time in this system may be less dpendent on DL-A or MLC histocompatibility than on other genetic systems, which are hitherto not sufficiently defined. An accidental, speciesspecific accordance in these systems may explain the obviously weak histocompatbility barrier between wolf and dog. It is concluded that in certain species-combinations xenotransplantation could be more successful than random allotransplantation. The availability of a xenogeneic species related to man similar as wolf to dog would markedly facilitate clinical xenotransplantation.

Cumulation and elimination of horse-anti-dog lymphocyte and normal horse gammaglobulin in dogs

Two groups of dogs received daily intravenous doses of 20 mg/kg 131-I-labelled horse-anti-dog lymphocyte globulin or normal horse gammaglobulin respectively over a period of 11 days. Horse-anti-dog lymphocyte globulin showed a significantly higher eleimination rate than normal horse gammaglobulin. In contrary to the continuous increase in serum radioactivity during normal horse gammaglobulin treatment, there was a plateau after the 5th day in the horse-anti-dog lymphocyte globulin group. The xenogeneic protein concentration, measured with the single radial immunodiffusion technique, at the end of treatment was 165 +/- 8 mg/1 in the horse-anti-dog lymphocyte globulin, compared to 498 +/- 15 mg/1 in the normal horse gammaglobulin group. After treatment horse-anti-dog-lymphocyte globulin treated animals showed a significantly higher increase in active hemagglutination titer against horse erythrocytes with an average of 2(-8).