Treatment of Early Immunoglobulin A Nephropathy by Angiotensin-converting Enzyme Inhibitor

BackgroundThe treatment of immunoglobulin A (IgA) nephropathy with normal renal function and minimal proteinuria is unknown.MethodsWe randomly assigned 60 patients with IgA nephropathy, proteinuria <0.5 g/day, normal blood pressure and renal function to ramipril 2.5 mg daily or no treatment. Patients were followed for 5 years for the development of hypertension, proteinuria, or impaired renal function.ResultsThe blood pressure of the treatment group was marginally lower than the control group throughout the study period. At 60 months, the event-free survival was marginally higher for the treatment group as compared with the control group (81.1% vs 70.5%, P = .27). The proteinuria-free survival was similar at 82.9% and 79.3% for the treatment and control groups, respectively (P = .6); hypertension-free survival was 86.4% and 79.3% (P = .2). After 60 months of follow-up, the estimated glomerular filtration rate (GFR) was 108.1 ± 29.0 mL/min/1.73 m2 for the treatment group and 105.7 ± 17.7 mL/min/1.73 m2 for the control group (P = .7), but the difference was not statistically significant. None of the patients developed impaired renal function. The rate of GFR decline was similar between the treatment and control groups (−0.39 ± 2.57 vs −0.59 ± 1.63 mL/min/1.73 m2 per year, respectively, P = .7). In general, the study medication was well tolerated. Two patients needed to stop prematurely because of cough and dizziness.ConclusionFor early IgA nephropathy patients with minimal proteinuria, normal blood pressure, and normal renal function, treatment with 2.5 mg/daily of ramipril for 5 years does not offer any benefit.