Long-term efficacy of azathioprine treatment for proliferative lupus nephritis

Background. Combination therapy with cytotoxic drugs and corticosteroids reduces the risk for renal failure in patients with proliferative lupus nephritis (PLN), but uncertainty remains about the best mode of immunosuppression and its long-term effects. We report long-term results of combined azathioprine-prednisolone treatment for PLN, which has been the therapy of choice for the treatment of PLN at our centre for 15 yr. Patients and methods. A retrospective cohort study was carried out of 26 lupus patients, seen between 1978 and 1993, with histological and/or clinical evidence of PLN. Therapy consisted of prednisolone 1 mg/kg daily, tapered after 4 weeks to the lowest possible maintenance dose combined with azathioprine up to 2.5 mg/kg. Median duration of azathioprine treatment was 53 months. Standard statistical lifetable analyses were performed. Results. Median follow-up on 1 January 1998 was 119 months. Patient survival estimates after 5, 10 and 15 yr of follow-up were 96, 91 and 82%, respectively. Four patients (15%) developed end-stage renal failure and three received renal transplants after a mean period of 27 months on haemodialysis. Renal survival estimates after 5, 10 and 15 yr of follow-up were 92, 87 and 87%, respectively. No malignancies were seen during the study period. Conclusion. Azathioprine treatment for 4 1/2 yr was well tolerated in this cohort of Caucasian patients with PLN and was associated with outcomes similar to those reported for pulse cyclophosphamide therapy.