Why, When and How should Immunosuppressive Therapy considered in Patients with IgA Nephropathy

Abstract IgA Nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Lifelong mesangial deposition of IgA1 complexes subsist inflammation and nephron loss but the complex pathogenesis in detail remains still unclear. In regard to the heterogeneous course, classical immunosuppressive and specific therapeutic regimes adapted to the loss of renal function will here discussed in addition to the essential common renal supportive therapy. Renal supportive therapy alleviates secondary, surrogate effects or sequelae on renal function and proteinuria of high intraglomerular pressure and subsequent nephrosclerosis by inhibition of the renin angiotensin system (RAASB). In patients with physiological (ΔGFR  1 g/day after RAASB), corticosteroids have shown a reduction of proteinuria and might protect further loss of renal function. In patients with progressive loss of renal function (ΔGFR > 3 ml/min within 3 months) or rapidly progressive course with or without crescents in renal biopsy, cyclophosphamide with high dose corticosteroids as induction therapy and azathioprine maintenance is proven effective in one randomized controlled study a homogeneous cohort in loss of renal function (ΔGFR). Mycophenolic acid provided further maintenance in non randomized trials. Differentiated, precise, larger, randomized, placebo controlled studies focused on the loss of renal function in the heterogeneous forms of IgAN are still lacking. Prospectively, less toxic agents will be necessary in the treatment of IgAN. This article is protected by copyright. All rights reserved.