Effect of Antilymphocyte Globulin Potency on Survival of Cadaver Renal Transplants

71 recipients of cadaver primary and secondary renal transplants were investigated in a prospective randomised double-blind study. Patients were given one of two rabbit antilymphocyte globulin (A.L.G.) preparations made by similar techniques but differing in potency as measured by skingraft prolongation in rhesus monkeys. Patient selection and management were otherwise similar. A statistically significant difference (p<0•05) in graft survival (78% vs. 42%) developed between the two groups at a mean follow-up of 18•4 months and patient entry into the study was terminated. After a 3•5 year interval from the start of the trial the double-blind code was broken. It was found that the high-potency-A.L.G. group had better graft survival and fewer rejection episodes (p<0•05) than the moderate-potency group. The results suggest that preclinical testing of A.L.G. by the primate skin graft test can be a valid indicator of the potential efficacy of an A.L.G. preparation in renal-transplant recipients. It is suggested that quality-control standards may improve the clinical results of A.L.G. therapy.