Blocking antibodies and T cell subsets in long-term survivors of renal allografts.

Fc-receptor blocking antibodies as well as T cell subsets were studied in a group of 12 long-term survivors of renal allografts. The absolute number of T suppressor cells was similar to that found in a control group, but there was a significant decrease in the total number of T helper lymphocytes and a decreased helper/suppressor ratio. Sera from all patients tested showed inhibitory activity in the erythrocyte antibody model against leukemic B lymphocytes, demonstrating the presence of Fc-receptor blocking antibodies. Also inhibited was the ability of normal human lymphocytes to form E rosettes and to induce a local xenogeneic graft-versus-host reaction. These findings indicate that the Fc blocking antibodies are beneficial to the patient, possibly by abrogating the cellular and humoral immune mechanism that is detrimental to the kidney allograft.