Background: The adaptation of steroid therapy and the effect of renin-angiotensin-aldosterone system inhibitors (RASIs) for advanced immunoglobulin A nephropathy (IgAN) patients with impaired renal function are still controversial.
Methods: We divided 63 IgAN patients with an estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m(2) and proteinuria ≥ 0.5 g/day into two groups: the RASI group (RASI, n = 33), treated with RASIs alone; and the combination group (COMBI, n = 30), treated with corticosteroids and RASIs. We analyzed the clinical and histological background, renal survival rate, and the risk factors for progression.
Results: Renal function (mean eGFR: COMBI 46.4 vs. RASI 47.0 ml/min/1.73 m(2)), the amount of proteinuria (median: COMBI 1.39 vs. RASI 1.17 g/g creatinine) and histological backgrounds were not significantly different between the groups, but urinary red blood cells (U-RBCs) were significantly higher in the COMBI group than in the RASI group (median: COMBI 30.0 vs. RASI 10.0 counts/high-power field, P = 0.0171). The serial change in proteinuria did not differ until 5 years after treatment, but U-RBCs were significantly decreased in both groups (P < 0.0001), and eGFR was significantly decreased in the RASI group (P < 0.001) but not in the COMBI group. The results for each year after treatment did not differ significantly between both groups. The renal survival rate was not significantly different between the groups. There was no independent risk factor for progression by Cox regression analysis.
Conclusion: Combination therapy with steroids and RASIs was not superior to monotherapy with RASIs for advanced IgAN with impaired renal function.