Detection of Antibodies in Human Sera to Streptococcal Groups A and C Carbohydrates by a Radioimmunoassay

Publisher Website
Google Scholar
Abstract
Human antibodies [Ab] to streptococcal groups A and C carbohydrates were measured quantitatively with a radioimmunoassay using tyrosylated 125I carbohydrate. Analysis of acute and convalescent sera from people with groups A or C streptococcal pharyngeal infection or persistent carriage revealed a significant rise in Ab. Inhibition reactions with the cold carbohydrate indicated the specificity of the elicited Ab. In some instances, group C and group A Ab occurred after group A pharyngeal infections. Further clinical and epidemiological studies are required to determine the significance of group-specific Ab. Anti-streptolysin-O (ASO) rises were observed in individuals with group C Ab responses after persistent group C pharyngeal carriage. For this reason, epidemiological surveys that rely primarily on ASO surveys to determine the incidence of group A streptococcal infections must be interpreted with caution, at least in the developing countries, where group C pharyngeal carriage is common.