Since the frequent association of infection with the beta hemolytic streptococcus and acute rheumatic fever has been generally recognized, the possible etiologic significance of this organism has been extensively studied. No attempt will be made in this paper to summarize the entire literature, but certain contributions that have a direct bearing on the present study will be cited.
In 1932 Todd1 and Coburn2 studied the antistreptolysin titer in the serum of the same group of patients with rheumatic disease. This antibody inhibits the ability of the beta hemolytic streptococcus to hemolyze the red cells of the rabbit in vitro, and its concentration in blood serum can be readily measured by a standard dilution technic. The authors noted that in practically all cases of acute rheumatic infection there was a definite increase in the titer of this antibody and suggested that the results support the theory, advanced by Coburn,