Management of IgA nephropathy: evidence-based recommendations.

The condition known as IgA nephropathy was first identified when Berger observed mesangial staining for IgA in healthy patients with isolated hematuria. These patients often presented with recurrent synpharyngitic hematuria or less frequently with asymptomatic microscopic hematuria and proteinuria. Although initially considered benign, we now recognize it as a common cause of end-stage renal failure. The overall prognosis may be better than suggested in the literature, as patients with mild asymptomatic hematuria are often not biopsied and, therefore, frequently are not included in published articles. We reviewed prospective and retrospective adult studies published after 1976 and analyzed them to produce evidence-based recommendations. Patients with proteinuria over 3 g/day, mild glomerular changes only, and preserved renal function (creatinine clearance over 70 ml/min) should be treated with prednisone. Steroids reduce proteinuria (grade B recommendation) and stabilize kidney function (grade C). The combination of cyclophosphamide, dipyridamole and warfarin should not be used (grade A), nor should cyclosporine A (grade B). In patients with progressive disease (creatinine clearance of less than 70 ml/min), fish oil should be given (grade B). A tonsillectomy could reduce proteinuria and hematuria in those patients with recurrent tonsillitis (grade D). Those with hypertension should be treated promptly with an angiotensin-converting enzyme inhibitor (grade B).