Treatment of IgA nephropathy.

IgA nephropathy (IgAN) is an important cause of progressive kidney disease with 25-30% of patients developing end-stage renal disease within 20 years of diagnosis. There is still no treatment to modify mesangial IgA deposition and available treatments are those extrapolated from the management of other patterns of chronic glomerulonephritis. There remains no consensus on the use of immunosuppressive agents for treatment of progressive IgAN and this is compounded by the relative lack in IgAN of randomized controlled trials relevant to current clinical practice. Patients with recurrent macroscopic hematuria or isolated microscopic hematuria and proteinuria <1 g/24 h require no specific treatment. Those with nephrotic syndrome and minimal change on renal biopsy should be managed as for minimal change nephropathy. There is no evidence to support the use of corticosteroids for nephrotic IgAN outside this group of patients. Patients presenting with acute renal failure require evaluation to distinguish acute tubular necrosis, which requires supportive therapy only, from crescentic IgAN, for which treatment with cyclophosphamide and corticosteroids in a regimen similar to that for renal small vessel vasculitis is indicated in the absence of significant chronic histologic injury. Patients at greatest risk of progressive renal impairment are those with hypertension, proteinuria >1 g/24 h, and reduced glomerular filtration rate at diagnosis. All such patients should be treated to a blood pressure of 125/75 mm Hg with dual blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibition and angiotensin receptor blockade. At present, there is insufficient evidence for the additional use of immunosuppressive agents, antiplatelet agents, or anticoagulants.