The Response of Rheumatic and Non-rheumatic

The observation that individuals who acquire rheumatic fever following a streptococcal infection usually respond with higher streptococcal antibody titres than those who have streptococcal infections uncomplicated by rheumatic fever has been reported repeatedly (1-7). There are exceptions, but, if rheumatics are considered as a group, this observation seems to hold true and it has led to an assumption that rheumatic individuals, that is, those who acquire rheumatic fever or are especially susceptible because one or both parents, a sibling or near relative has had rheumatic fever, respond in a different manner to streptococcal infections than non-rheumatic persons. The response of rheumatic and non-rheumatic subjects to antigenic stimuli has been the objective of several recent investigations (8-11) none of which has shown any significant differences between rheumatics and non-rheumatics in their response to a variety of non-streptococcal antigens with the exception that when a strain of Brucella abortus was used as the antigen (12, 13) rheumatic subjects developed higher levels of agglutinins and incomplete antibodies than normal persons. However, the more crucial question would seem to be: "Do rheumatics respond differently to streptococcal infections or antigens than non-rheumatics ?" To conclude that rheumatic individuals respond with higher streptococcal antibody titres than non-rheumatics following a streptococcal infection because they are fundamentally different is open to a number of criticisms, one of which is that the dose of antigen in a streptococcal infection is unknown and it could be that some patients have higher antibody titres because they received a larger dose of antigen during the infection. It is the purpose of this paper to report an investigation of the problem of whether rheumatic individuals respond to equiva-