[Diagnostics of glomerulonephritis]

Glomerulonephritis occurs frequently in patients with multisystemic rheumatic disease, especially in collagen vascular disorders and vasculitides. From a clinical point of view nephrotic syndrome has to be distinguished from nephritic syndrome. Rapid deterioration of renal function is referred to as rapid progressive glomerulonephritis. The differential diagnosis of glomerulonephritis can be narrowed by the findings on urine sediment, amount of proteinuria, degree of renal insufficiency and serological findings. In particular, the presence of urine acanthocytes and cellular casts are diagnostic for glomerulonephritis or vasculitis. Renal biopsy is necessary to establish the final diagnosis in most cases; however, some histological pattern such as membranous glomerulonephritis may occur in several different etiopathogenetic diseases and one disease process may lead to different histomorphologic pictures. Rapid progressive glomerulonephritis is a nephrological emergency and should be diagnosed and treated early to prevent dialysis-dependent renal insufficiency.