RHEUMATOID FACTOR, COMPLEMENT, AND CONGLUTININ ABERRATIONS IN PATIENTS WITH SUBACUTE BACTERIAL ENDOCARDITIS*

Abstract

Subacute bacterial endocarditis produces in man a complex situation of interaction of host and invading organism. Little is known of anti-body response or of the specific mechanisms of immunity involved during the inception, course, and recovery from subacute bacterial endocarditis, although observations on streptococcal agglutinat-ing and complement-fixing antibodies have been made by numerous workers (1-7). Recent ob-servations (8, 9) have indicated that animals immunized with certain, streptococcal and coliform organisms develop factors capable of agglutinating y-globulin-coated red cells and other particles. These properties indicate a similarity to rheuma-toid factors, and the possibility is raised that organisms or their products play a role in the production of rheumatoid factors in human dis-ease. A natural parallel to production of such rheumatoid factors in animals would be their occurrence in human disease states in which bac-teria are constantly fed into the circulation, as in miliary tuberculosis or subacute bacterial endo-carditis. In the present study the effect of subacute bac-terial endocarditis on the serological behavior of systems designed to react with the rheumatoid factor was examined. Preliminary observations indicated a high incidence of positive tests for rheumatoid factor in these patients. It seemed of special interest to see whether these reversed after eradication of the offending organism under therapy. The constancy and prolonged duration of these factors in patients with rheumatoid arthritis is well recognized (10, 11) although some observers have reported decrease in titer with remission (12). In addition, observations were also made on conglutinin and serum com-plement in these patients because of certain gen-eral similarities of these various factors that appear to be indirectly involved in immune phe-nomena.