Adherence of Streptococcus pyogenes M type 5 to pharyngeal and buccal cells of patients with rheumatic fever and rheumatic heart disease during a one-year follow-up.

In vitro adherence of Streptococcus pyogenes M type 5 to isolated pharyngeal and buccal epithelial cells was studied in patients with acute recurrent rheumatic fever (n = 21), chronic rheumatic heart disease (n = 33), streptococcal pharyngitis (n = 12), and in normal controls. Patients were investigated at admission and one, six and 12 months later. Streptococci adhered significantly more to the pharyngeal cells of patients with rheumatic fever and rheumatic heart disease than to the pharyngeal cells of controls. Adherence of streptococci to pharyngeal cells of patients with pharyngitis was not different from age-matched controls. The adherence of streptococci to the pharyngeal cells of patients with acute rheumatic fever fell during follow-up but even after one year remained significantly higher than in the control group. These findings suggest that host factor(s) controlling streptococcal adhesion and colonization at the pharyngeal mucosa may be important in the pathogenesis of acute rheumatic fever.