Anti-streptococcal M protein antibody

Group A hemolytic streptococcus type 1, 3, 5, 9, 19, 24 contains more M protein, has anti-phagocytic effect, and can cause a strong immune response. It has cross-antigenicity, which can stimulate the body to produce anti-streptococcal wall M protein antibody after human infection with group A hemolytic streptococcus. This antibody can cause rheumatic carditis when it acts on myocardial tissue. The study found that the genetic patterns of rheumatic fever-induced and nephritogenic strains of group A hemolytic streptococcus (GAS) are different. The rheumatic fever-induced GAS is almost all A, B, and C gene patterns; GAS is almost all D and E gene patterns. At present, it has been found that the M protein contains three repeats, which are divided into three regions: A, B, and C. The A and B regions of different M types are highly variable, while the C region is highly conserved. Therefore, the C region of the M protein is considered to be GAS. Rheumatic fever-causing strains cause common epitopes of rheumatic fever and rheumatic heart disease. This antibody can be detected by ELISA method.