pathogenesis
Last reviewed 06/2022
There are two theories concerning the pathogenesis of rheumatic fever (RF):
Cross-reactive antibodies:
- clear association with previous streptococcal infection
- anti-viral titres are often elevated - antistreptolysin O antibodies
- streptococci are not directly involved as lesions are sterile
- the more serious the streptococcal infection, the more likely is the development of RF, on average 3% of all streptococcal pharyngitides will cause RF
- all recurrences of RF are preceded by strep infection
- recurrence rate range from 5-50%
- the development of RF depends on the virulence of the organism and also on the immune response genes of the host
- putative cross-reactive bacterial antigens include hyaluronic acid and M proteins
Autoimmunity:
- streptococcal infection stimulates the production of antibodies which react with the heart but not with the streptococci
- autoantibodies are present in Aschoff bodies