Persistent clonotypes associated with group A streptococcal polysaccharide antibody response in man.

Elevated anti-streptococcal group A polysaccharide antibodies are present in the sera of acute rheumatic fever patients. Analytical isoelectric focusing of sera taken in the acute phase of the disease and sequentially for up to 2 years later reveals a stable clonotype pattern of anti-group A polysaccharide antibodies. In addition, with reinfection and recurrence of the rheumatic fever, the same clonotype pattern of antibodies is present. This finding indicates that naturally acquired immunity is associated with persistence of clonotype expression.