We evaluated the safety and efficacy of leflunomide in patients with lupus nephritis in a prospective open label study. Nineteen consecutive patients who fulfilled the revised American College of Rheumatology criteria for systemic lupus erythematosus (SLE)¹ and with proteinuria ⩾2 g/day were invited to participate. The patients were chosen because of previous treatment related toxicities (six patients with severe sepsis) or a contraindication to the use of cyclophosphamide (one patient newly diagnosed with lupus nephritis and cryptococcal meningitis) or lack of response to immunosuppressive treatments including cyclophosphamide (mean (SD) cumulative dose 9 (6) g), azathioprine or ciclosporin for at least 6 months with persistent proteinuria ⩾2 g/day for at least 3 months (12 patients). Two patients were excluded because of increased liver enzymes (one patient) and refusal to give consent (one patient). The study protocol was approved by the local ethics committee and consent forms were signed by all 17 subjects.

Previous immunosuppressive drugs were …