The monitoring of canine LD responsiveness using two systems: (1) Blocking antibody in second-set renal allografts and (2) Modulation of cellular response stimuli

Therefore, the present experiments using D-R mongrel dog pairs with differing categories of MLC reactivity were performed to further define the development of blocking effects in the absence of controlled genetics. Recipients of first-set kidney allografts were followed (up to 2 years) until there was a loss of detectable lymphocytotoxic SD antibody from serum but with the persistence of MLC-inhibitory LD antibody, as confirmed by the d-MLC prior to transplantation of a second kidney from the original donor. No attempt was made to characterize the canine SD antigens, since in previous work, this had no predictive value. It was our hypothesis that conditions could be fulfilled in which the development of MLC blocking antibody could lead to prolonged renal allograft acceptance.