1. One hundred milliliters of stored whole blood DST, three times at weekly intervals is a practical, less immunizing and effective approach to enhance graft survival in recipients of a living-related donor kidney. 2. This protocol could also be used in sibling donor/recipient pairs who do not share a haplotype as well as in those who share two haplotypes to enhance graft survival. 3. The use of a short course of Cs (6 mg/kg/d for three weeks) along with DST appears to reduce the sensitization rate even lower. The dose of Cs used in this study produced no clinically significant adverse reactions, whereas Aza (1 mg/kg/d) often produces leukopenia. 4. DST produces significantly suppressed donor specific MLC responses in the early post-DST period; however, it increases the response at a later time. DST modulates immune responses in such a way that secondary responses upon grafting are more readily reversible by immunosuppressive agents.