Treatment of acute rejection of cadaveric renal allografts with rabbit antithymocyte globulin.

In a prospective randomized single-blind trial, we compared the effectiveness of rabbit antithymocyte globulin (RATG) in the treatment of acute renal graft rejection with the results of treatment by high oral doses of prednisone. Twenty recipients of cadaveric kidneys were included in each group. In the RATG group, the prednisone dose was not increased and a dose-by-rosette protocol was used to keep T cell levels between 50 and 150/mm3. In this group 15 of the 20 patients responded to the treatment. One of these patients lost her kidney afterward because of a technical failure. In five patients rejection was irreversible despite a subsequent course of high-dose prednisone orally. In the prednisone group, 13 patients showed a good response, but 3 of them only after a subsequent course of RATG. The remaining seven patients underwent nephrectomy before a course of RATG could be given. One patient in this group died of septicemia. In either group there were six second rejection episodes, but they developed 2.2 months later in the RATG group. All second rejection episodes were treated with the alternative regimen and all patients responded to this treatment. Renal function after 6 months was similar in both groups. Less infections occurred in the RATG group. Prior to rejection, there were no differences in concentrations of peripheral T cells between both groups. Treatment of acute rejections with RATG is an effective and safe procedure which is steroid sparing.