IgA Glomerulonephritis, Asymptomatic Hematuria, and Systemic Disease

Isolated persistent or recurrent hematuria is a common diagnostic problem in clinical practice. When extrarenal causes of hematuria are carefully excluded, a renal biopsy is usually indicated. Most often, light microscopy discloses a mild form of focal glomerulonephritis often indistinguishable from that seen in Henoch-Schölein purpura (HSP) or in some patients with systemic lupus erythematosus. The routine use of immunofluorescence and electron microscopy techniques has expanded our understanding of the conditions associated with renal hematuria.^1-4 A wellrecognized clinicopathologic entity is IgA glomerulonephritis, first described by Berger and Hinglais⁵ in 1968. This disease is characterized by preponderant mesangial deposits of IgA with or without IgG or C3 deposition.^6,7 The clinical course is usually benign, proteinuria is usually minimal, and gross hematuria typically develops in association with upper respiratory tract infections.^5-7 Hypertension and progression to renal failure are not as rare as originally thought.^7,8 Nephrotic syndrome and