Primary hematuria (idiopathic benign and recurrent hematuria, Berger’s disease) is now known to be an immune complex glomerulopathy in which deposition of IgA occurs in a granular pattern in the mesangium of the glomerulus. The associated light microscope findings are variable and range from normal to extensive crescentic glomerulonephritis.
Recurrent macroscopic and microscopic hematuria and mild proteinuria are usually the only manifestations of renal disease. Most patients with IgA nephropathy are between the ages of 16 and 35 years at the time of diagnosis. The disease occurs much more frequently in males than females and is the most common cause of glomerulonephritis in Asians. While most patients continue to have episodes of gross hematuria or microscopic hematuria, the renal function is likely to remain stable. However, approximately 30% of patients will have progressive renal dysfunction and develop end-stage renal disease.
Clinical features that indicate a poor prognosis include male sex, older age at onset of disease, the presence of nephrotic-range proteinuria, hypertension, or renal dysfunction at presentation.
There is no satisfactory therapy for IgA nephropathy.
The role of immunosuppressive drugs such as steroids and cytotoxic agents is not clear, and there have been few rigorously performed controlled trials. A more intriguing approach is the use of omega-3 fatty acids (fish oils) to delay progression of the renal disease. A large prospective randomized placebo-controlled trial in patients with IgA nephropathy using 12 g of omega-3 fatty acids has shown that fish oils probably can reduce the deterioration of renal function and the number of patients in whom end-stage renal disease develops.