Optimal blood pressure control versus additional immunosuppressive therapy in idiopathic membranous nephropathy - a retrospective analysis.

The treatment of idiopathic membranous nephropathy (MN) with nephrotic syndrome comprises immunosuppressive therapy and antihypertensive treatment with the blockade of the renin-angiotensin system (RAS). Given the relatively benign natural history of MN, an immunosuppressive-free therapeutic regimen should be considered as the primary treatment option. In a single-center, retrospective analysis we compared the outcome of 54 patients with biopsy-proven idiopathic MN 12, 24 and 60 months after initiation of therapy. All patients had RAS-blocking agents and 36 patients received additionally an immunosuppressive regimen. In both groups the patients initially had a nephrotic proteinuria (median 8.7 vs. 6.0 g/day, n.s.). Median blood pressure reduction was comparable after 12, 24 and 60 months in both groups. The median evolution of proteinuria during therapy after 12, 24 and 60 months was 3.4, 1.7 and 1.1 g/day in the group with immunosuppression compared to 3.0, 1.1 and 0.32 g/day in the non-immunosuppressive group. After 60 months no patient developed end-stage renal failure. The number of severe side effects was significantly higher in patients with immunosuppression. Regarding renal function and reduction of proteinuria, patients with idiopathic MN treated without immunosuppressive therapy but with measures to ensure optimal blood pressure control and the full blockade of RAS had a similar outcome after 60 months as compared to patients who received additional immunosuppressive therapy.