Antibiotic therapy has decreased the incidence of glomerulonephritis related to subacute bacterial endocarditis (SBE). Kidney involvement may be the initial manifestation of SBE in about 20% of patients. Hematuria and mild proteinuria are commonly present. Hypertension and nephrotic syndrome are rare. Serum complement levels may be low. Gross hematuria may be present in patients with renal infarctions related to embolic events. The degree of GFR loss correlates with the severity of glomerulonephritis; diffuse glomerulonephritis causes moderate GFR loss, and necrotizing glomerulonephritis with crescents can cause a rapid GFR decline.