The Diagnosis of Acute Glomerulonephritis

WE define acute glomerulonephritis as the sudden appearance of hematuria, proteinuria, and red-cell casts. The last finding, which rarely occurs in other types of renal disease,¹ is virtually diagnostic of active glomerular inflammation. The clinician should carefully examine the urinary sediment for red-cell casts and should not delegate this critical test to the laboratory performing routine urinalysis. In the absence of such casts, dysmorphic red cells in the urine viewed under a phase-contrast microscope have also been shown to correlate closely with active glomerular disease.² Hematuria, which is virtually always present, can be persistent or intermittent, gross or microscopic. Proteinuria.