Reactivity of rheumatic fever and scarlet fever patients' sera with group A streptococcal M protein, cardiac myosin, and cardiac tropomyosin: A retrospective study

Archived sera (collected in 1946) from acute rheumatic fever (ARF) and untr eated scarlet fever and/or pharyngitis patients were reacted with streptoco ccal M protein, cardiac myosin, and cardiac tropomyosin. Except for very lo w levels to tropomyosin, antibodies to other antigens were not elevated in the sera of ARF patients relative to those of non-ARE patients, even though there was roughly equivalent exposure to group A streptococci. This sugges ts that antibodies to these molecules may not play a central role in the in duction of ARF.