Comparison of the antibody response to streptococcal cellular and extracellular antigens in acute pharyngitis.

The antibody response to the group A carbohydrate moiety of the streptococcal cell wall is of special interest because of its postulated role in the pathogenesis of rheumatic valvulitis. The immune response to this somatic antigen was measured in 159 children with culture-proved group A streptococcal pharyngitis and was compared with that to two extracellular antigens of the Group A streptococcus: streptolysin O and streptococcal DNase B. The data suggest that the maximum anti-A-carbohydrate rise occurs soon after the onset of streptococcal pharyngitis in a fashion similar to the response to some streptococcal extracellular antigens. However, the anti-A-carbohydrate antibody response appeared to be a less sensitive indicator of streptococcal upper respiratory tract infection.