Treatment of early immunoglobulin A nephropathy by angiotensin-converting enzyme inhibitor

Abstract

Background: The treatment of immunoglobulin A (IgA) nephropathy with normal renal function and minimal proteinuria is unknown.

Methods: We 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.

Results: The 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 m(2) for the treatment group and 105.7±17.7 mL/min/1.73 m(2) 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 m(2) per year, respectively, P=.7). In general, the study medication was well tolerated. Two patients needed to stop prematurely because of cough and dizziness.

Conclusion: For 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.