Persistent immunologic abnormalities in long term survivors of kidney transplantation: role of different immunosuppressive treatments.

: Although immunosuppressive treatment with corticosteroids and azathioprine has become a widely employed and highly effective mode of therapy in a variety of conditions, its influence on cellular and humoral immunity is still somewhat intriguing and controversial. In order to further investigate the status of the immune system during various maintenance immunosuppressive treatments, we have studied a group of 32 long term survivors of kidney transplantation who were treated with different immunosuppressive regimens. The present investigation demonstrates the presence of a persistent defect of T and B peripheral lymphocytes in long term kidney transplant recipients. Moreover, it shows that the immune deficits are influenced by the time-dose schedule of the maintenance immunosuppressive therapy but not by the duration of the treatment. In particular methylprednisolone in a daily dose schedule (8 mg per day as a single oral dose in the morning) with or without azathioprine (1.5-3 mg/kg per day as a single oral dose in the morning) produces a global defect of T and B cell populations, while the same dosage of methylprednisolone administered every other day (16 mg every other day as a single oral dose in the morning) in association with daily doses of azathioprine exerts a sparing effect on T cell populations. The humoral parameters do not show definite abnormalities. The factors that may have contributed to the genesis of the immune imbalances we have detected are discussed.