Patients at either low or high risk of graft dysfunction were ineligible; a majority of the participating centers maintained low immunological risk patients on cyclosporine alone and those with a high risk of graft dysfunction were usually maintained on corticosteroids. For this study, low risk was defined as the presence of the following: zero or one acute rejection episode with a return of renal function to previous levels after corticosteroid treatment, panel-reactive antibody titer <25%, serum creatinine level <125 µmol/L, age >25 years, and donor age <40 years. High risk was defined as the presence of at least one of the following: a serum creatinine level >250 µmol/L, proteinuria >1 g/day, panel-reactive antibody titer >80%, >1 episode of T-cell-mediated rejection or at least one episode of antibody-mediated rejection posttransplant, or the presence of vasculitis or systemic lupus erythematosus which usually were treated with corticosteroids.