Supportive Versus Immunosuppressive Therapy of Progressive IgA nephropathy (STOP) IgAN trial: rationale and study protocol.

INTRODUCTION: The best treatment of IgA nephropathy (IgAN) is currently not well defined. The Supportive Versus Immunosuppressive Therapy of Progressive IgA Nephropathy (STOP IgAN) trial aims to answer if, in IgAN patients, an immunosuppressive treatment is more effective than a supportive treatment.

METHODS: In a randomized prospective multicenter study (www.clinicaltrials.gov, NCT00554502), we will treat 148 patients at risk for progressive IgA nephropathy following a 6-month run-in phase, in 2 groups: (group a) supportive treatment: patients with a persistent proteinuria >0.75 g/day will receive a maximized therapy to reduce blood pressure and urinary protein loss using angiotensin-converting enzyme inhibitors and AT1 blockers, statins, dietary counseling for a low-sodium and low-protein diet and education/intervention programs to stop smoking. (group b) immunosuppressive treatment: in addition to the identical treatment of group a, patients will receive treatment with steroids (glomerular filtration rate [GFR] > or =60 ml/min) or steroids plus cyclophosphamide/azathioprine (GFR <60 ml/min). Study end points are the complete remission of the disease and the individual degree of renal functional loss. If the immunosuppressive therapy shows a superior efficacy with respect to prevention of renal failure, the potentially higher therapy cost and risk might be justified. Finally, our trial can serve as a model for various other types of glomerulonephritis, for which such trials are very difficult to perform, given their infrequency.