Efficacy of induction therapy in cadaveric renal transplantation comparing rabbit antithymocyte serum and Minnesota antilymphoblast globulin. From August 1986 to July 1989, 98 patients receiving primary cadaveric kidney transplants received either RATS (n = 50) or MALG (n = 48) during the induction phase of a quadruple immunosuppressive protocol. Patient groups were well matched. The duration of RATS and MALG treatment and the time of CyA induction were equivalent. Serum creatinine and rejection episodes up to 1 year were not statistically different. Hematologic side effects resulted in dose reduction of MALG in 42% of patients without adverse rejection results. In the RATS group, no dosage reductions were required. One-year patient survivals (96% to 100%), and 1-year graft survival (82% to 85%) were not significantly different in the 2 groups. Infectious complications were 30% higher in the MALG group and a significant factor in 2 deaths. Monitoring of lymphocyte subsets revealed insignificant differences in the percent of decrease of each cell population between MALG and RATS groups during induction. 