Titrations of antibodies to four streptococcal antigens have been carried out in the sera of patients with rheumatic fever and of convalescents from streptococcal infections. These antigens are the hyaluronidase, the hemolysin, and two somatic fractions, the cytoplasmic particles and supernate proteins.
Mean titers to all of these antigens were elevated in both rheumatic and streptococcal infection. The mean titer was somewhat higher in rheumatic than in streptococcal infection in the case of three of these antibodies. In the case of the fourth, antihyaluronidase, this difference was considerably greater.
The antihyaluronidase titer showed better correlation with changes in the activity of the rheumatic infection than did the other tests. There was, however, no striking correlation between this titer and the severity of the illness.
Application was made of these findings to the problem of laboratory diagnosis of rheumatic fever by streptococcal serology. A method is presented for assessing the relative usefulness of such tests in terms of the, distribution of their titers in this disease and in health. By this method the antihyaluronidase test was found to be most useful of the four.
The comparative diagnostic value for rheumatic fever was studied in the case of the antihyaluronidase test, the antistreptolysin test, and of combinations of both tests.
Group A Beta Hemolytic Streptococcus and Rheumatic Fever in Miami, Fla.: 8-Month Bacteriological and Serologic Study
