Effect of antilyphocyte-globulin potency on survival of cadaver renal transplants. Prospective randomised double-blind trial

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 skin-graft prolongation in rhesus monkeys. Patient selection and management were otherwise similar. A statistically significant difference (P less than 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 less than 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.