Long-term outcome of a prospective randomized trial of conversion from cyclosporine to azathioprine treatment one year after renal transplantation

Transplantation. 1998 Nov 15;66(9):1186-92. doi: 10.1097/00007890-199811150-00013.


Background: Since the introduction of cyclosporine (CsA), 1-year renal allograft survival has improved, but concern persists about the long-term adverse effects of CsA, especially with respect to renal function and blood pressure. This randomized controlled trial was set up to establish whether withdrawal of CsA would alter long-term outcome.

Methods: Adult patients who, at 1 year after renal transplantation, had a stable serum creatinine of less than 300 micromol/L and who had not had acute rejection within the last 6 months were eligible for entry. Patients were randomized either to continue on CsA (n=114) or to stop CsA and start azathioprine (Aza, n=102). All patients remained on prednisolone. Median follow-up was 93 months after transplantation (range: 52-133 months).

Results: There was no significant difference in actuarial 10-year patient or graft survival (Kaplan-Meier), despite an increased incidence of acute rejection within the first few months after conversion. Median serum creatinine was lower in the Aza group (Aza: 119 micromol/L; CsA. 153 micromol/L at 5 years after randomization, P=0.0002). The requirement for antihypertensive treatment was also reduced after conversion to Aza; 75% of patients required antihypertensive treatment at the start of the study, decreasing to 55% from 1 year after randomization in the Aza group and increasing to >80% in the CsA group (55% (Aza) and 84% (CsA) at 5 years after randomization, P<0.005).

Conclusions: Conversion from CsA to Aza at 1 year after renal transplantation results in improvement in both blood pressure control and renal allograft function, and is not associated with significant adverse effects on long-term patient or graft survival.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Acute Disease
  • Adolescent
  • Adult
  • Aged
  • Azathioprine / adverse effects
  • Azathioprine / therapeutic use*
  • Blood Pressure
  • Cardiovascular Diseases / etiology
  • Cyclosporine / adverse effects
  • Cyclosporine / therapeutic use*
  • Female
  • Follow-Up Studies
  • Graft Rejection / prevention & control
  • Graft Survival / drug effects
  • Humans
  • Infections / etiology
  • Kidney / physiology
  • Kidney Transplantation / immunology*
  • Male
  • Middle Aged
  • Prospective Studies
  • Time Factors
  • Treatment Outcome


  • Cyclosporine
  • Azathioprine