MICROSCOPIC hematuria of renal origin associated with repeated episodes of gross hematuria is often considered to indicate the continued activity of chronic progressive glomerulonephritis. Several studies have shown that during the natural history of chronic glomerulonephritis, episodes of gross hematuria can follow upper-respiratory-tract infections, usually streptococcal but occasionally of nonstreptococcal etiology.1 Although in chronic poststreptococcal glomerulonephritis these episodes of gross hematuria are usually associated with edema, worsening of the hypertension and evidence of a reduction in glomerular filtration rate, they are said to cause a permanent reduction in renal function only rarely.1 Nevertheless, the persistence of repeated episodes of hematuria . . .