Immunogenetic studies in semi-inbred pigs.

Seventy-six siblings from 11 semi-inbred families of Landrace pigs (inbreeding coefficient 0.70-0.82) were used for transplantation of skin and renal allografts. The animals were selected with regard to the major histocompatibility complex SLA, alloantigenic systems SLB, SLC and blood groups. Using the test of the difference in mean level between two groups of observations, the influence of compatibility in the E blood group system on the survival of transplants was proved. The observed difference suggests that the E blood group complex or a linked locus behaves as a minor histocompatibility system. The induction of tolerance in piglets treated and non-treated with allogeneic sera from long-term liver recipients was also investigated. Large doses of sera did not exert any effect on skin graft survival.