Immune-Complex Nephritis in Bacterial Endocarditis

Patients with subacute bacterial endocarditis (SBE) may develop focal or diffuse proliferative glomerulonephritis.1These lesions were believed originally to be secondary to emboli that originated from the heart valves. Recent evidence, coupled with the rarity of bacterial isolation from the glomerular lesions, suggests that they are immunological in origin. Deposits of immunoglobulins and complement on the glomerular basement membrane and depressed serum complement levels have been taken as indirect evidence that renal disease in SBE represents a form of immunecomplex nephritis.2-4This theory of the pathogenesis of SBE nephritis is further supported by the recent demonstration by Levy and Hong5that eluates from a kidney of a patient dying of SBE specifically combined with the bacteria cultured from the patient's blood antemortem. The present study constitutes further evidence that glomerular immunecomplex deposition may be involved in SBE nephritis, since streptococcal bacterial antigen has been identified in glomerular