Background: IgA nephropathy is the most common form of idiopathic glomerulonephritis. There is no current consensus on treatment for this condition. We report on the effect of immunosuppression with corticosteroids and cyclophosphamide for the treatment of IgA nephropathy associated with crescenteric change.
Methods: The effect of oral prednisolone (0.8 mg/kg initially, reducing to 0.4 mg/kg after 4 weeks) and cyclophosphamide (1.5 mg/kg) given until a plateau of response was obtained was studied in 9 patients with IgA nephropathy associated with severe inflammatory change and crescents. The initial diagnostic renal biopsies of these patients revealed 25-70% of the glomeruli effected with active cellular crescents. When response to therapy, plateaued cyclophosphamide was discontinued and prednisolone reduced from 0.4 mg/kg. Follow-up renal biopsy was performed in 8 of the 9 patients. Patients were maintained on prednisolone (5- 7.5 mg) and azathioprine (1 mg/kg) for further 2 years.
Results: The mean time until discontinuation of cyclophosphamide was 17.8 weeks (+/-1.23, range 12-25 weeks). There were no serious complications of therapy. There was an improvement in renal function in all patients with serum creatinine falling from a mean of 149.6+/-16.5, range 81-227 micromol/l to 116.4+/-8.6, range 80-158 micromol/l, p=0.01. Creatinine clearance improved from a mean of 57.1+/-9.9, range 21-104 ml/min to 87.2+/-10.1, range 39-125 ml/min, p=0.004. 24-hour urinary total protein fell over the same time m period from a mean of 4.54+/-1.1, range 1.0-11.27 g to 1.2+/-0.27, range 0.01-2.65 g, p=0.004. There were no significant differences in blood pressure during this time. Repeat renal biopsies showed significant degrees of histological improvement with healing of crescents and a reduction in acute inflammatory change in all except one patient. The mean period of follow-up after cessation of cyclophosphamide was 17.4+/-2.8 months, range 10-36 months. There was no significant change over this period in serum creatinine, creatinine clearance or urinary protein losses.
Conclusion: These data suggest that IgA nephropathy associated with severe inflammatory and crescenteric change can be effectively and safely treated with a low-cost regime based on oral corticosteroids and cyclophosphamide tailored to a plateau of treatment response in individual patients.