This retrospective study sought to compare two modes of administration of antithymocyte globulin (RATG) after renal transplantation.
Methods: Before 1993, group I patients (n = 93) received fixed doses of RATG (1 mg/kg per day) for 8 consecutive days. Thereafter, RATG was either continued at the same dose for 15 days, in cases of delayed graft function, or was infused every other day at the same dose until serum creatinine level became <150 micromol/L. After 1993, group II patients (n = 66) received RATG at full dose (1 mg/kg per day) during the first 3 days and thereafter the doses were adjusted to target a CD2 T-cell count <50/mm3. Both groups received steroids, azathioprine, and cyclosporine. The mean follow-up after transplantation was 117 +/- 31 months in group I and 93 +/- 19 months in group II.
Results: The RATG cumulative dose and consequently cost were significantly higher among group I than group II patients. Long-term patient and graft survival were similar in both groups. The rate of acute graft-rejection episodes was significantly higher among group I than group II patients. At 7 years posttransplantation, the serum creatinine level and creatinine clearance were similar in the two groups. The rate of cytomegalovirus infection, as well as the cumulative incidence of severe infections and cancers were also similar in both groups. Among the cancers, skin neoplasms represented 30% in group I and 26% in group II (P = ns).
Conclusion: Adjusting RATG doses according to the CD2 lymphocyte count is safe, and a less expensive than using full doses.