The antibody respones in man to infection with different serotypes of group-A streptococci.

Abstract

SUMMARY The influence of the infecting serotype on streptococcal antibody response in man was investigated in a series of twelve incidents of streptococcal infection due to nine different M-types. The percentage of patients who developed type-specific M antibody after throat infection with opacity-factor-negative M-types varied between 64 and 100% and was in general three times greater than the percentage who developed this antibody to opacity-factor-positive M types. The type-specific antibody response was poor after skin infection with both opacity-factor-positive and opacity-factor-negative serotypes and varied between 0 and 33%. Antistreptolysin O and anti-deoxyribonuclease B titres were on the whole similar in the different outbreaks, except that anti-streptolysin O titres were low and anti-deoxyribonuclease B titres were high in patients with skin infection. The antibody response to M-associated protein varied widely between outbreaks. In incidents due to opacity-factor-positive serotypes, the titres were generally low, but opacity-factor-negative serotypes showed great variation in their ability to cause production of the antibody. In outbreaks of tonsillitis in which some of the patients later suffered from rheumatic fever, many persons formed large amounts of the antibody in response to an uncomplicated infection. Because high titres of antibody against M-associated protein are almost invariable in rheumatic fever it seems possible that the “rheumatogenic” strains of group-A streptococci are to be found among the opacity-factor-negative serotypes.