Hemorrhagic Glomerular Lesions Produced by Filtrates of Streptococcus Viridans Cultures.

Abstract

It is well known that hemorrhagic, glomerulo-nephritis occurs with great frequency in association with Streptococcus viridans endocarditis. The glomerular changes are generally regarded as a direct result of damage caused by minute emboli from the vegetations on the heart valves. The following considerations led us to question the assumed embolic nature of the nephritis: (1) If the nephritis associated with Streptococcus viridans endocarditis is merely the result of emboli, one might reasonably expect to encounter a similar nephritis quite as commonly in every form of endocarditis characterized by profuse, friable vegetations, regardless of the etiology. This, however, is not the case. (2) There is no relation between the size of the valvular vegetations and the occurrence or degree of nephritis. (3) We have observed florid hemorrhagic nephritis in association with gonococcal endocarditis, in which the vegetations were confined to the right side of the heart, and in which therefore, the capillary bed of the lungs could act as a filter for emboli escaping from the vegetations. It may be remarked that gonococcal endocarditis resembles Streptococcus viridans endocarditis in the extraordinary frequency with which it is accompanied by hemorrhagic nephritis. (4) Our microscopic studies failed to convince us that damage to glomerular tufts in the nephritis associated with Streptococcus viridans endocarditis is necessarily dependent upon the presence of emboli. (5) The glomerular damage differs in no way from that observed in cases of nephritis in which emboli could have played no rôle.

It seemed possible that the high incidence of nephritis occurring in association with certain forms of bacterial endocarditis might be referable to the action of toxins produced by the microorganisms in question, rather than to emboli. We, have, therefore, carried out experiments with a strain of Streptococcus viridans which was obtained from the blood of a patient suffering, in a typical manner, from subacute endocarditis, with evidences of renal involvement.