Large doses of antihuman lymphoblast globulin (AHLG) were used prophylactically in three recipients of renal allografts from living related donors. These recipients received 1,500 mg/day of AHLG for 14 days beginning on the second day before transplantation in addition to the standard immunosuppression. Serum AHLG levels, serum anti-AHLG antibodies and T cell subsets were checked serially. The results were as follows:
1) No side effects and or complications of AHLG were encountered in these recipients.
2) None of patients treated with AHLG had any rejection episodes within three months after transplantation but after that several rejections occurred in two patients.
3) Maximum serum AHLG concentrations, reached at 10-12 days after transplantation, ranged from 252 mg/dl to 465 mg/dl. Serum AHLG levels were detected at least one month after final injection of AHLG.
4) No patients made detectable antibodies to horse IgG.
5) The values of T cell counts, % T cell and T cell subsets (Leu 3a/2a) varied considerable from patient to patient, in two cases were kept moderately low by AHLG treatment. We concluded that the effect of AHLG on T cell subsets was not distinctive.